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Surgery_Schwartz. background, experimental progress, and clinical prospects. Ann Thorac Surg. 2016;101(4):1605-1613. 190. O’Brien SM, Clarke DR, Jacobs JP, et al. An empirically based tool for analyzing mortality associated with congenital heart surgery. J Thorac Cardiovasc Surg. 2009;138:1139-1153. 191. https://www.sts.org/congenital-public-reporting-module-search. March 2017. 192. Jacobs JP, Mayer JE Jr, Mavroudis C, et al. The Society of Thoracic Surgeons Congenital Heart Surgery Database: 2017 Update on Outcomes and Quality. Ann Thorac Surg. 2017;103(3):699-709. An important article to understand the STS database, outcomes reporting, and where the future of the filed of public reporting is headed. 193. Bramlet M, Olivieri L, Farooqi K, Ripley B, Coakley M. Impact of three-dimensional printing on the study and treatment of congenital heart disease. Circ Res. 2017;120(6): 904-907. This article describes the new and innovative tech-nology of three-dimensional printing and its impact on the field of


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Surgery_Schwartz. study and treatment of congenital heart disease. Circ Res. 2017;120(6): 904-907. This article describes the new and innovative tech-nology of three-dimensional printing and its impact on the field of pediatric and congenital cardiac surgery. 194. Yoo SJ, Spray T, Austin EH 3rd, Yun TJ, van Arsdell GS. Hands-on surgical training of congenital heart surgery using 3-dimensional print models. J Thorac Cardiovasc Surg. 2017 Feb 9. 195. Seghaye MC. Management of children with congenital heart defect: state of the art and future prospects. Future Cardiol. 2017;13(1):65-79. doi:10.2217/fca-2016-0039. 196. Ryan JR, Moe TG, Richardson R, Frakes DH, Nigro JJ, Pophal S. A novel approach to neonatal management of tetralogy of Fallot, with pulmonary atresia, and multiple aortopulmonary collaterals. JACC Cardiovasc Imaging. 2015;8(1):103-104. 197. Ferro G, Murthy R, Sebastian VA, Guleserian KJ, Forbess JM. Single-center experience with the Senning Proce-dure in the Current Era. Semin Thorac


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Surgery_Schwartz. JACC Cardiovasc Imaging. 2015;8(1):103-104. 197. Ferro G, Murthy R, Sebastian VA, Guleserian KJ, Forbess JM. Single-center experience with the Senning Proce-dure in the Current Era. Semin Thorac Cardiovasc Surg. 2016;28(2):514-520. 198. Zuluaga MA, Burgos N, Mendelson AF, Taylor AM, Ourselin S. Voxelwise atlas rating for computer assisted diagnosis: Application to congenital heart diseases of the great arteries. Med Image Anal. 2015;26(1):185-194.Brunicardi_Ch20_p0751-p0800.indd 80022/02/19 2:57 PM


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Surgery_Schwartz. Acquired Heart DiseaseMatthew R. Schill, Ali J. Khiabani, Puja Kachroo, and Ralph J. Damiano Jr 21chapterCardiac Assessment 801Clinical Evaluation / 801History / 801Physical Examination / 803Cardiac Risk Assessment in Noncardiac Surgery Patients / 804Diagnostic Studies / 804Extracorporeal Perfusion 807History / 807Technique / 807Adverse Effects / 808Myocardial Protection / 808Coronary Artery Disease 808History / 808Etiology and Pathogenesis / 809Risk Factors and Prevention / 809Clinical Manifestations / 809Preoperative Evaluation / 809Coronary Artery Bypass Grafting 809Indications / 809Percutaneous Coronary Intervention vs. Coronary Artery Bypass Grafting / 810Summary / 811Operative Techniques and Results / 811New Developments / 814Valvular Heart Disease 814General Principles / 814Surgical Options / 815Mitral Valve Disease 817Mitral Stenosis / 817Mitral Regurgitation / 819Mitral Valve Operative Techniques and Results / 821Aortic Valve Disease 823Aortic Stenosis / 823Aortic


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Surgery_Schwartz. 814Surgical Options / 815Mitral Valve Disease 817Mitral Stenosis / 817Mitral Regurgitation / 819Mitral Valve Operative Techniques and Results / 821Aortic Valve Disease 823Aortic Stenosis / 823Aortic Insufficiency / 825Aortic Valve Operative Techniques and Results / 828Tricuspid Valve Disease 829Tricuspid Stenosis and Insufficiency / 829Multivalve Disease / 831Surgical Therapy for the Failing Heart 831Epidemiology of Heart Failure / 831Etiology and Pathophysiology / 831CABG for Ischemic Cardiomyopathy / 831Secondary Mitral Regurgitation / 832Left Ventricular Aneurysmorrhaphy and Surgical Ventricular Restoration / 833Mechanical Circulatory Support / 835Right Ventricular Assist Devices and Biventricular Assist Devices / 837Total Artificial Heart / 837Surgery For Arrhythmias 837Atrial Fibrillation / 838Surgery for Pericardial Disease 839Acute Pericarditis / 839Relapsing Pericarditis / 840Chronic Constrictive Pericarditis / 840Cardiac Neoplasms 841Overview and General Clinical


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Surgery_Schwartz. Fibrillation / 838Surgery for Pericardial Disease 839Acute Pericarditis / 839Relapsing Pericarditis / 840Chronic Constrictive Pericarditis / 840Cardiac Neoplasms 841Overview and General Clinical Features / 841Myxoma / 842Other Benign Cardiac Tumors / 843Malignant Cardiac Tumors / 843Metastatic Cardiac Tumors / 843CARDIAC ASSESSMENTClinical EvaluationAs with any other field in medicine, the history and physical examination form the foundation for the evaluation of a patient with acquired heart disease requiring surgical intervention. Obtaining a complete history identifies comorbid conditions and assists in delineating the operative risks and prognosis after sur-gery. Physical examination reveals factors that may increase the complexity of surgery, such as previous surgery or the presence of peripheral arterial or cerebrovascular disease. These may influence the operative approach, but they also help guide the choice and sequence of diagnostic studies. A complete assess-ment of the


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Surgery_Schwartz. of peripheral arterial or cerebrovascular disease. These may influence the operative approach, but they also help guide the choice and sequence of diagnostic studies. A complete assess-ment of the patient allows the surgeon to make educated deci-sions regarding the optimal treatment strategy for the patient.HistorySymptoms suggestive of heart disease include: chest discomfort, fatigue, edema, dyspnea, palpitations, and syncope. Adequate definition of these symptoms calls for detailed history-taking, paying particular attention to onset, intensity, radiation, dura-tion, and exacerbating or alleviating factors. The demands on the heart are determined by its loading conditions and the metabolic state of the patient. Cardiac symptoms are commonly accentuated with physical exertion or postural changes.Angina pectoris is the hallmark of coronary artery disease (CAD), but may occur with other cardiac pathologies that result in ischemia from a mismatch between the supply of oxygen by the


Surgery_Schwartz

Surgery_Schwartz. changes.Angina pectoris is the hallmark of coronary artery disease (CAD), but may occur with other cardiac pathologies that result in ischemia from a mismatch between the supply of oxygen by the coronary circulation and the metabolic demand of the myo-cardium. Typically, angina is described as tightness, heaviness, or dull pain, frequently substernal, that lasts for a few minutes. This discomfort may radiate to the left arm, neck, mandible, or epigastrium. Angina is most often provoked by activities that increase metabolic demand on the heart such as exercise, eating, and states of intense emotion, and it is typically alleviated by rest or use of nitroglycerin. It is important to note that a signifi-cant number of patients with myocardial ischemia, particularly diabetics, females, and the elderly, may have “silent” angina or angina equivalents (dyspnea, diaphoresis, nausea, or fatigue). The overlap of these features with those of noncardiac etiologies Brunicardi_Ch21_p0801-p0852.indd


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Surgery_Schwartz. elderly, may have “silent” angina or angina equivalents (dyspnea, diaphoresis, nausea, or fatigue). The overlap of these features with those of noncardiac etiologies Brunicardi_Ch21_p0801-p0852.indd 80101/03/19 5:32 PM 802such as costochondritis, biliary colic, gastroesophageal reflux disease, diffuse esophageal spasm, and peptic ulcer disease, to name a few, can sometimes lead to misdiagnosis.Heart failure can occur from either left and/or right heart dysfunction, and respective symptoms arise from congestion of blood flow owing to an inadequate cardiac output. Left heart failure manifests as dyspnea, usually with exertion. Orthopnea, defined as dyspnea while lying flat, suggests worsened pulmo-nary congestion with increased venous return. Ascites, periph-eral edema, and hepatomegaly reflect congestion in the systemic venous circulation and are prominent features of right heart failure. Peripheral edema can occur in right heart failure second-ary to systemic venous congestion or


Surgery_Schwartz

Surgery_Schwartz. reflect congestion in the systemic venous circulation and are prominent features of right heart failure. Peripheral edema can occur in right heart failure second-ary to systemic venous congestion or in left heart failure due to salt and fluid retention as a result of impaired renal perfusion. Patients with chronic suboptimal perfusion and oxygenation can also have digital clubbing and cyanosis.It is difficult to implicate cardiac disease based solely on the presence of fatigue, which is a very nonspecific symptom. However, most cardiac pathologies do result in fatigue or exer-cise intolerance to some degree. It is important to differenti-ate fatigue from exertional dyspnea which some patients may describe as “fatigue.”Dyspnea is another common symptom. Although gen-erally a late symptom in patients with valvular heart disease or cardiomyopathy, it may be a relatively early complaint in some patients, particularly those with mitral stenosis. As stated previously, dyspnea is also an


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Surgery_Schwartz. in patients with valvular heart disease or cardiomyopathy, it may be a relatively early complaint in some patients, particularly those with mitral stenosis. As stated previously, dyspnea is also an anginal equivalent and may sig-nal a myocardial ischemic episode. Many primary pulmonary disorders feature dyspnea as their cardinal symptom and should be evaluated simultaneously as the physiology of the heart and lungs are intimately related and can have dramatic influences on one another.Patients typically describe palpitations as a “skipped beat” or “racing heart.” Depending on the clinical context, such as occasional premature atrial or ventricular beats in otherwise healthy individuals, these may be benign. Clinically significant arrhythmias, however, require thorough investigation. Atrial fibrillation is the most common arrhythmia and can occur alone or with other cardiac pathologies. It results in an irregular, and at times, rapid heartbeat. Concurrent symptoms such as angina,


Surgery_Schwartz

Surgery_Schwartz. Atrial fibrillation is the most common arrhythmia and can occur alone or with other cardiac pathologies. It results in an irregular, and at times, rapid heartbeat. Concurrent symptoms such as angina, lightheadedness, or syncope are particularly worrisome for life-threatening arrhythmias such as ventricular tachycardia or ventricular fibrillation, particularly in patients with preexisting heart failure.Syncope associated with heart disease results from an abrupt reduction in cerebral perfusion. Many of the potential cardiac etiologies are serious, including sinus node dysfunction, atrioventricular conduction abnormalities, malignant arrhyth-mias, aortic stenosis, and hypertrophic obstructive cardiomy-opathy. Noncardiac causes of syncope includes, but are not limited to, neurologic causes (e.g., transient ischemic attacks [TIAs]), orthostatic hypotension, vasavagal events, and carotid sinus hypersensitivity. Any episode of syncope warrants a thor-ough evaluation and search for the root


Surgery_Schwartz

Surgery_Schwartz. transient ischemic attacks [TIAs]), orthostatic hypotension, vasavagal events, and carotid sinus hypersensitivity. Any episode of syncope warrants a thor-ough evaluation and search for the root cause.1,2 In addition to a thorough inquiry regarding the aforementioned symptoms, it is important to obtain details about the patient’s medical and Key Points1 Although advances have been made in percutaneous coro-nary intervention techniques for coronary artery disease, survival is superior with coronary artery bypass grafting in patients with left main disease, multivessel disease, and in diabetic patients.2 Despite the theoretical advantages, the superiority of off-pump coronary artery bypass to conventional coronary artery bypass grafting has not been clearly established, and other factors likely dominate the overall outcome for either technique.3 Although mechanical valves offer enhanced durability over tissue valve prosthesis, they require permanent systemic anticoagulation therapy to


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Surgery_Schwartz. dominate the overall outcome for either technique.3 Although mechanical valves offer enhanced durability over tissue valve prosthesis, they require permanent systemic anticoagulation therapy to mitigate the risk of valve throm-bosis and thromboembolic sequelae and thus are associated with an increased risk of hemorrhagic complications.4 Mitral valve repair is recommended over mitral valve replacement in the majority of patients with severe chronic mitral regurgitation. The decision to proceed with mitral valve repair is based on the skill and experience of the sur-geon in performing the repair and on the pathology of mitral valve disease encountered at the time of operation. Trans-catheter mitral valve therapies are also becoming increas-ingly available as options to offer patients who are deemed high risk for surgical intervention for their mitral valve disease.5 Although open aortic valve replacement has traditionally been the only effective treatment in patients with severe


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Surgery_Schwartz. who are deemed high risk for surgical intervention for their mitral valve disease.5 Although open aortic valve replacement has traditionally been the only effective treatment in patients with severe cal-cific aortic stenosis, transcatheter aortic valve replacement is a developing technology that has proven beneficial for the treatment of aortic stenosis in seriously ill patients that had previously been deemed high risk or inoperable. It has also recently been approved for us in patients at moderate risk for surgical aortic valve replacement and is in clinical trials for low-risk patients.6 Mechanical circulatory support with newer generation con-tinuous flow left ventricular assist devices has proven to be durable and effective both as a bridge to transplant and as a means of destination therapy for patients who are not trans-plant candidates.7 Performing a biatrial Cox-Maze lesion set results in freedom from atrial fibrillation in approximately 90% of patients and is superior to


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Surgery_Schwartz. therapy for patients who are not trans-plant candidates.7 Performing a biatrial Cox-Maze lesion set results in freedom from atrial fibrillation in approximately 90% of patients and is superior to both catheter-ablation and more limited lesion sets for patients with persistent atrial fibrillation or enlarged left atria. Surgical ablation of atrial fibrillation is recom-mended for patients referred with concomitant valvular dis-ease and those who have previously failed or are poor candidates for catheter-based approaches.8 The preferred treatment for pericarditis depends on the underlying cause, although the disease typically follows a self-limited course and is best managed medically. Surgical pericardiectomy may have a role in treating relapsing peri-carditis and, more commonly, chronic constrictive pericarditis.9 Myxomas are the most common cardiac tumors, and, while benign, they should be promptly excised after diagnosis due to the risk of embolization, obstructive complications,


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Surgery_Schwartz. constrictive pericarditis.9 Myxomas are the most common cardiac tumors, and, while benign, they should be promptly excised after diagnosis due to the risk of embolization, obstructive complications, and arrhythmias.Brunicardi_Ch21_p0801-p0852.indd 80201/03/19 5:32 PM 803ACQUIRED HEART DISEASECHAPTER 21Table 21-1New York Heart Association (NYHA) functional classificationCLASSDESCRIPTIONIPhysical activity not limited by symptoms: fatigue, palpitations, or dyspnea.IIComfortable at rest. Slight limitation of physical activity. Fatigue, palpitations, or dyspnea with ordinary physical activity.IIIComfortable at rest. Marked limitation of physical activity. Fatigue, palpitations, or dyspnea with less than ordinary physical activity.IVInability to carry out any physical activity. Symptoms may be present at rest and increase with activity.Table 21-2Canadian Cardiovascular Society (CCS) angina classificationCLASSDESCRIPTIONIOrdinary physical activity (walking, climbing stairs) does not


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Surgery_Schwartz. may be present at rest and increase with activity.Table 21-2Canadian Cardiovascular Society (CCS) angina classificationCLASSDESCRIPTIONIOrdinary physical activity (walking, climbing stairs) does not cause angina. Angina occurs with strenuous, rapid, or prolonged exertion during work or recreation.IISlight limitation of ordinary activity. Angina occurs with climbing stairs rapidly, walking uphill in the wind, under emotional stress, in the cold, or after meals. Walking more than 2 blocks or climbing one flight of stairs causes angina.IIIMarked limitation of ordinary physical activity (climbing a flight of stairs or walking 1 to 2 blocks at a normal pace).IVInability to carry out any physical activity without discomfort. Angina may be present at rest.surgical history, family history, social habits (including alcohol and tobacco use), current medications, focused review of sys-tems, as well as an assessment of the patient’s functional status and frailty. Frailty is often defined as a


Surgery_Schwartz

Surgery_Schwartz. habits (including alcohol and tobacco use), current medications, focused review of sys-tems, as well as an assessment of the patient’s functional status and frailty. Frailty is often defined as a state of increased vul-nerability to adverse health outcomes. Clinicians can use frailty index calculators to assess a patient’s risk for adverse outcomes following cardiac intervention. Specific attention should also be directed to the patient’s comorbidities which not only sheds light on their general health but also helps delineate expected risks from surgery. A strong family history of coronary artery disease, myocardial infarction, hypertension, or diabetes is of particular importance as they increase the individual’s risk for having an adverse cardiac event.Functional Disability and Angina. With regard to heart failure, functional capacity is strongly correlated with mortality. The New York Heart Association (NYHA) functional class is a widely used classification system in categorizing


Surgery_Schwartz

Surgery_Schwartz. regard to heart failure, functional capacity is strongly correlated with mortality. The New York Heart Association (NYHA) functional class is a widely used classification system in categorizing patients based on their functional status (Table 21-1).3 The NYHA clas-sification has become one basis by which to compare patient populations in many studies. Although less commonly used, the Canadian Cardiovascular Society (CCS) angina classification is also used to incorporate anginal symptoms into the functional assessment for prognostic value (Table 21-2).Physical ExaminationThe physical examination is an invaluable tool in directing further diagnostic studies in the management of a patient with suspected heart disease. The astute clinician may be able to detect subtle signs that may further characterize the underlying pathology.The general appearance of a patient is important in the clinical assessment. A pale, diaphoretic, and obviously uncom-fortable patient is more likely to be in a


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Surgery_Schwartz. characterize the underlying pathology.The general appearance of a patient is important in the clinical assessment. A pale, diaphoretic, and obviously uncom-fortable patient is more likely to be in a clinically critical condition than one who is conversing comfortably with an unre-markable demeanor. In addition to basic vital signs, particular attention should be directed to the patient’s mental status as well as the color and temperature of the skin, as these may be reflec-tive of the general adequacy of perfusion. Overall frailty and dementia have also been shown to be predictors of operative and late mortality.4Palpation of the precordium may demonstrate devia-tion in the point of maximal impulse, indicative of ventricular hypertrophy, or parasternal heaves, seen in right ventricular overload. Auscultation should be performed in a quiet envi-ronment as critical murmurs, rubs, or gallops may be subtle. Murmurs are characterized by their location, timing, quality, and radiation. They


Surgery_Schwartz

Surgery_Schwartz. Auscultation should be performed in a quiet envi-ronment as critical murmurs, rubs, or gallops may be subtle. Murmurs are characterized by their location, timing, quality, and radiation. They are typically secondary to valvular or other structural pathology, and new findings require further investi-gation. A rub due to pericardial friction is indicative of pericar-ditis. A third heart sound (S3) is generated by the rapid filling of a stiff ventricle and can be normal in young patients, but when present in older adults, is indicative of diastolic dysfunction and is pathologic. Increased contribution of the atrial pump function to ventricular filling may manifest as a fourth heart sound (S4) and is also suggestive of ventricular dysfunction.Palpation of peripheral pulses is important not only to assess the adequacy of perfusion, but also the burden of coro-nary artery disease often correlates with the degree of peripheral arterial disease. The presence of a carotid bruit may indicate


Surgery_Schwartz

Surgery_Schwartz. only to assess the adequacy of perfusion, but also the burden of coro-nary artery disease often correlates with the degree of peripheral arterial disease. The presence of a carotid bruit may indicate clinically significant stenosis and may alter the course and tim-ing of treatment, especially if symptomatic.Heart failure will frequently have extracardiac manifesta-tions and examination of the other organ systems should not be neglected. For example, auscultation of the lung fields may reveal rales in patients with pulmonary edema. The use of acces-sory muscles of breathing may be present in patients with sig-nificant pleural effusions and volume overload. The presence of jugular venous distention and hepatosplenomegaly may signal right heart failure.Additionally, clinicians should know the manifestation of other cardiac pathologies including endocarditis and rheu-matic heart disease, although less commonly seen. Endocarditis is an inflammation of the endocardium, usually on the heart


Surgery_Schwartz

Surgery_Schwartz. manifestation of other cardiac pathologies including endocarditis and rheu-matic heart disease, although less commonly seen. Endocarditis is an inflammation of the endocardium, usually on the heart valves. A cardiac murmur is a common physical exam finding. Relatively uncommon but more specific clinical manifestations for infectious endocarditis are: Janeway lesions, which are nontender erythematous macules on the palms and soles; Osler nodes, which are described as tender subctanous nodules mostly on the pads of the fingers and toes; and Roth spots, which are exudative hemorrhagic lesions of the retina with pale centers.Brunicardi_Ch21_p0801-p0852.indd 80301/03/19 5:32 PM 804SPECIFIC CONSIDERATIONSPART IICardiac Risk Assessment in Noncardiac Surgery PatientsCardiovascular complications occur in approximately 3% of patients undergoing inpatient noncardiac surgery.5 The American College of Cardiology (ACC) and American Heart Association (AHA) have formed a joint task force to


Surgery_Schwartz

Surgery_Schwartz. occur in approximately 3% of patients undergoing inpatient noncardiac surgery.5 The American College of Cardiology (ACC) and American Heart Association (AHA) have formed a joint task force to publish a consensus statement, with periodic focused updates, on guide-lines and recommendations that were revised in 2017.6 The aim of these guidelines is to incorporate surgery-specific risks and patient characteristics to guide perioperative decision-making in the management of patient with valvular heart disease.Surgical procedures have been categorized based on cardiovascular risk into low risk, moderate risk, and vascu-lar procedures. Vascular procedures, likely due to both the nature of the procedures themselves as well as the associated cardiovascular pathology in many of these patients, carry the highest reported risk of cardiac events at more than 7%.5 Low risk procedures, including endoscopic procedures, superficial operations, cataract surgery, breast surgery, and ambulatory


Surgery_Schwartz

Surgery_Schwartz. carry the highest reported risk of cardiac events at more than 7%.5 Low risk procedures, including endoscopic procedures, superficial operations, cataract surgery, breast surgery, and ambulatory surgeries, have a risk generally less than 1%. Intermediate risk procedures include intraperitoneal and intrathoracic surgery, head and neck surgery, orthopedic procedures, and prostate surgery.5Patient characteristics can be classified by the status of the patient’s cardiac disease, comorbid conditions, and functional capacity. Patients are considered to be at major perioperative clinical risk if they have one or more of the following active car-diac conditions: acute coronary syndrome, decompensated heart failure, significant arrhythmias, or severe valvular heart disease. In these patients, intensive evaluation and treatment prior to sur-gery (unless emergent) is warranted, prior to proceeding with the noncardiac surgery.If the patient does not have any of the previously men-tioned active


Surgery_Schwartz

Surgery_Schwartz. evaluation and treatment prior to sur-gery (unless emergent) is warranted, prior to proceeding with the noncardiac surgery.If the patient does not have any of the previously men-tioned active cardiac conditions, the perioperative risk of major adverse cardiac events (MACE) should be estimated. Both the operation performed and the patient’s risk factors are predictive of MACE, and the ACC/AHA guidelines recommend the use of either the American College of Surgeons’ NSQIP risk calculator or the Revised Cardiac Risk Index for the estimation of patient-specific risk. Patients at low (<1%) risk or patients at elevated risk with functional capacity greater than or equal to 4 metabolic equivalents (METs), should proceed to surgery without further testing. It is reasonable to perform pharmacologic stress testing in patients with poor or unknown functional capacity if this test-ing will impact decision making or perioperative care. Patients with abnormal stress test results should undergo


Surgery_Schwartz

Surgery_Schwartz. stress testing in patients with poor or unknown functional capacity if this test-ing will impact decision making or perioperative care. Patients with abnormal stress test results should undergo confirmatory test such as coronary angiography, if indicated, before an elec-tive noncardiac surgery. The previous guidelines included inter-mediate and low cardiovascular risk profiles, but this has been replaced by cardiovascular risk factors in the update. These risk factors are: history of ischemic heart disease, history of prior or compensated heart failure, history of cerebrovascular dis-ease, diabetes mellitus, and renal insufficiency. Based on the number of present risk factors and the surgery-specific risk, the guidelines recommend pathways for further evaluation and risk management. The most recent guidelines from ACC/AHA were published in 2014 (Fig. 21-1).7 One important subgroup of patients at elevated risk are those who have recently undergone percutaneous coronary intervention. In


Surgery_Schwartz

Surgery_Schwartz. recent guidelines from ACC/AHA were published in 2014 (Fig. 21-1).7 One important subgroup of patients at elevated risk are those who have recently undergone percutaneous coronary intervention. In these patients, elective noncardiac surgery should be delayed until the risk of stent thrombosis decreases (30 days for bare metal stents and 180 to 365 days for drug-eluting stents), and dual antiplatelet therapy should be continued unless the risk of bleeding exceeds the risk of stent thrombosis.5Diagnostic StudiesElectrocardiogram and Chest X-ray. Electrocardiograms (ECGs) and chest X-rays are noninvasive diagnostic studies that provide invaluable information in the preoperative assess-ment of patients with cardiac pathology. ECGs can be useful in detecting old myocardial infarction, dilation or hypertrophy of the cardiac chambers, arrhythmias, and conduction abnormali-ties. A stress ECG requires a patient to exercise to a target heart rate and is used to help diagnose ischemic


Surgery_Schwartz

Surgery_Schwartz. dilation or hypertrophy of the cardiac chambers, arrhythmias, and conduction abnormali-ties. A stress ECG requires a patient to exercise to a target heart rate and is used to help diagnose ischemic pathologies that may not be evident at rest.A plain film of the chest can detect pulmonary pathol-ogy, sequelae of heart failure (e.g., pulmonary edema, cardiac enlargement, pleural effusions), as well as presence of hardware (e.g., prosthetic heart valves, sternal wires, pacemakers, and defibrillators).Echocardiography. Echocardiography utilizes reflected sound waves to image the heart. Transthoracic echocardiography (TTE) is used widely due to its noninvasive nature. It is the pri-mary diagnostic tool used to evaluate structural diseases of the heart, including valvular pathology, septal defects, cardiomyop-athies, and cardiac masses. Although more invasive, transesoph-ageal echocardiography (TEE) can provide more information and better definition of some valvular and structural


Surgery_Schwartz

Surgery_Schwartz. defects, cardiomyop-athies, and cardiac masses. Although more invasive, transesoph-ageal echocardiography (TEE) can provide more information and better definition of some valvular and structural abnormali-ties. It is particularly useful in identifying left atrial thrombi in patients with atrial fibrillation. Echocardiography is indispens-able in assessing surgical prostheses such as valves, leads, or mechanical circulatory support devices. These examinations can be performed with M-mode imaging (motion along a single line) as well as two-dimensional (2D) and three-dimensional (3D) imaging depending on the information required.Doppler technology has become a standard addition to assess changes in flow patterns across dysfunctional valves. Velocity measurements can be obtained to estimate pres-sure gradients across structures using the continuity equation. A common example would be the estimation of pulmonary arterial systolic pressure calculated from the regurgitant tricuspid jet


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Surgery_Schwartz. pres-sure gradients across structures using the continuity equation. A common example would be the estimation of pulmonary arterial systolic pressure calculated from the regurgitant tricuspid jet profile during right ventricular systole.Transthoracic echocardiography requires no sedation and is generally performed with the patient in a slight left lateral decubitus position. Standardized views are obtained with the ultrasound probe placed in the apical, parasternal, subcostal, and suprasternal positions. The apical four-chamber view is a use-ful window for visualizing all four cardiac chambers simultane-ously as well as the tricuspid and mitral valves. Other windows can be obtained to assess specific structures such as the individ-ual valve anatomy or myocardial wall segments. Dobutamine-stress echocardiography is a study similar in idea to the stress ECG that utilizes a pharmacologic agent to assess the patient for ischemia or stress-induced valvular abnormalities.Transesophageal


Surgery_Schwartz

Surgery_Schwartz. echocardiography is a study similar in idea to the stress ECG that utilizes a pharmacologic agent to assess the patient for ischemia or stress-induced valvular abnormalities.Transesophageal echocardiography, on the other hand, is performed using a special endoscope with an ultrasound probe mounted on its end that is introduced orally into the esophagus under sedation. Posterior structures such as the mitral valve and left atrium are particularly well visualized. TEEs are frequently used intraoperatively during cardiothoracic surgery to assess global cardiac function, integrity of valve repairs and replace-ments, intracavitary thrombus and/or air, and aortic athero-sclerosis or dissections that can have significant influences on operative strategy.Brunicardi_Ch21_p0801-p0852.indd 80401/03/19 5:32 PM 805ACQUIRED HEART DISEASECHAPTER 21Figure 21-1. Stepwise approach to perioperative cardiac assessment for coronary artery disease. (Reproduced with permission from Fleisher LA,


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Surgery_Schwartz. 80401/03/19 5:32 PM 805ACQUIRED HEART DISEASECHAPTER 21Figure 21-1. Stepwise approach to perioperative cardiac assessment for coronary artery disease. (Reproduced with permission from Fleisher LA, Fleischmann KE, Auerbach AD, et al: 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines, Circulation. 2014 Dec 9;130(24):2215-2245.)EmergencyACS†(Step 2)YesYesNoNoModerate or greater(˜4 METs) functionalcapacityPoor OR unknownfunctional capacity(<4 METs):Will further testing impactdecision making ORperioperative care?(Step 6)No orunknownPatient scheduled for surgery withknown or risk factors for CAD*(Step 1)Clinical risk stratiÿcationand proceed to surgeryEvaluate and treataccording to GDMT†Estimated perioperative risk of MACEbased on combined clinical/surgical risk(Step 3)Low risk (<1%)(Step


Surgery_Schwartz

Surgery_Schwartz. 1)Clinical risk stratiÿcationand proceed to surgeryEvaluate and treataccording to GDMT†Estimated perioperative risk of MACEbased on combined clinical/surgical risk(Step 3)Low risk (<1%)(Step 4)Proceed tosurgeryElevated risk(Step 5)No furthertesting(Class III:NB)Proceed to surgeryaccording to GDMT ORalternate strategies(noninvasive treatment,palliation)(Step 7)No furthertesting(Class lIa)No furthertesting(Class IIb)Pharmacologicstress testing(Class lIa)Coronaryrevascularizationaccording toexisting CPGs(Class I)Proceed tosurgeryYesIfnormalIfabnormalNoExcellent(>10 METs)Moderate/Good(˜4–10 METs)Brunicardi_Ch21_p0801-p0852.indd 80501/03/19 5:32 PM 806SPECIFIC CONSIDERATIONSPART IIThere are some more recent additions to the echocardio-graphic armamentarium that capitalize on the strengths of ultra-sound imaging. Three-dimensional TEE is playing an increasing role in the preoperative and intraoperative evaluation of patients with valvular heart disease and is especially helpful in


Surgery_Schwartz

Surgery_Schwartz. of ultra-sound imaging. Three-dimensional TEE is playing an increasing role in the preoperative and intraoperative evaluation of patients with valvular heart disease and is especially helpful in percuta-neous mitral intervention. Tissue Doppler imaging is based on principles akin to conventional Doppler echocardiography, but attention is directed to the myocardium itself as opposed to the motion of blood to quantify abnormalities in wall motion. Strain imaging with speckle-tracking echocardiography measures the actual deformation of the myocardium by following inhomoge-neities inherent to the myocardium and is a useful measure of myocardial function.Radionuclide Studies. Although ECGs are useful, inexpen-sive, and safe, baseline abnormalities in the ECG may limit its diagnostic capacity. In particular, ventricular rhythms, bundle-branch blocks, left ventricular hypertrophy, drug effects, and baseline ST-segment depressions can make stress ECGs dif-ficult to interpret for the presence


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Surgery_Schwartz. In particular, ventricular rhythms, bundle-branch blocks, left ventricular hypertrophy, drug effects, and baseline ST-segment depressions can make stress ECGs dif-ficult to interpret for the presence of myocardial ischemia. In this setting, myocardial perfusion imaging (MPI) using radionu-clides can be utilized. Thallium 201 (201Tl) was the initial radio-nuclide used for MPI, but due to its long half-life and relatively low photopeak, it has largely been replaced by technetium-99m (sestamibi and tetrofosmin) because of its more favorable char-acteristics. In the past, planar imaging with three separate 2D views of the heart were obtained. Currently, it is more common to have the images acquired by single-photon emission com-puted tomography (SPECT) technology, which detects emit-ted photons from 180° to 360° around the patient. The signals are then processed to reconstruct multiple slices that together provide a 3D image. The distribution of radionuclides depends on perfusion, and


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Surgery_Schwartz. from 180° to 360° around the patient. The signals are then processed to reconstruct multiple slices that together provide a 3D image. The distribution of radionuclides depends on perfusion, and therefore areas that show uptake at rest, but not during stress, are concerning for ischemia. The amount of uptake at both rest and stressed states is compared to assess ischemia and viability of the myocardium. Territories that do not show uptake at rest or during stress are likely to be nonvi-able scar. The sensitivity and specificity of exercise SPECT are 87% and 73%, respectively.8,9The image acquisition may also be gated to a simultane-ously obtained ECG to assess global ventricular function. The endocardial and epicardial borders (as delineated by radionu-clide uptake) are detected throughout the cardiac cycle and the ejection fraction, along with end-systolic and end-diastolic vol-umes, can be calculated. This study is also useful in revealing hypokinetic segments of the myocardium.One


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Surgery_Schwartz. the cardiac cycle and the ejection fraction, along with end-systolic and end-diastolic vol-umes, can be calculated. This study is also useful in revealing hypokinetic segments of the myocardium.One significant drawback of SPECT imaging is that it shows regional ischemia well, but it does not adequately detect global or “balanced” ischemia that can occur with diffuse CAD. Positron emission tomography (PET) has been used due to its ability to obtain absolute quantitative data on both myocardial perfusion and metabolism. Tracers used in PET scans can be divided into those that assess perfusion (oxygen-15, nitrogen-13, and rubidiuim-82) and those that assess metabolism (carbon-11 and fluorine-18). The specificity of PET in detecting CAD is better than SPECT at 86% due to its superior spatial resolution.10Magnetic Resonance Imaging. Magnetic resonance imaging (MRI) has a wide variety of uses in cardiac imaging depending on the pulse sequence and signal weighting. Cine-loop imaging of the


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Surgery_Schwartz. resolution.10Magnetic Resonance Imaging. Magnetic resonance imaging (MRI) has a wide variety of uses in cardiac imaging depending on the pulse sequence and signal weighting. Cine-loop imaging of the heart throughout the cardiac cycle can yield information on global chamber function, geometry, and valvular pathologies. The differential response of normal and ischemic myocardium to certain pulse sequences allows imaging of myocardial per-fusion using MRI. Use of contrast agents such as gadolinium can enhance scar tissue and are very useful in viability assess-ment. Myocardial strain imaging can also be performed taking advantage of radio-frequency tagging of the myocardium, which deforms with the tissue and can be followed throughout the car-diac cycle.Cardiac Catheterization. Cardiac catheterization involves access to the cardiac chambers, coronary arteries, and great vessels with a peripherally inserted catheter under fluoroscopic guidance. It is a versatile tool used to investigate


Surgery_Schwartz

Surgery_Schwartz. involves access to the cardiac chambers, coronary arteries, and great vessels with a peripherally inserted catheter under fluoroscopic guidance. It is a versatile tool used to investigate cardiac cham-ber pressures, valvular abnormalities, wall motion, and coronary artery anatomy. While some of these roles are being replaced by less invasive techniques mentioned previously, cardiac cath-eterization continues to be widely performed and is the gold standard for the assessment of coronary artery disease.11Left heart catheterization is performed by percutaneous access of the femoral, or radial, artery. Under fluoroscopic guid-ance, the catheter is threaded into the ascending aorta where a contrast aortogram may be performed. Coronary angiography requires manipulation of this catheter into the coronary ostia where contrast is directly injected. With advancement of the catheter retrograde through the aortic valve, left ventricular pressures can be obtained. This measurement is used to


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Surgery_Schwartz. the coronary ostia where contrast is directly injected. With advancement of the catheter retrograde through the aortic valve, left ventricular pressures can be obtained. This measurement is used to calcu-late direct pressure gradients across the aortic valve, in con-trast to echocardiography that indirectly measures pressure, and can be used to confirm severe aortic stenosis. Again, contrast injection into the left ventricle can be used to estimate ejection fraction and visualize hypokinetic segments of the myocardium. Inappropriate retrograde leakage of contrast may indicate insuf-ficiency of the aortic and/or mitral valves.Coronary angiography provides information on hemody-namically significant stenoses in the coronary circulation as well as an anatomical roadmap for surgeons to plan revascularization (Fig. 21-2A,B). A stenosis is considered to be significant if it narrows the lumen of the artery by 70% (or 50% in the case of left main coronary artery). Borderline lesions or


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Surgery_Schwartz. plan revascularization (Fig. 21-2A,B). A stenosis is considered to be significant if it narrows the lumen of the artery by 70% (or 50% in the case of left main coronary artery). Borderline lesions or complex lesions may be assessed by fractional flow reserve (FFR) or instant wave-free radio (iFR), which obviates the need of adenosine.12 This has been shown to very helpful in guiding revasculariza-tion strategies in recent clinical trials.13 Additional assessment can also be done using intravascular ultrasound (IVUS) inside the coronary circulation. There is some variability in the coro-nary arterial anatomy with the posterior descending artery being supplied by the right coronary artery in approximately 80% of patients (right dominant) or the left coronary artery in approxi-mately 15% of patients (left dominant). The remaining patients have a codominant circulation where the posterior descending artery is supplied by both the right and left coronaries.Right heart catheterization is


Surgery_Schwartz

Surgery_Schwartz. patients (left dominant). The remaining patients have a codominant circulation where the posterior descending artery is supplied by both the right and left coronaries.Right heart catheterization is performed by the introduc-tion of catheter through a peripheral vein that is advanced into the right side of the heart.14 Right-sided pressures and structures are assessed in a similar fashion as in the left heart. Extension of the catheter into the pulmonary artery allows measurement of pulmonary artery pressures as well as pulmonary capillary wedge pressure (reflecting left ventricular end diastolic pres-sure) with an occlusive balloon. In addition to these measure-ments, cardiac output can be measured using thermodilution or by the Fick method using oxygen saturations of blood sampled from the various locations during the procedure.Brunicardi_Ch21_p0801-p0852.indd 80601/03/19 5:32 PM 807ACQUIRED HEART DISEASECHAPTER 21Figure 21-2. Cardiac catheterization angiography. A. Stenosis of


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Surgery_Schwartz. the various locations during the procedure.Brunicardi_Ch21_p0801-p0852.indd 80601/03/19 5:32 PM 807ACQUIRED HEART DISEASECHAPTER 21Figure 21-2. Cardiac catheterization angiography. A. Stenosis of right coronary artery indicated by the arrow. B. Still image of a normal left ventriculogram.ABAn advantage of cardiac catheterization is that it offers an opportunity for interventional therapy of coronary artery disease, arrhythmias, valvular abnormalities, and other struc-tural defects of the heart. Cardiac catheterization is generally safe, but being an invasive procedure, it is associated with rare complications. The overall mortality is 0.11%, and total rate of major complications, including MI, stroke, arrhythmia, vascular injury, contrast reaction including allergic reaction and contrast-induced nephropathy, hemodynamic instability, and cardiac per-foration is usually <2%.15Cardiac Computed Tomography. Multislice computed tomography (CT) imaging can be used to assess the coronary


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Surgery_Schwartz. nephropathy, hemodynamic instability, and cardiac per-foration is usually <2%.15Cardiac Computed Tomography. Multislice computed tomography (CT) imaging can be used to assess the coronary vasculature. The coronary calcium score is an index devel-oped to quantify the degree of coronary atherosclerotic burden by measuring Hounsfield units in a noncontrast cardiac CT. Although this technique is quite sensitive for angiographic stenoses (>50%) it remains fairly nonspecific as calcification often precedes significant luminal narrowing.16 CT coronary angiography using intravenous contrast is also utilized clini-cally to assess coronary pathology and is particularly useful in the emergency room to perform a “triple rule-out” for acute coronary events, pulmonary embolism, and aortic dissection in patients who present with undifferentiated chest pain. LV ejec-tion fraction may be measured by this technique, and, together with the degree of coronary stenosis, it has been shown to have


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Surgery_Schwartz. in patients who present with undifferentiated chest pain. LV ejec-tion fraction may be measured by this technique, and, together with the degree of coronary stenosis, it has been shown to have incremental prognostic value for the presence of coronary artery disease and in the prediction of adverse coronary events.17EXTRACORPOREAL PERFUSIONHistoryPrior to the development of extracorporeal perfusion, heart sur-gery was rarely performed and was limited to brief periods of asystole and/or hypothermia. The need for obtaining a bloodless operating field, while maintaining perfusion of heart and other organs, was evident.John Gibbon’s motivation to develop a means for extra-corporeal perfusion came from a desire to safely open the pulmonary artery in a patient who suffered from a pulmonary embolus following a cholecystectomy. After numerous experi-mental iterations, Gibbon’s cardiopulmonary bypass machine was first used clinically in 1953 to repair an atrial septal defect in an 18-year-old


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Surgery_Schwartz. following a cholecystectomy. After numerous experi-mental iterations, Gibbon’s cardiopulmonary bypass machine was first used clinically in 1953 to repair an atrial septal defect in an 18-year-old woman.18 Although Gibbon is credited for its invention, the development of modern cardiopulmonary bypass (CPB) is a culmination of the work of many investi-gators throughout the world. The early bubble oxygenators have evolved into the currently used membrane oxygenators. The search for an ideal biocompatible material that minimizes the inflammatory cascade initiated by the contact of blood with the circuit components continues to this day.TechniqueThe basic CPB circuit consists of the venous cannulae, a venous reservoir, pump, oxygenator, filter, and the arterial cannula.Anticoagulation is required during CPB, and 300 to 400 units/kg of heparin are given to increase the activated clotting time (ACT) to greater than 450 seconds. Once an ade-quate level of anticoagulation is achieved,


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Surgery_Schwartz. required during CPB, and 300 to 400 units/kg of heparin are given to increase the activated clotting time (ACT) to greater than 450 seconds. Once an ade-quate level of anticoagulation is achieved, arterial cannulation is performed through a purse-string suture or through a side graft sewn onto the native artery. The distal ascending thoracic aorta is the most common site of cannulation. Other routinely utilized sites of cannulation include the femoral artery, the axillary artery, the innominate artery, or the distal aortic arch, and they are altered based on the indicated surgical repair and the pres-ence of native arterial disease. Venous cannulation is performed through purse-string sutures placed on the right atrium either for a single cannula or for two separate cannulae placed into the superior and inferior vena cava, respectively. Alternatively, the venous cannula may be inserted from the femoral vein and advanced into the right atrium and superior vena cava using TEE guidance.


Surgery_Schwartz

Surgery_Schwartz. superior and inferior vena cava, respectively. Alternatively, the venous cannula may be inserted from the femoral vein and advanced into the right atrium and superior vena cava using TEE guidance. This technique is frequently used in minimally invasive cardiac surgery.Effective communication between the surgeon, the anes-thesiologist, and the perfusionist is mandatory for effective Brunicardi_Ch21_p0801-p0852.indd 80701/03/19 5:32 PM 808SPECIFIC CONSIDERATIONSPART IIcardiopulmonary bypass. Once the appropriate cannulations and connections are complete, CPB is commenced. Venous return is initiated followed by arterial flow while monitoring systemic blood pressure. At normothermia, the flow required is approxi-mately 2.4 L/min/m2, but with hypothermia, oxygen consump-tion is reduced by 50% for every 10°C drop in temperature, and a flow of only 1 L/min/m2 is required at 18°C. Once the heart is decompressed and hemodynamics are acceptable, ventilation is stopped. The oxygenator is


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Surgery_Schwartz. by 50% for every 10°C drop in temperature, and a flow of only 1 L/min/m2 is required at 18°C. Once the heart is decompressed and hemodynamics are acceptable, ventilation is stopped. The oxygenator is adjusted to maintain a Pao2 of 150 mmHg and normocarbia. Blood can also be filtered and returned through vents that are placed in chambers of the heart (such as the left ventricle or pulmonary artery) or through the cardiotomy suction used to aspirate blood from the surgical field. When the cardiac procedure is complete, the patient is rewarmed, the lungs ventilated, and the heart defibrillated, if needed. The venous return to the CPB machine is gradually reduced allowing the heart to fill. The pump is also slowed while hemodynamics and global cardiac function are assessed with a TEE probe. Ino-tropic and vasopressor support may be used to augment cardiac function and treat hypotension. Once CPB has been weaned and stable hemodynamics achieved, the cannulae are removed. The heparin


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Surgery_Schwartz. Ino-tropic and vasopressor support may be used to augment cardiac function and treat hypotension. Once CPB has been weaned and stable hemodynamics achieved, the cannulae are removed. The heparin anticoagulation is reversed with 1 mg protamine per 100 units of heparin and hemostasis is achieved.19Adverse EffectsCardiopulmonary bypass has a number of deleterious effects as various intertwining processes result in derangements in hemo-stasis, an enhanced systemic inflammatory response, and end-organ function.Anticoagulation prior to the commencement of CPB is required as contact of blood with the artificial surfaces of the cir-cuit can initiate a thrombogenic cascade. Generation of thrombin plays a major role in both thrombotic and bleeding phenomena during CPB. The endothelium that normally regulates the fine balance between procoagulant and anticoagulant pathways is perturbed. Fibrinogen is consumed rapidly as thrombin converts fibrinogen to fibrin while fibrinolytic mechanisms


Surgery_Schwartz

Surgery_Schwartz. regulates the fine balance between procoagulant and anticoagulant pathways is perturbed. Fibrinogen is consumed rapidly as thrombin converts fibrinogen to fibrin while fibrinolytic mechanisms (initiated by the activated endothelium) degrade the fibrin macromolecules. Platelets are activated by the converging hemostatic pathways and are consumed.The response of the humoral and cellular immune systems partly overlap with the hemostatic pathways. The classic and alternative complement pathways are activated by CPB gen-erating powerful chemotaxic molecules and anaphylatoxins.20 Monocytes, platelets, and neutrophils are activated releasing acute inflammatory mediators and cytokines that persist even after conclusion of CPB.21 These inflammatory cells also pro-duce reactive oxidants that may have cytotoxic and cardiovas-cular effects such as vasodilation and hypotension.The large quantity of unfractionated heparin used during cardiac surgery predisposes patients to developing


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Surgery_Schwartz. that may have cytotoxic and cardiovas-cular effects such as vasodilation and hypotension.The large quantity of unfractionated heparin used during cardiac surgery predisposes patients to developing heparin-induced thrombocytopenia (HIT) with an incidence of 1% to 5%.22 Platelet factor-4 (PF4) is produced by platelets and avidly binds to heparin to form a heparin-PF4 complex that can be antigenic in some patients binding IgG. The IgG-heparin-PF4 complex can bind to platelets, which causes release of more PF4, perpetuating the process. The earliest sign is a sudden drop of more than 50% in the platelet count, usually seen from sev-eral hours to days after surgery. HIT can be confirmed with an enzyme-linked immunosorbent assay (ELISA) or serotonin release assay (SRA). Of the patients with HIT, 20% to 50% of patients develop thromboses in arterial or venous beds, designated as heparin-induced thrombocytopenia and thrombo-sis (HITT), which can be life-threatening.23 Treatment is


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Surgery_Schwartz. with HIT, 20% to 50% of patients develop thromboses in arterial or venous beds, designated as heparin-induced thrombocytopenia and thrombo-sis (HITT), which can be life-threatening.23 Treatment is anti-coagulation with nonheparin anticoagulant (e.g., argatroban, bivalirudin).The etiology of end-organ dysfunction resulting from extracorporeal circulation can mostly be categorized into one of three mechanisms: hypoperfusion, embolization, and whole-body inflammatory response. Although cardiac output and blood pressure are monitored carefully during CPB, they are surrogates for regional perfusion and cannot detect end-organ hypoperfusion directly. This can be a problem particularly with the cerebral, renal, and mesenteric circulations. With manip-ulation of diseased vessels and dysregulation of the native coagulation system, macroscopic and microscopic emboli are a concern. Activated cells and circulating cytotoxic products of the immune response may cause microvascular injury and edema


Surgery_Schwartz

Surgery_Schwartz. of the native coagulation system, macroscopic and microscopic emboli are a concern. Activated cells and circulating cytotoxic products of the immune response may cause microvascular injury and edema of other organs manifesting as neurocognitive deficits, respiratory failure, and renal injury.24Myocardial ProtectionDuring CPB, pharmacologic agents in cardioplegic solutions may be delivered into the coronary circulation to arrest the heart, allowing for a still operating target and improved myocardial protection. The most common cardioplegia consists of potas-sium-rich solutions that can be mixed with autologous blood and are delivered into the coronary circulation.25 Antegrade cardioplegia is delivered into the root of a cross-clamped aorta or directly into the individual coronary ostial using specialized catheters. A retrograde cardioplegia catheter is a balloon-cuffed catheter that is placed through the right atrium into the coro-nary sinus and is used to perfuse the coronary


Surgery_Schwartz

Surgery_Schwartz. using specialized catheters. A retrograde cardioplegia catheter is a balloon-cuffed catheter that is placed through the right atrium into the coro-nary sinus and is used to perfuse the coronary circulation in the opposite direction through the venous circulation. This has the advantage of more uniform distribution in patients with diffuse coronary artery disease and is not dependent on a competent aortic valve for delivery.There is continued debate regarding the best method (ante-grade vs. retrograde vs. both), type (crystalloid vs. blood), tem-perature (cold vs. warm vs. tepid), and interval (continuous vs. intermittent) of cardioplegia delivery. The optimal combination is beyond the scope of this text. However, most cardiac surgeons in the United States favor cold blood potassium cardioplegia.CORONARY ARTERY DISEASEHistoryAortocoronary bypass for myocardial ischemia was first pro-posed and performed in laboratory animals by Carrel in 1910.26 The Vineberg operation, one of the


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Surgery_Schwartz. cardioplegia.CORONARY ARTERY DISEASEHistoryAortocoronary bypass for myocardial ischemia was first pro-posed and performed in laboratory animals by Carrel in 1910.26 The Vineberg operation, one of the initial attempts at surgical revascularization of the myocardium, was introduced in 1951.27 This procedure involved implantation of the internal thoracic artery directly into the myocardium itself. While some patients were relieved of their anginal symptoms, this resulted in vir-tually no increase in coronary flow and was soon supplanted by methods to restore flow directly. Coronary endarterectomy was introduced by Longmire during this time period but had high rates of restenosis and occlusion.28 The use of vein patches to repair the arteriotomy sites was described by Senning in 1961.29 The first saphenous vein coronary artery bypass grafting (CABG) was performed by Sabiston in 1962,30 but was popular-ized by Favalaro and Sones in 1967.31 In 1968, the internal tho-racic artery was


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Surgery_Schwartz. The first saphenous vein coronary artery bypass grafting (CABG) was performed by Sabiston in 1962,30 but was popular-ized by Favalaro and Sones in 1967.31 In 1968, the internal tho-racic artery was introduced as a bypass conduit by Green, who used it to bypass the left anterior descending coronary artery.32Brunicardi_Ch21_p0801-p0852.indd 80801/03/19 5:32 PM 809ACQUIRED HEART DISEASECHAPTER 21Etiology and PathogenesisAtherosclerotic stenoses are the primary mechanism of CAD. The pathophysiologic process is initiated with vascular endo-thelial injury and is potentiated by inflammatory mechanisms, circulating lipids, toxins, and other vasoactive agents in the blood. Macrophages and platelets are attracted to this area of endothelial dysfunction inciting a local inflammatory response. During this process, macrophages infiltrate into the intimal lay-ers and accumulate cholesterol-containing low-density lipo-proteins. The growth factors secreted promote proliferation of smooth muscle


Surgery_Schwartz

Surgery_Schwartz. this process, macrophages infiltrate into the intimal lay-ers and accumulate cholesterol-containing low-density lipo-proteins. The growth factors secreted promote proliferation of smooth muscle cells within the intima and media of the arteries. Together with the accumulation of the lipid-laden macrophages, the smooth muscle hyperplasia results in an atheroma and subse-quent stenosis of the vessel. These atheromas have a fibrous cap that may rupture, exposing the underlying cells and extracellular matrix, which are very prothrombotic. Acute plaque rupture and thrombus formation is thought to be the main pathophysiologic mechanism responsible for acute coronary syndromes.33-35Risk Factors and PreventionPrior to the establishment of modern management strategies, the annual mortality rate from ischemic heart disease was 482 out of 100,000 persons.36 Since the peak of coronary heart dis-ease mortality in 1968, modern primary and secondary preven-tion strategies such as risk factor


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Surgery_Schwartz. rate from ischemic heart disease was 482 out of 100,000 persons.36 Since the peak of coronary heart dis-ease mortality in 1968, modern primary and secondary preven-tion strategies such as risk factor modification, percutaneous and surgical revascularization, use of medications (e.g., aspirin, HMG-CoA reductase inhibitors [statins], and β-blockers), has decreased mortality from coronary artery disease by 74%.36The major risk factors for atherosclerosis include advanced age, cigarette smoking, hypertension, dyslipidemias, sedentary lifestyle, obesity, and diabetes. Likely due to increased public awareness and aggressive medical management, these risk fac-tors (with the exception of glucose intolerance and obesity) have recently been on the decline.Current guidelines outlined in the AHA/ACC consensus statement summarize the secondary prevention recommendations.37 Class I recommendations include smoking cessation and avoid-ance of environmental tobacco exposure, blood pressure con-trol to


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Surgery_Schwartz. statement summarize the secondary prevention recommendations.37 Class I recommendations include smoking cessation and avoid-ance of environmental tobacco exposure, blood pressure con-trol to under 140/90 mmHg (under 130/80 mmHg in those with diabetes or chronic kidney disease), LDL cholesterol levels less than 100 mg/dL, aspirin therapy in all patients without contra-indications, a BMI target of less than 25 kg/m2, diabetes man-agement with target HbA1c <7%, and encouragement of daily moderate-intensity aerobic exercise. β-Blockers should be used in all patients with LV dysfunction and following MI, ACS, or revascularization, unless a specific contraindication is pres-ent. Renin-angiogensin-aldosterone system blockade in patients with hypertension, LV dysfunction, diabetes, or chronic kidney disease should also be considered.Clinical ManifestationsPatients with CAD may have a spectrum of presentations, including angina pectoris, myocardial infarction, ischemic heart failure,


Surgery_Schwartz

Surgery_Schwartz. kidney disease should also be considered.Clinical ManifestationsPatients with CAD may have a spectrum of presentations, including angina pectoris, myocardial infarction, ischemic heart failure, arrhythmias, and sudden death.Angina pectoris is the pain or discomfort caused by myo-cardial ischemia and is typically substernal and may radiate to the left upper extremity, neck, or epigastrium. The variety of presentations can make myocardial ischemia challenging to diagnose. Characteristics of chest pain that make myocardial ischemia less likely include pleuritic chest pain, pain reproduc-ible by movement or palpation, or brief episodes lasting only seconds. Typical angina is relieved by rest and/or use of sub-lingual nitroglycerin. Differential diagnoses to be considered include, but are not limited to, musculoskeletal pain, pulmonary disorders, esophageal spasm, pericarditis, aortic dissection, gas-troesophageal reflux, neuropathic pain, and anxiety.Myocardial infarction is a serious


Surgery_Schwartz

Surgery_Schwartz. limited to, musculoskeletal pain, pulmonary disorders, esophageal spasm, pericarditis, aortic dissection, gas-troesophageal reflux, neuropathic pain, and anxiety.Myocardial infarction is a serious consequence of CAD occurring when ischemia results in myocardial necrosis. This may be silent and need not be preceded by angina. Necrosis may result in disruption of the myocardial integrity leading to devastating conditions such as intracardiac shunts from ventric-ular septal defects, acute valvular regurgitation from rupture of necrotic papillary muscles, and cardiac aneurysms, which have the potential for fatal rupture.Ischemic insults from CAD may lead to congestive heart failure. The initial myocardial damage sets off a cascade of both local and systemic responses. Over time, these changes can cause deleterious myocardial loading and abnormal neuro-humoral responses that result in pathologic remodeling of the heart. Heart failure should be suspected in patients who present with


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Surgery_Schwartz. changes can cause deleterious myocardial loading and abnormal neuro-humoral responses that result in pathologic remodeling of the heart. Heart failure should be suspected in patients who present with dyspnea, orthopnea, fatigue, and edema.Arrhythmias may also be sequelae of CAD. Ischemic etiologies should be investigated in patients who present with new arrhythmias. CAD may result in arrhythmias following an acute MI or as the result of ultrastructural and electrophysi-ologic remodeling secondary to chronic ischemic heart disease. Ischemia of the electrical conduction system may be present in the form of new onset complete or partial atrioventricular conduction blocks.Preoperative EvaluationA focused history and physical examination is essential with par-ticular attention directed to the signs, symptoms, and clinical man-ifestations mentioned previously. The patient’s functional status is of importance not only because it is a component of preoperative risk assessment, but also


Surgery_Schwartz

Surgery_Schwartz. the signs, symptoms, and clinical man-ifestations mentioned previously. The patient’s functional status is of importance not only because it is a component of preoperative risk assessment, but also because quality of life improvement and symptomatic relief are both goals of surgical therapy.Coronary angiography is the primary diagnostic tool. The coronary anatomy and degrees of stenoses are delineated allow-ing for planning of surgical revascularization.Noninvasive diagnostic studies, in combination with pro-vocative maneuvers (exercise or pharmacologic agents) offer information regarding the functional significance of ischemic disease. A stress ECG is frequently used as a screening tool with 50% sensitivity and 90% specificity for coronary artery with a threshold of 1 mm of ST-segment depression.38 This test, how-ever, requires patients to achieve a certain elevation in their heart rate and is therefore not suitable for those that cannot achieve this goal. Furthermore, baseline ECG


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Surgery_Schwartz. This test, how-ever, requires patients to achieve a certain elevation in their heart rate and is therefore not suitable for those that cannot achieve this goal. Furthermore, baseline ECG abnormalities may render it impossible to detect typical ischemic changes with stress.Echocardiography and nuclear imaging may be performed under pharmacologic stress (with dobutamine or dipyridamole) to assess reversible ischemia and myocardial viability. Technetium-99m or thallium-201 perfusion scans and stress echocardiogra-phy are more sensitive than stress ECG.39 These studies also have the ability to assess global ventricular function in terms of left ventricle ejection fraction, which can be used to determine operative risk. Please refer to the diagnostic studies section for more details.CORONARY ARTERY BYPASS GRAFTINGIndicationsA joint committee established by the ACC/AHA have pub-lished guidelines for surgical revascularization (CABG) in Brunicardi_Ch21_p0801-p0852.indd 80901/03/19 5:32


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Surgery_Schwartz. ARTERY BYPASS GRAFTINGIndicationsA joint committee established by the ACC/AHA have pub-lished guidelines for surgical revascularization (CABG) in Brunicardi_Ch21_p0801-p0852.indd 80901/03/19 5:32 PM 810SPECIFIC CONSIDERATIONSPART IITable 21-3Algorithm set forth by ACC/AHA guidelines for preoperative cardiovascular evaluation before noncardiac surgery for patients who are scheduled for nonemergent, non-low risk surgery, no active cardiac disease, and less than 3 METsNUMBER OF RISK FACTORSaRECOMMENDATION0Proceed with planned surgery.1–2Control HR and proceed with planned surgery or pursue further testing if it will change management.3–5Pursue further testing if it will advance management.aRisk factors are history of ischemic heart disease, history of prior or compensated heart failure, history of cerebrovascular disease, diabetes mellitus, and renal insufficiency.Table 21-4Data from ACC/AHA guidelines for CABG in CAD to improve survivalANATOMYCLASS OF RECOMMENDATIONLEVEL OF


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Surgery_Schwartz. history of cerebrovascular disease, diabetes mellitus, and renal insufficiency.Table 21-4Data from ACC/AHA guidelines for CABG in CAD to improve survivalANATOMYCLASS OF RECOMMENDATIONLEVEL OF EVIDENCE• LMIB• 3-vessel +/− proximal LADIB• 2-vessel + proximal LADIB• 2-vessel – proximal LADIIa – with extensive ischemiaIIb – without extensive ischemiaBC• Multivessel disease with DMIIa (CABG preferred over PCI)B• Proximal LAD onlyIIa – with LITA for long-term benefitB• 1-vessel – proximal LADIII – HarmB• LV dysfunctionIIa – LVEF 35%–50%IIb – LVEF <35% without LM diseaseBB• Survivor of ischemia-mediated VTIBDM = Diabetes mellitus; LITA = Left internal thoracic/mammary artery; LM = Left main coronary artery; LV = left ventricle; VT = ventricular tachycardia. Class of recommendation: I – Benefit far outweighs risks and procedure should be performed; IIa – Benefit outweighs risks and procedure is considered to be reasonable; IIb – Potential benefits may exceed risks and procedure may be


Surgery_Schwartz

Surgery_Schwartz. far outweighs risks and procedure should be performed; IIa – Benefit outweighs risks and procedure is considered to be reasonable; IIb – Potential benefits may exceed risks and procedure may be considered; III – Procedure not helpful and may cause harm. Level of evidence: A – Strong; multiple supporting randomized controlled trials or meta-analyses, B – Limited; data based on a single randomized trial or nonrandomized trials, C – Very limited; based on expert consensus, case studies or standards of care.CAD. The indications, categorized by presentation and angio-graphic disease burden as well as by treatment intention (sur-vival improvement and symptom relief), are summarized later (Tables 21-3, 21-4, and 21-5).40,41Percutaneous Coronary Intervention vs. Coronary Artery Bypass GraftingThere have been multiple prospective, randomized, controlled trials as well as large retrospective studies looking at the com-parative effectiveness of percutaneous coronary interventions (PCI) and CABG.


Surgery_Schwartz

Surgery_Schwartz. have been multiple prospective, randomized, controlled trials as well as large retrospective studies looking at the com-parative effectiveness of percutaneous coronary interventions (PCI) and CABG. Some of the representative studies are sum-marized here.The New York State Study (2005). A retrospective review of 59,314 patients in a New York state registry with multivessel (two or more) coronary disease was performed. Of these, 37,212 patients received a CABG, and the remainder underwent a PCI. After adjusting by means of proportional-hazards methods, CABG was associated with higher adjusted rates of long-term survival than PCI.42Stent or Surgery Trial (2008). An international multicenter, randomized, controlled trial of 988 patients (n = 488 PCI, n = 500 CABG) with multivessel CAD was performed to compare revascularization strategies. The median follow-up was extended to 6 years, and a survival advantage persisted in the CABG group over the PCI group.43Synergy Between Percutaneous


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Surgery_Schwartz. performed to compare revascularization strategies. The median follow-up was extended to 6 years, and a survival advantage persisted in the CABG group over the PCI group.43Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX Trial, 2009, updated 2013). Revascularization strategies, CABG vs. PCI, were compared in a 1:1 randomized prospective trial of 1800 patients with high-risk coronary artery disease (left-main or triple-vessel disease). Rates of requirement for repeat revascu-larization and major adverse cardiac or cerebrovascular events (MACCE) at 1 year were lower in the CABG patients (5.9% and 12.4%, respectively) compared to PCI patients (13.5% and 17.8%, respectively). No difference in mortality was seen between the groups at 1 year.44 At 5 years, the estimated rate of MACCE was 26.9% in the CABG group vs. 37.3% in the PCI group. No difference in all-cause mortality was seen. The dif-ference in MACCE between PCI and CABG was confined to


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Surgery_Schwartz. years, the estimated rate of MACCE was 26.9% in the CABG group vs. 37.3% in the PCI group. No difference in all-cause mortality was seen. The dif-ference in MACCE between PCI and CABG was confined to patients with intermediate or high SYNTAX scores.45The ACCF and STS Database Collaboration on the Com-parative Effectiveness of Revascularization Strategies (ASCERT Study, 2012). This study, performed by collabo-ration of the American College of Cardiology Foundation and the Society of Thoracic Surgeons, reviewed their respective national databases of patients over the age of 65 who had multi-vessel coronary disease (excluding those with left main disease). CABG was performed on 86,244 patients, and 103,549 under-went PCI. There was no difference in adjusted mortality at 1 year, but there was a significantly lower mortality with CABG than PCI at 4 years.46 Although CABG had higher cost, this was Brunicardi_Ch21_p0801-p0852.indd 81001/03/19 5:32 PM 811ACQUIRED HEART DISEASECHAPTER


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Surgery_Schwartz. was a significantly lower mortality with CABG than PCI at 4 years.46 Although CABG had higher cost, this was Brunicardi_Ch21_p0801-p0852.indd 81001/03/19 5:32 PM 811ACQUIRED HEART DISEASECHAPTER 21Table 21-5Data from ACC/AHA guidelines for CABG in CAD to improve symptomsANATOMY ASSOCIATED SYMPTOMSCLASS OF RECOMMENDATIONLEVEL OF EVIDENCE• Unacceptable angina with presence of ≥1 stenoses amenable to revascularization despite medical treatmentIA• Complex 3-vessel CAD +/− proximal LAD involvementIIa (CABG preferred over PCI)B• Unacceptable angina with presence of ≥1 stenoses amenable to revascularization but medical treatment is not possibleIIaC• Previous CABG with ≥1 stenoses associated with ischemia and angina despite medical treatmentIIbCmodest with an incremental cost-effectiveness ratio of $30,454 per quality-adjusted life year gained.47Everolimus-Eluting Stents or Bypass Surgery for Left Main Coronary Artery Disease (EXCEL Trial, 2016). This study randomized 1905 patients with


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Surgery_Schwartz. of $30,454 per quality-adjusted life year gained.47Everolimus-Eluting Stents or Bypass Surgery for Left Main Coronary Artery Disease (EXCEL Trial, 2016). This study randomized 1905 patients with left main coronary artery disease of low or intermediate complexity to PCI or CABG. At 3 years, no difference was observed in the primary endpoint of death, stroke, myocardial infarction or ischemia-driven revas-cularization. However, it should be noted that the PCI group exhibited a greater increase in these events between 30 days and three years than the CABG group (11.5% vs. 7.9%).48SummaryPCI technology has improved over time, and rates of periproce-dural adverse events have decreased significantly. Man-agement strategies must be tailored to the individual patient’s clinical status and context, but CABG maintains improved long-term outcome and remains the standard of care for patients with left-main, multivessel coronary artery disease and patients with diabetes. Recent and upcoming trials


Surgery_Schwartz

Surgery_Schwartz. but CABG maintains improved long-term outcome and remains the standard of care for patients with left-main, multivessel coronary artery disease and patients with diabetes. Recent and upcoming trials will con-tinue to clarify which patient populations benefit most from either revascularization strategy.Operative Techniques and ResultsBypass Conduit Selection. The most important criterion in conduit selection is graft patency. The conduit with the highest patency rate (98% at 5 years and 85%–90% at 10 years) is the internal thoracic artery, which is most commonly left attached proximally to the subclavian artery (although occasionally used as a free graft) and anastomosed distally to the target coronary artery.49,50 The use of both internal thoracic arteries has been shown to increase event-free survival in a number of studies.51,52The greater saphenous vein can be harvested using an open or endoscopic technique. In the open technique, the initial inci-sion is made along the course of


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Surgery_Schwartz. survival in a number of studies.51,52The greater saphenous vein can be harvested using an open or endoscopic technique. In the open technique, the initial inci-sion is made along the course of the vein on the medial aspect of the lower extremity. The vein is harvested with meticulous attention directed towards minimizing manipulation of the vein itself. The incision may be continuous or bridged in an attempt to decrease the size of the incision, but multiple bridged inci-sions may have the potential risk of increased conduit manipula-tion during harvest. Endoscopic harvest is performed by making a small incision just above and medial to the knee where the endoscope is inserted. Side branches are cauterized under endo-scopic visualization using bipolar electrocautery until dissec-tion is carried proximally until the required length of vein is mobilized. A proximal counterincision is then made to extract the venous conduit, which is prepared in the standard fashion.1The radial artery is


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Surgery_Schwartz. proximally until the required length of vein is mobilized. A proximal counterincision is then made to extract the venous conduit, which is prepared in the standard fashion.1The radial artery is another frequently used conduit. After confirmation of ulnar collateral flow to the hand by the clinical Allen’s test or a duplex ultrasound study, an incision is made from a point just proximal to the radial styloid process and end-ing just medial and distal to the biceps tendon on the nondomi-nant hand. With lateral retraction of the brachioradialis muscle, the radial artery is dissected sharply with care to avoid injury to the cutaneous nerves in this area and minimize manipulation of the artery itself. This artery can also be harvested using an endoscopic technique.Many studies have looked at the patency rates of the radial artery graft in comparison to the saphenous vein graft. Although some studies have resulted in equivocal data, general consen-sus favors the use of radial arterial


Surgery_Schwartz

Surgery_Schwartz. at the patency rates of the radial artery graft in comparison to the saphenous vein graft. Although some studies have resulted in equivocal data, general consen-sus favors the use of radial arterial grafts over vein grafts with 5-year patency rates of 98% and 86%, respectively.53,54From a historical perspective, the anterior circulation (left anterior descending artery) is generally bypassed using the internal thoracic artery, and the lateral (circumflex artery) or inferior (right coronary artery) territories are bypassed using a saphenous vein or radial artery graft. These conduits may be combined to form a composite Tor Y-graft, or sewn to multiple targets as sequential grafts. Since patency is best with arterial grafts, recent data have suggested that the best long-term results are achieved using a multiple or all-arterial revascularization strategy, particularly in patients >70 years of age and patients with diabetes.55-57 Other conduits such as the gastroepiploic arteries, lesser


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Surgery_Schwartz. using a multiple or all-arterial revascularization strategy, particularly in patients >70 years of age and patients with diabetes.55-57 Other conduits such as the gastroepiploic arteries, lesser saphenous veins, and cephalic veins have been described, but these are not widely used and will not be dis-cussed here.Conventional Coronary Artery Bypass Grafting. Tradi-tionally, CABGs are performed with the patient lying supine through a median sternotomy. Left internal thoracic artery and other conduit harvests are performed. After the patient is heparinized, cardiopulmonary bypass is initiated. The aorta is cross-clamped, and cardioplegia is delivered. Once adequate myocardial protection has been achieved, coronary arterioto-mies are made, and distal anastomoses are performed using polypropylene suture (Fig. 21-3A,B). The proximal anastomo-ses are then performed directly onto the ascending aorta or onto preexisting grafts. It is important to note that significant coro-nary stenoses can


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Surgery_Schwartz. suture (Fig. 21-3A,B). The proximal anastomo-ses are then performed directly onto the ascending aorta or onto preexisting grafts. It is important to note that significant coro-nary stenoses can cause differential distribution of cardioplegia and myocardial protection. It is therefore recommended to use retrograde cardioplegia or to revascularize the area with the most concern for ischemia first and give cardioplegia down the completed graft. The left internal thoracic artery to left anterior descending (LAD) graft is frequently performed last to avoid kinking or disruption of this important conduit. Once all grafts Brunicardi_Ch21_p0801-p0852.indd 81101/03/19 5:32 PM 812SPECIFIC CONSIDERATIONSPART IIFigure 21-3. Coronary artery bypass grafting. A. Intraoperative photograph of the distal anastomoses performed between the left internal thoracic artery and left anterior descending coronary artery with a continuous 8-0 suture. B. Fifteen-year follow-up coronary angiogram of a left


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Surgery_Schwartz. anastomoses performed between the left internal thoracic artery and left anterior descending coronary artery with a continuous 8-0 suture. B. Fifteen-year follow-up coronary angiogram of a left internal thoracic artery to left anterior descend-ing coronary artery bypass demonstrating a widely patent free of any significant atherosclerotic stenosis. Anastomotic site is shown by the arrow.Figure 21-4. Epicardial stabilizing device used during off-pump coronary anastomosis.ABare in place, the patient is weaned from bypass. During this time, the heart is monitored closely by direct visual inspection, transesophageal echocardiography. It is recommended that bypass graft patency be assessed with ultrasonic flow probes or Doppler to confirm flow and determine the pulsatility index (PI). These tools are utilized to detect abnormalities that may signify inadequate revascularization or technical problems with the bypass grafts. Upon confirmation of hemostasis, chest tubes are placed, the


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Surgery_Schwartz. tools are utilized to detect abnormalities that may signify inadequate revascularization or technical problems with the bypass grafts. Upon confirmation of hemostasis, chest tubes are placed, the sternum is approximated with sternal wires, and the incisions are closed.Conventional CABG Results. Several early randomized trials showed improved survival in patients who received a CABG as opposed to medical therapy.58-60 A propensity-matched study identified that CABG greatly benefited patients with LV dysfunction and left main stenosis >50% compared to medi-cal management.61 The Bypass Angioplasty Revascularization Investigation (BARI) trial demonstrated impressively superior results with CABG compared to PCI in terms of 5-year cardiac mortality (5.8% vs. 20.6%) in patients with diabetes in addi-tion to CAD.62 In a study examining the benefits of CABG over medical management for specific CAD distributions, survival was better in patients with proximal LAD stenoses, regardless of the


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Surgery_Schwartz. in addi-tion to CAD.62 In a study examining the benefits of CABG over medical management for specific CAD distributions, survival was better in patients with proximal LAD stenoses, regardless of the number of diseased vessels.63 In general, these studies show survival rates of over 90% at 5 years and approximately 75% at 10 years following CABG.The mortality and morbidity of the procedure itself has changed over time. Data from the Society of Thoracic Surgeons (STS) database accounts for 1,497,254 patients who under-went solitary CABG from 2000 to 2009. The mortality rate of CABGs has improved significantly from 2.4% in 2000 to 1.9% in 2009, despite the relatively constant predicted mortality rate of around 2.3%. In parallel with this, postoperative complication rates have also decreased: stroke (1.6%–1.2%), bleeding requir-ing reoperation (2.4%–2.2%), and deep sternal wound infection (0.59%–0.37%).64Off-pump Coronary Artery Bypass. To avoid the adverse consequences of cardiopulmonary


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Surgery_Schwartz. stroke (1.6%–1.2%), bleeding requir-ing reoperation (2.4%–2.2%), and deep sternal wound infection (0.59%–0.37%).64Off-pump Coronary Artery Bypass. To avoid the adverse consequences of cardiopulmonary bypass, off-pump coronary artery bypass (OPCAB) was developed and has been adopted in some centers over the past two decades.With OPCAB, the heart is left beating. Performing anas-tomoses on the beating heart requires the use of myocardial sta-bilization devices, which help portions of the epicardial surface to remain relatively immobile while the anastomoses are being performed (Fig. 21-4).Apical suction devices are used to aid in exposure, particu-larly of the lateral and inferior vessels. Many creative maneu-vers have been developed, including patient repositioning, opening the right pleural space to allow for cardiac displace-ment, and creation of a pericardial cradle to minimize compro-mise of cardiac function while exposing the various surfaces of the heart. Temporary proximal


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Surgery_Schwartz. pleural space to allow for cardiac displace-ment, and creation of a pericardial cradle to minimize compro-mise of cardiac function while exposing the various surfaces of the heart. Temporary proximal occlusion of the target coronary artery, or the use of an intracoronary shunt, are necessary to Brunicardi_Ch21_p0801-p0852.indd 81201/03/19 5:32 PM 813ACQUIRED HEART DISEASECHAPTER 21provide adequate exposure of the anastomosis. Occlusion causes temporary ischemia, and if not tolerated during a test occlusion, coronary shunts can be employed.OPCAB Results. The superiority of OPCAB over on-pump CABG remains a controversy despite the large body of literature on this topic. A pooled analysis of two random-ized trials, the Beating Heart Against Cardioplegic Arrest Studies (BHACAS 1 & 2), is one of several studies that have touted lower short-term mortality rates with the off-pump com-pared to the on-pump technique.65-67 Other studies, however, have demonstrated equivocal or contrary


Surgery_Schwartz

Surgery_Schwartz. is one of several studies that have touted lower short-term mortality rates with the off-pump com-pared to the on-pump technique.65-67 Other studies, however, have demonstrated equivocal or contrary results.68-70 Further-more, the prospective and much larger ROOBY (Randomized On/Off Bypass) trial showed increased rates of adverse cardiac events with OPCAB compared to conventional CABG.71 Despite the initial enthusiasm for the theoretical advantages of avoiding cardiopulmonary bypass, consistent benefits in clinical outcome have not been observed. There does seem to be a more or less uniform trend towards decreased perioperative blood product transfusions with OPCAB compared to on-pump CABG. In terms of other measures of early outcome, postoperative renal failure, stroke, and acute MI, the superiority of OPCAB has been unclear.69,72,73 A more recent Cochrane review by Moller et al did not demonstrate any significant benefit of off-pump compared with on-pump CABG regarding mortality,


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Surgery_Schwartz. superiority of OPCAB has been unclear.69,72,73 A more recent Cochrane review by Moller et al did not demonstrate any significant benefit of off-pump compared with on-pump CABG regarding mortality, stroke, or myocardial infarction. In contrast, better long-term survival in the group of patients undergoing on-pump CABG with the use of cardiopul-monary bypass and cardioplegic arrest was observed.74The higher cardiac morbidity in the ROOBY trial was associated with decreased 1-year angiographic patency rates.71 However, studies with contrasting findings exist, quoting equiv-alent rates of graft patency for OPCAB usage.75,76 The broad variety in results may be suggestive that other factors (e.g., surgeon skill, technical difficulty, patient factors) may be dom-inating the outcome rather than the use or avoidance of cardio-pulmonary bypass.77 After almost two decades, OPCAB has not been widely adopted and remains less than 20% of all CABG procedures in the United States.Minimally Invasive


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Surgery_Schwartz. the use or avoidance of cardio-pulmonary bypass.77 After almost two decades, OPCAB has not been widely adopted and remains less than 20% of all CABG procedures in the United States.Minimally Invasive Direct Coronary Artery Bypass. As an extension of the off-pump coronary revascularization technique, minimally invasive direct coronary artery bypass (MIDCAB) has been described. MIDCAB is performed using a left ante-rior mini-thoracotomy through which mobilization of the left internal thoracic and direct in situ anastomosis to the left ante-rior descending artery (or its diagonal branches) is performed. This technique is primarily applicable to single-vessel disease, although reports of multivessel revascularizations do exist.MIDCAB Results. A review of 411 patients undergoing MID-CAB quotes an operative mortality >1%. In this study, all patients received revascularization of the LAD only, regard-less of the number of diseased vessels. The 3-year mortality in patients with single-vessel


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Surgery_Schwartz. an operative mortality >1%. In this study, all patients received revascularization of the LAD only, regard-less of the number of diseased vessels. The 3-year mortality in patients with single-vessel disease following a MIDCAB was 3.1%, which was, not surprisingly, lower than those with multi-vessel disease (8.7%).78There is an inherent selection bias in retrospective reviews comparing MIDCAB to OPCAB or conventional CABG as MIDCAB patients tend to have less extensive disease. Because of this, there have been multiple randomized controlled trials looking at the efficacy of MIDCAB compared to PCI. A meta-analysis of 12 randomized prospective trials comparing PCI to MIDCAB revascularization of isolated proximal left anterior descending artery demonstrated comparable results in terms of 2mortality and MI but a lower revascularization requirement in the MIDCAB group.79A recent meta-analysis by Lee et al revealed CABG, as compared with PCI with DES, reduced long-term rates of the composite


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Surgery_Schwartz. and MI but a lower revascularization requirement in the MIDCAB group.79A recent meta-analysis by Lee et al revealed CABG, as compared with PCI with DES, reduced long-term rates of the composite of all-cause death, myocardial infarction, or stroke in patients with left main or multivessel CAD. Compared to PCI with DES, CABG was found to be superior in patients with multivessel CAD (P = 0.001), but no between-group differences in those with left main CAD (P = 0.427).80 Similar conclusions have been made by multiple other studies.Total Endoscopic Coronary Artery Bypass. With the advent of robotic surgical technology allowing stereoscopic visual-ization and increased instrument dexterity, total endoscopic coronary artery bypass (TECAB) has become possible. In July of 2004, the da Vinci robotic surgical system received FDA approval for use in coronary anastomoses. Extracorporeal cir-culation with peripheral cannulation has been used in earlier reports, but the development of mechanical


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Surgery_Schwartz. surgical system received FDA approval for use in coronary anastomoses. Extracorporeal cir-culation with peripheral cannulation has been used in earlier reports, but the development of mechanical stabilizers has pro-vided the ability to perform the internal thoracic artery harvest and coronary anastomosis off-pump with use of the robotic arms only. Several studies have looked at the feasibility of TECAB and have shown acceptable results, but this procedure has not been adopted by most surgeons because of its steep learning curve, longer operative times, and lack of demonstrable clinical benefit.81-83 Although the volume of robotic-assisted CABG is increasing, such procedures constituted <1% of all CABG pro-cedures performed in the United States in 2012.84Hybrid Coronary Revascularization. With the increasing collaboration between cardiothoracic surgeons and interven-tional cardiologists, hybrid coronary revascularization (HCR) combining a minimally invasive surgical technique (MIDCAB


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Surgery_Schwartz. the increasing collaboration between cardiothoracic surgeons and interven-tional cardiologists, hybrid coronary revascularization (HCR) combining a minimally invasive surgical technique (MIDCAB or TECAB) with PCI has become a reality. This capitalizes on a major advantage of both treatments, utilizing the durable left internal thoracic artery to left anterior descending coronary artery bypass graft while treating other stenoses with PCI, obvi-ating the need for a large surgical incision or cardiopulmonary bypass. HCR is not without its downsides as there are some concerns with this approach because aggressive anti-platelet therapy is required with PCI and may increase the hemorrhagic complications of surgical revascularization. A small study com-paring HCR to OPCAB showed comparable graft patency and decreased hospital stay with HCR without an increase in com-plication rates.85 There are, however, some studies that have reported increased rates of requirement for reintervention in


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Surgery_Schwartz. patency and decreased hospital stay with HCR without an increase in com-plication rates.85 There are, however, some studies that have reported increased rates of requirement for reintervention in patients undergoing HCR, and this requires further study.86,87 A recent multicenter prospective observational study showed equivalent outcomes between HCR and multivessel PCI.88 HCR has not gained widespread acceptance, and its clinical value remains a matter of debate.Transmyocardial Laser Revascularization. Despite the advancement of technology and revascularization strategies, patients with end-stage coronary artery disease may not be amenable to complete revascularization. Transmyocardial laser revascularization (TMR) relies on a CO2 or holmium:yttrium-aluminum-garnet (Ho:YAG) laser to create multiple transmu-ral channels (1 mm in diameter) through the myocardium. The initial concept was that these channels would serve as conduits for direct perfusion from the ventricle, but evidence


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Surgery_Schwartz. multiple transmu-ral channels (1 mm in diameter) through the myocardium. The initial concept was that these channels would serve as conduits for direct perfusion from the ventricle, but evidence suggests that the resultant angiogenesis is primarily responsible for the improved perfusion. A meta-analysis of seven randomized con-trolled trials comparing TMR to medical therapy for chronic Brunicardi_Ch21_p0801-p0852.indd 81301/03/19 5:32 PM 814SPECIFIC CONSIDERATIONSPART IITable 21-6Classification of cardiac murmursMURMURCONDITIONMECHANISM/ETIOLOGYSYSTOLIC MURMURSHolosystolic (pansystolic)VSDFlow between chambers that have widely different pressures throughout systoleMid-systolic (systolic ejection)High flow rate, MS, MR, TS, TIOften crescendo-decrescendo in configuration; occur as blood is ejected into the left and right ventricular outflow tractsEarly systolicEarly TI, acute MRLess commonMid to late systolicMR, MVPSoft to moderate high-pitched murmurs at the LV apex; often due to


Surgery_Schwartz

Surgery_Schwartz. is ejected into the left and right ventricular outflow tractsEarly systolicEarly TI, acute MRLess commonMid to late systolicMR, MVPSoft to moderate high-pitched murmurs at the LV apex; often due to apical tethering and malcoaptation of MV leaflets; an associated click indicates prolapse of the MV leafletsDIASTOLIC MURMURSEarly high-pitchedAI, PRGenerally decrescendo in configuration; occur when the associated ventricular pressure drops sufficiently below that of the outflow tractMid-diastolicMS, TS, PDA*, VSD*, ASD*Due to a relative disproportion between valve orifice size and diastolic blood flow volume; seen in normal MV and TV with increased diastolic blood flow associated with these conditions*PresystolicMS, TSOccur during the period of ventricular filling that follows atrial contraction (i.e., only occur in sinus rhythm)CONTINUOUS MURMURSPDAUncommon, due to shunts that persist through the end of systole and the some or all of diastoleAI = aortic insufficiency; ASD = atrial septal


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Surgery_Schwartz. (i.e., only occur in sinus rhythm)CONTINUOUS MURMURSPDAUncommon, due to shunts that persist through the end of systole and the some or all of diastoleAI = aortic insufficiency; ASD = atrial septal defect; MR = mitral regurgitation; MS = mitral stenosis; MVP = mitral valve prolapse; PDA = patent ductus arteriosus; PR = pulmonic regurgitation; TI = tricuspid insufficiency; TS = tricuspid stenosis; VSD = ventricular septal defect.angina has shown higher rates of angina improvement in the TMR but was not able to show a difference in mortality between the two groups.89TMR is also being used as an adjunct to CABG in the treatment of extensive CAD that is not amenable to surgical revascularization alone. In a study looking at the benefits of TMR in addition to CABG, Allen et al concluded that TMR decreases angina burden when added to CABG in patients who cannot be revascularized by CABG alone.90 The current STS guidelines support the consideration of TMR in patients with ischemic myocardial