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Surgery_Schwartz. period. Incisional hernias can present as asymptom-atic bulges or with severe discomfort. Multiple hernias can be present along the length of the incision. Elective surgery should be recommended in patients who are symptomatic. Small defects pose a higher risk of incarceration and should be repaired. To improve operative outcome, patient associated factors, including smoking and obesity, should be remedied prior to surgical repair.Surgical management of incisional hernias include either primary tissue or mesh repairs. Hernias can also be repaired via a laparoscopic or open approach. Simple suture repair is associ-ated with recurrence rates as high as 54%. A Cochrane review of several randomized controlled trials found that open mesh repair improved hernia recurrence rates when compared to simple closure (33% with simple repair vs. 16% with mesh repair). Mesh repairs are, however, associated with a higher rate of infections.To reduce tension at the suture line associated with pri-mary


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Surgery_Schwartz. simple closure (33% with simple repair vs. 16% with mesh repair). Mesh repairs are, however, associated with a higher rate of infections.To reduce tension at the suture line associated with pri-mary suture repair Ramirez described the components separa-tion technique in 1990. This procedure entails dividing portions of the bilateral external oblique aponeuroses forming musculo-fascial advancement flaps. The posterior rectus sheath can also be incised, allowing up to 10 cm of medial mobilization and ten-sionless approximation of the midline fascia. This technique can cause large skin flaps and initially had high rates of infection. Overtime, techniques have been developed to decrease flap for-mation and decreased rates of surgical site infection. Endoscopic component separation can also be used to mobilize flaps with minimal ischemia to overlying subcutaneous and skin tissue, theoretically decreasing infection rates. Mobilization of midline fascia is reduced with endoscopic methods.


Surgery_Schwartz

Surgery_Schwartz. be used to mobilize flaps with minimal ischemia to overlying subcutaneous and skin tissue, theoretically decreasing infection rates. Mobilization of midline fascia is reduced with endoscopic methods. Mesh can also be utilized to reinforce the repair. Overall, component separation without mesh compares to standard mesh repair with respect to hernia recurrence, but precludes the risk of mesh implantation. When mesh is added to component separation, recurrence rates may be as low as 4% to 10% depending on follow up period.Mesh repair has become the standard for elective manage-ment of most incisional hernias. Position of mesh placement is controversial. Mesh can be placed above the midline fascia (overlay), bridged across fascial defects (interlay), underneath fascia (sublay), or within the abdominal cavity (underlay). A systematic review found that sublay placement of mesh may reduce hernia recurrence and prevent wound related compli-cations. The sublay technique is performed by


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Surgery_Schwartz. the abdominal cavity (underlay). A systematic review found that sublay placement of mesh may reduce hernia recurrence and prevent wound related compli-cations. The sublay technique is performed by developing the plane between the rectus muscle and the posterior sheath, and affixing mesh in this space. The anterior sheath can be approxi-mated if there is no tension.Material used for mesh manufacturing can be classified into two classes: synthetic and biologic. Synthetic meshes can be either permanent or degradable, while all biologic meshes are degradable. Permanent mesh is currently made of either poly-propylene, polyethylene terephthalate polyester, or expanded polytetrafluoroethylene. Permanent mesh is durable and of rel-atively low cost. Degradable synthetic mesh, including Vicryl mesh, is eventually eliminated and loses structural support, but it does offer the advantage of lower mesh infection rates. Degrad-able mesh is associated with high recurrence rates, but it can be used


Surgery_Schwartz

Surgery_Schwartz. is eventually eliminated and loses structural support, but it does offer the advantage of lower mesh infection rates. Degrad-able mesh is associated with high recurrence rates, but it can be used for temporary abdominal wall closure in contaminated or infected fields. Newer synthetic biomaterial meshes, includ-ing Gore BioA or Phasix, degrade over a longer period of time and may reduce recurrence rates, but long-term effectiveness is unknown. Biologic meshes are decellularized, collagen-rich porcine, bovine, or human tissue. These meshes are designed to allow host cellular ingrowth, promoting incorporation and eventual replacement of the mesh with host tissue. Biologic meshes are a high cost alternative to synthetic degradable mesh and can be used in infected fields. However, their efficacy in preventing recurrence is unclear. Composite products contain two components and are used during intraperitoneal repair. One side of composite mesh, which is placed on the abdominal wall side of


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Surgery_Schwartz. in preventing recurrence is unclear. Composite products contain two components and are used during intraperitoneal repair. One side of composite mesh, which is placed on the abdominal wall side of implantation, is made of typical nondegradable synthetic material and promotes integration of host tissue. The other side is covered in a synthetic or biologic material, allowing contact with viscera and preventing adhesion formation. These materi-als include polyglactin, collagen, cellulose, titanium, omega-3, and hyaluronate. This allays concerns of direct mesh contact 3Figure 35-6. Computed tomography scan imaging of Spigelian hernia. Hernia contents traverse through the arcuate line but remain covered by the external oblique aponeurosis. (Reproduced with permission from Martin M, Paquette B, Badet N, et al: Spigelian hernia: CT findings and clinical relevance, Abdom Imaging. 2013 Apr;38(2):260-264.)Brunicardi_Ch35_p1549-p1566.indd 155512/02/19 9:58 AM 1556SPECIFIC


Surgery_Schwartz

Surgery_Schwartz. M, Paquette B, Badet N, et al: Spigelian hernia: CT findings and clinical relevance, Abdom Imaging. 2013 Apr;38(2):260-264.)Brunicardi_Ch35_p1549-p1566.indd 155512/02/19 9:58 AM 1556SPECIFIC CONSIDERATIONSPART IIwith viscera that may cause adhesions, erosion, and eventual fistula formation. Pore size and mesh weight are also important aspects of mesh design. Recently, large-pore, lightweight mesh has been developed. This was initially thought to delay incorpo-ration, but that has not been seen in practice. They do allow the theoretical advantage of increased incorporation of host tissue and potentially better elasticity and improved postoperative pain when compared to microporous heavier meshes. There is also initial data which suggests lower rates of mesh infection with the use of large pore mesh.Initially described by LeBlanc and Booth in 1993, laparo-scopic repair is now an accepted modality for treatment of inci-sional hernias. Several studies have found that laparoscopic


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Surgery_Schwartz. large pore mesh.Initially described by LeBlanc and Booth in 1993, laparo-scopic repair is now an accepted modality for treatment of inci-sional hernias. Several studies have found that laparoscopic repair has a lower incidence of surgical site and mesh infections compared to open repair. It also seems that lapa-roscopic repair allows faster recovery with less postoperative pain. A meta-analysis of 11 studies comparing laparoscopic and open ventral hernia repair found no difference in hernia recur-rence and lower rates of wound infection and wound drainage. There was however, a higher risk of bowel injury in the laparo-scopic group. Another meta-analysis of six randomized con-trolled trials had similar findings. Follow-up in these studies is relatively short, and more long-term data is needed at this time to compare these two modalities of repair.Laparoscopic hernia repair is performed by initially plac-ing lateral ports for midline defects and contralaterally placed ports for lateral


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Surgery_Schwartz. at this time to compare these two modalities of repair.Laparoscopic hernia repair is performed by initially plac-ing lateral ports for midline defects and contralaterally placed ports for lateral defects. Adhesions between the abdominal wall and intestine are carefully taken down, and the hernia contents are completely reduced. The sac is normally left in situ. Once the fascial defect is defined, a mesh is properly shaped and fash-ioned over the hernia. Transfascial sutures are placed circum-ferentially to position the mesh with sufficient overlap (4–5 cm) with healthy abdominal wall. Spiral tacks may be placed accord-ing to surgeon preference. Even more recently, robotic surgery has been established as another surgical modality in the treat-ment of ventral hernias. The theoretical advantage of improved visualization and articulating instruments may improve out-comes, but the cost-effectiveness of robotic repair is unclear. Overall, more studies are needed to evaluate the role of


Surgery_Schwartz

Surgery_Schwartz. of improved visualization and articulating instruments may improve out-comes, but the cost-effectiveness of robotic repair is unclear. Overall, more studies are needed to evaluate the role of robotics in ventral hernia surgery.Although still rare, given the increase in laparoscopic procedures, the incidence of laparoscopic port site hernias is becoming more common. Given the size of the hernias, there is a substantial risk of bowel strangulation and ischemia. These hernias commonly present as Richter’s hernia, or a hernia con-taining only a portion of bowel wall. A recent meta-analysis found that the incidence of port site hernia after laparoscopic procedure was less than 1%. Patients can present either early or several years after surgery. Risk factors are similar to other incisional hernias. The most common site of herniation is at an umbilical incision, but it may be found elsewhere. In adults, hernias usually occur in ports that are greater than 5 mm in size, but they can occur in


Surgery_Schwartz

Surgery_Schwartz. The most common site of herniation is at an umbilical incision, but it may be found elsewhere. In adults, hernias usually occur in ports that are greater than 5 mm in size, but they can occur in any size ports in children. Depending on the timing of presentation, these are usually repaired via an open approach by increasing the size of the skin incision, reducing the hernia, and approximating all layers of fascia.Rectus Abdominis Diastasis. Rectus abdominis diastasis (diastasis recti) is an anatomic term referring to an abnormal separation of rectus muscles and a laxity at the linea alba. Although there is controversy regarding normal separation dis-tances between rectus muscles, a distance of two centimeters is usually considered abnormal in the midline abdomen above the umbilicus. This can either be a congenital or acquired abnor-mality. This is not a true hernia as the midline fascia is intact, and as such incarceration and strangulation do not occur. Risk factors for acquired


Surgery_Schwartz

Surgery_Schwartz. can either be a congenital or acquired abnor-mality. This is not a true hernia as the midline fascia is intact, and as such incarceration and strangulation do not occur. Risk factors for acquired rectus abdominis diastasis include condi-tions that elevate intraabdominal pressure, including obesity and pregnancy, as well as conditions which weaken the abdominal wall, including connective tissue disorders or prior abdominal surgery. Risk factors of developing a diastasis recti after preg-nancy include older age at the time of pregnancy, multiple preg-nancies, and recurrent ceasarean sections. Postpartum exercise reduces the risk of developing diasthesis recti. Most patients with diastasis recti can be diagnosed based on physical exam where a fusiform bulge is usually apparent. This bulge worsens with contraction of the rectus muscles or Valsalva maneuver. If imaging is needed, ultrasonography can be used to confirm dia-thesis and rule out hernia. CT scan can also be used to confirm


Surgery_Schwartz

Surgery_Schwartz. worsens with contraction of the rectus muscles or Valsalva maneuver. If imaging is needed, ultrasonography can be used to confirm dia-thesis and rule out hernia. CT scan can also be used to confirm diagnosis and measure distance between muscle pillars. Rectus diastasis does not require surgical repair and may be improved via weight loss and exercise. Indications for repair include dis-ability of abdominal wall muscular function or cosmesis. Sur-gical repair includes both open and laparoscopic plication of the rectus sheath. Mesh can also be used to bridge the muscle; however, complication rates increase with mesh usage. These procedures do, unfortunately, have a high risk of recurrence long term and introduce a new risk of incisional hernia.Rectus Sheath Hematoma. Disruption of one of the branches of the inferior epigastric artery as well as an inability to tampon-ade the hemorrhage results in a rectus sheath hematoma. This occurs commonly around the arcuate line where the artery and


Surgery_Schwartz

Surgery_Schwartz. branches of the inferior epigastric artery as well as an inability to tampon-ade the hemorrhage results in a rectus sheath hematoma. This occurs commonly around the arcuate line where the artery and its branches are relatively fixed causing vulnerability to shearing forces. Several risk factors are associated with rectus hematoma formation via either proclivity to disruption of blood vessels or by inability to cease bleeding. Trauma to the abdominal wall, including iatrogenic trauma with laparoscopic trocar placement, can lead to disruption of blood vessels. Vigorous contraction of the rectus muscle, either with coughing, sneezing, or exercise, can also induce hemorrhage formation. Chronic pulmonary dis-ease can lead to hemorrhage because of coughing fits. Patients on anticoagulation also present with higher risk of hematoma formation. This condition presents with acute abdominal pain and a palpable abdominal wall mass. Rectus sheath hematoma may be mistaken with intraperitoneal


Surgery_Schwartz

Surgery_Schwartz. also present with higher risk of hematoma formation. This condition presents with acute abdominal pain and a palpable abdominal wall mass. Rectus sheath hematoma may be mistaken with intraperitoneal pathology, including appendicitis if on the right side. However, in patients with rec-tus sheath hematomas, pain usually increases with contraction of the rectus muscles as opposed to intraperitoneal conditions. In addition, palpation of a mass that does not change during contraction of the rectus muscle, known as Fothergill’s sign, is also associated with rectus sheath pathology. The diagnosis should be confirmed via ultrasound or CT scan with intravenous contrast. Obtaining a type and screen, hemoglobin/hematocrit, and coagulation factors are critical in the management of these patients.Treatment of patients with rectus sheath hematoma depends on the hemodynamic stability of the patient as well as the size of the hematoma. Hemodynamically stable patients with small hematomas, stable


Surgery_Schwartz

Surgery_Schwartz. of patients with rectus sheath hematoma depends on the hemodynamic stability of the patient as well as the size of the hematoma. Hemodynamically stable patients with small hematomas, stable serial hemoglobin/hematocrits, and normal coagulation factors may be observed without hospital-ization. Hemodynamically stable patients with larger or bilateral hematomas and decreases in hemoglobin should be monitored in the hospital setting, with serial hemoglobin levels, compres-sion of the hematoma, and bedrest. If anticoagulated, reversal is necessary and transfusions of packed red blood cells may 4Brunicardi_Ch35_p1549-p1566.indd 155612/02/19 9:58 AM 1557ABDOMINAL WALL, OMENTUM, MESENTERY, AND RETROPERITONEUMCHAPTER 35be required in some situations. Patients in hypovolemic shock should be aggressively resuscitated with the use of blood prod-ucts and treated via angiographic embolization. Angiographic intervention may also be required if the hematoma increases in size or if clinical


Surgery_Schwartz

Surgery_Schwartz. be aggressively resuscitated with the use of blood prod-ucts and treated via angiographic embolization. Angiographic intervention may also be required if the hematoma increases in size or if clinical deterioration occurs. Surgical therapy can be performed if angiographic intervention has failed. Surgical treatment includes operative evacuation of hematoma and liga-tion of bleeding vessels.Desmoid Tumors. Also known as aggressive fibromatosis, desmoid tumors are fibroblastic neoplasms with aggressive infiltrative behavior but no metastatic potential. These tumors can occur anywhere in the body but commonly occur in the abdomen or abdominal wall. Desmoid tumors are rare and usu-ally occur sporadically. They are, however, also associated with familial adenomatous polyposis (FAP), with an even greater risk in patients with Gardner’s syndrome. Of patients with FAP, 10% to 15% develop desmoid tumors. After prophylactic col-ectomy, desmoid tumors becomes the primary cause of death in


Surgery_Schwartz

Surgery_Schwartz. an even greater risk in patients with Gardner’s syndrome. Of patients with FAP, 10% to 15% develop desmoid tumors. After prophylactic col-ectomy, desmoid tumors becomes the primary cause of death in patients with FAP. Risk factors for sporadic development of desmoid tumors include previous surgical incision, pregnancy, hormonal exposure, and trauma. Females have a higher pre-dilection for formation of desmoid tumors. Diagnosis can be performed via core-needle or incisional biopsy. Larger tumor size, young patient age, and extra-abdominal tumor location all predict poor recurrence free survival.The gold standard of treatment of abdominal wall desmoid tumors, historically, is margin-negative resection with immedi-ate mesh reconstruction. However, more recently there has been controversy as to whether complete microscopic resection is necessary. It is now commonly agreed that while complete microscopic resection is ideal, with the emergence of adjuvant therapy a positive margin may not


Surgery_Schwartz

Surgery_Schwartz. to whether complete microscopic resection is necessary. It is now commonly agreed that while complete microscopic resection is ideal, with the emergence of adjuvant therapy a positive margin may not require additional surgery, especially if re-resection would cause high morbidity. There is also some evidence to suggest a period of close watchful wait-ing, as some tumors appear to remain stable or even regress over time. In one cohort of 106 abdominal wall desmoids managed initially without surgery, 16% of patients went on to require surgery in a follow-up period of three years. Interestingly, 29 patients had spontaneous regression of their tumors over that time. The National Comprehensive Cancer Network (NCCN) now suggests initial close observation for patients with asymptomatic, non–life-threatening tumors. Surgery is indicated in patients with symptomatic disease, risk of invasion of surrounding structures, or enlarging tumors. There may be a role for adjuvant or neoadjuvant


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Surgery_Schwartz. tumors. Surgery is indicated in patients with symptomatic disease, risk of invasion of surrounding structures, or enlarging tumors. There may be a role for adjuvant or neoadjuvant radiation therapy, although the data are unclear at this time. Primary radiation therapy may be an option for patients who are not surgical candidates. There may also be a role for systemic therapy, especially if tumors are unre-sectable. Options include hormonal therapy, nonsteroidal anti-inflammatory agents, cytotoxic chemotherapies (doxorubicin or carboplatin), or imatinib.Other Abdominal Wall Tumors. Various tumors may also be found within the abdominal wall including lipomas and neu-rofibromas (Fig. 35-7). Surgical resection is recommended for symptomatic or enlarging lesions. Abdominal wall malignancies are exceedingly rare and include several histologic subtypes of sarcomas, dermatofibrosarcoma protuberans, schwannomas, and melanomas. Workup of abdominal wall tumors should include core needle biopsy


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Surgery_Schwartz. exceedingly rare and include several histologic subtypes of sarcomas, dermatofibrosarcoma protuberans, schwannomas, and melanomas. Workup of abdominal wall tumors should include core needle biopsy or excisional biopsy if the tumor is small enough. Magnetic resonance imaging (MRI) or CT scan with IV contrast should be utilized to define local extent of disease. MRI is preferred as this modality provides more detail on extent of disease. Chest CT should also be obtained to rule out pulmo-nary metastasis in high-grade tumors. Chest X-ray may be suf-ficient to stage tumors that are low grade, given the lower risk of distant disease. Surgical resection is the mainstay of treatment for nonmetastatic disease. For most soft tissue sarcomas, 1 cm margins are usually sufficient, but 2 cm margins may be needed for dermatofibrosarcoma protuberans. Tumors of the superficial abdominal wall should be resected with the underlying fascia, which may require use of mesh to prevent abdominal wall laxity


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Surgery_Schwartz. be needed for dermatofibrosarcoma protuberans. Tumors of the superficial abdominal wall should be resected with the underlying fascia, which may require use of mesh to prevent abdominal wall laxity or hernia.Given the rarity of these tumors, the efficacy of adjuvant or neoadjuvant chemoradiation is unclear. Adjuvant or neo-adjuvant therapy may be recommended in patients with large (>5 cm) or high-grade tumors. Some centers administer neoad-juvant radiation therapy to patients with high-risk tumors to monitor response. Chemotherapy may also be used in certain situations. If tumors involve underlying viscera, en bloc resec-tion may be required. Primary closure may be feasible, but pros-thetic mesh use (even in the setting of bowel resection) may be required. Options for abdominal wall closure after resection include absorbable or biologic mesh reinforcement, and myocu-taneous flap reconstruction.OMENTUMSurgical AnatomyThe omentum is a fibrous adipose apron providing support and


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Surgery_Schwartz. closure after resection include absorbable or biologic mesh reinforcement, and myocu-taneous flap reconstruction.OMENTUMSurgical AnatomyThe omentum is a fibrous adipose apron providing support and protection of the intraabdominal viscera. Embryologically, the omentum originated from the dorsal mesogastrium. Anatomi-cally, the omentum is divided into the greater and lesser omen-tums. The greater omentum begins to form during the fourth week of gestation. Initially, the omentum forms as a double-layered structure, with the spleen developing between the two layers. As development proceeds, the layers of mesentery fuse, the spleen assumes its position in the peritoneum, and the gas-trosplenic ligament forms. The greater omentum, therefore, is a double-layered sheet of visceral fibroadipose tissue descending from the greater curvature of the stomach, covering the small intestines. The omentum folds back on itself and attaches onto the anterior peritoneum of the transverse colon (Fig.


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Surgery_Schwartz. tissue descending from the greater curvature of the stomach, covering the small intestines. The omentum folds back on itself and attaches onto the anterior peritoneum of the transverse colon (Fig. 35-8). 5Figure 35-7. Abdominal wall lipoma.Brunicardi_Ch35_p1549-p1566.indd 155712/02/19 9:59 AM 1558SPECIFIC CONSIDERATIONSPART IIIn an adult, the greater omentum lies between the abdominal wall and the hollow viscera, usually extending into the pelvis. The greater omental tissue connecting the stomach to transverse colon, as well as the stomach to the spleen, are known as the gastrocolic and gastrosplenic ligaments, respectively. The blood supply to the greater omentum is derived from the right and left gastroepiploic arteries. The venous system parallels the arterial supply and ultimately drains into the portal system. Lymphatic drainage of the greater omentum occurs via the subpyloric or splenic nodes depending on laterality ultimately culminating in the celiac nodes and subsequently


Surgery_Schwartz

Surgery_Schwartz. drains into the portal system. Lymphatic drainage of the greater omentum occurs via the subpyloric or splenic nodes depending on laterality ultimately culminating in the celiac nodes and subsequently the thoracic duct.Forming the anterior boundary of the lesser sac, the lesser omentum extends between the liver and lesser curvature of the stomach. Also known as the hepatoduodenal and hepatogastric ligaments, the portal triad (including the common bile duct, por-tal vein, and hepatic artery) is located within the inferolateral margin of the lesser omentum. This free edge of lesser omentum forms the foramen of Winslow, which is used to encircle the portal triad during a pringle maneuver (see Fig. 35-8).PhysiologyInitially described by the British surgeon Rutherford Morison as the “policeman of the abdomen,” the greater omentum is under-stood as a peritoneal defense organ. The omentum forms fibrin adhesions at sites of inflammation, effectively attempting to wall off peritoneal


Surgery_Schwartz

Surgery_Schwartz. of the abdomen,” the greater omentum is under-stood as a peritoneal defense organ. The omentum forms fibrin adhesions at sites of inflammation, effectively attempting to wall off peritoneal infections. The greater omentum is known to respond to a foreign stimulus by expanding stro-mal tissue that expresses chemotactic, inflammatory, and hemo-static factors, which promote tissue inflammation and subsequent repair. Forming a fibrin bridge between omental tis-sue and the injured site allows passage of inflammatory factors and immune cells. The Graham Patch repair of a perforated ulcer utilizes the complex inflammatory interactions of the omentum to improve leak rates after repair.The visceral fat of the greater omentum is also involved in metabolic functions of the body. Increased visceral fat, including the greater omentum, is an independent risk factor for insulin resistance and high triglyceride levels. This may be, in part, mediated by the increase in visceral inflammation seen in


Surgery_Schwartz

Surgery_Schwartz. fat, including the greater omentum, is an independent risk factor for insulin resistance and high triglyceride levels. This may be, in part, mediated by the increase in visceral inflammation seen in intra-abdominal obesity. Several adipokines, or cell-signaling molecules secreted by adipose tissue, are secreted by the greater omentum and act on peripheral tissues, affecting metabolic health throughout the body.Acquired DisordersOmental Infarction. Omental infarction is a rare cause of acute abdominal pain. Omental infarction may be primary or 6DiaphragmGastrohepaticligamentRight colic (hepatic)flexureAscending colonGreater omentum(gastrocolic ligament)Falciform ligamentRound ligamentof liverHepatoduodenalligament (containingportal triad)Arrow passingthrough omentalforamen intoomental bursaGastrophrenicligamentCoronaryligament (cut)StomachSpleenDescending colonPhrenicocolicligamentInferior recess ofomental bursa(between layers ofgreater omentum)GastrocolicligamentTransverse


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Surgery_Schwartz. bursaGastrophrenicligamentCoronaryligament (cut)StomachSpleenDescending colonPhrenicocolicligamentInferior recess ofomental bursa(between layers ofgreater omentum)GastrocolicligamentTransverse colon(sectioned)GastrosplenicligamentLeft colic (splenic)flexureTransversemesocolonLiver: Diaphragmatic surface Visceral surfaceAnterior view** Parts of greater omentum* Parts of lesser omentum********Figure 35-8. Greater and lesser omentum. The greater omentum begins along the greater curvature of the stomach, drapes over the transverse colon into the pelvis, and folds back on itself inserting along the posterior wall of the transverse colon. The greater omentum includes the gastrophrenic and gastro splenic ligament. The lesser omentum includes the gastrohepatic and hepatoduodenal ligaments, covering the lesser sac of the abdomen. The free lateral edge of the lesser omentum includes the portal triad, forming the foramen of Winslow below. (Reproduced with permission from Moore KL, Agur AM:


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Surgery_Schwartz. the lesser sac of the abdomen. The free lateral edge of the lesser omentum includes the portal triad, forming the foramen of Winslow below. (Reproduced with permission from Moore KL, Agur AM: Essential Clinical Anatomy, 5th edition. Philadelphia, PA: Lippincott Williams & Wilkins; 2014.)Brunicardi_Ch35_p1549-p1566.indd 155812/02/19 9:59 AM 1559ABDOMINAL WALL, OMENTUM, MESENTERY, AND RETROPERITONEUMCHAPTER 35secondary depending on the etiology. Primary infarction may be caused by torsion of the omentum from sudden or force-ful movements, thrombosis or vasculitis of omental vessels, or omental venous outflow obstruction. Secondary causes of torsion are most often due to hernias, tumors, or adhesions. Only about 250 cases of primary omental infarction have been reported in the literature. This occurs most often in male and obese patients. Omental infarction may mimic other intra-abdominal pathologies such as appendicitis, cholecystitis, or diverticulitis. Abdominal exam usually


Surgery_Schwartz

Surgery_Schwartz. This occurs most often in male and obese patients. Omental infarction may mimic other intra-abdominal pathologies such as appendicitis, cholecystitis, or diverticulitis. Abdominal exam usually demonstrates perito-neal tenderness, with a possible palpable mass. Ultrasonogra-phy (US) and abdominal CT scan are used to assist diagnosis. US may demonstrate a hyperechoic, noncompressible intra-abdominal mass attached to the abdominal wall. CT scan demonstrates a streaking whirling pattern of fatty tissue in the anterior abdomen (Fig. 35-9). Regardless, only a small percent-age of patients are preoperatively diagnosed. Omental infarction can be treated conservatively, but this leads to several possible complications, including abscess or adhesion formation. Lapa-roscopic exploration and resection of infarcted tissue is the usual treatment of choice and leads to rapid resolution of symptoms.Omental Cysts. Cystic lesions of the omentum are rare dis-orders, related in pathogenesis to mesenteric


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Surgery_Schwartz. of infarcted tissue is the usual treatment of choice and leads to rapid resolution of symptoms.Omental Cysts. Cystic lesions of the omentum are rare dis-orders, related in pathogenesis to mesenteric cysts. Most are thought to form through degeneration or inclusion of lymphatic structures. Case reports described these lesions presenting as vague abdominal pain or nausea or vomiting. Cysts may also present as a lead point for omental torsion and infarction. Physi-cal exam may or may not reveal evidence of an intra-abdominal mass. Cysts may also be diagnosed incidentally on imaging exams performed for other reasons. CT scan and US are largely diagnostic and reveal a well-circumscribed cystic appearing lesion arising from the greater omentum. A very small percent-age may transform to malignancy. Most are resected, especially if symptomatic, via open or laparoscopic approaches. Cysts may relapse if treated conservatively via laparoscopic unroofing or percutaneous drainage.Omental


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Surgery_Schwartz. malignancy. Most are resected, especially if symptomatic, via open or laparoscopic approaches. Cysts may relapse if treated conservatively via laparoscopic unroofing or percutaneous drainage.Omental Neoplasms. Most omental neoplasms are meta-static disease. Ovarian cancer is the most common cancer to have omental involvement. Other metastatic cancers include gastrointestinal tract tumors, melanoma, endometrial cancer, and kidney cancer.Primary tumors of the omentum are exceedingly rare. Benign masses may include lipomas, myxomas, and desmoid tumors. Extra gastrointestinal stromal tumors are a rare malig-nant tumor of the omentum that have been described in several case series. These tumors share many genetic and immuno-phenotypic similarities to classical GISTS, including c-kit and PDGFRA mutations. In one review of case reports, the median age of diagnosis was noted to be 65 years and had equal predi-lection for male and female patients.MESENTERYSurgical AnatomyThe mesentery is a


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Surgery_Schwartz. mutations. In one review of case reports, the median age of diagnosis was noted to be 65 years and had equal predi-lection for male and female patients.MESENTERYSurgical AnatomyThe mesentery is a contiguous structure suspending and fix-ing bowel to the abdominal wall providing housing for arterial, venous, nervous, and lymphatic structures connecting hollow viscera with the body. The mesentery is derived from the meso-dermal germ layer becoming the dorsal mesentery. Previous theories of development included sliding and regression models of mesenteric development. However, with a new contiguous model of development of the mesentery, several key simple steps are proposed to take place. Initially, the mesentery provides a point of suspension from vascular connections. As the intestine and mesentery elongate, they undergo a 270° counterclockwise rotation leaving the primordial abdominal cavity. Eventually, the duodenum and ascending/descending colon flatten against the posterior abdominal


Surgery_Schwartz

Surgery_Schwartz. elongate, they undergo a 270° counterclockwise rotation leaving the primordial abdominal cavity. Eventually, the duodenum and ascending/descending colon flatten against the posterior abdominal wall returning the bowel back into the abdomen and taking its normal shape. The resultant develop-ment of the white line of Toldt along the lateral border of the ascending and descending large bowel provides an avascular fascial plan between the colon, its mesentery, and the underlying retroperitoneal space. The small intestine mesentery, transverse colon mesentery, and sigmoid colon mesentery remain mobile.Defects in the proper rotation and fixation of the bowel results in the spectrum of congenital disorders known as intesti-nal malrotation. In this scenario, the intestine and mesentery are simply suspended from vascular connection, making intestinal volvulus common. Defects that form in anatomical positions may act as routes for intestinal herniation. Common sites of her-niation include the


Surgery_Schwartz

Surgery_Schwartz. suspended from vascular connection, making intestinal volvulus common. Defects that form in anatomical positions may act as routes for intestinal herniation. Common sites of her-niation include the paraduodenal or mesocolic areas, leading to either acute or chronic intestinal obstruction in pediatric or adult populations. Areas where mesenteric attachment is incomplete may predispose patients to volvulus. Attachments of the cecum may degrade overtime leading to an area of laxity and possible twisting. The sigmoid mesentery can also increase in size over time also leading to possible sigmoid volvulus. Rarely, other areas of the colon can develop volvulus if differential mesen-teric lengths form.Sclerosing MesenteritisSclerosing mesenteritis is a rare disorder characterized by idio-pathic fibrosis of the mesentery, affecting hollow viscera as well as mesenteric vessels. The disease is part of a spectrum of inflammation and fibrosis, which when localized is known as mesenteric


Surgery_Schwartz

Surgery_Schwartz. fibrosis of the mesentery, affecting hollow viscera as well as mesenteric vessels. The disease is part of a spectrum of inflammation and fibrosis, which when localized is known as mesenteric lipodystrophy and when diffuse is known as mes-enteric panniculitis. The cause of this disease is unknown, but it may be instigated by antecedent abdominal surgery, an auto-immune disease, a paraneoplastic syndrome, a previous infec-tion (including typhoid, tuberculosis, influenza, and rheumatic fever), or vascular insult. This disease most commonly effects Figure 35-9. Computed tomography scan findings indicative of omental infarction. The area demonstrated by the bold arrow appears congested with a streaking whirling pattern of fatty tissue in the anterior abdomen. (Reproduced with permission from Barai KP, Knight BC: Diagnosis and management of idiopathic omental infarc-tion: A case report, Int J Surg Case Rep. 2011;2(6):138-140.)Brunicardi_Ch35_p1549-p1566.indd 155912/02/19 9:59 AM


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Surgery_Schwartz. from Barai KP, Knight BC: Diagnosis and management of idiopathic omental infarc-tion: A case report, Int J Surg Case Rep. 2011;2(6):138-140.)Brunicardi_Ch35_p1549-p1566.indd 155912/02/19 9:59 AM 1560SPECIFIC CONSIDERATIONSPART IIwhite patients between 50 and 70 years of age, although it has been rarely described in children. Most studies report a predi-lection for male patients. Most patients with this disease pres-ent with abdominal pain. Other symptoms include nausea and vomiting, weight loss, anorexia, and altered bowel habits. This may appear as a chronic or acute disorder. On physical exam, patients may be found to have tenderness and distension. Up to 50% of patients are found to have an abdominal mass that often transmits aortic pulsations.Abdominal CT with IV contrast is used to assist in diag-nosis (Fig. 35-10). The most common finding is that of a soft tissue mass with a higher density than normal mesenteric tis-sue. Although it is sometimes difficult to distinguish


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Surgery_Schwartz. to assist in diag-nosis (Fig. 35-10). The most common finding is that of a soft tissue mass with a higher density than normal mesenteric tis-sue. Although it is sometimes difficult to distinguish mesen-teric fibrosis from a mesenteric tumor, two CT findings may add specificity. The “tumor pseudocapsule” refers to a hypodense zone around the associated fibrotic mass, and the “fat ring sign” refers to an area of preserved fat near mesenteric vessels cours-ing through areas of fibrosis. These lesions may also be calcified on CT scan.Pathologic confirmation is required to confirm the diagno-sis. This usually requires laparoscopic or open biopsy to provide adequate tissue for confirmation. Treatment of sclerosing mesenteritis is complex, with surgery having a mini-mal role. Patients who present with bowel ischemia may require bowel and mesenteric resection; however, the extent and loca-tion of mesenteric involvement may preclude complete resec-tion. If obstructive symptoms are dominant,


Surgery_Schwartz

Surgery_Schwartz. with bowel ischemia may require bowel and mesenteric resection; however, the extent and loca-tion of mesenteric involvement may preclude complete resec-tion. If obstructive symptoms are dominant, intestinal bypass may be indicated. Aggressive surgical treatment is not indicated because in many cases symptoms may improve with medical treatment or even without intervention. Steroids, hormonal ther-apy, colchicine, thalidomide, and cyclophosphamide have all been reported to be beneficial.Mesenteric CystsMesenteric cysts are a rare benign disorder with an incidence ranging from 1 in 27,000 to 1 in 250,000 admissions. Cysts are thought to be caused by disruption of the lymphatics in the mes-entery either by traumatic disruption, mechanical obstruction, or congenital lymphatic malformations. Most cysts are unilocular, but they also may have multiple loculations. They are usually lined with a single layer of columnar epithelial cells. Presenta-tion of mesenteric cyst is varied, with some


Surgery_Schwartz

Surgery_Schwartz. Most cysts are unilocular, but they also may have multiple loculations. They are usually lined with a single layer of columnar epithelial cells. Presenta-tion of mesenteric cyst is varied, with some being found inciden-tally on imaging exams and others causing acute abdominal pain because of cyst rupture or bowel torsion. Chronic symptoms are usually nonspecific, including abdominal pain or discomfort, anorexia, distension, nausea, vomiting, or changes in bowel habits. Symptoms are due to local compression of abdominal structures. Up to 45% of cysts are found incidentally.Physical exam revels an abdominal mass in up to 60% of patients. The classic Tillaux’s sign is an abdominal mass lesion that is only mobile laterally, contrasting omental cysts which are usually freely mobile in all directions. CT scan and ultra-sound can be used to make an accurate diagnosis. Cystic lesions usually appear as a fluid filled mass without solid components (Fig. 35-11). It can sometimes be difficult to


Surgery_Schwartz

Surgery_Schwartz. CT scan and ultra-sound can be used to make an accurate diagnosis. Cystic lesions usually appear as a fluid filled mass without solid components (Fig. 35-11). It can sometimes be difficult to differentiate cystic masses from solid tumors based on imaging. Mesenteric cys-tic lymphangioma may present as numerous cysts on imaging. Up to 3% of mesenteric cysts contain malignancy, mostly as a sarcomatous lesion. In one recently published series, 19% of patients harbored malignancy. Solid components within the cystic structure are associated with higher rates of malignancy.Most mesenteric cysts are treated surgically. Marsupial-ization and simple aspiration have high rates of recurrence and 7Figure 35-11. Computed tomography scan demonstrating a mes-enteric cyst. White arrow points to a homogenous cystic structure located in the mesentery of the small bowel. (Reproduced with per-mission from Jain V, DeMuro JP, Geller M, et al. A case of laparo-scopic mesenteric cyst excision. Case Rep Surg.


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Surgery_Schwartz. cystic structure located in the mesentery of the small bowel. (Reproduced with per-mission from Jain V, DeMuro JP, Geller M, et al. A case of laparo-scopic mesenteric cyst excision. Case Rep Surg. 2012;2012:594095.)ABFigure 35-10. Computed tomography scan findings of sclerosing mesenteritis in (A) coronal view and (B) cross-sectional view. The area demonstrated with arrows depicts an area of higher density and edema representing inflamed mesentery. (Reproduced with per-mission from Daumas A, Agostini S, Villeret J, et al. Spontaneous resolution of severe, symptomatic mesocolic panniculitis: a case report, BMC Gastroenterol. 2012 Jun 6;12:59.)Brunicardi_Ch35_p1549-p1566.indd 156012/02/19 9:59 AM 1561ABDOMINAL WALL, OMENTUM, MESENTERY, AND RETROPERITONEUMCHAPTER 35are generally discouraged. Benign lesions should be enuclu-ated, and malignant cysts should be resected with clear margins. Intestines or surrounding viscera may require resection if the associated vasculature is excised.


Surgery_Schwartz

Surgery_Schwartz. Benign lesions should be enuclu-ated, and malignant cysts should be resected with clear margins. Intestines or surrounding viscera may require resection if the associated vasculature is excised. Resection can be performed either via a laparoscopic or open procedure.Mesenteric TumorsPrimary mesenteric tumors are rare but represent several histo-logic patterns. Benign tumors include desmoid tumors, lipomas, and cystic lymphangiomas. The most common malignant neo-plasm of the mesentery is lymphoma. On imaging, lymphoma may appear as bulky adenopathy, usually surrounding and not obstructing nearby structures. Lymphomas should not be resected, but they may require operative biopsy for diagnosis. Other malignant tumors of the mesentery include gastrointesti-nal stromal tumors, carcinoids, liposarcoma, leiomyosarcoma, malignant fibrous histiocytomoas, lipoblastomas, or lymphan-giosarcoma. Treatment of malignant mesenteric masses usually involves wide resection; however, given the proximity


Surgery_Schwartz

Surgery_Schwartz. leiomyosarcoma, malignant fibrous histiocytomoas, lipoblastomas, or lymphan-giosarcoma. Treatment of malignant mesenteric masses usually involves wide resection; however, given the proximity to mes-enteric vessels, resection may not be feasible or require removal of large portions of bowel.RETROPERITONEUMSurgical AnatomyThe retroperitoneum is bound by the peritoneum anteriorly, the iliopsoas and lumbar muscles posteriorly, the diaphragm superiorly, and the levator ani muscles inferiorly. It is divided into the three spaces: the anterior pararenal space, the perirenal space, and the posterior pararenal space (Fig. 35-12). The ante-rior pararenal space refers to the area anterior to the renal fascia but posterior to the peritoneum. This area contains the ascend-ing and descending colon, the duodenum, and the pancreas. Posterior to this space is the perirenal space, which houses the inferior vena cava, the aorta, kidneys, and adrenal glands. The posterior pararenal space is in continuity


Surgery_Schwartz

Surgery_Schwartz. duodenum, and the pancreas. Posterior to this space is the perirenal space, which houses the inferior vena cava, the aorta, kidneys, and adrenal glands. The posterior pararenal space is in continuity with preperitoneal fat of the anterior abdomen. Given the compliance of the anterior boundary of the retroperitoneum and the rigidity of other mar-gins, tumors, hematomas, and abscesses tend to expand anteri-orly toward the peritoneal cavity.With the expansion of minimally invasive techniques in surgery, the retroperitoneoscopic approach has emerged as a potential modality for access to retroperitoneal organs. Patients are positioned in the prone or lateral decubitus positions. The retroperitoneoscopic approach allows access to the kidneys, adrenal glands, and retroperitoneal lymph nodes. One system-atic review found no difference when comparing laparoscopic to retroperitoneoscopic adrenalectomy in terms of operative outcomes, complications, or postoperative recovery.


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Surgery_Schwartz. lymph nodes. One system-atic review found no difference when comparing laparoscopic to retroperitoneoscopic adrenalectomy in terms of operative outcomes, complications, or postoperative recovery. Retroperi-toneoscopic approach did, however, lead to shorter hospital stay likely because of reduced postoperative pain. The majority of the studies evaluating the retroperitoneoscopic approach are retrospective, and more randomized trials are needed to provide further guidance.Retroperitoneal InfectionsInfections of the retroperitoneum can be due to primary hema-togenous spread of microbes or due to secondary infection from retroperitoneal or nearby organs. Examples include abscesses due to a perforated retrocecal appendix, diverticulitis, a con-tained perforated duodenal ulcer, iatrogenic perforation of the gastrointestinal tract, or pancreatitis. Patients may develop back, Inferiorvena cavaDiaphragmEsophagusAbdominal aortaSplenorenal ligamentPancreasRoot of


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Surgery_Schwartz. duodenal ulcer, iatrogenic perforation of the gastrointestinal tract, or pancreatitis. Patients may develop back, Inferiorvena cavaDiaphragmEsophagusAbdominal aortaSplenorenal ligamentPancreasRoot of transversemesocolonDuodenojejunaljunctionLeft kidneyPsoas majorInferior mesenteric arterySite of descending mesocolonRoot of sigmoidmesocolonRectumSite of barearea of liverHepatic portalveinDuodenumSuperiormesenteric vein and arterySite of ascending colonRoot of mesenteryTesticular (or ovarian) vesselsUreterAnterior viewRight kidneyRightparacolic gutterFigure 35-12. Anatomy of the retroperitoneum. (Reproduced with permission from Moore KL, Agur AM: Essential Clinical Anatomy, 5th edition. Philadelphia, PA: Lippincott Williams & Wilkins; 2014.)Brunicardi_Ch35_p1549-p1566.indd 156112/02/19 9:59 AM 1562SPECIFIC CONSIDERATIONSPART IIflank, or groin pain and suffer from fevers or chills. Depend-ing on severity, patients may present with fulminant sepsis. Abscesses may become quite large


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Surgery_Schwartz. 9:59 AM 1562SPECIFIC CONSIDERATIONSPART IIflank, or groin pain and suffer from fevers or chills. Depend-ing on severity, patients may present with fulminant sepsis. Abscesses may become quite large given the substantial retro-peritoneal space. On physical exam, patients may present with erythema of the umbilicus or flank. Abscesses are usually found easily on CT scan of the abdomen with IV contrast, which can also show if the collection is loculated. Treatment of retroperi-toneal abscesses includes source control via treatment of the underlying condition, drainage of well-defined collections, and IV antibiotics. Image guided drainage is preferred, but it may be unsuccessful if the abscess is multiloculated or in an inacces-sible area. For these cases, operative drainage may be required. Given the insidious nature of this disease and a lack of abdomi-nal findings on physical exam, recognition of a retroperitoneal abscess may be delayed. Delays in diagnosis and insufficient drainage


Surgery_Schwartz

Surgery_Schwartz. Given the insidious nature of this disease and a lack of abdomi-nal findings on physical exam, recognition of a retroperitoneal abscess may be delayed. Delays in diagnosis and insufficient drainage may lead to high morbidity and mortality. Depending on severity, mortality of retroperitoneal abscess can be as high as 25%. Rarely, patients may develop necrotizing fasciitis of the retroperitoneum, a condition with high mortality.Retroperitoneal FibrosisRetroperitoneal fibrosis is a rare disease characterized by inflammation and fibrosis of the tissue of the retroperitoneum. It exists as a spectrum of disease with chronic periaortitis, which affects the retroperitoneal tissue near large arteries of the retro-peritoneum. Fibrosis gradually expands, encasing the ureters, inferior vena cava, aorta, mesenteric vessels, or sympathetic nerves. Bilateral involvement is noted in up to 70% of cases. The condition may either be idiopathic or due to a secondary cause, including aortic aneurysms,


Surgery_Schwartz

Surgery_Schwartz. aorta, mesenteric vessels, or sympathetic nerves. Bilateral involvement is noted in up to 70% of cases. The condition may either be idiopathic or due to a secondary cause, including aortic aneurysms, pancreatitis, certain drugs (Ergot-derivatives, β-blockers, hydralazine, methyldopa, among others), malignancies (including lymphoma, carcinoids, sarco-mas, colorectal, breast, and others), infections such as tuber-culosis, radiation, retroperitoneal hematoma, surgery, asbestos, or tobacco use. Retroperitoneal fibrosis has been described in association with several autoimmune disorders including anky-losing spondylitis, systemic lupus erythematosus, Wegener’s granulomatosis, and polyarteritis nodosa.Idiopathic retroperitoneal fibrosis accounts for 70% of cases and is thought to be an immune-mediated disorder. Theo-ries regarding the pathogenesis of idiopathic fibrosis of the retro-peritoneum include exaggerated local reactions to aortic or iliac atherosclerosis or autoimmune deposition of


Surgery_Schwartz

Surgery_Schwartz. disorder. Theo-ries regarding the pathogenesis of idiopathic fibrosis of the retro-peritoneum include exaggerated local reactions to aortic or iliac atherosclerosis or autoimmune deposition of fibroinflammatory cytokines. Retroperitoneal fibrosis is also a manifestation of IgG4-related disease, a multisystem disease characterized by lymphocytic infiltrate and variable degrees of fibrosis of sev-eral affected organs. One study has associated retroperitoneal fibrosis with the HLA-DRB1*03 allelle, which has been linked to autoimmune diseases such as systemic lupus erythematosus, type 1 diabetes mellitus, and myasthenia gravis.Idiopathic retroperitoneal fibrosis is rare, with an incidence of 1.3 per 100,000 people per year. It most commonly affects individuals in the fourth to sixth decades of life. Some studies suggest a 2:1 male-to-female predominance, but others have not found a gender predilection. Patients with this condition present with nonspecific findings. Most patients are


Surgery_Schwartz

Surgery_Schwartz. of life. Some studies suggest a 2:1 male-to-female predominance, but others have not found a gender predilection. Patients with this condition present with nonspecific findings. Most patients are diagnosed after ure-teral obstruction. Patients may complain of dull or acute back or flank pain. Systemic complaints include anorexia, weight loss, nausea, vomiting, fever, and malaise. Decreased urinary out-put may ensue if the ureters become fibrotic. Because of renal artery impingement, patients are commonly hypertensive on exam. Other physical exam findings include lower extremity edema and diminished lower extremity pulses if the vessels of the lower extremities are compressed. New hydrocele or varico-cele can also be associated with fibrosis of the retroperitoneum. Laboratory analysis is also nonspecific. If there is renal obstruc-tion, patients may have elevated serum blood urea nitrogen and creatinine. Erythrocyte sedimentation rate and C-reactive pro-tein is elevated in most


Surgery_Schwartz

Surgery_Schwartz. is also nonspecific. If there is renal obstruc-tion, patients may have elevated serum blood urea nitrogen and creatinine. Erythrocyte sedimentation rate and C-reactive pro-tein is elevated in most patients with retroperitoneal fibrosis. Antinuclear antibodies may also be elevated, highlighting the autoimmune nature of this disease.Contrast-enhanced CT scan is the modality of choice to visualize the extent of disease. On CT scan, fibrotic ret-roperitoneum appears to have similar attenuation to muscle tissue (Fig. 35-13). The fibrotic mass can appear to encase the aorta and often compresses the inferior vena cava. If renal insufficiency precludes the use of IV contrast, MRI can be used to clarify the extent of fibrosis. Renal US can also be used to document ureteral compression and hydronephrosis. In some cases, a compressing mass lesion can also be found on abdominal US. Lower-extremity US may show deep venous thrombosis.Pathologic examination of tissue is necessary to confirm the


Surgery_Schwartz

Surgery_Schwartz. In some cases, a compressing mass lesion can also be found on abdominal US. Lower-extremity US may show deep venous thrombosis.Pathologic examination of tissue is necessary to confirm the diagnosis and to rule out malignancy. Differential of ret-roperitoneal masses include lymphomas or sarcomas, desmoid Figure 35-13. Computed tomography findings of retroperitoneal fibrosis. Arrows point to a soft tissue mass surrounding the aorta and common iliac arteries. Also present is hydronephrosis of the right kidney because of ureteral compression. (Reproduced with permission from Vagilo A. Salvarani C, Buzio C. Retroperitoneal Fibrosis, Lancet. 2006 Jan 21;367(9506):241-251.)Brunicardi_Ch35_p1549-p1566.indd 156212/02/19 9:59 AM 1563ABDOMINAL WALL, OMENTUM, MESENTERY, AND RETROPERITONEUMCHAPTER 35tumors, and infections such as tuberculosis. Biopsy can be obtained either via image-guided or surgical techniques, which may be performed laparoscopically or during an open procedure.Once the


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Surgery_Schwartz. 35tumors, and infections such as tuberculosis. Biopsy can be obtained either via image-guided or surgical techniques, which may be performed laparoscopically or during an open procedure.Once the diagnosis of retroperitoneal fibrosis is estab-lished, treatment is initiated. Surgical treatment is aimed at relieving ureteral obstruction either by ureterolysis or stenting. Surgery is reserved for patients who develop renal insufficiency as any surgical intervention in these patients car-ries several associated risks. In patients with secondary fibro-sis, treatment is aimed at the underlying etiology or discontinuation of the causative medication. For patients with idiopathic retroperitoneal fibrosis, corticosteroids are the mainstay of treatment. Patients are usually started on one month of high-dose prednisone, followed by maintenance therapy and subsequent taper. Alternatively, tamoxifen can be used if patients have contraindications to steroids. Within days of instituting therapy,


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Surgery_Schwartz. of high-dose prednisone, followed by maintenance therapy and subsequent taper. Alternatively, tamoxifen can be used if patients have contraindications to steroids. Within days of instituting therapy, symptoms and inflammatory markers should improve. Over the course of a few weeks, renal func-tion should improve. Interval imaging studies are usually obtained after 1 month to evaluate for efficacy. If steroids fail to cause regression of disease, patients can be started on immunosuppressant medications including methotrexate, aza-thioprine, cyclophosphamide, or mycophenolate mofetil. Recurrence of retroperitoneal fibrosis varies between studies from 10% to 30%. In patients who respond to steroid therapy, 5-year survival is as high as 90%.BIBLIOGRAPHYEntries highlighted in bright blue are key references.Aguirre DA, Santosa AC, Casola G, Sirlin CB. Abdominal wall her-nias: imaging features, complications, and diagnostic pitfalls at multi-detector row CT. RadioGraphics.


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Surgery_Schwartz. bright blue are key references.Aguirre DA, Santosa AC, Casola G, Sirlin CB. Abdominal wall her-nias: imaging features, complications, and diagnostic pitfalls at multi-detector row CT. RadioGraphics. 2005;25:1501-1520.Ahmad G, Gent D, Henderson D, O’Flynn H, Phillips K, Watson A. Laparoscopic entry techniques. Cochrane Data-base Syst Rev. 2015;8:CD006583. doi: 10.1002/14651858.CD006583.pub4Awaiz A, Rahman F, Hossain MB, et al. Meta-analysis and system-atic review of laparoscopic versus open mesh repair for elec-tive incisional hernia. Hernia. 2015;19:449-463. doi: 10.1007/s10029-015-1351-zBagade S, Khanna G. Imaging of omphalomesenteric duct remnants and related pathologies in children. Curr Probl Diagn Radiol. 2015;44:246-255.Beer GM, Schuster A, Seifert B, et al. The normal width of the linea alba in nulliparous women. Clin Anat. 2009;22(6):706-711. doi: 10.1002/ca.20836Berrevoet F, Vanlander A, Sainz-Barriga M, et al. Infected large pore meshes may be salvaged by topical negative


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Surgery_Schwartz. linea alba in nulliparous women. Clin Anat. 2009;22(6):706-711. doi: 10.1002/ca.20836Berrevoet F, Vanlander A, Sainz-Barriga M, et al. Infected large pore meshes may be salvaged by topical negative pressure ther-apy. Hernia. 2013;17:67-73. doi: 10.1007/s10029-012-0969-3Bhangu A, Fitzgerald JE, Singh P, Battersby N, Marriott P, Pinkney T. Systematic review and meta-analysis of prophylactic mesh placement for prevention of incisional hernia follow-ing midline laparotomy. Hernia. 2013;17(4):445-455. doi: 10.1007/s10029-013-1119-2Bickenbach KA, Karanicolas PJ, Ammori JB, et al. Development of the ventral body wall in the human embryo. Ann Surg. 2013;227:276-281. doi: 10.1053/j.sempedsurg.2014.09.009Bickenbach KA, Karanicolas PJ, Ammori JB, et al. Up and down or side to side? A systematic review and meta-analysis examining the impact of incision on outcomes after abdominal surgery. Am J Surg. 2013;206:400-409. doi: 10.1016/j.amjsurg.2012.11.008Bilsel Y, Abci I. The search for ideal hernia


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Surgery_Schwartz. and meta-analysis examining the impact of incision on outcomes after abdominal surgery. Am J Surg. 2013;206:400-409. doi: 10.1016/j.amjsurg.2012.11.008Bilsel Y, Abci I. The search for ideal hernia repair; mesh materi-als and types. Int J Surg. 2012;10:317-321. doi: 10.1016/j.ijsu.2012.05.002Brown SR, Tiernan J. Transverse verses midline incisions for abdom-inal surgery. Cochrane Database Syst Rev. 2005;(4):CD005199. doi: 10.1002/14651858.CD005199.pub2Caro-Tarrago A, Olona Casas C, Jimenez Salido A, et al. Prevention of incisional hernia in midline laparotomy with an onlay mesh: a randomized clinical trial. World J Surg. 2014;38:2223-2230. doi: 10.1007/s00268-014-2510-6Conze J, Kingsnorth AN, Flament JB, et al. Randomized clinical trial comparing lightweight composite mesh with polyester or polypropylene mesh for incisional hernia repair. Br J Surg. 2005;92:1488-1493. doi: 10.1002/bjs.5208de Vries Reilingh TS, van Goor H, Rosman C, et al. “Compo-nents separation technique” for the


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Surgery_Schwartz. or polypropylene mesh for incisional hernia repair. Br J Surg. 2005;92:1488-1493. doi: 10.1002/bjs.5208de Vries Reilingh TS, van Goor H, Rosman C, et al. “Compo-nents separation technique” for the repair of large abdominal wall hernias. J Am Coll Surg. 2003;196:32-37. doi: 10.1016/S1072-7515(02)01478-3Deerenberg EB, Harlaar JJ, Steyerberg EW, et al. Small bites versus large bites for closure of abdominal midline incisions (STITCH): a double-blind, multicentre, randomised con-trolled trial. Lancet. 2015;386(10000):1254-1260. doi: http://dx.doi.org/10.1016/S0140-6736(15)60459-7DeMaria EJ, Moss JM, Sugerman HJ. Laparoscopic intraperito-neal polytetrafluoroethylene (PTFE) prosthetic patch repair of ventral hernia. Surg Endosc. 2000;14:326-329. doi: 10.1007/s004640020013den Hartog D, Dur AHM, Tuinebreijer WE, Kreis RW. Open surgi-cal procedures for incisional hernias. Cochrane Database Syst Rev. 2008; doi: 10.1002/14651858.CD006438.pub2Ellis H. Applied anatomy of abdominal incisions. Br J


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Surgery_Schwartz. Tuinebreijer WE, Kreis RW. Open surgi-cal procedures for incisional hernias. Cochrane Database Syst Rev. 2008; doi: 10.1002/14651858.CD006438.pub2Ellis H. Applied anatomy of abdominal incisions. Br J Hosp Med. 2010;71:M36-M37. doi: 10.12968/hmed.2010.71.Sup3.46991Franz MG. The biology of hernia formation. Surg Clin North Am. 2008;88:1-15.García CM, Ruiz SG, Franco CC. Anatomy of the abdominal wall. In: Suárez Grau JM, Bellido Luque JA, eds. Advances in Lap-aroscopy of the Abdominal Wall Hernia. London: Springer; 2014:7-22.Halm JA, Heisterkamp J, Veen HF, Weidema WF. Long-term follow-up after umbilical hernia repair: are there risk factors for recurrence after simple and mesh repair. Hernia. 2005;9: 334-337. doi: 10.1007/s10029-005-0010-1Hanson J. Netter’s Clinical Anatomy. 3rd ed. Philadelphia: Elsevier; 2014.Hasson HM. A modified instrument and method for laparoscopy. Am J Obset Gynecol. 1971;110:886-887. doi: 10.1016/0002-9378(71)90593-XHegazy AA. Anatomy and embryology of


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Surgery_Schwartz. Philadelphia: Elsevier; 2014.Hasson HM. A modified instrument and method for laparoscopy. Am J Obset Gynecol. 1971;110:886-887. doi: 10.1016/0002-9378(71)90593-XHegazy AA. Anatomy and embryology of umbilicus in newborns: a review and clinical correlations. Frontiers Med. 2016;10: 271-277. doi: 10.1007/s11684-016-0457-8Henrich K, Huemmer HP, Reingruber B, Weber PG. Gastroschisis and omphalocele: treatments and long-term outcomes. Ped Surg Int. 2008;24:167-173. doi: 10.1007/s00383-007-2055-yHoward JH, Pollock R. Intra-abdominal and abdominal wall des-moid fibromatosis. Oncol Ther. 2016;4:57-72.Inaba T, Okinaga K, Fukushima R, et al. Prospective randomized study of two laparotomy incisions for gastrectomy: midline incision versus transverse incision. Gastric Cancer. 2004;7: 167-171. doi: 10.1007/s10120-004-0291-6Le Huu Nho R, Mege D, Ouaïssi M, et al. Incidence and prevention of ventral incisional hernia. J Visc Surg. 2012;149:e3-e14.Lowe JB, Garza JR, Bowman JL, Rohrich RJ, Strodel


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Surgery_Schwartz. 10.1007/s10120-004-0291-6Le Huu Nho R, Mege D, Ouaïssi M, et al. Incidence and prevention of ventral incisional hernia. J Visc Surg. 2012;149:e3-e14.Lowe JB, Garza JR, Bowman JL, Rohrich RJ, Strodel WE. Endoscopically assisted “components separation” for closure of abdominal wall defects. Plast Reconstr Surg. 2000; 105(2):720-729.Luijendijk RW, Hop WCJ, van den Tol MP, et al. A compari-son of suture repair with mesh repair for incisional her-nia. N Engl J Med. 2000;343:392-398. doi: 10.1056/NEJM200008103430603Maingot R, Zinner M, Ashley SW. Maingot’s Abdominal Opera-tions. New York: McGraw-Hill Medical; 2013.8Brunicardi_Ch35_p1549-p1566.indd 156312/02/19 9:59 AM 1564SPECIFIC CONSIDERATIONSPART IIMcBurney C. IV. The incision made in the abdominal wall in cases of appendicitis, with a description of a new method of operat-ing. Ann Surg. 1894;20:38-43.Mekonen HK, Hikspoors JPJM, Mommen G, et al. Develop-ment of the ventral body wall in the human embryo. J Anat. 2015;227:673-685. doi:


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Surgery_Schwartz. of a new method of operat-ing. Ann Surg. 1894;20:38-43.Mekonen HK, Hikspoors JPJM, Mommen G, et al. Develop-ment of the ventral body wall in the human embryo. J Anat. 2015;227:673-685. doi: 10.1111/joa.12380Millbourn D, Cengiz Y, Israelsson L. Effect of stitch length on wound complications after closure of mid-line incisions. Arch Surg. 2009;144(11):1056-1059.Murphy KP, O’Connor OJ, Maher MM. Adult abdominal her-nias. Am J Roentgenol. 2014;202:W506-W511. doi: 10.2214/AJR.13.12071Mwachaka PM, Saidi HS, Odula PO, et al. Locating the arcuate line of Douglas: is it of surgical relevance? Clin Anat. 2010;23: 84-86. doi: 10.1002/ca.20877Nachiappan S, Markar S, Karthikesaligam A, et al. Prophylactic mesh placement in high-risk patients undergoing elective lapa-rotomy: a systematic review. World J Surg. 2013;37:1861-1871. doi: 10.1007/s00268-013-2046-1Palmer R. Safety in laparoscopy. J Reprod Med. 1974;13:1-5.Ponten JEH, Somers KYA, Nienhuijs SW. Pathogenesis of the epigastric hernia. Hernia.


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Surgery_Schwartz. Surg. 2013;37:1861-1871. doi: 10.1007/s00268-013-2046-1Palmer R. Safety in laparoscopy. J Reprod Med. 1974;13:1-5.Ponten JEH, Somers KYA, Nienhuijs SW. Pathogenesis of the epigastric hernia. Hernia. 2012;16:627-633. doi: 10.1007/s10029-012-0964-8Ramirez O, Ruas E, Dellon A. “Components separation” method for closure for abdominal-wall defects: an anatomic and clinical study. Plast Reconstr Surg. 1990;86(3):519-526.Rastegarpour A, Cheung M, Vardhan M, et al. Surgical mesh for ventral incisional hernia repairs: understanding mesh design. Plast Surg. 2016;24(1):41-50.Reilingh TS de V, van Goor H, Charbon JA, et al. Repair of giant midline abdominal wall hernias: “components separation tech-nique” versus prosthetic repair. World J Surg. 2007;31:756-763. doi: 10.1007/s00268-006-0502-xRozen WM, Ashton MW, Taylor GI. Reviewing the vascular supply of the anterior abdominal wall: redefining anatomy for increas-ingly refined surgery. Clin Anat. 2008;21:89-98. doi: 10.1002/ca.20585Salameh JR.


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Surgery_Schwartz. Ashton MW, Taylor GI. Reviewing the vascular supply of the anterior abdominal wall: redefining anatomy for increas-ingly refined surgery. Clin Anat. 2008;21:89-98. doi: 10.1002/ca.20585Salameh JR. Primary and unusual abdominal wall hernias. Surg Clin North Am. 2008;88:45-60. doi: 10.1016/j.suc.2007.10.004Sanders DL, Kingsnorth AN. The modern management of inci-sional hernias. BMJ. 2012;344:e2843. doi: 10.1136/bmj.e2843Seiler CM, Deckert A, Diener MK, et al. Midline versus trans-verse incision in major abdominal surgery: a randomized, double-blind equivalence trial (POVATI: ISRCTN60734227). Ann Surg. 2009;249(6):913-920.Skandalakis P, Odyseas Z, Skandalakis J, Petros M. Spigelian her-nia: surgical anatomy, embryology, and technique of repair. Am Surg. 2006;72:42-48.Timmermans L, de Goede B, van Dijk SM, et al. Meta-analysis of sublay versus onlay mesh repair in incisional hernia surgery. Am J Surg. 2014;207:980-988. doi: 10.1016/j.amjsurg.2013.08.030Wilder F, D’Angelo S, Crago AM. Soft


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Surgery_Schwartz. van Dijk SM, et al. Meta-analysis of sublay versus onlay mesh repair in incisional hernia surgery. Am J Surg. 2014;207:980-988. doi: 10.1016/j.amjsurg.2013.08.030Wilder F, D’Angelo S, Crago AM. Soft tissue tumors of the trunk: management of local disease in the breast and chest and abdom-inal walls. J Surg Oncol. 2015;111:546-552. doi: 10.1002/jso.23843Zhang Y, Zhou H, Chai Y, Cao C, Jin K, Hu Z. Laparoscopic versus open incisional and ventral hernia repair: a systematic review and meta-analysis. World J Surg. 2014;38(9):2233-2240. doi: 10.1007/s00268-014-2578-zOmentumAbdulAziz A, El Zalabany T, Al Sayed AR, Al Ansari A. Idiopathic omental infarction, diagnosed and managed laparoscopi-cally: a case report. Case Rep Surg. 2013;2013:193546. doi: 10.1155/2013/193546Anyfantakis D, Kastanakis M, Petrakis G, et al. Rectus sheath hematoma in a single secondary care institution: a retrospective study. Hernia. 2015;19(3):509-512.Collins D, Hogan AM, O’Shea D, Winter DC. The omentum:


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Surgery_Schwartz. M, Petrakis G, et al. Rectus sheath hematoma in a single secondary care institution: a retrospective study. Hernia. 2015;19(3):509-512.Collins D, Hogan AM, O’Shea D, Winter DC. The omentum: ana-tomical, metabolic, and surgical aspects. J Gastrointest Surg. 2009;13:1138-1146. doi: 10.1007/s11605-009-0855-1Dedemadi G, Georgoulis G, Kontopanos D, et al. Extragastroin-testinal stromal tumors of the omentum: review apropos of a case with a novel gain-of-function KIT mutation. J Gastrointest Cancer. 2009;40:73-78. doi: 10.1007/s12029-009-9089-4Giovanni C, Riccardo V, Grazia EM, et al. Laparoscopic treatment of an omental cyst: a case report and review of the literature. Surg Laparosc Endosc Percutan Tech. 2005;15(1):33-35.Katagiri H, Honjo K, Nasu M, et al. Omental infarction due to omental torsion. Case Rep Surg. 2013;2013:373810. doi: 10.1155/2013/373810Kranendonk MEG, van Herwaarden JA, Stupkova T, et al. Inflam-matory characteristics of distinct abdominal adipose tissue depots relate


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Surgery_Schwartz. Case Rep Surg. 2013;2013:373810. doi: 10.1155/2013/373810Kranendonk MEG, van Herwaarden JA, Stupkova T, et al. Inflam-matory characteristics of distinct abdominal adipose tissue depots relate differently to metabolic risk factors for cardiovascular disease. Atherosclerosis. 2017;239:419-427. doi: 10.1016/j.atherosclerosis.2015.01.035Morison R. Remarks on some functions of the Omentum. Br Med J. 1906;1(2350):76-78.Motie MR, Asadi M. Large omental cyst: a case report and review of the literature. Acta Medica Iranica. 2011;49(10):690-693.Mouaqit O, Jahid A, Ifrine L, et al. Primary omental gastrointestinal stromal tumors. Clin Res Hepatol Gastroenterol. 2011;35: 590-593. doi: http://dx.doi.org/10.1016/j.clinre.2010.11.012Occhionorelli S, Zese M, Cappellari L, et al. Acute abdomen due to primary omental torsion and infarction. Case Rep Surg. 2014;2014:208382. doi: 10.1155/2014/208382Park TU, Oh JH, Chang IT, et al. Omental infarction: case series and review of the literature. J Emerg


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Surgery_Schwartz. primary omental torsion and infarction. Case Rep Surg. 2014;2014:208382. doi: 10.1155/2014/208382Park TU, Oh JH, Chang IT, et al. Omental infarction: case series and review of the literature. J Emerg Med. 2017;42:149-154. doi: 10.1016/j.jemermed.2008.07.023Platell C, Cooper D, Papadimitriou JM, Hall JC. The omentum. World J Gastroenterol. 2000;6:169-176. doi: 10.3748/wjg.v6.i2.169Rangel-Moreno J, Moyron-Quiroz JE, Carragher DM, et al. Omental milky spots develop in the absence of lymphoid tissue-inducer cells and support B and T cell responses to peritoneal antigens. Immunity. 2017;30:731-743. doi: 10.1016/j.immuni.2009.03.014Rao TN, Parvathi T, Suvarchala A. Omental lymphangioma in adults—rare presentation report of a case. Case Rep Surg. 2012;2012:629482. doi: 10.1155/2012/629482Schwartz R, Reames M, McGrath P, et al. Primary solid neoplasms of the greater omentum. Surgery. 1991;109:543-539.Seow-En I, Seow-Choen F, Lim TKH, Leow WQ. Primary omen-tal gastrointestinal stromal tumour


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Surgery_Schwartz. R, Reames M, McGrath P, et al. Primary solid neoplasms of the greater omentum. Surgery. 1991;109:543-539.Seow-En I, Seow-Choen F, Lim TKH, Leow WQ. Primary omen-tal gastrointestinal stromal tumour (GIST) presenting with a large abdominal mass and spontaneous haemoperitoneum. BMJ Case Rep. 2014;2014:bcr2014205528. doi: 10.1136/bcr-2014-205528Tarantino G, Lobello R, Scopacasa F, et al. The contribution of omen-tal adipose tissue to adipokine concentrations in patients with the metabolic syndrome. Clin Invest Med. 2007;30:E192–E199.Uramatsu M, Saida Y, Nagao J, et al. Omental cyst: report of a case. Surg Today. 2001;31:1104-1106. doi: 10.1007/s595-001-8068-0Yoo E, Kim JH, Kim M-J, et al. Greater and lesser omenta: nor-mal anatomy and pathologic processes. RadioGraphics. 2007;27:707-720. doi: 10.1148/rg.273065085MesenteryAdams SD, Stanton MP. Malrotation and intestinal atre-sias. Early Hum Dev. 2017;90:921-925. doi: 10.1016/j.earlhumdev.2014.09.017Akram S, Pardi DS, Schaffner JA, Smyrk


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Surgery_Schwartz. 10.1148/rg.273065085MesenteryAdams SD, Stanton MP. Malrotation and intestinal atre-sias. Early Hum Dev. 2017;90:921-925. doi: 10.1016/j.earlhumdev.2014.09.017Akram S, Pardi DS, Schaffner JA, Smyrk TC. Sclerosing mesenteritis: clinical features, treatment, and outcome in ninety-two patients. Clin Gastroenterol Hepatol. 2017;5: 589-596. doi: 10.1016/j.cgh.2007.02.032Avincsal MO, Otani K, Kanzawa M, et al. Sclerosing mes-enteritis: a real manifestation or histological mimic of Brunicardi_Ch35_p1549-p1566.indd 156412/02/19 9:59 AM 1565ABDOMINAL WALL, OMENTUM, MESENTERY, AND RETROPERITONEUMCHAPTER 35IgG4-related disease? Pathol Int. 2016;66(3):158-163. doi: 10.1111/pin.12386Coffey JC, O’Leary DP. The mesentery: structure, function, and role in disease. Lancet Gastroenterol Hepatol. 2017;1(3): 238-247. doi: 10.1016/S2468-1253(16)30026-7Daskalogiannaki M, Voloudaki A, Prassopoulos P, et al. CT evalu-ation of mesenteric panniculitis. Am J Roentgenol. 2000;174: 427-431. doi:


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Surgery_Schwartz. 2017;1(3): 238-247. doi: 10.1016/S2468-1253(16)30026-7Daskalogiannaki M, Voloudaki A, Prassopoulos P, et al. CT evalu-ation of mesenteric panniculitis. Am J Roentgenol. 2000;174: 427-431. doi: 10.2214/ajr.174.2.1740427Del Gobbo A, Bimbatti M, Ferrero S. A case report of mesenteric mucinous cystoadenoma with review of the literature. BMC Gastroenterol. 2010;10:105. doi: 10.1186/1471-230X-10-105Dequanter D, Lefebvre J, Belva P, Takieddine M, Vaneukem P. Mes-enteric cyst. A case treated by laparoscopy and a review of the literature. Surg Endosc. 2002;16(10):1493.Ezhapilli SR, Moreno CC, Small WC, et al. Mesenteric masses: approach to differential diagnosis at MRI with histopathologic correlation. J Magn Reson Imaging. 2014;40(4):753-769. doi: 10.1002/jmri.24690Halabi WJ, Jafari MD, Kang CY, et al. Colonic volvulus in the United States: trends, outcomes, and predictors of mortality. Ann Surg. 2014;259(2):293-301.Horton KM, Lawler LP, Fishman EK. CT findings in sclerosing mesenteritis


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Surgery_Schwartz. CY, et al. Colonic volvulus in the United States: trends, outcomes, and predictors of mortality. Ann Surg. 2014;259(2):293-301.Horton KM, Lawler LP, Fishman EK. CT findings in sclerosing mesenteritis (panniculitis): spectrum of disease. RadioGraph-ics. 2003;23:1561-1567. doi: 10.1148/rg.1103035010Hussein MRA, Abdelwahed SR. Mesenteric panniculitis: an update. Exp Rev Gastroenterol Hepatol. 2015;9:67-78. doi: 10.1586/17474124.2014.939632Kikiros CS, Edis AJ. Mesenteric panniculitis resulting in bowel obstruction: response to steroids. N Z J Surg. 1989;59(3): 287-290. doi: 10.1111/j.1445-2197.1989.tb01565.xKirby R, Rajasagaram N, Ghusn M. Primary mesenteric gastroin-testinal stromal tumour. J Surg Case Rep. 2014;2014:rju050. doi: 10.1093/jscr/rju050Park I-S, Kye B-H, Kim H-S, et al. Primary mesenteric carcinoid tumor. J Korean Surg Soc. 2013;84:114-117. doi: 10.4174/jkss.2013.84.2.114Parra-Davila E, McKenney M, Sleeman D, et al. Mesenteric panniculitis: case report and literature


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Surgery_Schwartz. mesenteric carcinoid tumor. J Korean Surg Soc. 2013;84:114-117. doi: 10.4174/jkss.2013.84.2.114Parra-Davila E, McKenney M, Sleeman D, et al. Mesenteric panniculitis: case report and literature review. Am Surg. 1998;64:768-771.Peng L, Yang L, Wu N, Wu B. Primary primitive neuroectoder-mal tumor arising in the mesentery and ileocecum: a report of three cases and review of the literature. Exp Ther Med. 2015;9(4):1299-1303. doi: 10.3892/etm.2015.2242Rajendran S, Khan A, Murphy M, O’Hanlon D. The diagnosis and treatment of a symptomatic mesenteric cyst. BMJ Case Reports. 2014;2014:bcr2013202410. doi: 10.1136/bcr-2013-202410Salar O, El-Sharkawy AM, Singh R, Speake W. Internal her-nias: a brief review. Hernia. 2013;17:373-377. doi: 10.1007/s10029-012-1023-1Tan JJ-Y, Tan K-K, Chew S-P. Mesenteric cysts: an institution experience over 14 years and review of literature. World J Surg. 2009;33:1961-1965. doi: 10.1007/s00268-009-0133-0van Putte-Katier N, van Bommel EFH, Elgersma OE, Hendriksz TR.


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Surgery_Schwartz. cysts: an institution experience over 14 years and review of literature. World J Surg. 2009;33:1961-1965. doi: 10.1007/s00268-009-0133-0van Putte-Katier N, van Bommel EFH, Elgersma OE, Hendriksz TR. Mesenteric panniculitis: prevalence, clinicoradiological presentation and 5-year follow-up. Br J Radiol. 2014;87:20140451. doi: 10.1259/bjr.20140451RetroperitoneumConstantinides VA, Christakis I, Touska P, Palazzo FF. System-atic review and meta-analysis of retroperitoneoscopic versus laparoscopic adrenalectomy. Br J Surg. 2012;99:1639-1648. doi: 10.1002/bjs.8921Goenka AH, Shah SN, Remer EM. Imaging of the retroperitoneum. Radiol Clin North Am. 2017;50(2):333-355. doi: 10.1016/j.rcl.2012.02.004Huang S-H, Lo W-O, Lin C-M, et al. Retroperitoneal abscess: 7-year experience of 29 cases in a tertiary care center in Taiwan. Urol Sci. 2015;26:218-221. doi: http://dx.doi.org/10.1016/j.urols.2015.01.009Kermani TA, Crowson CS, Achenbach SJ, Luthra HS. Idio-pathic retroperitoneal fibrosis: a


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Surgery_Schwartz. a tertiary care center in Taiwan. Urol Sci. 2015;26:218-221. doi: http://dx.doi.org/10.1016/j.urols.2015.01.009Kermani TA, Crowson CS, Achenbach SJ, Luthra HS. Idio-pathic retroperitoneal fibrosis: a retrospective review of clini-cal presentation, treatment, and outcomes. Mayo Clin Proc. 2011;86(4):297-303. doi: 10.4065/mcp.2010.0663Knezevic S, Ignjatovic I, Lukic S, et al. Primary retroperitoneal mucinous cystadenoma: a case report. World J Gastroenterol. 2015;21(17):5427-5431. doi: 10.3748/wjg.v21.i17.5427Martorana D, Vaglio A, Greco P, et al. Chronic periaortitis and HLA–DRB1*03: another clue to an autoimmune origin. Arthri-tis Care Res. 2006;55:126-130. doi: 10.1002/art.21698Messiou C, Moskovic E, Vanel D, et al. Primary retroperitoneal soft tissue sarcoma: imaging appearances, pitfalls and diag-nostic algorithm. Eur J Surg Oncol. 2017;43(7):1191-1198. doi: 10.1016/j.ejso.2016.10.032Miralas P, Skandalakis J. Surgical Anatomy of the retroperitoneal spaces part II: the architecture


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Surgery_Schwartz. and diag-nostic algorithm. Eur J Surg Oncol. 2017;43(7):1191-1198. doi: 10.1016/j.ejso.2016.10.032Miralas P, Skandalakis J. Surgical Anatomy of the retroperitoneal spaces part II: the architecture of the retroperitoneal space. Am Surg. 2010;76(1):33-42.Osman S, Lehnert B, Eloseimy S, et al. A comprehensive review of the retroperitoneal anatomy, neoplasms, and pattern of disease spread. Curr Probl Diagn Radiol. 2013;42(5):191-208.Scali EP, Chandler TM, Heffernan EJ, Coyle J, Harris AC, Chang SD. Primary retroperitoneal masses: what is the differential diagnosis? Abdom Imaging. 2015;40:1887-1903. doi: 10.1007/s00261-014-0311-xScheel P, Feeley N. Retroperitoneal fibrosis: the clinical, labora-tory, and radiographic presentation. Medicine (Baltimore). 2009;88(4):202-207.Stone JR. Aortitis, periaortitis, and retroperitoneal fibrosis, as mani-festations of IgG4-related systemic disease. Curr Opin Rheu-matol. 2011;23(1):88-94.Vaglio A, Salvarani C, Buzio C. Retroperitoneal fibrosis.


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Surgery_Schwartz. periaortitis, and retroperitoneal fibrosis, as mani-festations of IgG4-related systemic disease. Curr Opin Rheu-matol. 2011;23(1):88-94.Vaglio A, Salvarani C, Buzio C. Retroperitoneal fibrosis. Lancet. 2017;367(9506):241-251. doi: 10.1016/S0140-6736(06)68035-5van Bommel EFH, Siemes C, Hak LE, et al. Long-term renal and patient outcome in idiopathic retroperitoneal fibrosis treated with prednisone. Am J Kidney Dis. 2017;49:615-625. doi: 10.1053/j.ajkd.2007.02.268Brunicardi_Ch35_p1549-p1566.indd 156512/02/19 9:59 AM


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Surgery_Schwartz. INTRODUCTIONSarcomas are a heterogeneous group of neoplasms that arise predominantly from cells of the embryonic mesoderm. While the majority of sarcomas are soft tissue sarcomas, other types of sarcoma include bone sarcomas (osteosarcoma, chondrosarcoma, and rare bone tumors like chordoma, angiosar-coma, and leiomyosarcoma of bone) and Ewing’s sarcoma/peripheral primitive neuroectodermal tumor, which can occur either in the bone or in the soft tissues. The primary focus of this chapter is soft tissue sarcomas. Most primary soft tissue sarco-mas originate in an extremity (50–60%); the next most common sites are the trunk (19%), retroperitoneum (15%), and head and neck (9%). The anatomic site of a primary sarcoma influ-ences treatment and outcome.1Soft tissue sarcomas include more than 70 histologic sub-types (Table 36-1). Historically, the most common subtypes in adults (excluding Kaposi’s sarcoma) were malignant fibrous histiocytoma (28%), liposarcoma (15%), leiomyosarcoma (12%),


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Surgery_Schwartz. 70 histologic sub-types (Table 36-1). Historically, the most common subtypes in adults (excluding Kaposi’s sarcoma) were malignant fibrous histiocytoma (28%), liposarcoma (15%), leiomyosarcoma (12%), synovial sarcoma (10%), and malignant peripheral nerve sheath tumor (6%).2 Today, malignant fibrous histiocytoma is classified as either leiomyosarcoma, pleomorphic undifferenti-ated sarcoma, myxofibrosarcoma, or dedifferentiated liposar-coma based on cellular differentiation and genetics. Embryonal/alveolar rhabdomyosarcomas are the most common soft tissue sarcomas of childhood, whereas pleomorphic rhabdomyosar-coma occurs predominantly in adults, and although it shares part 12of the name, it has a different biology and should not be treated as a pediatric sarcoma.During the past 25 years, patients with extremity sarcomas have been treated with a multimodality approach, which has led to some improvements in survival, local control, and quality of life.3 However, patients with abdominal


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Surgery_Schwartz. patients with extremity sarcomas have been treated with a multimodality approach, which has led to some improvements in survival, local control, and quality of life.3 However, patients with abdominal sarcomas con-tinue to have high rates of recurrence and poor overall survival.4 The overall 5-year survival rate for patients with all stages of soft tissue sarcoma is 50% to 60%. Of the patients who die of sarcoma, most succumb to lung metastasis, which 80% of the time occurs within 2 to 3 years after initial diagnosis.INCIDENCEIn the United States in 2012, approximately 11,280 new cases of soft tissue sarcoma were diagnosed, and 3900 deaths were attributable to this disease.5 The incidence of soft tissue sarcomas increased 1.3% per year from 1995 to 2009, and subsequently leveled off while mortality rates increased slightly (0.5% per year) from 2001 to 2014.5 The true incidence of sarcoma is thought to be higher than reported, and gastrointestinal stromal tumors (GISTs) likely account


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Surgery_Schwartz. mortality rates increased slightly (0.5% per year) from 2001 to 2014.5 The true incidence of sarcoma is thought to be higher than reported, and gastrointestinal stromal tumors (GISTs) likely account for an additional 5000 new sarcoma cases per year.1 Overall, sarcomas affect 5 to 6 individuals per 100,000 inhabitants per year,6 accounting for less than 1% of all malignancies in adults and 15% of malignancies in children.7345Soft Tissue SarcomasRicardo J. Gonzalez, Alessandro Gronchi, and Raphael E. Pollock 36chapterIntroduction1567Incidence1567Epidemiology1568Radiation Exposure / 1568Occupational Chemical Exposure / 1568Trauma / 1568Chronic Lymphedema / 1568Molecular Pathogenesis1569Translocation-Associated Sarcomas / 1569Amplification-Associated Sarcomas / 1569Oncogenic Mutations / 1569Complex Genomic Rearrangements / 1570Initial Assessment1570Clinical Presentation / 1570Diagnostic Imaging / 1570Biopsy Techniques / 1571Pathologic Assessment and Classification / 1572Staging and


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Surgery_Schwartz. 1569Complex Genomic Rearrangements / 1570Initial Assessment1570Clinical Presentation / 1570Diagnostic Imaging / 1570Biopsy Techniques / 1571Pathologic Assessment and Classification / 1572Staging and Prognostic Factors / 1573Treatment of Extremity and Trunk Wall Sarcoma1574Surgery / 1575Radiation Therapy / 1577Systemic Therapy / 1578Concurrent Chemoradiation Therapy / 1580Posttreatment Surveillance / 1580Management of Recurrent Sarcoma / 1581Special Clinical Situations1582Myxoid Liposarcoma / 1582Retroperitoneal Sarcoma / 1582Gastrointestinal Sarcoma / 1583Breast Sarcoma / 1584Uterine Sarcoma / 1584Gastrointestinal Stromal Tumors1585Radiologic Assessment / 1585Management of Localized Disease / 1585Management of Locally Advanced or Metastatic Disease / 1585Multidisciplinary Treatment / 1586Postoperative Imatinib / 1586Preoperative Imatinib / 1587Desmoids1588Dermatofibrosarcoma Protuberans1588Pediatric Sarcomas1589Rhabdomyosarcoma / 1589Nonrhabdomyosarcoma Soft Tissue Sarcomas /


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Surgery_Schwartz. / 1586Postoperative Imatinib / 1586Preoperative Imatinib / 1587Desmoids1588Dermatofibrosarcoma Protuberans1588Pediatric Sarcomas1589Rhabdomyosarcoma / 1589Nonrhabdomyosarcoma Soft Tissue Sarcomas / 1589Research Perspectives1590Conclusions1590Brunicardi_Ch36_p1567-p1598.indd 156701/03/19 6:38 PM 1568Table 36-1Relative frequency of histologic subtypes of soft tissue sarcomaHISTOLOGIC SUBTYPESNO.%Liposarcoma18815Leiomyosarcoma14812Unclassified sarcoma14011Synovial sarcoma12510Malignant peripheral nerve sheath tumor726Rhabdomyosarcoma605Fibrosarcoma383Ewing sarcoma252Angiosarcoma252Osteosarcoma141Epithelioid sarcoma141Chondrosarcoma131Clear cell sarcoma121Alveolar soft part sarcoma71Malignant hemangiopericytoma50.4Data from Coindre JM, Terrier P, Guillou L, et al. Predictive value of grade for metastasis development in the main histologic types of adult soft tissue sarcomas: a study of 1240 patients from the French Federation of Cancer Centers Sarcoma Group, Cancer. 2001 May


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Surgery_Schwartz. of grade for metastasis development in the main histologic types of adult soft tissue sarcomas: a study of 1240 patients from the French Federation of Cancer Centers Sarcoma Group, Cancer. 2001 May 15;91(10):1914-1926.EPIDEMIOLOGYExcept for malignant peripheral nerve sheath tumors in patients with neurofibromatosis, sarcomas do not seem to result from progression or dedifferentiation of a benign soft tissue tumor. While most sarcomas are of unknown cause, a few sarcoma sub-types have been observed in settings suggesting etiology.Radiation ExposureExternal radiation therapy is a rare but well-established risk factor for soft tissue sarcoma that may be associated with radiation-induced mutations of the p53 gene.8 The incidence of sarcoma among patients who are often treated with radiation for cancer of the breast, cervix, ovary, testes, or lymphatic system is 8 to 50 times the general-population risk.9,10 In a review of 160 patients with postirradiation sarcomas, the most common


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Surgery_Schwartz. for cancer of the breast, cervix, ovary, testes, or lymphatic system is 8 to 50 times the general-population risk.9,10 In a review of 160 patients with postirradiation sarcomas, the most common histologic types were osteogenic sarcoma, pleomorphic undifferentiated sarcoma, angiosarcoma, and lymphangiosarcoma.9 The risk of developing a sarcoma increased with radiation dose, and the median time between radiation therapy and diagnosis of sarcoma was 10 years.9 A review of 44 patients with radiation-associated sarcomas identified between 1989 and 2009 noted that the average period from initial radiation treatment to diagnosis was 16 years and that radiation-associated sarcomas occurred most commonly in patients treated for breast cancer (36% of the patients in the series) and lymphoma (34% of the patients in the series).11 The 5-year overall survival rate for patients presenting without metastasis was 44%. A recent review of undifferentiated pleomorphic sarcoma characterizing outcomes


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Surgery_Schwartz. of the patients in the series).11 The 5-year overall survival rate for patients presenting without metastasis was 44%. A recent review of undifferentiated pleomorphic sarcoma characterizing outcomes between sporadic and radiation-associated presentation identified a higher incidence of local recurrence and worse overall and disease specific survival among patients who presented with radiation-associated undifferentiated pleomorphic sarcoma.12Occupational Chemical ExposureExposure to herbicides such as phenoxyacetic acids and to wood preservatives containing chlorophenols has been linked to an increased risk of soft tissue sarcoma.13 Several chemi-cal carcinogens, including thorium oxide (Thorotrast), vinyl chloride, and arsenic, have been associated with hepatic angiosarcomas.14TraumaAlthough patients with sarcoma often report a history of trauma, no causal relationship has been established. More often, a minor injury calls attention to a preexisting tumor.Chronic LymphedemaIn 1948,


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Surgery_Schwartz. patients with sarcoma often report a history of trauma, no causal relationship has been established. More often, a minor injury calls attention to a preexisting tumor.Chronic LymphedemaIn 1948, Stewart and Treves first described the association between chronic lymphedema after axillary dissection and sub-sequent lymphangiosarcoma (Fig. 36-1).15 Lymphangiosarcoma has been estimated to occur in 0.07% of patients who undergo axillary node dissection.16 It also has been reported to occur after filarial infections and in the lower extremities of patients with congenital lymphedema.17,18 Lymphangiosarcoma is gen-erally an aggressive tumor; average survival of patients with lymphangiosarcoma is 19 months.19Key Points1 Sarcomas are a heterogeneous group of tumors that can occur throughout the body and encompass more than 50 subtypes with distinct histologic lines of differentiation.2 Approximately two-thirds of soft tissue sarcomas arise in the extremities; the remaining one-third is


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Surgery_Schwartz. the body and encompass more than 50 subtypes with distinct histologic lines of differentiation.2 Approximately two-thirds of soft tissue sarcomas arise in the extremities; the remaining one-third is distributed between the retroperitoneum, trunk, abdomen, head, and neck.3 Multimodality treatment, including surgical resection, radia-tion therapy, and, in selected cases, systemic chemotherapy, has been applied to patients with locally advanced, high-grade, extremity sarcomas.4 Overall 5-year survival rate for patients with all stages of soft tissue sarcoma is 50% to 60%.5 These rare tumors account for less than 1% of cancer in adults (estimated 10,000 cases per year in the United States) and represent 15% of cancers in children.6 The treatment algorithm for soft tissue sarcomas depends on tumor stage, site, and histology.7 Of the patients who die of sarcoma, most will succumb to metastatic disease in the lungs, which 80% of the time occurs within 2 to 3 years of the initial


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Surgery_Schwartz. depends on tumor stage, site, and histology.7 Of the patients who die of sarcoma, most will succumb to metastatic disease in the lungs, which 80% of the time occurs within 2 to 3 years of the initial diagnosis.8 Progress in the understanding of soft tissue sarcoma biology is crucial for the development of new treatments.Brunicardi_Ch36_p1567-p1598.indd 156801/03/19 6:38 PM 1569SOFT TISSUE SARCOMASCHAPTER 36Figure 36-1. A 57-year-old with a chronic, progressive lymph-edema of the left upper extremity developed lymphangiosarcoma 10 years after breast cancer treatment.Table 36-2Fusion transcripts in soft tissue sarcomaDIAGNOSISCHROMOSOMAL ABNORMALITYGENES INVOLVEDAlveolar rhabdomyosarcomat(2;13)(q35;q14)t(1;13)(p36;q14)PAX3-FKHRPAX7-FKHRAlveolar soft part sarcomat(X;17)(p11.2;q25)TFE3-ASPLAngiomatoid fibrous histiocytomat(12;16)(q13;p11)FUS-ATF1Clear cell sarcomat(12;22)(q13;q12)EWS-ATF1Congenital fibrosarcoma/congenital mesoblastic


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Surgery_Schwartz. soft part sarcomat(X;17)(p11.2;q25)TFE3-ASPLAngiomatoid fibrous histiocytomat(12;16)(q13;p11)FUS-ATF1Clear cell sarcomat(12;22)(q13;q12)EWS-ATF1Congenital fibrosarcoma/congenital mesoblastic nephromat(12;15)(p13;q25)ETV6-NTRK3Dermatofibrosarcoma protuberanst(17;22)(q22;q13)PDFGB-COL1A1Desmoplastic small round cell tumort(11;22)(p13;q12)EWS-WT1Endometrial stromal sarcomat(7;17)(p15;q21)JAZF1-JJAZ1Ewing’s sarcoma/peripheral primitive neuroectodermal tumort(11;22)(q24;q12)t(21;22)(q22;q12)t(7;22)(p22;q12)t(17;22)(q12;q12)t(2;22)(q33;q12)t(16;21)(p11;q22)EWS-FLI1EWS-ERGEWS-ETV1EWS-FEVEWS-E1AFFUS-ERGLow-grade fibromyxoid sarcomat(7;16)(q33;p11)FUS-CREB3I2Inflammatory myofibroblastic tumort(1;2)(q22;p23)t(2;19)(p23;p13)t(2;17)(p23;q23)TPM3-ALKTPM4-ALKCLTC-ALKMyxoid liposarcomat(12;16)(q13;p11)t(12;22)(q13;q12)TLS-CHOPEWS-CHOPMyxoid chondrosarcomat(9;22)(q22;q12)t(9;15)(q22;q21)t(9;17)(q22;q11)EWS-CHNTFC12-CHNTAF2N-CHNSynovial sarcomat(x;18)(p11;q11)SSX1-SYTSSX2-SYTSSX4-SYTMOLECULAR


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Surgery_Schwartz. chondrosarcomat(9;22)(q22;q12)t(9;15)(q22;q21)t(9;17)(q22;q11)EWS-CHNTFC12-CHNTAF2N-CHNSynovial sarcomat(x;18)(p11;q11)SSX1-SYTSSX2-SYTSSX4-SYTMOLECULAR PATHOGENESISSarcomas can be broadly classified into three groups accord-ing to the genetic events underlying their development: specific translocations or gene amplification, defining oncogenic muta-tions, and complex genomic rearrangements.20 In general, sar-comas resulting from identifiable molecular events tend to occur in younger patients with histology suggesting a clear line of differentiation. The identifiable molecular events include point mutations, translocations causing overexpression of an autocrine grow factor, and oncogenic fusion transcription factor produc-ing a cellular environment prone to malignant transformation. In contrast, sarcomas without identifiable genetic changes or expression profile signatures tend to occur in older patients and exhibit pleomorphic cytology and p53 dysfunction.21 Improved understanding of


Surgery_Schwartz

Surgery_Schwartz. sarcomas without identifiable genetic changes or expression profile signatures tend to occur in older patients and exhibit pleomorphic cytology and p53 dysfunction.21 Improved understanding of the molecular pathogenesis of sarcomas has revealed several potential targets against which investigators are working to develop subtype-specific targeted therapy.Translocation-Associated SarcomasTo date, translocations have been identified in 14 subtypes of soft tissue sarcoma, accounting for 20% to 30% of all sarcomas22 (Table 36-2). Translocations result in in-frame gene fusion, which in turn results in fused products encoding oncoproteins that function as transcriptional activators or repressors.23,24 The best characterized gene fusions are in Ewing’s sarcoma (EWS-FLI1), clear cell sarcoma (EWS-ATF1), myxoid/round cell liposarcoma (TLS-CHOP), alveolar rhabdomyosarcoma (PAX3-FHKR), desmoplastic small round cell tumor (EWS-WT1), and synovial sarcoma (SS18-SSX). Fusion gene–related sarcomas


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Surgery_Schwartz. myxoid/round cell liposarcoma (TLS-CHOP), alveolar rhabdomyosarcoma (PAX3-FHKR), desmoplastic small round cell tumor (EWS-WT1), and synovial sarcoma (SS18-SSX). Fusion gene–related sarcomas have been estimated to account for 30% or more of all sarcomas.25Direct or indirect interactions between fusion transcripts and cell cycle regulators have been elucidated by several inves-tigators and identify these transcripts as potentially promising molecular therapeutic targets.26 However, fusion genes in sar-coma have been successfully targeted in only a few cases, in which fusion resulted in overexpression of a growth factor or growth factor receptor. Several growth factors and their recep-tors (e.g., epidermal growth factor receptor) previously reported to play an important role in autocrine or paracrine stimulation of carcinoma growth have been associated with high histologic grade and poor prognosis in soft tissue sarcomas.Amplification-Associated SarcomasOncogenes are genes that can


Surgery_Schwartz

Surgery_Schwartz. or paracrine stimulation of carcinoma growth have been associated with high histologic grade and poor prognosis in soft tissue sarcomas.Amplification-Associated SarcomasOncogenes are genes that can induce malignant transformation and tend to drive cell proliferation. Several oncogenes have been associated with soft tissue sarcomas, including MDM2, N-myc, c-erbB2, and members of the ras family. These onco-genes produce specific oncoproteins that either play a role in nuclear function and cellular signal transduction or function as growth factors or growth factor receptors. This typically occurs in dedifferentiated liposarcoma, where the amplification of MDM2 drives the neoplastic process. Amplification of these genes has been shown to correlate with adverse outcome in sev-eral types of soft tissue sarcoma.23Oncogenic MutationsGISTs are the classic example of sarcomas in which tumorigen-esis is primarily driven by a single activating mutation, in the Brunicardi_Ch36_p1567-p1598.indd


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Surgery_Schwartz. tissue sarcoma.23Oncogenic MutationsGISTs are the classic example of sarcomas in which tumorigen-esis is primarily driven by a single activating mutation, in the Brunicardi_Ch36_p1567-p1598.indd 156901/03/19 6:38 PM 1570SPECIFIC CONSIDERATIONSPART IIgene encoding KIT receptor tyrosine kinase or platelet-derived growth factor receptor-α (PDGFRA).20 The majority of GISTs have mutations in either exon 11 or exon 9 of KIT and respond dramatically to the tyrosine kinase inhibitor imatinib mesylate, although this treatment rarely produces cure.Complex Genomic RearrangementsThe largest group of sarcomas is the group with complex cytoge-netic alterations, which includes high-grade spindle cell sarco-mas and pleomorphic sarcomas.20 Many sarcomas in this group exhibit inactivation of tumor suppressor genes. The two genes most relevant to soft tissue sarcoma are retinoblastoma (Rb) and p53. Mutations or deletions in Rb can lead to retinoblastoma, the most common malignant ocular neoplasm of