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Surgery_Schwartz. (and may be present at rest)May be relieved by not bearing weightVariable, may relate to activity levelBrunicardi_Ch23_p0897-p0980.indd 95327/02/19 4:15 PM 954SPECIFIC CONSIDERATIONSPART IITable 23-18Nonatherosclerotic causes of intermittent claudication• Aortic coarctation• Arterial fibrodysplasia• Iliac syndrome of the cyclist• Peripheral emboli• Persistent sciatic artery• Popliteal aneurysm• Popliteal cyst• Popliteal entrapment• Primary vascular tumors• Pseudoxanthoma elasticum• Remote trauma or radiation injury• Takayasu’s disease• Thromboangiitis obliteransTable 23-19Classification of peripheral arterial disease based on the Fontaine and Rutherford classificationsFONTAINE CLASSIFICATIONRUTHERFORD CLASSIFICATIONSTAGECLINICALGRADECATEGORYCLINICALIAsymptomatic00AsymptomaticIIaMild claudicationI1Mild claudicationIIbModerate to severe claudicationI2Moderate claudication I3Severe claudicationIIIIschemic rest painII4Ischemic rest painIVUlceration or gangreneIII5Minor tissue


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Surgery_Schwartz. claudicationI1Mild claudicationIIbModerate to severe claudicationI2Moderate claudication I3Severe claudicationIIIIschemic rest painII4Ischemic rest painIVUlceration or gangreneIII5Minor tissue loss III6Major tissue losscardiomyopathy. Emboli that arise from a ventricular aneurysm or from a dilated cardiomyopathy can be very large and can lodge at the aortic bifurcation (saddle embolus), thus rendering both legs ischemic. Diseased valves are another source of distal embolization. Historically, this occurred as a result of rheumatic heart disease. Currently, subacute endocarditis and acute bacte-rial endocarditis are the more common causes. Infected emboli can seed the recipient vessel wall, creating mycotic aneurysms.An electrocardiogram (ECG) will diagnose atrial fibrilla-tion. A transthoracic or transesophageal echocardiogram should be performed looking for a cardiac source. It is important to seek other sources of the embolus using CT scanning of the descending thoracic and


Surgery_Schwartz

Surgery_Schwartz. transthoracic or transesophageal echocardiogram should be performed looking for a cardiac source. It is important to seek other sources of the embolus using CT scanning of the descending thoracic and abdominal aorta. More unusual sources include mural thrombus from an aortic aneurysm, and occa-sionally, idiopathic arterial-to-arterial thrombus occurs, usually from thrombus that has formed in an atherosclerotic aortic arch or descending thoracic aorta. The presence of mobile plaque on transesophageal echocardiography is suggestive of this source.Paradoxical embolus occurs when a patient has a patent foramen ovale and an embolus from a deep venous thrombosis crosses through the atrial defect into the left side of the heart and passes into the peripheral circulation. This is diagnosed using a bubble echocardiography, in which air bubbles introduced into the venous circulation can be seen traversing the septal defect.Arterial Thrombosis. Thrombosis can occur in native arteries and in


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Surgery_Schwartz. a bubble echocardiography, in which air bubbles introduced into the venous circulation can be seen traversing the septal defect.Arterial Thrombosis. Thrombosis can occur in native arteries and in arterial reconstructions. Patients with thrombosed arte-rial segments often have an underlying atherosclerotic lesion at the site of thrombosis or aneurysmal degeneration with mural thrombosis. It is important to obtain a history, determine risk factors for atherosclerosis and hypercoagulable status, and examine the contralateral extremity for circulatory problems. Patients with thrombosis of prior arterial reconstructions have limb incisions from previous surgery, and graft occlusion can be confirmed with duplex imaging.Clinical Manifestations of Acute Limb IschemiaAcute lower extremity ischemia manifests with the “five Ps”: pain, pallor, paresthesias, paralysis, and pulselessness, to which some add a sixth “P”—poikilothermia or “perishing cold.” Pain is the usual symptom that causes a


Surgery_Schwartz

Surgery_Schwartz. manifests with the “five Ps”: pain, pallor, paresthesias, paralysis, and pulselessness, to which some add a sixth “P”—poikilothermia or “perishing cold.” Pain is the usual symptom that causes a patient to present to the emergency room. The most common location for an embolus to lodge in the leg is at the common femoral bifurcation. Typically, a patient will complain of foot and calf pain. Pulses are absent, and there may be diminution of sensation. Inability to move the affected muscle group is a sign of very severe ischemia and necessitates urgent revascularization. During evaluation of the affected extremity, it is important to compare findings with the contralateral limb. Clinical evaluation is extremely important in determining the etiology and location of the obstruction. One of the most important pieces of information to obtain is whether the patient has had prior vascular procedures or if there is a history of lower extremity claudication. Either of these features suggests


Surgery_Schwartz

Surgery_Schwartz. the most important pieces of information to obtain is whether the patient has had prior vascular procedures or if there is a history of lower extremity claudication. Either of these features suggests preexisting vascular disease, renders revasculariza-tion more complicated, and usually mandates angiography to permit surgical planning. On the contrary, in a patient with no history suggestive of prior vascular disease, the etiology is most likely embolic, and simple thrombectomy is more likely to be successful.Absent bilateral femoral pulses in a patient with bilateral lower extremity ischemia is most likely due to saddle embolus to the aortic bifurcation. A palpable femoral pulse and absent popliteal and distal pulses may either be due to distal common femoral embolus (the pulse being palpable above the level of occlusion) or embolus to the superficial femoral or popliteal arteries. Typically, emboli lodge at arterial bifurcations where they are trapped due to sudden reductions in


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Surgery_Schwartz. palpable above the level of occlusion) or embolus to the superficial femoral or popliteal arteries. Typically, emboli lodge at arterial bifurcations where they are trapped due to sudden reductions in arterial diameter. A popliteal trifurcation embolus will present with calf ischemia and absent pedal pulses, possibly with a popliteal pulse present. The finding of palpable contralateral pulses and the absence of ipsilateral pulses in the acutely ischemic leg are suggestive of an embolus, irrespective of presence of Doppler signals. Brunicardi_Ch23_p0897-p0980.indd 95427/02/19 4:15 PM 955ARTERIAL DISEASECHAPTER 23Table 23-20TransAtlantic Inter-Society Consensus classification of femoral popliteal occlusive lesionsType A lesions• Single stenosis ≤10 cm in length• Single occlusion ≤5 cm in lengthType B lesions• Multiple lesions (stenoses or occlusions), each ≤5 cm• Single stenosis or occlusion ≤15 cm not involving the infrageniculate popliteal artery• Single or multiple lesions in the


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Surgery_Schwartz. lengthType B lesions• Multiple lesions (stenoses or occlusions), each ≤5 cm• Single stenosis or occlusion ≤15 cm not involving the infrageniculate popliteal artery• Single or multiple lesions in the absence of continuous tibial vessels to improve inflow for a distal bypass• Heavily calcified occlusion ≤5 cm in length• Single popliteal stenosisType C lesions• Multiple stenoses or occlusions totaling >15 cm with or without heavy calcification• Recurrent stenoses or occlusions that need treatment after two endovascular interventionsType D lesions• Chronic total occlusions of CFA or SFA (>20 cm, involving the popliteal artery)• Chronic total occlusion of popliteal artery and proximal trifurcation vesselsCFA = common femoral artery; SFA = superficial femoral artery.Type A lesionsType B lesionsType C lesionsType D lesionsFigure 23-61. Schematic depiction of TransAtlantic Inter-Society Consensus classification of femoral popliteal occlusive lesions.Arteriography is not mandatory in patients


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Surgery_Schwartz. C lesionsType D lesionsFigure 23-61. Schematic depiction of TransAtlantic Inter-Society Consensus classification of femoral popliteal occlusive lesions.Arteriography is not mandatory in patients without antecedent history suggestive of vascular disease; nevertheless, all patients should be positioned on the operating room table in such a way that fluoroscopic access to the entire inflow and outflow tract is possible if necessary.The main question to be answered by the history and phys-ical examination is the severity of the ALI, which is the major consideration in early management decisions. Patients with ALI should be evaluated in a fashion that considers the severity and duration of ischemia at the time of presentation. Ideally, all patients with acute ischemia should be investigated with imag-ing, especially if there is an antecedent vascular reconstruction; however, the clinical condition and access to resources must guide further investigations. Unnecessary delays can result in


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Surgery_Schwartz. imag-ing, especially if there is an antecedent vascular reconstruction; however, the clinical condition and access to resources must guide further investigations. Unnecessary delays can result in amputation. Arteriography, if it can be performed in a timely fashion, is an excellent modality for localizing obstructions and deciding which type of intervention (endovascular, embolec-tomy, or bypass) patients will benefit more from. One of the goals of treatment for ALI is to prevent thrombus propagation; therefore, expedient anticoagulation with heparin is indicated as soon as the diagnosis is suspected.Treatment Considerations for Acute Limb IschemiaIn the absence of any significant contraindication, the patient with an ischemic lower extremity should be immediately anti-coagulated. This will prevent propagation of the clot into unaf-fected vascular beds. Intravenous fluid should be started and a Foley catheter inserted to monitor urine output. Baseline labs should be obtained and


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Surgery_Schwartz. will prevent propagation of the clot into unaf-fected vascular beds. Intravenous fluid should be started and a Foley catheter inserted to monitor urine output. Baseline labs should be obtained and creatinine levels noted. A hypercoagula-ble workup should be performed prior to initiation of heparin if there is sufficient suspicion. According to results from random-ized trials, there is no clear superiority for thrombolysis over surgery in terms of 30-day limb salvage or mortality. Access to each treatment option is a major issue in the decision-making process, as time is often critical. National registry data from the United States reveal that surgery is used threeto five-fold more frequently than thrombolysis. Three randomized studies have investigated the role of catheter-directed thrombolytic therapy in the treatment of ALI.145Endovascular TreatmentThe potential to reduce mortality and morbidity while achiev-ing limb salvage is the impetus that makes thrombolysis prefer-able to open


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Surgery_Schwartz. therapy in the treatment of ALI.145Endovascular TreatmentThe potential to reduce mortality and morbidity while achiev-ing limb salvage is the impetus that makes thrombolysis prefer-able to open surgery as first-line treatment in patients with ALI (classes I and IIa). Advantages of thrombolytic therapy over balloon embolectomy include the reduced endothelial trauma and potential for more gradual and complete clot lysis in branch vessels usually too small to access by embolectomy balloons. It is hoped that the more gradual clot dissolution with throm-bolysis may decrease the incidence of reperfusion injury that is encountered after open surgical procedures where rapid return of blood flow may precipitate compartment syndrome. Skeletal muscle tissue appears to be most vulnerable to ischemia. Patho-physiologic studies reveal that irreversible damage to muscle tissue starts after 3 hours of ischemia and is nearly complete at 6 hours. Progressive microvascular damage appears to follow


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Surgery_Schwartz. Patho-physiologic studies reveal that irreversible damage to muscle tissue starts after 3 hours of ischemia and is nearly complete at 6 hours. Progressive microvascular damage appears to follow rather than precede skeletal muscle tissue damage. The more severe the cellular damage, the greater are the microvascu-lar changes. When the musculature and microvasculature are severely damaged, amputation rather than attempts at revascu-larization may be the most prudent course to prevent wash-out of toxic by-product from the ischemic limb into the systemic circulation. The mortality rate associated with reperfusion syn-drome is high because of the development of concomitant adult respiratory distress syndrome, shock, disseminated intravascular coagulation, and renal failure.Patients with small-vessel occlusion are poor candidates for surgery because they lack distal target vessels to use for bypass. These patients should be offered a trial of thromboly-sis, unless they have contraindications


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Surgery_Schwartz. occlusion are poor candidates for surgery because they lack distal target vessels to use for bypass. These patients should be offered a trial of thromboly-sis, unless they have contraindications to thrombolysis or their Brunicardi_Ch23_p0897-p0980.indd 95527/02/19 4:15 PM 956SPECIFIC CONSIDERATIONSPART IIischemia is so severe that the time needed to achieve adequate lysis is considered too long. The major contraindications of thrombolysis are recent stroke, intracranial primary malignancy, brain metastases, or intracranial surgical intervention. Relative contraindications for performance of thrombolysis include renal insufficiency, allergy to contrast material, cardiac thrombus, diabetic retinopathy, coagulopathy, and recent arterial puncture or surgery (Table 23-21).Advances in clot removal techniques with percutaneous mechanical thrombectomy and thromboaspiration may extend the applicability of this intervention to patients with more advanced degrees of ALI (class IIb) and


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Surgery_Schwartz. clot removal techniques with percutaneous mechanical thrombectomy and thromboaspiration may extend the applicability of this intervention to patients with more advanced degrees of ALI (class IIb) and contraindications to thrombolysis. Several thrombectomy devices have received FDA approval for acute lower extremity arterial thrombosis. The utility of these thrombectomy devices is that they can be used as standalone therapy when there are contraindications for thrombolytic therapy. Additionally, these thrombectomy devices can be used in conjunction with thrombolytic agents, for pharmacomechanical thrombectomy, to enhance clot lysis and to limit the doses and time required for thrombolysis.145Surgical TreatmentEmbolectomy. When a decision is made to proceed with open surgical intervention, the abdomen, contralateral groin, and entire lower extremity are prepped in the field. The groin is opened through a vertical incision, exposing the CFA and its bifurcation. Frequently, the location


Surgery_Schwartz

Surgery_Schwartz. the abdomen, contralateral groin, and entire lower extremity are prepped in the field. The groin is opened through a vertical incision, exposing the CFA and its bifurcation. Frequently, the location of the embolus at the femo-ral bifurcation is readily apparent by the presence of a palpable proximal femoral pulse, which disappears distally. The artery is clamped and opened transversely over the bifurcation. Throm-bus is extracted by passing a Fogarty balloon embolectomy catheter. Good back-bleeding and antegrade bleeding suggest that the entire clot has been removed. Embolic material often forms a cast of the vessel and is sent for culture and histologic examination. Completion angiography is advisable to ascertain Table 23-21Contraindications to thrombolytic therapyAbsolute contraindicationsEstablished cerebrovascular events (including transient ischemic attack) within last 2 monthsActive bleeding diathesisRecent (<10 days) gastrointestinal bleedingNeurosurgery (intracranial or


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Surgery_Schwartz. cerebrovascular events (including transient ischemic attack) within last 2 monthsActive bleeding diathesisRecent (<10 days) gastrointestinal bleedingNeurosurgery (intracranial or spinal) within last 3 monthsIntracranial trauma within last 3 monthsIntracranial malignancy or metastasisRelative major contraindicationsCardiopulmonary resuscitation within last 10 daysMajor nonvascular surgery or trauma within last 10 daysUncontrolled hypertension (>180 mmHg systolic or >110 mmHg diastolic)Puncture of noncompressible vesselIntracranial tumorRecent eye surgeryMinor contraindicationsHepatic failure, particularly with coagulopathyBacterial endocarditisPregnancyDiabetic hemorrhagic retinopathythe adequacy of clot removal. The artery is then closed and the patient fully anticoagulated.When an embolus lodges in the popliteal artery, in most cases it can be extracted via a femoral incision using the tech-niques previously described. A femoral approach is preferred because the larger diameter of


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Surgery_Schwartz. lodges in the popliteal artery, in most cases it can be extracted via a femoral incision using the tech-niques previously described. A femoral approach is preferred because the larger diameter of the femoral artery results in decreased likelihood of arterial compromise when the arte-riotomy is closed. The disadvantage with using the femoral approach for embolectomy is the greater difficulty involved in directing the embolectomy catheter into each of the infrapopli-teal arteries. Use of fluoroscopic imaging and an over-the-wire thrombectomy catheter can overcome this problem. Alterna-tively, use of a separate incision to expose the popliteal bifurca-tion may be necessary to achieve a complete thrombectomy.A more complex situation arises when a patient has antecedent peripheral vascular disease and in situ thrombosis develops on top of preexisting atheroma because, frequently, embolectomy catheters will not pass through these occlusions. Similarly, when a bypass graft fails, it is


Surgery_Schwartz

Surgery_Schwartz. disease and in situ thrombosis develops on top of preexisting atheroma because, frequently, embolectomy catheters will not pass through these occlusions. Similarly, when a bypass graft fails, it is usually due to progres-sion of atheroma proximal or distal to the graft anastomoses or to intrinsic stenoses that develop within a vein graft. In these scenarios, expeditious angiography is useful to determine the extent of the occlusion, to search for inflow and distal outflow vessels, and to decide whether thrombolysis or surgery will be the better intervention. Although the surgeon’s preference tends to dictate the approach selected, the decision is based on the presence or absence of good target vessels and availability of a suitable bypass conduit. If there are good distal vessels and the saphenous vein is suitable, surgical bypass is recommended because it is fast, durable, and reliable. In the absence of a good distal target and saphenous vein, or in a patient at high risk for


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Surgery_Schwartz. the saphenous vein is suitable, surgical bypass is recommended because it is fast, durable, and reliable. In the absence of a good distal target and saphenous vein, or in a patient at high risk for surgery, lysis is recommended.Bypass Graft Thrombectomy. Bypass thrombectomy is more likely to succeed with prosthetic bypasses. Bypass graft revision or replacement is more appropriate for acute vein graft failures because they are less likely to respond to thrombolysis and require some type of revision, such as valve lysis, interposition, or extension. Thrombectomy of autogenous grafts is prone to failure unless an anatomic cause for failure such as a retained valve or unligated side branch is found and corrected. The per-formance of a fasciotomy to circumvent reperfusion injury/com-partment syndrome is an important consideration.Complications Related to Treatment for Acute Limb IschemiaAdverse events related to catheter-directed thrombolysis are primarily related to bleeding


Surgery_Schwartz

Surgery_Schwartz. syndrome is an important consideration.Complications Related to Treatment for Acute Limb IschemiaAdverse events related to catheter-directed thrombolysis are primarily related to bleeding complications. The overall risk of hemorrhagic stroke from a thrombolysis procedure has been reported to be 1% to 2.3%, with 50% of hemorrhagic compli-cations occurring during the thrombolytic procedure.146 Hema-toma at the vascular puncture site has been reported in 12% to 17% of cases. Gastrointestinal bleeding is reported in 5% to 10% of cases. Hematuria following thrombolysis is uncom-mon and should prompt a search for urinary tumors. Hemor-rhage requiring transfusion can occur in approximately 25% of patients undergoing thrombolysis. Lytic agents are absolutely contraindicated in patients with intracranial surgery, intracra-nial hemorrhage within the last 3 months, or any active bleed-ing. Most bleeding complications occur at the arterial puncture sites, but concealed retroperitoneal bleeding


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Surgery_Schwartz. surgery, intracra-nial hemorrhage within the last 3 months, or any active bleed-ing. Most bleeding complications occur at the arterial puncture sites, but concealed retroperitoneal bleeding is possible. The most feared complication that patients can sustain is intrace-rebral hemorrhage. Older patients may be more susceptible Brunicardi_Ch23_p0897-p0980.indd 95627/02/19 4:15 PM 957ARTERIAL DISEASECHAPTER 23to this complication, and thus many interventionalists are extremely reticent to use thrombolysis in patients older than 80 years of age.Patients who are treated for acute ischemia are susceptible to two major complications following revascularization: reper-fusion and compartment syndromes. Other procedure-related complications include arterial rethrombosis, recurrent emboli-zation, and arterial injuries secondary to the balloon catheter manipulations.Reperfusion of the ischemic limb is variable in its physi-ologic effects and directly relates to the severity and extent of the


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Surgery_Schwartz. and arterial injuries secondary to the balloon catheter manipulations.Reperfusion of the ischemic limb is variable in its physi-ologic effects and directly relates to the severity and extent of the ischemia. Patients with a saddle embolus of the aortic bifurcation and severely ischemic limbs may develop the full-blown “reperfusion syndrome,” whereas patients with minimal muscle ischemia who are reperfused in a timely fashion essen-tially develop no effects. Many patients with ALI have severe underlying cardiac disease and are unable to tolerate even short ischemic periods. Complications occurring after revasculariza-tion of the lower extremity and causes of recurrent thrombosis are listed in Table 23-22.Compartment syndrome occurs after prolonged ischemia is followed by reperfusion. The capillaries leak fluid into the interstitial space in the muscles, which are enclosed within a nondistensible fascial envelope. When the pressure inside the compartment exceeds the capillary perfusion


Surgery_Schwartz

Surgery_Schwartz. leak fluid into the interstitial space in the muscles, which are enclosed within a nondistensible fascial envelope. When the pressure inside the compartment exceeds the capillary perfusion pressure, nutrient flow ceases and progressive ischemia occurs, even in the pres-ence of peripheral pulses. Consequently, every patient who has sustained an ischemic event and is reperfused is monitored for compartment syndrome, which is characterized by excessive Table 23-22Complications of arterial revascularizationCompartment syndromeIschemic neuropathyMuscle necrosisRecurrent thrombosisLower leg swellingReperfusion syndrome Hypotension Hyperkalemia Myoglobinuria Renal failureTable 23-23Fascial compartments of the lower leg ANTERIOR COMPARTMENTLATERAL COMPARTMENTSUPERFICIAL POSTERIOR COMPARTMENTDEEP POSTERIOR COMPARTMENTMusclesTibialis anteriorExtensor digitorum longusPeroneus tertiusExtensor hallucis longusExtensor digitorum brevisExtensor hallucis brevisPeroneus longusPeroneus


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Surgery_Schwartz. COMPARTMENTDEEP POSTERIOR COMPARTMENTMusclesTibialis anteriorExtensor digitorum longusPeroneus tertiusExtensor hallucis longusExtensor digitorum brevisExtensor hallucis brevisPeroneus longusPeroneus brevisGastrocnemiusPlantarisSoleusTibialis posteriorFlexor digitorum longusFlexor hallucis longusArteryAnterior tibial arteryAnterior and posterior tibial branches of the popliteal arteryPosterior tibial arteryPeroneal arteryNerveDeep peroneal nerveSuperficial peroneal nerve Tibial nervepain in the compartment, pain on passive stretching of the com-partment, and sensory loss due to nerve compression of the nerves coursing through the compartment (Table 23-23 and Fig. 23-62). The most commonly affected compartment is the anterior compartment in the leg. Numbness in the web space between the first and second toes is diagnostic due to com-pression of the deep peroneal nerve. Compartment pressure is measured by inserting an arterial line into the compartment and recording the pressure.


Surgery_Schwartz

Surgery_Schwartz. the first and second toes is diagnostic due to com-pression of the deep peroneal nerve. Compartment pressure is measured by inserting an arterial line into the compartment and recording the pressure. Although controversial, pressures greater than 20 mmHg are an indication for fasciotomy. Com-partment pressures are relieved in the leg by medial and lateral incisions. Through the medial incision, long openings are then made in the fascia of the superficial and deep posterior com-partments. Through the lateral incision, the anterior and pero-neal compartments are opened. Both skin and fascial incisions should be of adequate length to ensure full compartment decom-pression. Laboratory evidence of rhabdomyolysis is seen in 20% of cases. The myoglobin from damaged muscle precipitates in kidney tubules and causes acute tubular necrosis. Alkalinization of urine increases the solubility of myoglobin, thus preventing Tibia AnteriorcompartmentLateralcompartmentFibulaDeep


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Surgery_Schwartz. in kidney tubules and causes acute tubular necrosis. Alkalinization of urine increases the solubility of myoglobin, thus preventing Tibia AnteriorcompartmentLateralcompartmentFibulaDeep posteriorcompartmentSuperficial posterior compartmentFigure 23-62. Schematic illustration of fascial compartments of the lower extremity.Brunicardi_Ch23_p0897-p0980.indd 95727/02/19 4:15 PM 958SPECIFIC CONSIDERATIONSPART IIit from crystallizing in the tubules. In addition to alkalinization, therapy consists of forced saline diuresis and removal of the source of dead muscle that is releasing the myoglobin.Clinical Manifestations of Chronic Limb IschemiaThe term CLI is reserved for patients with objectively proven arterial occlusive disease and symptoms lasting for more than 2 weeks. Symptoms include rest pain and tissue loss, such as ulceration or gangrene (Table 23-24). The diagnosis should be corroborated with noninvasive diagnostic tests, such as the ABI, toe pressures, and transcutaneous


Surgery_Schwartz

Surgery_Schwartz. rest pain and tissue loss, such as ulceration or gangrene (Table 23-24). The diagnosis should be corroborated with noninvasive diagnostic tests, such as the ABI, toe pressures, and transcutaneous oxygen measurements. Ischemic rest pain most commonly occurs below an ankle pres-sure of 50 mmHg or a toe pressure less than 30 mmHg. Ulcers are not always of an ischemic etiology (Table 23-25). In many instances, there are other etiologic factors (traumatic, venous, or neuropathic) that are contributory, but it is underlying peripheral arterial disease that may be responsible for delayed or absent healing (Fig. 23-63). Healing of ulcers requires an inflammatory response and greater perfusion than is required to support intact skin and underlying tissues. As a result, the ankle and toe pres-sure levels needed for healing are higher than the pressures seen with ischemic rest pain. For patients with ulcers or gangrene, the presence of CLI is suggested by an ankle pressure less than 70 mmHg or a


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Surgery_Schwartz. needed for healing are higher than the pressures seen with ischemic rest pain. For patients with ulcers or gangrene, the presence of CLI is suggested by an ankle pressure less than 70 mmHg or a toe systolic pressure less than 50 mmHg.147 It is important to understand that there is no definite consensus regarding the vascular hemodynamic parameters required to make the diagnosis of CLI.One of the most common sites for occlusive disease is in the distal SFA as it passes deep through the adductor canal. It may be that the entrapment by the adductor hiatus prevents the compensatory dilation that occurs in atherosclerotic vessels. Stenoses, which develop here, progress to occlusion of the dis-tal third of the SFA (Fig. 23-64). When distal SFA occlusion develops slowly, it may be totally asymptomatic because of development of collaterals from the proximal SFA, or the PFA can bypass the occlusion and reconstitute the popliteal artery. Table 23-24Clinical categories of chronic limb


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Surgery_Schwartz. asymptomatic because of development of collaterals from the proximal SFA, or the PFA can bypass the occlusion and reconstitute the popliteal artery. Table 23-24Clinical categories of chronic limb ischemiaGRADECATEGORYCLINICAL DESCRIPTIONOBJECTIVE CRITERIA00Asymptomatic—no hemodynamically significant occlusive diseaseNormal treadmill or reactive hyperemia test 1Mild claudicationAble to complete treadmill exercisea; AP after exercise >50 mmHg but at least 20 mmHg lower than resting valueI2Moderate claudicationBetween categories 1 and 3 3Severe claudicationCannot complete standard treadmill exercisea and AP after exercise <50 mmHgIIb4Ischemic rest painResting AP <40 mmHg, flat or barely pulsatile ankle or metatarsal PVR; TP <30 mmHgIIIb5Minor tissue loss—nonhealing ulcer, focal gangrene with diffuse pedal ischemiaResting AP <60 mmHg, ankle or metatarsal PVR flat or barely pulsatile; TP <40 mmHg 6Major tissue loss—extending above TM level, functional foot no longer salvageableSame as


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Surgery_Schwartz. with diffuse pedal ischemiaResting AP <60 mmHg, ankle or metatarsal PVR flat or barely pulsatile; TP <40 mmHg 6Major tissue loss—extending above TM level, functional foot no longer salvageableSame as category 5aFive minutes at 2 miles per hour on a 12% incline of treadmill exercise.bGrades II and III, categories 4, 5, and 6, are encompassed by the term chronic critical ischemia.AP = ankle pressure; PVR = pulse volume recording; TM = transmetatarsal; TP = toe pressure.Table 23-25Symptoms and signs of neuropathic ulcer versus ischemic ulcerNEUROPATHIC ULCERISCHEMIC ULCERPainlessPainfulNormal pulsesAbsent pulsesRegular margins, typically punched-out appearanceIrregular marginOften located on plantar surface of footCommonly located on toes, glabrous marginsPresence of callusesCalluses absent or infrequentLoss of sensation, reflexes, and vibrationVariable sensory findingsIncreased in blood flow (arteriovenous shunting)Decreased in blood flowDilated veinsCollapsed veinsDry, warm footCold


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Surgery_Schwartz. or infrequentLoss of sensation, reflexes, and vibrationVariable sensory findingsIncreased in blood flow (arteriovenous shunting)Decreased in blood flowDilated veinsCollapsed veinsDry, warm footCold footBony deformitiesNo bony deformitiesRed or hyperemic in appearancePale and cyanotic in appearanceSymptom development is a function of the extent of occlusion, adequacy of collaterals, and the activity level of the patients.Presenting symptoms of femoropopliteal occlusive dis-ease are broadly classified into two types: limb-threatening and non–limb-threatening ischemia. Claudication is non– limb-threatening, while rest pain, ulceration, and gangrene are limb-threatening and warrant urgent intervention. Occlusive disease of the femoral artery may be isolated or occur in con-junction with multilevel disease that involves both the aortoil-iac segment and the tibial vessels. Symptoms in patients with Brunicardi_Ch23_p0897-p0980.indd 95827/02/19 4:15 PM 959ARTERIAL DISEASECHAPTER


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Surgery_Schwartz. multilevel disease that involves both the aortoil-iac segment and the tibial vessels. Symptoms in patients with Brunicardi_Ch23_p0897-p0980.indd 95827/02/19 4:15 PM 959ARTERIAL DISEASECHAPTER 23BAFigure 23-63. A. A neuropathic ulcer is characterized by a punched-out appearance with loss of sensation in the surrounding skin. The foot may be warm to touch, and pulses may be present in the distal pedal arteries. B. An ischemic ulcer is characterized by a gangrenous skin change in the foot or toes. The foot is usually cold to touch with absent pedal pulses. The foot is painful to touch with decreased distal capil-lary refills.Figure 23-64. Computed tomography angiogram of a patient with an occluded left superficial femoral artery (single long arrow) with reconstituted superficial femoral artery at the level of mid-thigh. Diffuse arterial calcifications (double small arrows) are noted in the mid and distal left superficial femoral arteries.multilevel disease are more severe than in


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Surgery_Schwartz. artery at the level of mid-thigh. Diffuse arterial calcifications (double small arrows) are noted in the mid and distal left superficial femoral arteries.multilevel disease are more severe than in those with single-level disease. Pain from isolated SFA and popliteal occlusion typically manifests as calf claudication. Cramping pain develops in the calf on ambulation, occurs at a reproducible distance, and is relieved by rest. Activities such as climbing stairs or going uphill also exacerbate the pain. Many patients report worsen-ing symptoms during cold weather. It is important to evaluate whether the symptoms are progressive or static. In greater than 70% of patients, the disease is stable, particularly with risk fac-tor modification.Progression of the underlying atherosclerotic process is more likely to occur in patients with diabetes, those who con-tinue to smoke, and those who fail to modify their atherosclerotic risk factors. In comparison, rest pain is constant, and usually


Surgery_Schwartz

Surgery_Schwartz. is more likely to occur in patients with diabetes, those who con-tinue to smoke, and those who fail to modify their atherosclerotic risk factors. In comparison, rest pain is constant, and usually occurs in the forefoot across the metatarsophalangeal joint. It is worse at night and requires placing the foot in a dependent posi-tion to improve symptoms. Patients may report that they either sleep in a chair or hang the foot off the side of the bed. The pain is severe and relentless, even with narcotics. Ischemic ulcer-ation most commonly involves the toes. Any toe can be affected. Occasionally ulcers develop on the dorsum of the foot. Ulcer-ation can occur in atypical positions in an ischemic foot from trauma such as friction from poorly fitting shoes. Injury to a foot with borderline ischemia can convert an otherwise stable situ-ation into one that is limb-threatening. The initial development of gangrene commonly involves the digits. As with all vascular patients, it is important to


Surgery_Schwartz

Surgery_Schwartz. can convert an otherwise stable situ-ation into one that is limb-threatening. The initial development of gangrene commonly involves the digits. As with all vascular patients, it is important to evaluate their risk factors, intercurrent cardiac diseases, and any prior vascular interventions.Treatment Considerations for Chronic Limb IschemiaPatients with vascular diseases frequently have complicated medical comorbidities. Careful patient evaluation and selection should be performed for any peripheral arterial vascular proce-dure. The fundamental principle is to assess not only the surgi-cal risk from the peripheral arterial system but also the global nature of the atherosclerotic process. Full cardiac evaluations are often necessary due to the high incidence of concomitant atherosclerotic coronary artery disease, resulting in a high risk for ischemic events. Hertzer and associates reviewed coronary angiographies on 1000 patients undergoing elective vascu-lar procedure and identified


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Surgery_Schwartz. coronary artery disease, resulting in a high risk for ischemic events. Hertzer and associates reviewed coronary angiographies on 1000 patients undergoing elective vascu-lar procedure and identified 25% of concomitant correctable coronary artery disease, including 21% in patients undergoing elective peripheral vascular intervention.5 Conte and associates analyzed their 20-year experience in 1642 open lower extremity reconstructive surgeries and concluded that patients requiring lower extremity reconstruction presented an increasingly com-plex medical and surgical challenge compared with the previous decade in a tertiary practice setting.148 With aging of the popu-lation, a growing number of vascular patients have prohibitive medical comorbidities and are deemed high-risk for open sur-gical repair. Endovascular intervention provides an attractive alternative.As for open surgical repair, the clinical indications for endovascular intervention of lower extremity peripheral arte-rial


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Surgery_Schwartz. repair. Endovascular intervention provides an attractive alternative.As for open surgical repair, the clinical indications for endovascular intervention of lower extremity peripheral arte-rial diseases include lifestyle-limiting claudication, ischemic rest pain, and tissue loss or gangrene. Importantly, endovas-cular procedures should be performed by a competent vas-cular interventionist who understands the vascular disease process and is familiar with a variety of endovascular tech-niques. In addition, certain lesions may not be amendable Brunicardi_Ch23_p0897-p0980.indd 95927/02/19 4:15 PM 960SPECIFIC CONSIDERATIONSPART IIto endovascular treatment or may be associated with poor outcomes, such as long segment occlusion, heavily calcified lesion, orifice lesion, or lesions that cannot be traversed by a guidewire. Proper selection of patients and techniques is criti-cal in achieving good long-term outcome.Endovascular intervention for lower extremity occlusive disease is


Surgery_Schwartz

Surgery_Schwartz. cannot be traversed by a guidewire. Proper selection of patients and techniques is criti-cal in achieving good long-term outcome.Endovascular intervention for lower extremity occlusive disease is continuously evolving. Success and patency rates of endovascular intervention are closely related to the anatomic and morphologic characteristics of the treated lesions. The TASC work group made recommendations on the intervention strate-gies of lower extremity arterial diseases based on the morpho-logic characteristics. Based on TASC guidelines, endovascular treatment is recommended for type A lesions, open surgery is recommended for type D lesions, and no recommendations were made for types B and C lesions. However, with rapid advance-ment in endovascular technologies, there are increased numbers of lesions amendable to endovascular interventions.There is less literature support for infrapopliteal endo-vascular intervention due to higher complication and lower success rates. The treatment


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Surgery_Schwartz. of lesions amendable to endovascular interventions.There is less literature support for infrapopliteal endo-vascular intervention due to higher complication and lower success rates. The treatment is restricted for patients with limb-threatening ischemia who lack surgical alternatives. However, with further advancement of endovascular technology and the development of new devices, endovascular intervention is becoming an integral part of treatment (Table 23-26). By itself or combined with open technique, percutaneous intervention plays an important role in therapeutic options for lower extrem-ity occlusive disease. As described by TASC guidelines, four criteria should be measured to evaluate the clinical success of the treatment: improvement in walking distance, symptomatic improvement, quality of life, and overall graft patency. These criteria should all be carefully weighed and evaluated for each individual prior to endovascular therapy.Table 23-26Summary of endovascular treatment


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Surgery_Schwartz. quality of life, and overall graft patency. These criteria should all be carefully weighed and evaluated for each individual prior to endovascular therapy.Table 23-26Summary of endovascular treatment strategies using device-based infrapopliteal interventionINTERVENTIONADVANTAGESDISADVANTAGESAngioplasty• Easy to use• Broad range of applications• Failure in long lesions, calcified lesions, and disease at multiple levelsBalloon-expandable stent• Overcomes arterial recoil from angioplasty• Useful in treatment of flow-limiting dissection• Crushability can lead to restenosis• Poor distal runoff can result in stent thrombosis• Limited dataSelf-expanding stent• Vessel conformability and wall apposition prevent kinking and crushing of stent• Limited sizes• Limited data; multicenter trials under wayBioabsorbable stent• Overcomes arterial recoil from angioplasty• Absorbed long term to prevent risk of stent thrombosis• Limited data; multicenter trials under wayCryoplasty• Reduces the risk of


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Surgery_Schwartz. wayBioabsorbable stent• Overcomes arterial recoil from angioplasty• Absorbed long term to prevent risk of stent thrombosis• Limited data; multicenter trials under wayCryoplasty• Reduces the risk of flow-limiting dissection, therefore reducing the need for stent implantation• Short-term results of a multicenter trial are promising; however, long-term data are limitedCutting balloon• Useful in anastomotic segments of bypass grafts and in-stent restenosis where “watermelon seeding” can prevent adequate expansion of plaque• Limited dataMechanical atherectomy• Allows for debulking of plaque without the need for stent implantation in most cases• Allows for removal of plaque for histologic analysis• Limited use in areas of heavy calcification• No large, randomized, prospective trial comparing this technique to angioplasty and stentingLaser• Useful in acute thrombotic and chronic total occlusions• Minimal data in infrapopliteal arteries• Need adjunctive treatment with angioplasty, stenting,


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Surgery_Schwartz. technique to angioplasty and stentingLaser• Useful in acute thrombotic and chronic total occlusions• Minimal data in infrapopliteal arteries• Need adjunctive treatment with angioplasty, stenting, or atherectomyEndovascular TreatmentTechnical Considerations. A sterile field is required in either an operating room or an angiography suite with image capabil-ity. The most common and safest access site is CFA via either a retrograde or an antegrade approach. For diagnostic angiogra-phy, arterial access should be contralateral to the symptomatic sides. For therapeutic procedures, location of the lesion and the anatomic structures of the arterial tree determine the puncture site. To avoid puncturing the iliac artery or SFA, the femoral head is located under the fluoroscopy and used as the guide for the level of needle entry. In addition, there are several useful techniques to help access a pulseless CFA including ultrasound-guided puncture, using a micropuncture kit, and targeting


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Surgery_Schwartz. the guide for the level of needle entry. In addition, there are several useful techniques to help access a pulseless CFA including ultrasound-guided puncture, using a micropuncture kit, and targeting cal-cification in a calcified vessel. The antegrade approach may be challenging, particularly in obese patients. Meticulous technique is crucial in preventing complications, and a bony landmark can be used as guidance to ensure CFA puncture.Traversing the lesion with a wire is the most critical part of the procedure. Typically, 0.035-inch guidewires are used for femoropopliteal lesions, and 0.014or 0.018-inch guidewires are used for infrapopliteal access. Hydrophilic-coated wires, such as Glidewires, are useful in navigating through tight ste-nosis or occlusion. An angled-tip wire with a torque device may be helpful in crossing an eccentric lesion, and a shaped selective catheter is frequently used to help manipulate the wire across the lesion. The soft and floppy end of the wire is


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Surgery_Schwartz. torque device may be helpful in crossing an eccentric lesion, and a shaped selective catheter is frequently used to help manipulate the wire across the lesion. The soft and floppy end of the wire is care-fully advanced crossing the lesion under fluoroscopy, and gentle force is applied while manipulating the wire. Once the lesion us traversed, one needs to pay particular attention on the tip of the wire to ensure a secure wire access and avoid vessel wall perforation or dissection.Brunicardi_Ch23_p0897-p0980.indd 96027/02/19 4:15 PM 961ARTERIAL DISEASECHAPTER 23Once the access to the diseased vessel is secured and the wire has successfully traversed the lesion, several treatment modalities can be used either alone or in conjunction with oth-ers, including angioplasty, stent or stent graft placement, and atherectomy. The available angioplasty techniques are balloon angioplasty, cryoplasty, subintimal angioplasty, and cutting bal-loon; the most commonly used atherectomy techniques


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Surgery_Schwartz. graft placement, and atherectomy. The available angioplasty techniques are balloon angioplasty, cryoplasty, subintimal angioplasty, and cutting bal-loon; the most commonly used atherectomy techniques include percutaneous atherectomy catheter and laser atherectomy device.Systemic anticoagulation should be maintained routinely during lower extremity arterial interventions to minimize the risk of pericatheter thrombosis. Unfractionated heparin is the most commonly used agent, administered using a weight-based formula. We typically use 80 to 100 mg/kg initial bolus for therapeutic procedure to achieve an activated clotting time above 250 seconds upon catheter insertion and administer a sub-sequent 1000 units for each additional hour of the procedure. Newer agents, such as low molecular weight heparin, platelet IIb/IIIa inhibitors, direct thrombin inhibitors, or recombinant hirudin, have been available and can be used either alone or in conjunction with heparin, particularly in patients


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Surgery_Schwartz. heparin, platelet IIb/IIIa inhibitors, direct thrombin inhibitors, or recombinant hirudin, have been available and can be used either alone or in conjunction with heparin, particularly in patients who are sensi-tive to unfractionated heparin. After the procedure, all patients are placed on antiplatelet therapy, such as aspirin. Additional antiplatelet agents, such as clopidogrel (Plavix), are given to selected patients with stent placement for at least 6 weeks after lower extremity interventions unless otherwise contraindicated.Percutaneous Transluminal Balloon Angioplasty. After the lesion is crossed with a wire, an appropriated balloon angio-plasty catheter is selected and tracked along the wire to traverse the lesion. The length of the selected catheter should be slightly longer than the lesion, and the diameter should be equal to the adjacent normal vessel. The balloon tends to be approximately 10% to 20% oversized. The radiopaque markers of the balloon catheter are placed so that


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Surgery_Schwartz. lesion, and the diameter should be equal to the adjacent normal vessel. The balloon tends to be approximately 10% to 20% oversized. The radiopaque markers of the balloon catheter are placed so that they will straddle the lesion. Then, the balloon is inflated with saline and contrast mixture to allow visualization of the insufflation process under the fluoroscopy (Fig. 23-65). The patient may experience mild pain, which is not uncommon. However, severe pain can be indicative of ves-sel rupture, dissection, or other complications. An angiography is crucial in confirming the intraluminal location of the catheter and absence of contrast extravasation. The inflation is continued until the waist of the atherosclerotic lesion is disappeared and the balloon is at the full profile. Frequently, several inflations are required to achieve a full profile of the balloon (Fig. 23-66). Occasionally, a lower profile balloon is needed to predilate the tight stenosis so that the selected balloon


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Surgery_Schwartz. several inflations are required to achieve a full profile of the balloon (Fig. 23-66). Occasionally, a lower profile balloon is needed to predilate the tight stenosis so that the selected balloon catheter can cross the lesion.Besides length and diameter, the operators need to be familiar with several balloon characters. Noncompliant and low-compliant balloons tend to be inflated to their preset diam-eter and offer greater dilating force at the site of stenosis. Low-compliant balloons are the mainstay for peripheral intervention. A balloon with a low profile is used to minimize complications at the entry site and for crossing the tight lesions. Upon infla-tion, most balloons do not rewrap to their preinflation diameter and assume larger profiles. Furthermore, trackability, pushabil-ity, and crossability of the balloon should be considered when choosing a particular type of balloon. Lastly, shoulder length is an important characteristic when performing PTA to avoid injury to the


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Surgery_Schwartz. and crossability of the balloon should be considered when choosing a particular type of balloon. Lastly, shoulder length is an important characteristic when performing PTA to avoid injury to the adjacent arterial segments. After PTA, a comple-tion angiogram is performed while the wire is still in place. Leaving the wire in place provides access for repeating the pro-cedure if the result is unsatisfactory.PTA is an established and effective therapy for select patients with lower extremity occlusive diseases. Studies have shown that PTA of femoropopliteal segment achieved over 90% technical success rate and 38% to 58% 5-year primary patency rates.149,150 However, efficacy of PTA is highly dependent on anatomic selection and patient condition. PTA of lesions longer than 7 to 10 cm offers limited patency, whereas PTA of shorter lesions, such as those less than 3 cm, has fairly good results. Lofberg and associates performed 127 femoropopliteal PTA Figure 23-65. A. Angiogram demonstrating a


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Surgery_Schwartz. patency, whereas PTA of shorter lesions, such as those less than 3 cm, has fairly good results. Lofberg and associates performed 127 femoropopliteal PTA Figure 23-65. A. Angiogram demonstrating a focal stenosis in the superficial femoral artery (arrow). B. This lesion was treated with a bal-loon angioplasty catheter that inflated a dilating balloon and expanded the flow lumen. C. Completion angiogram demonstrating satisfactory radiographic result.Brunicardi_Ch23_p0897-p0980.indd 96127/02/19 4:15 PM 962SPECIFIC CONSIDERATIONSPART IIFigure 23-66. A. Angiogram demonstrating a segmental occlusion in the distal superficial femoral artery (single arrow). B. This lesion was treated with cryoplasty, which lowered the balloon catheter temperature to a temporary freezing state during the balloon angioplasty procedure (double arrows). C. Completion angiogram demonstrated satisfactory result with no evidence of vessel dissection.procedures and reported a primary 5-year success rate of 12% in


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Surgery_Schwartz. angioplasty procedure (double arrows). C. Completion angiogram demonstrated satisfactory result with no evidence of vessel dissection.procedures and reported a primary 5-year success rate of 12% in limbs with occlusion longer than 5 cm versus 32% in limbs with occlusion less than 5 cm in length.151 Occlusive lesions have much worse initial technical success rates than stenotic lesions. Concentric lesions respond better to PTA than eccentric lesions, and heavy calcifications have a negative impact on success rates. A meta-analysis by Hunink and associates showed that adjusted 5-year primary patencies after angioplasty of femoropopliteal lesions varied from 12% to 68%, with the best results being for patients with claudication and stenotic lesions.152 Distal runoff is another powerful predictor of long-term success. Johnston analyzed 254 consecutive patients who underwent femoral and popliteal PTA and reported a 5-year patency rate of 53% for ste-notic lesions and 36% for occlusive


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Surgery_Schwartz. of long-term success. Johnston analyzed 254 consecutive patients who underwent femoral and popliteal PTA and reported a 5-year patency rate of 53% for ste-notic lesions and 36% for occlusive lesions in patients with good runoff versus a 5-year patency rate of 31% for stenotic lesions and 16% for occlusive lesions in patients with poor runoff.149 Literature reviews showed that 5-year patency rates varied from 27% to 67% based on runoff status.152Due to limited success with infrapopliteal PTA, the indi-cation for infrapopliteal PTA is stringent and reserved for limb salvage. Current patency rates from infrapopliteal PTA can be improved further by proper patient selection, ensuring straight-line flow to the foot in at least one tibial vessel, and close patient surveillance for early reintervention. Possible future advances, including the use of drug-eluting stents, cutting balloons, and atherectomy devices, are being investigated to improve clini-cal outcomes following endovascular


Surgery_Schwartz

Surgery_Schwartz. Possible future advances, including the use of drug-eluting stents, cutting balloons, and atherectomy devices, are being investigated to improve clini-cal outcomes following endovascular interventions on the tibial arteries. Varty and associates reported a 1-year limb salvage rate of 77% in patients with critical ischemia who underwent infrapopliteal PTA.153 In patients with favorable anatomies, the 2-year limb salvage rate after infrapopliteal PTA is expected to exceed 80%.Subintimal Angioplasty. The technique of subintimal angio-plasty was first described in 1987 when successful establish-ment of flow was made by accidental creation of a subintimal channel during treatment of a long popliteal artery occlusion. Subintimal angioplasty is recommended for chronic occlusion, long segment of lesion, and heavily calcified lesions. In addi-tion, this technique is applicable for vessels with diffuse dis-ease and for vessels that had previously failed an intraluminal approach, when it is


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Surgery_Schwartz. of lesion, and heavily calcified lesions. In addi-tion, this technique is applicable for vessels with diffuse dis-ease and for vessels that had previously failed an intraluminal approach, when it is difficult to negotiate the wire across the entire diseased segment without dissection.The principle of this technique is to bypass the occlusion by deliberately creating a subintimal dissection plan commenc-ing proximal to the lesion and continuing in the subintimal space before retry into the true lumen distal to the lesion. The occluded lumen is recanalized through the subintimal plan. Sub-intimal angioplasty can be performed through either an ipsilat-eral antegrade or contralateral retrograde approach using the CFA approach. If selecting contralateral CFA puncture, a long guiding sheath is placed across the aortic bifurcation to provide access for the femoropopliteal and infrapopliteal vessels. The subintimal dissection is initiated at the origin of an occlusion by directing the tip of


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Surgery_Schwartz. placed across the aortic bifurcation to provide access for the femoropopliteal and infrapopliteal vessels. The subintimal dissection is initiated at the origin of an occlusion by directing the tip of an angled guide wire, usually an angled hydrophilic wire, such as a Glidewire. A supporting catheter is used to guide the tip of the guidewire away from the impor-tant collaterals. When the wire is advanced, a loop is naturally formed at the tip of the guidewire. Once the subintimal plan is entered, the wire tends to move freely in dissection space. Sub-intimal location of the wire and the catheter can be confirmed by injecting a small amount of diluted contrast. At this point, the wire and the catheter are then advanced along the subintimal plan until the occlusion segment is passed. A loss of resistance is often encountered as the guidewire reenters the true lumen distal to the occlusion. Recanalization is confirmed by advanc-ing the catheter over the guidewire beyond the point of


Surgery_Schwartz

Surgery_Schwartz. loss of resistance is often encountered as the guidewire reenters the true lumen distal to the occlusion. Recanalization is confirmed by advanc-ing the catheter over the guidewire beyond the point of reen-try and obtaining an angiogram. This is followed by a balloon angioplasty. To confirm the patency following balloon dilata-tion, a completion angiogram is performed prior to withdraw-ing the catheter and wire. If flow is impaired, repeat balloon Brunicardi_Ch23_p0897-p0980.indd 96227/02/19 4:15 PM 963ARTERIAL DISEASECHAPTER 23dilatation may be necessary. Frequently, a stent is required to maintain a patent lumen and treat residual stenosis if more than 30% luminal reduction is confirmed on completion angiogram.Multiple studies have demonstrated the efficacy of subin-timal angioplasty. Bolia and colleagues reported their extensive experiences on subintimal angioplasty for treating long-segment occlusions of infrainguinal vessels.154 They achieved a techni-cal success rate of over


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Surgery_Schwartz. Bolia and colleagues reported their extensive experiences on subintimal angioplasty for treating long-segment occlusions of infrainguinal vessels.154 They achieved a techni-cal success rate of over 80% for both femoropopliteal and tibial arteries. One-year patency rates varied from 53% for infrapopli-teal vessels to 71% for femoropopliteal segments. Limb salvage rates reached over 80% at 12 months. They also reported that the factors influencing patency are smoking, number of runoff vessels, and occlusion length. Studies by other groups showed similar results.155 Treiman and colleagues treated 25 patients with 6to 18-cm femoropopliteal occlusion and achieved a technical success rate of 92% and a 13-month primary patency rate of 92%,156 whereas Lipsitz and associates reported a techni-cal success rate of 87% in 39 treated patients and a 12-month cumulative patency rate of 74%.155 In addition, Ingle and asso-ciates reported a technical success rate of 87% in 67 patients with


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Surgery_Schwartz. techni-cal success rate of 87% in 39 treated patients and a 12-month cumulative patency rate of 74%.155 In addition, Ingle and asso-ciates reported a technical success rate of 87% in 67 patients with femoropopliteal lesions and a 36-month limb salvage rate of 94%.157 As demonstrated herein, although technical success rates are similar in most series, the patency rates vary widely in different studies. Patient selection, anatomic character, and lesion locations may account for the wide range of outcomes.Stent Placement. Although suggested by Dotter during the late 1960s, the use of an endoluminal stent was not pursued until the limitations of PTA were widely recognized. There are sev-eral situations where stent placement is appealing. The primary indication is the potential salvage of an unacceptable angio-plasty result. Stent placement is typically used when residual stenosis after PTA is 30% or greater. An endoluminal stent is also used for dissection, perforation, and other PTA


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Surgery_Schwartz. an unacceptable angio-plasty result. Stent placement is typically used when residual stenosis after PTA is 30% or greater. An endoluminal stent is also used for dissection, perforation, and other PTA complica-tions. Primary stent placement has become a viable alternative for treating ulcerative lesions that may potentially be the source for embolization. Primary stent is also used to treat occlusive lesions that have a tendency for reocclusion and distal emboliza-tion after PTA. In addition, an endoluminal stent is potentially beneficial for early restenosis after PTA. Drug-eluting stents are currently under investigation in the United States and may be promising in decreasing restenosis rates.Although technical success rates are high, published series on femoropopliteal artery stents show that patency rates are comparable to PTA alone, with primary patency rates vary-ing from 18% to 72% at 3 years.158 Gray and associates stented 58 limbs after suboptimal PTA for long SFA lesions and


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Surgery_Schwartz. that patency rates are comparable to PTA alone, with primary patency rates vary-ing from 18% to 72% at 3 years.158 Gray and associates stented 58 limbs after suboptimal PTA for long SFA lesions and dem-onstrated a 1-year primary patency rate of 22%.159 However, Mewissen treated 137 limbs using self-expanding SMART niti-nol stents in patients with TASC A, B, and C femoropopliteal lesions and reported a 1-year primary patency of 76% and a 24-month primary patency rate of 60%.160 Appropriate patient selection and the anatomic characteristics of the lesions are cru-cial in the success of treatment outcomes. Additionally, stent characteristics may contribute to the patency rate.Several clinical studies have demonstrated the significant improvements of the new generation of nitinol stents for the SFA lesions: the German Multicenter Experience, the Mewis-sen trial, the BLASTER Trial, and the SIROCCO trial.161 The German Multicenter Experience was a retrospective review of 111 SFA stenting


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Surgery_Schwartz. the SFA lesions: the German Multicenter Experience, the Mewis-sen trial, the BLASTER Trial, and the SIROCCO trial.161 The German Multicenter Experience was a retrospective review of 111 SFA stenting procedures and predicted that the 6-month patency rate for SMART stents was 82% versus 37% for the Wallstent. The BLASTER (Bilateral Lower Arterial Stenting Employing Reopro) Trial evaluated the feasibility of using nitinol stents with and without intravenous abciximab for the treatment of femoral artery disease, and the preliminary results showed a 1-year clinical patency rate of 83%.162Furthermore, the drug-eluting stent, which proved effec-tive in decreasing restenosis in coronary intervention, may offer another promising alternative in lower extremity diseases. The drug released over a period of time interferes with smooth mus-cle cell proliferation, the main cellular element and source of extracellular matrix–producing restenosis. The first drug-eluting stent clinical trial used


Surgery_Schwartz

Surgery_Schwartz. a period of time interferes with smooth mus-cle cell proliferation, the main cellular element and source of extracellular matrix–producing restenosis. The first drug-eluting stent clinical trial used Cordis Cypher SMART stents coated with sirolimus (SIROCCO trial).163 The SIROCCO results showed binary in-lesion restenosis rates of 0% in the sirolimus-eluting group versus 23.5% in the noneluting group at 6-month follow-up angiography. The PaRADISE (Preventing Amputa-tions Using Drug-Eluting Stents) Trial investigated the efficacy and safety of using balloon-expandable drug-eluting stents to prevent amputations in patients with below-the-knee critical limb ischemia.164 One hundred six patients (118 limbs) were treated with drug-eluting stents in this prospective, nonrandom-ized trial. There were 228 drug-eluting stents implanted (83% Cypher [Cordis, Johnson & Johnson, Warren, NJ], 17% Taxus [Boston Scientific, Maple Grove, MN]). The average length treated was 60 mm. The 3-year


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Surgery_Schwartz. There were 228 drug-eluting stents implanted (83% Cypher [Cordis, Johnson & Johnson, Warren, NJ], 17% Taxus [Boston Scientific, Maple Grove, MN]). The average length treated was 60 mm. The 3-year cumulative incidence of amputa-tion was 6%, the survival rate was 71%, and the amputation-free survival rate was 68%. Only 12% of patients who died had a preceding major amputation. Rutherford category, age, creati-nine level, and dialysis were predictors of death but not amputa-tion. Target limb revascularization occurred in 15% of patients.Stent Graft. The concept of endoluminal bypass using stent graft in treating atherosclerotic SFA disease has been enter-tained. A stent graft is placed percutaneously across a long segment or multiple segments of lesions and is used to create a femoropopliteal bypass. Theoretically, endobypass has the potential of being as successful as surgical bypass graft by relin-ing the vessel wall in its anatomic position without the nega-tive impact of anastomosis.


Surgery_Schwartz

Surgery_Schwartz. bypass. Theoretically, endobypass has the potential of being as successful as surgical bypass graft by relin-ing the vessel wall in its anatomic position without the nega-tive impact of anastomosis. Stent grafts can be divided into two categories: unsupported and fully supported. The unsupported grafts consist of segments of bypass graft, such as PTFE, with an expandable stent at one or both ends. The unsupported grafts are flexible with a low profile, but prone to external compres-sion. The supported stent grafts consist of a metallic skeleton covered with graft fabric. The presence of a dense metal skele-ton promotes an extensive inflammatory response and increases the risk of thrombosis. There is no FDA-approved stent graft for peripheral intervention. However, Viabahn (WL Gore & Associates, Flagstaff, AZ) is the most commonly used device in the United States and is composed of an ultra-thin PTFE graft externally supported by self-expanding nitinol meshwork. The Viabahn device has


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Surgery_Schwartz. Flagstaff, AZ) is the most commonly used device in the United States and is composed of an ultra-thin PTFE graft externally supported by self-expanding nitinol meshwork. The Viabahn device has a specific delivery mechanism by pulling back the attached string, which results in proximal-to-distal delivery of the endoprosthesis.Although it is an intriguing concept, data on endobypass results are limited, and the graft thrombosis rate is high. Addi-tionally, covering major collateral vessels can potentially jeop-ardize the viability of the limb if stent graft occlusion occurs. Bauermeister treated 35 patients with Hemobahn and reported a 28.6% occlusion rate at an average 7-month follow-up.165 Kedora and colleagues recently conducted a prospective, randomized study comparing covered PTFE/nitinol self-expanding stent grafts with prosthetic above-the-knee femoropopliteal bypass. Fifty limbs were randomized into each group. Primary patency Brunicardi_Ch23_p0897-p0980.indd 96327/02/19


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Surgery_Schwartz. self-expanding stent grafts with prosthetic above-the-knee femoropopliteal bypass. Fifty limbs were randomized into each group. Primary patency Brunicardi_Ch23_p0897-p0980.indd 96327/02/19 4:15 PM 964SPECIFIC CONSIDERATIONSPART IIat 1 year was approximately 74% for both cohorts, with a mean follow-up of 18 months. The covered nitinol/PTFE stent graft in the SFA had a 1-year patency comparable to surgical bypass, with a significantly shorter hospital stay (0.9 vs. 3.1 days).166 A recent randomized prospective study comparing the treatment of SFA occlusive disease percutaneously with an expanded PTFE (ePTFE)/nitinol self-expanding stent graft (stent graft) versus surgical femoral to above-knee popliteal artery bypass with synthetic graft material showed no difference between the two groups with respect to primary or secondary patency rates at 48 months.167 Mean total lesion length of the treated arterial seg-ment in the stent graft group was 25.6 cm. The stent graft group


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Surgery_Schwartz. two groups with respect to primary or secondary patency rates at 48 months.167 Mean total lesion length of the treated arterial seg-ment in the stent graft group was 25.6 cm. The stent graft group demonstrated a primary patency of 72%, 63%, 63%, and 59% with a secondary patency of 83%, 74%, 74%, and 74% at 12, 24, 36, and 48 months, respectively. The surgical femoral-popliteal group demonstrated a primary patency of 76%, 63%, 63%, and 58% with a secondary patency of 86%, 76%, 76%, and 71% at 12, 24, 36, and 48 months, respectively. The authors concluded that ePTFE/nitinol self-expanding stent graft placement can be offered as an alternative to treatment of the SFA segment for revascularization when prosthetic bypass is being considered or when autologous conduit is unavailable.Atherectomy. The basic principle of atherectomy is to remove the atheroma from obstructed arterial vessels. The currently available atherectomy devices can be generally categorized into directional,


Surgery_Schwartz

Surgery_Schwartz. basic principle of atherectomy is to remove the atheroma from obstructed arterial vessels. The currently available atherectomy devices can be generally categorized into directional, nondirectional, orbital, and rotational types based on their mechanism. A few examples of FDA-approved atherectomy devices are Simpson AtheroCath (DVI, Redwood City, CA), Transluminal Extraction Catheter (Interventional Technologies, San Diego, CA), Thoratec recanalization arterial catheter (Thoratec, Pleasanton, CA), Auth Rotablator (Heart Technologies, Redmond, WA), SilverHawk system (FoxHollow Technologies, Redwood City, CA), Jetstream atherectomy sys-tem (Bayer, Indianola, PA), Diamondback 360° orbital atherec-tomy device (Cardiovascular Systems, Inc, St. Paul, MN), and Rotablator system (Boston Scientific Corporation, Natick, MA). These devices either cut and remove or pulverize the atheroma plaques.The Simpson AtheroCath has a directional cutting ele-ment that is exposed to one-third of the


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Surgery_Schwartz. Corporation, Natick, MA). These devices either cut and remove or pulverize the atheroma plaques.The Simpson AtheroCath has a directional cutting ele-ment that is exposed to one-third of the circumference of the arterial wall. The atheroma protruding into the window is excised and pushed into the collection chamber. The Translu-minal Extraction Catheter has an over-the-wire nondirectional cutter mounted on the distal end of a torque tube. The excised atheroma is simultaneously removed by aspiration through the torque tube. The Thoratec recanalization arterial catheter is a nondirectional, noncoaxial, atheroablative device. The rotating cam tip pulverizes the atheromatous lesion into minute particles. The Auth Rotablator is a nondirectional, coaxial, atheroablative device with a metal burr embedded with fine diamond chips. SilverHawk device is a monorail catheter designed to overcome the drawbacks of a directional atherectomy catheter. The work-ing end consists of a hinged housing unit


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Surgery_Schwartz. embedded with fine diamond chips. SilverHawk device is a monorail catheter designed to overcome the drawbacks of a directional atherectomy catheter. The work-ing end consists of a hinged housing unit containing a carbide cutting blade. The blade is activated from the motor drive unit, and the catheter is then advanced through the length of the lesion. Once each pass is completed, the cutter then packs the tissue into the distal end of the nosecone to maximize collec-tion capacity. The SilverHawk can then either be removed or torqued to treat a different quadrant in the same lesion or other lesions. Jetstream atherectomy system is a rotating, aspirat-ing catheter with tip sizes of 1.6 and 1.8 mm for tibial arteries, and an expandable catheter with a tip size ranging from 2.1 to 3.4 mm for active removal of atherosclerotic debris and throm-bus. The Diamondback 360° orbital atherectomy device uses a drive shaft with an eccentrically mounted, diamond-coated crown to create an orbital


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Surgery_Schwartz. for active removal of atherosclerotic debris and throm-bus. The Diamondback 360° orbital atherectomy device uses a drive shaft with an eccentrically mounted, diamond-coated crown to create an orbital spin. As the speed of the crown increases from centrifugal force, it sands wider spaces, thereby providing variability in its working range. It can create a lumen that is >1.75 times the crossing profile depending on the size of the grit and the eccentricity of the offset. The greater the speed of the crown, the larger is the arc of debulking and, ultimately, the resultant lumen size. A constant flow of saline solution is delivered by a roller pump that lubricates the device and helps to flush the debris. The Rotablator system high-speed rotational device uses calcium ablation to achieve larger lumens. It has been used for more than 20 years to treat challenging, calcified coronary artery disease. The diamond-coated burr is designed to preferentially engage calcium and modify lesion


Surgery_Schwartz

Surgery_Schwartz. larger lumens. It has been used for more than 20 years to treat challenging, calcified coronary artery disease. The diamond-coated burr is designed to preferentially engage calcium and modify lesion compliance.Despite the promising early technical and clinical success, the midand long-term results have been disappointing due to high incidence of restenosis. A multicenter clinical registry of plaque atherectomy in patients with femoropopliteal occlusive disease showed potential clinical efficacy of this technology, as the 6and 12-month rates of survival free of target lesion revascularization were 90% and 80%, respectively.168 Impor-tantly, nearly three-quarters (73%) of patients treated with plaque excision modality did not require adjunctive endovas-cular therapy as infrainguinal stenting was necessary in only 6.3% of lesions. Results from the TALON registry support the role of plaque excision in selected patients with lower extremity arterial disease.Recent technologic advances have


Surgery_Schwartz

Surgery_Schwartz. was necessary in only 6.3% of lesions. Results from the TALON registry support the role of plaque excision in selected patients with lower extremity arterial disease.Recent technologic advances have made it possible to increase the spectrum of treatable peripheral arterial lesions with high acute procedure success rates. Recently presented data from multiple registries have shown some promising results in terms of short-term primary patency rates and freedom from unplanned major amputation.169 Randomized clinical trials, which may provide conclusions on the effectiveness of these procedures, are expected.Laser Atherectomy. Since laser atherectomy was reported in the 1960s, a variety of innovative approaches have been devel-oped trying to overcome the limitation of laser angioplasty. Recent developments in Excimer laser technology have led to increased optimism regarding the ability to safely deliver laser energy. Excimer laser atherectomy approved by the FDA for peripheral artery


Surgery_Schwartz

Surgery_Schwartz. developments in Excimer laser technology have led to increased optimism regarding the ability to safely deliver laser energy. Excimer laser atherectomy approved by the FDA for peripheral artery intervention employs precision laser energy control (shallow tissue penetration) and safer wavelengths (ultraviolet as opposed to the infrared spectra in older laser technology), which decrease perforation and thermal injury to the treated vessels.A laser atherectomy catheter, with diameters varying from 0.9 to 2.5 mm, is tracked over the guidewire to the desired tar-get. Once activated, the Excimer laser uses ultraviolet energy to ablate the lesion and create a nonthrombogenic arterial lumen. This lumen is further dilated by an angioplasty balloon. Because the Excimer laser can potentially reduce the rate of distal embo-lization by evaporating the lesion, it may be used as an adjunct tool for ostial lesions and lesions that can be traversed by a wire but not an angioplasty balloon


Surgery_Schwartz

Surgery_Schwartz. reduce the rate of distal embo-lization by evaporating the lesion, it may be used as an adjunct tool for ostial lesions and lesions that can be traversed by a wire but not an angioplasty balloon catheter.Several studies regarding the use of Excimer laser atherectomy combined with balloon angioplasty on lower extremity occlusive disease have shown promising clinical outcomes.199,200 The Peripheral Excimer Laser Angioplasty (PELA) trial involved 318 patients with chronic SFA occlusion Brunicardi_Ch23_p0897-p0980.indd 96427/02/19 4:15 PM 965ARTERIAL DISEASECHAPTER 23and achieved a technical success rate of 83.2%, a 1-year pri-mary patency rate of 33.6%, and an assisted-primary patency rate of 65%.170 Steinkamp and colleagues treated 127 patients with long-segment popliteal artery occlusion using laser ather-ectomy followed by balloon angioplasty and reported a 3-year primary patency rate of 22%.171 A multicenter clinical trial, the Laser Angioplasty for Critical Limb Ischemia (LACI)


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Surgery_Schwartz. using laser ather-ectomy followed by balloon angioplasty and reported a 3-year primary patency rate of 22%.171 A multicenter clinical trial, the Laser Angioplasty for Critical Limb Ischemia (LACI) trial, sup-ports the efficacy of this treatment modality in selected patients, with 6-month primary patency and clinical improvement rates of 33% and 89%, respectively.172 The technology and devices continue to evolve. With the TurboBooster and Turbo-Tandem technologies (Spectranetics Corporation, Colorado Springs, CO), the efficacy of plaque reduction was reported to be sig-nificantly improved in the CliRpath Excimer Laser System to Enlarge Lumen Openings (CELLO) study.173 The CELLO study was a single-arm, prospective registry trial conducted at 17 investigational sites in the United States to evaluate the safety and efficacy of a modified laser catheter designed for the endovascular treatment of peripheral artery disease affecting the SFA and proximal popliteal artery. Laser ablation


Surgery_Schwartz

Surgery_Schwartz. to evaluate the safety and efficacy of a modified laser catheter designed for the endovascular treatment of peripheral artery disease affecting the SFA and proximal popliteal artery. Laser ablation reduced percent diameter stenosis from 77% to 21% after adjunctive therapy with balloon angioplasty or balloon angioplasty with stenting; 12.3% patients did not receive postlaser adjunctive therapy. Patency rates were 59% and 54% at 6 and 12 months, respectively. Target lesion revascularization was not required in 76.9% of CELLO participants within the 1-year follow-up.Complications of Endovascular InterventionsAngioplasty-Related Complications. Complications related to PTA vary widely and include dissection, rupture, emboliza-tion, pseudoaneurysms, restenosis, hematoma, and acute occlu-sion secondary to thrombosis, vasospasm, or intimal injury. Clark and associates analyzed the data from 205 patients in the SCVIR Transluminal Angioplasty and Revascularization (STAR) registry and reported a


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Surgery_Schwartz. to thrombosis, vasospasm, or intimal injury. Clark and associates analyzed the data from 205 patients in the SCVIR Transluminal Angioplasty and Revascularization (STAR) registry and reported a complication rate of 7.3% for patients undergoing femoropopliteal angioplasty.174 Minor complications accounted for 75% of the cases, including distal emboli (41.7%), puncture site hematomas (41.7%), contained vessel rupture (8.3%), and vagal reactions (8.3%). In another study, Axisa and colleagues reported an overall rate of significant complica-tions for patients undergoing PTA of the lower extremities of 4.2%, including retroperitoneal bleeding (0.2%), false aneurysm (0.2%), ALI (1.5%), and vessel perforation (1.7%).175Complications limiting the application of subintimal angioplasty are parallel to those of PTA. A study investigating the use of subintimal angioplasty in 65 patients with SFA occlu-sion found that complications developed in 15% of patients.176 These complications included


Surgery_Schwartz

Surgery_Schwartz. to those of PTA. A study investigating the use of subintimal angioplasty in 65 patients with SFA occlu-sion found that complications developed in 15% of patients.176 These complications included significant stenosis (44%), SFA rupture (6%), distal embolization (3%), retroperitoneal hemor-rhage (1.5%), and pseudoaneurysm (1.5%). Additional compli-cations reported included perforation, thrombosis, dissection, and extensions beyond the planned reentry site.177 Importantly, damage to significant collateral vessels may occur in 1% to 1.5% of patients who undergo subintimal angioplasty. If a suc-cessful channel is not achieved in this situation, the patient may have a compromised distal circulation that necessitates dis-tal bypass. Cryoplasty is a modified form of angioplasty, and long-term results on lower extremity intervention are not yet available. Fava and associates treated 15 patients with femo-ropopliteal disease and had a 13% complication rate involving guidewire dissection and


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Surgery_Schwartz. results on lower extremity intervention are not yet available. Fava and associates treated 15 patients with femo-ropopliteal disease and had a 13% complication rate involving guidewire dissection and PTA-induced dissection of a tandem lesion remote to the cryoplasty zone.178Endoluminal Stent– and Stent Graft–Related Complica-tions. In addition to the aforementioned complications with angioplasty, endoluminal stent is associated with the risk of stent fraction and deformity. The adductor canal has nonlami-nar flow dynamics, especially with walking. The forces exerted on the SFA include torsion, compression, extension, and flex-ion. These forces exert significant stress on the SFA and stents. In addition, the lower extremity is subject to external trauma, which further increases the risk of stent deformity and fracture (Fig. 23-67). The SIROCCO study showed that stent fracture, although not associated with clinical symptoms, occurs in 18.2% of the procedures involving both drug-eluting


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Surgery_Schwartz. stent deformity and fracture (Fig. 23-67). The SIROCCO study showed that stent fracture, although not associated with clinical symptoms, occurs in 18.2% of the procedures involving both drug-eluting stents and control stents.163Stent grafts may present the additional complication of covering important collaterals, which results in compromised distal circulation. A prospective study evaluating Hemo-bahn stent grafts in the treatment of femoropopliteal arterial Figure 23-67. Due to various geometric forces, including torsion, compression, extension, and flexion, exerted on the superficial fem-oral artery (SFA), stent fracture (arrows) is a known complication following SFA stent placement.Brunicardi_Ch23_p0897-p0980.indd 96527/02/19 4:15 PM 966SPECIFIC CONSIDERATIONSPART IIocclusions demonstrated a 23% immediate complication rate including distal embolization (7.7%), groin hematoma (13.5%), and arteriovenous fistula (1.9%).179Atherectomy-Related Complications. Overall complication


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Surgery_Schwartz. a 23% immediate complication rate including distal embolization (7.7%), groin hematoma (13.5%), and arteriovenous fistula (1.9%).179Atherectomy-Related Complications. Overall complication rates associated with atherectomy range from 15.4% to 42.8%, including spasm, thrombosis, dissection, perforation, distal emboli, no reflow, and hematoma.180,181 Jahnke and associates conducted a prospective study evaluating high-speed rotational atherectomy in 15 patients with infrapopliteal occlusive disease. They yielded a 94% technical success rate, but success was complicated by vessel rupture (5%), distal embolization (5%), and arterial spasm (5%).179 Although Excimer laser atherectomy reduces embolic events by evaporating the lesion, embolization still remains a problematic complication. Studies show that dis-tal embolic events occur in 3% to 4% of procedures and perfora-tion occurs in 2.2% to 4.3% of cases.170,171 Other complications associated with laser atherectomy therapy include acute


Surgery_Schwartz

Surgery_Schwartz. show that dis-tal embolic events occur in 3% to 4% of procedures and perfora-tion occurs in 2.2% to 4.3% of cases.170,171 Other complications associated with laser atherectomy therapy include acute throm-bosis, vasospasm, direct vessel injury, and dissection.170,171Surgical Treatment for Chronic Limb Ischemia due to Femoropopliteal DiseaseEndarterectomy. Endarterectomy has a limited, albeit impor-tant role in lower extremity occlusive disease. It is most fre-quently used when there is disease in the CFA or involving the PFA. In this procedure, the surgeon opens the diseased segment longitudinally and develops a cleavage plane within the media that is developed proximally and distally. This permits the inner layer containing the atheroma to be excised. Great care must be taken at the distal end of the endarterectomy to either ensure a smooth transition or tack down the distal endpoint to prevent the flow from elevating a potentially occlusive atheromatous flap. Currently, there is


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Surgery_Schwartz. end of the endarterectomy to either ensure a smooth transition or tack down the distal endpoint to prevent the flow from elevating a potentially occlusive atheromatous flap. Currently, there is essentially no role for long open endar-terectomy in the treatment of SFA stenoses or occlusions. The high incidence of restenosis is what limits utility of endarterec-tomy in this location. Short-segment stenoses are more appro-priately treated with balloon angioplasty. Endarterectomy using a catheter-based approach (e.g., Moll endarterectomy device) supplemented with stent grafting or stenting across the endpoint of the endarterectomy is currently being reevaluated; however, no long-term data are available.Bypass Grafting. Bypass grafting remains the primary inter-vention for lower extremity occlusive disease. The type of bypass and the type of conduit are important variables to con-sider. Patients with occlusive disease limited to the SFA, who have at least 4 cm (ideally 10 cm) of normal


Surgery_Schwartz

Surgery_Schwartz. disease. The type of bypass and the type of conduit are important variables to con-sider. Patients with occlusive disease limited to the SFA, who have at least 4 cm (ideally 10 cm) of normal popliteal artery reconstituted above the knee joint, and with at least one continu-ous vessel to the foot can be treated with an above-knee femo-ropopliteal bypass graft. Despite the fact that in this above-knee location, the differential patencies between prosthetic (PTFE) and vein graft are comparable, undoubtedly, it remains ideal to use a saphenous vein as the bypass conduit if possible. Saving the vein for future coronary artery bypass or distal leg bypass grafting has been shown to be a flawed argument. One must also consider that the consequences to the vascular outflow after a thrombosed prosthetic are worse than after a thrombosed vein graft.When the disease extends to involve the popliteal artery or the tibial vessels, the surgeon must select an appropriate out-flow vessel to perform a


Surgery_Schwartz

Surgery_Schwartz. are worse than after a thrombosed vein graft.When the disease extends to involve the popliteal artery or the tibial vessels, the surgeon must select an appropriate out-flow vessel to perform a bypass. Suitable outflow vessels are defined as uninterrupted flow channels beyond the anastomosis into the foot. Listed in order of descending preference, they are as follows: above-knee popliteal artery, below-knee popli-teal artery, posterior tibial artery, anterior tibial artery, and peroneal artery. In patients with diabetes, it is frequently the peroneal artery that is spared. Although it has no direct flow into the foot, collateralization to the posterior tibial and anterior tibial arteries makes it an appropriate outflow vessel. There is no objective evidence to preferentially select tibial over peroneal arteries if they are vessels of equal caliber and quality. The dor-salis pedis, which is the continuation of the anterior tibial in the foot, is frequently spared from atherosclerotic


Surgery_Schwartz

Surgery_Schwartz. over peroneal arteries if they are vessels of equal caliber and quality. The dor-salis pedis, which is the continuation of the anterior tibial in the foot, is frequently spared from atherosclerotic disease and can be used as a target for distal bypasses. Patency is affected by the length of the bypass (longer bypasses have reduced patency), quality of the recipient artery, extent of runoff to the foot, and quality of the conduit (saphenous vein/graft). Five-year assisted patency rate for infrapopliteal venous bypasses is 60%. Venous conduits have also been shown to be suitable for bypasses to plantar arteries. In this location, venous conduits have a 3-year limb salvage rate of 84% and a 3-year secondary patency rate of 74%.1 A meta-analysis suggests unsatisfactory results when PTFE-coated grafts are used to bypass to infrapopliteal arteries. In this location, prosthetic grafts have a 5-year primary patency rate of 30.5%.182 Additionally, due to distal embolization and compromise of


Surgery_Schwartz

Surgery_Schwartz. grafts are used to bypass to infrapopliteal arteries. In this location, prosthetic grafts have a 5-year primary patency rate of 30.5%.182 Additionally, due to distal embolization and compromise of outflow vessels, prosthetic graft occlusion may have more severe consequences than vein graft occlusion.Two techniques are used for distal bypass grafting: reversed saphenous vein grafting and in situ saphenous vein grafting. There is no difference in outcomes (patency or limb salvage) between these techniques. In the former, the vein is excised in its entirety from the leg using open or endoscopic vein harvest, reversed to render the valves nonfunctional, and tunneled from the CFA inflow to the distal target vessels. End-to-side anastomoses are then created.Several adjunctive techniques have been used to try to improve the patency of bypass grafts to tibial arteries. Cre-ation of an arteriovenous fistula at the distal anastomosis is one option, but it has not been shown to improve


Surgery_Schwartz

Surgery_Schwartz. have been used to try to improve the patency of bypass grafts to tibial arteries. Cre-ation of an arteriovenous fistula at the distal anastomosis is one option, but it has not been shown to improve patency.183 Another method involves creating varying configurations of vein cuffs or patches at the distal anastomosis in an attempt to streamline the flow and to reduce the likelihood of neointimal hyperplasia. Results with this approach are more promising, especially when done to improve patency of a below-the-knee prosthetic; how-ever, there are no definitive comparative trials that support the superiority of one configuration over another.Amputation. Primary amputation is defined as an amputation that is performed without a prior attempt at surgical or endovas-cular revascularization. It is rarely necessary in patients who, as a result of neglect, present with class III ALI. Primary ampu-tation may play a role in patients with critical limb ischemia who are deemed nonambulatory because


Surgery_Schwartz

Surgery_Schwartz. rarely necessary in patients who, as a result of neglect, present with class III ALI. Primary ampu-tation may play a role in patients with critical limb ischemia who are deemed nonambulatory because of knee contractures, debilitating strokes, or dementia.Complications of Surgical ReconstructionVein Graft Stenoses. Fifteen percent of vein grafts will develop intrinsic stenoses within the first 18 months follow-ing implantation. Consequently, patients with vein grafts were entered into duplex surveillance protocols (scans every 3 months) to detect elevated (>300 cm/s) or abnormally low (<45 cm/s) graft velocities early. Stenoses greater than 50%, especially if associated with changes in ABI, should be repaired to prevent graft thrombosis. Repair usually entails patch angio-plasty or short-segment venous interposition, but PTA/stenting Brunicardi_Ch23_p0897-p0980.indd 96627/02/19 4:15 PM 967ARTERIAL DISEASECHAPTER 23is an option for short, focal lesions. Grafts with stenoses that are


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Surgery_Schwartz. venous interposition, but PTA/stenting Brunicardi_Ch23_p0897-p0980.indd 96627/02/19 4:15 PM 967ARTERIAL DISEASECHAPTER 23is an option for short, focal lesions. Grafts with stenoses that are identified and repaired prior to thrombosis have assisted-primary patency identical to primary patency, whereas a throm-bosed autogenous bypass has limited longevity resulting from ischemic injury to the vein wall. Secondary patency is mark-edly inferior to primary assisted patency. The recommenda-tion for routine duplex ultrasound surveillance of autogenous infrainguinal bypasses was recently brought into question by a randomized controlled trial that demonstrated no cost benefit or quality-of-life improvement in patients with femoropopliteal venous bypasses after 18 months.184 Many surgeons continue with programs of vein graft surveillance, as has been suggested in older trials, awaiting further confirmation of the findings from the more recent study. When intervening in a failing


Surgery_Schwartz

Surgery_Schwartz. continue with programs of vein graft surveillance, as has been suggested in older trials, awaiting further confirmation of the findings from the more recent study. When intervening in a failing infraingui-nal bypass, the original indication for surgery is an important consideration. Limb salvage rates for occluded grafts are better if the indication for the original bypass was claudication rather than rest pain or tissue loss. An acutely occluded infrainguinal graft (≤30 postoperative days) has a 25% limb salvage rate.185Limb Swelling. Limb swelling is common following revascu-larization and usually returns to baseline within 2 to 3 months. The etiology is multifactorial with lymphatic interruption, inter-stitial edema, and disruption of venous drainage all contributing. Limb swelling tends to worsen with repeat revascularization (see Table 23-22).Wound Infection. Since the most common inflow vessel for distal bypass is the CFA, groin infection is common and occurs in 7% of cases.186


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Surgery_Schwartz. to worsen with repeat revascularization (see Table 23-22).Wound Infection. Since the most common inflow vessel for distal bypass is the CFA, groin infection is common and occurs in 7% of cases.186 When an autogenous conduit such as the saphenous vein is used, most infections can be managed with local wound care because the infection involves the subcutane-ous tissue or skin rather than infection of the actual vein. When a prosthetic graft has been used, management of graft infection is a major undertaking. Infection of a lower extremity prosthetic bypass graft is associated with a significant amputation rate because of the tendency for graft thrombosis and anastomotic disruption. Prosthetic graft infections cannot be eradicated with antibiotics and mandate graft excision and complex revascular-ization using a vein if available.Choice of Conduit for Infrainguinal Bypass GraftingAutogenous Vein. The autogenous vein is superior to pros-thetic conduits for all infrainguinal bypasses,


Surgery_Schwartz

Surgery_Schwartz. using a vein if available.Choice of Conduit for Infrainguinal Bypass GraftingAutogenous Vein. The autogenous vein is superior to pros-thetic conduits for all infrainguinal bypasses, even in the above-knee position. This preference is applicable not only for the initial bypass but also for reoperative cases. For long bypasses, the ipsilateral great saphenous vein, contralateral great saphe-nous vein, small saphenous vein, arm vein, and spliced vein are used in decreasing order of preference. If only a short segment of vein is missing, the SFA can be endarterectomized and the proximal anastomosis performed distally to decrease the length of the conduit and to avoid harvesting and splicing additional vein. When the great saphenous vein is not available and a rela-tively short bypass is necessary, the arm vein or small saphe-nous vein is effective. The small saphenous vein is of particular utility when a posterior approach is used. If a longer bypass with vein is necessary, the arm vein


Surgery_Schwartz

Surgery_Schwartz. the arm vein or small saphe-nous vein is effective. The small saphenous vein is of particular utility when a posterior approach is used. If a longer bypass with vein is necessary, the arm vein is preferable because it is less awkward to harvest. Another conduit alternative is to har-vest the upper arm basilic, median cubital, and cephalic veins in continuity, while incising valves in the basilic segment and using the cephalic segment in reversed configuration to provide a relatively long, unspliced autogenous conduit.187Cryopreserved Grafts. Cryopreserved grafts are usually cadaveric arteries or veins that have been subjected to rate-controlled freezing with dimethyl sulfoxide (DMSO) and other cryopreservants. Cryopreserved vein grafts are more expensive than prosthetic grafts and are more prone to failure. The endo-thelial lining is lost as part of the freezing process, making these grafts prone to early thrombosis. Cryopreserved grafts are also prone to aneurysmal degeneration.