	August Challenge: What is the likely cause of this radiographic abnormality?

	Each month, Dr. Maria Flynn issues a Radiology Challenge, presenting images from one of a variety of imaging modalities and a case report. Can you diagnose the condition? Follow the link to find out whether your answer was correct, what was really wrong with the patient, and how the patient was treated. Then, come back next month to test your radiographic reading skills on a new case!

	A previously healthy 36-year-old man presented to the emergency department because of diffuse abdominal pain, which had started several days earlier. A contrast-enhanced computed tomography (CT) scan of his abdomen and pelvis ruled out an intra-abdominal infection or mesenteric ischemia (Figure 1). Right upper quadrant ultrasonography was undertaken (Figures 2 and 3).

Based on the diagnostic images and the patient?s history, acute cholecystitis is the most likely cause of his abdominal pain. The ultrasound images show the gallbladder wall to be irregularly thickened, with abnormal echogenic material in the nondependent portion. What is the likely cause of this radiographic abnormality?

		Gangrenous cholecystitis is a progression of acute cholecystitis in which the increased intraluminal pressure leads to necrosis of the gallbladder wall. Various series report that 2% to 38% of acute cholecystitis cases can progress to gangrenous cholecystitis.

 The condition is more prevalent among older patients, men, patients who have cardiovascular disease but not diabetes, and those with leukocytosis of more than 17,000 white blood cells/mL.

 The complication rate for gangrenous cholecystitis is between 16% and 22% and its mortality rate can approach 22%, compared with a complication rate between 6% and 15% and a mortality rate between 0.5% and 6% for nongangrenous acute cholecystitis.

 Because of the increased morbidity and mortality rates of gangrenous cholecystitis, it is important to distinguish this condition from its nongangrenous counterpart preoperatively to ensure rapid surgical intervention.

		The clinical picture of gangrenous cholecystitis can be confusing, with up to 50% of patients presenting with only generalized abdominal pain and 6% presenting with no abdominal pain.

 Generalized abdominal pain is thought to be secondary to generalized peritonitis from inflammation of the parietal peritoneum. Imaging studies can be extremely helpful with these patients. Both ultrasonography and contrast-enhanced CT scanning have been used as first-line modalities. Typically, if the clinical picture is more consistent with acute cholecystitis, ultrasonography will be used first. In more confusing cases, a contrast-enhanced CT scan may be the initial imaging modality, as was the case with our patient.

		Ultrasonography findings for acute nongangrenous cholecystitis include cholelithiasis, Murphy?s sign (ultrasonographically localized maximum tenderness over the gallbladder), a notably distended gallbladder, a thickened gallbladder wall (> 3 mm), and pericholecystic fluid.

 Of these findings, the most sensitive is the combination of cholelithiasis and a positive Murphy?s sign.

 Although it is not always possible to distinguish uncomplicated acute cholecystitis from gangrenous cholecystitis using ultrasonography, the presence of intraluminal membranes or marked irregularity of the gallbladder wall are specific for gangrenous cholecystitis.

 The intraluminal membranes are from the desquamated gallbladder mucosa.

 In up to 66% of patients with gangrenous cholecystitis, the ultrasonographic Murphy?s sign will be absent.

 This is thought to be secondary to denervation of the gallbladder wall.

 The absence of a Murphy?s sign on ultrasonography increases the likelihood of gangrenous cholecystitis in patients with other ultrasonographic signs of acute cholecystitis.

		Sensitive contrast-enhanced CT findings for gangrenous cholecystitis include gas in the lumen wall, intraluminal membranes, an irregular or absent wall, hemorrhage into the gallbladder wall and lumen, and pericholecystic abscess.

 Other findings associated with gangrenous cholecystitis include lack of mural enhancement, pericholecystic fluid, marked gallbladder distension, and gallbladder wall thickening.

			Jeffrey RB, Laing FC, Wong W, et al. Gangrenous cholecystitis: diagnosis by ultrasound. 

			Bennett GL, Rusinek H, Lisi V, et al. CT findings in acute gangrenous cholecystitis. 

			Merriam LT, Kanaan SA, Dawes LG, et al. Gangrenous cholecystitis: analysis of risk factors and experience with laparoscopic cholecystectomy. 

			Hunt DR, Chu FC. Gangrenous cholecystitis in the laparoscopic era. 

			Simeone JF, Brink JA, Mueller PR, et al. The sonographic diagnosis of acute gangrenous cholecystitis: importance of the Murphy sign. 

			Hanbidge AE, Buckler PM, O?Malley ME, et al. From the RSNA refresher courses: imaging evaluation for acute pain in the right upper quadrant. 

Articles

Surgical Rounds

What is the likely cause of this radiographic abnormality?

August Challenge: What is the likely cause of this radiographic abnormality?

	Endometriosis is a condition in which endometrial stroma and glands are found outside of the uterine cavity. The endometrial tissue is generally found within the pelvic cavity and involves the ovaries, uterine ligaments, fallopian tubes, pouch of Douglas, or pelvic sidewall. Extra-pelvic sites also have been reported, including the abdominal viscera, abdominal wall, extremities, lungs, and brain. We describe our experience with an umbilical hernia that was associated with endometriosis and initially thought to be an incarcerated hernia with possible bowel strangulation.

	A 29-year-old woman was referred to our clinic for repair of an umbilical hernia. She had a 7-month history of a tender umbilical mass that had increased in size gradually and was sometimes associated with right lower quadrant pain. She had no other symptoms suggestive of endometriosis and reported normal menstruation. The patient noted that the mass had slowly changed from its initial reddish-pink color to a bluish-grey color. When queried, she could not recall any specific changes to the mass or associated pain in relation to her menstrual cycle. Her only history of abdominal surgery was a Cesarean section to deliver twins 5 years earlier, which had left a low, transverse incision scar.

	Physical examination revealed a 2 x 2-cm, tender, irreducible umbilical hernia with dark skin discoloration. No other masses were observed in the abdomen or by the low transverse scar. The initial impression was that she had an incarcerated hernia with possible bowel strangulation. The possibility of a Sister Joseph's nodule representing an underlying malignancy was also considered.

	Surgical exploration revealed an umbilical hernia. A firm, dark-grey lesion was identified within the tissue and excised. The hernia defect was repaired, and the surgical specimen was sent to pathology for evaluation. Microscopic sections revealed an admixture of benign endometrial glands and stroma consistent with endometriosis (Figure). There was associated reactive fibrosis and chronic inflammation. The endometrial tissue was in the dermis and in the soft tissue adjacent to the peritoneal lining of the hernia sac, but no endometrial tissue was found within the hernia sac itself. The patient was released to home the same day as the procedure, recovered well from surgery, and continues to be asymptomatic. Follow-up vaginal pelvic ultrasonography performed several weeks postoperatively showed no evidence of endometriosis.

	There are a variety of theories regarding the cause of endometriosis. None have been proven, nor does any one theory explain all the different manifestations of the disease. The retrograde theory, which contends that endometrial tissue refluxes through the fallopian tubes during menstruation and implants at ectopic sites, would explain the high percentage of cases occurring in the pelvis. The presence of remote, extra-pelvic sites is better explained by the metaplasia theory, which suggests that multipotential cells can develop into endometrial tissue, often stimulated by inflammation.

	A series of 82 cases of cutaneous endometriosis indicates that scar tissue is particularly susceptible to endometrial implantation.

 Abdominal wall endometriosis is usually associated with incisional abdominal scars and occurs most commonly following a Cesarean section. It has been suggested that the umbilicus acts as a physiologic scar with a predisposition for developing endometriosis. Umbilical endometriosis has been well described in the literature, occurring either spontaneously or following laparoscopic procedures in which a trocar was placed through the umbilicus. To our knowledge, only three cases of endometriosis occurring in association with an umbilical hernia have been reported previously.

	In 1994, Yu and associates described their experience with a 30-year-old woman who had an 18-month history of cyclic umbilical pain and bleeding.

 A 1.5 x 1.5 x 1.0-cm lesion was found in the umbilical area, adjacent to a small umbilical hernia. Histologic analysis of the lesion revealed endometriosis with chronic inflammation, hemosiderin, and fibrosis.

	In 2000, Ramsanahie and associates reported a case of endometriosis in the scarless abdominal wall of a 33-year-old woman.

 She had a 2-year history of intermittent pain associated with an umbilical mass and underlying umbilical hernia. The mass increased in size and tenderness prior to menstruation. The patient had borne nine children, all by normal vaginal delivery. Physical examination revealed a 2 x 1-cm, firm, round, cherry-red nodule at the umbilicus with an underlying umbilical hernia. Postoperative histological analysis showed endometriosis. Subsequent laparoscopy showed no signs of pelvic endometriosis.

	In 2001, Yuen and colleagues reported the case of a 43-year-old woman who, for several months, had experienced umbilical pain that came on during her menses.

 This patient, like ours, had no other symptoms suggestive of endometriosis. She had a lower midline incision scar from a Cesarean section that had been performed 9 years earlier. Physical examination revealed a tender, irreducible umbilical hernia with skin discoloration. Histologic analysis showed a focus of endometrial tissue within the lower dermis.

	Endometriosis is of interest to the general surgeon because it is often mistaken for a suture granuloma, abscess, cyst, lipoma, or incisional hernia.

 Between 0.5% and 1% of all endometriosis cases involve the umbilicus, thereby presenting a hazard in the diagnostic evaluation of umbilical hernias. As our case illustrates, some patients may perceive no correlation between their symptoms and menstrual cycle. The diagnosis is often made incidentally by histologic examination of the specimen.

	Endometriosis should be considered in the differential diagnosis of all premenopausal women who present with umbilical swelling and pain. In nonemergent cases, magnetic resonance imaging is the best modality for evaluating extrapelvic endometriosis.

 Making an appropriate diagnosis is important, because up to 50% of patients have concurrent pelvic endometriosis, which can lead to infertility and reseeding of endometrial tissue to extra-pelvic sites. Referral to a gynecologist for further evaluation is recommended when endometriosis is suspected.

	In rare incidences, endometriosis can present a diagnostic challenge to the general surgeon evaluating an umbilical hernia. Our patient presented with a 7-month history of a tender, discolored umbilical mass. She reported no correlation between her pain and menses and was initially thought have an incarcerated hernia with possible bowel strangulation. Histologic examination of the surgical specimen revealed endometriosis adjacent to the hernia sac. This case highlights the importance of considering endometriosis in the differential diagnosis of any premenopausal woman who presents with umbilical swelling and pain, regardless of whether the pain correlates with her menses.

		Steck WD, Helwig EB. Cutaneous endometriosis. 

		Yu CY, Perez-Reyes M, Brown JJ, et al. MR appearance of umbilical endometriosis. 

		Ramsanahie A, Giri SK, Velusamy S, et al. Endometriosis in a scarless abdominal wall with underlying umbilical hernia. 

		Yuen JS, Chow PK, Koong HN, et al. Unusual sites (thorax and umbilical hernial sac) of endometriosis. 

		Seydel AS, Sickel JZ, Warner ED, et al. Extrapelvic endometriosis: diagnosis and treatment. 

		Singh KK, Lessells AM, Adam DJ, et al. Presentation of endometriosis to general surgeons: a 10-year experience. 

Sari H. Green, Resident, Surgical Education, Los Angeles County Harbor UCLA Medical Center, Torrance, CA; Kenneth S. Waxman, Director, Department of Surgical Education, Cottage Hospital, Santa Barbara, CA; Peter L. Morris, Director of Pathology, Cottage Hospital, Santa Barbara, CA; Benjamin D. Shadle, Resident, Surgical Education, Cottage Hospital, Santa Barbara, CA

Umbilical hernia and endometriosis: A diagnostic consideration

	These questions are similar to those asked on the American Board of Surgery Recerti%uFB01cation Examination. You can use them to prepare for the examination, ful%uFB01ll learning requirements for various maintenance of competence programs, or simply improve your surgical knowledge.

		The spleen filters all of the following particles/cells EXCEPT		

Can be injured easily at the internal spermatic ring

Provides sensation for the penis and upper scrotum

Induce more gastric ulcers than duodenal ulcers

Should never be taken in conjunction with steroids

Markedly stimulate gastric acid secretion

Are less likely to cause gastroduodenal problems in elderly patients

Decreases the risk of breast cancer in BRCA1-positive women

Is effective in ER-negative and PR-positive breast cancer

Is equally effective in adjuvant treatment of node-positive breast cancer in pre- and postmenopausal women

Is the most effective means of preventing breast cancer in women at high risk

Decreases the risk of ovarian cancer in BRCA1-positive women

		Exclusion criteria for laparoscopic colectomy for diverticulitis include all of the following EXCEPT		

		In the treatment of invasive fungal infections		

Flucytosine can be used as a single agent

Lysosomal amphotericin B is advantageous in that it is not nephrotoxic

Caspofungin is as effective as amphotericin B

Is diagnosed by elevated levels of CA-125

Is the female counterpart of the male seminoma

Octreotide scanning is the most effective scintigraphic technique

Elevation of plasma levels of catecholamines is the most specific modality

Normotensive patients with incidentalomas need not be screened

Increased excretion of urinary metanephrines is the most reliable study

The usual provocative test is a pentagastrin infusion

Is conjugated to glucuronic acid in the gallbladder

Is transported in hepatic sinusoidal blood bound to albumin

When conjugated, is secreted into bile by passive diffusion

Is converted to urobilinogen by jejunal enterocytes

Is produced predominantly by early phase (< 3 days) erythrocyte heme breakdown

		Pneumomediastinum commonly occurs as a complication of each of the following conditions EXCEPT		

		Thoracic aortic aneurisms most commonly cause		

Hoarseness due to pressure on the left recurrent laryngeal nerve

Dyspnea as a result of pressure on the tracheobronchial tree

Hematemesis as a complication of fistulization with the esophagus

		Survival rates from congenital diaphragmatic hernia are		

Improved by high-frequency oscillation ventilation

Best if symptoms develop more than 24 hours after birth

Determined by the severity of the pulmonary hypertension

The spleen is a source of T lymphocytes, not a site of their filtration. Splenic filtration of spherocytes and other types of deformed red blood cells results in anemia and, often, jaundice. The spleen is the first defense against circulating malarial parasites. Splenectomy reduces the ability of the body to clear and opsonize encapsulated bacteria like 

. Overly aggressive, immunologically mediated splenic filtration of platelets results in idiopathic thrombocytopenic purpura.

The ilioinguinal nerve is responsible for providing sensation to the penis, upper scrotum, and inner thigh. Injury during inguinal herniorrhaphy, which can only occur at the external (not internal) ring, causes disturbing numbness in these areas. The ilioinguinal nerve is derived from the first lumbar nerve (not the femoral nerve) and is purely sensory (it has no motor function). It runs along the iliac crest and penetrates the transversus abdominus muscle at the external spermatic ring; its course is far anterior to the posteriorly located hypogastric vein.

The ratio of induced gastric ulcers to duodenal ulcers is about 2:1. There are some clinical situations in which both medication groups are needed; steroids can be added safely if prostaglandins or antisecretory agents are also administered. Nonsteroidal anti-inflammatory drugs cause bleeding and perforation. The agents have a minimal effect on gastric acid secretion and cause ulcers by interfering with gastric cytoprotective mechanisms.

There are excellent data which document that tamoxifen induces a more than 50% decrease in breast cancer incidence in women at genetic risk for this disease. The same does not hold true for ovarian cancer, the other lesion increased in frequency by this genetic abnormality. Tamoxifen is ineffective against ER-negative tumors and has a differential effect depending on the menopausal state of the woman. The most effective way to prevent breast cancer is by prophylactic mastectomy.

Laparoscopy can be more difficult in the morbidly obese, but it is certainly not contraindicated. If an upper limit of size is utilized, it is always a BMI of 35 kg/m

 or greater. The determination of extent of resection in multifocal disease, either multilocular abscess or several areas of phlegmon, requires palpation and, thus, resection via laparoscopy cannot be performed safely. Laparoscopic colectomy takes longer to set up and perform than the open operation and is therefore contraindicated in emergency situations.

Recent studies have documented that caspofungin is at least as effective in this circumstance as amphotericin B, and it is safer and better-tolerated. Flucytosine induces resistance and must be used in combination therapy. Lysosomal amphotericin B is less nephrotoxic than the native compound, but it does induce renal and hepatic toxicity. Fluconazole is fungistatic, yet effective. Amphotericin B induces hypokalemia, which is surprising since it commonly causes renal failure; the electrolyte disturbance is unrelated to renal perfusion or clearance.

The dysgerminoma is a pure germ cell tumor, as is the male seminoma; these lesions behave in a very similar manner. As a germ cell tumor, dysgerminoma does not secrete estrogen. While this tumor often secretes hCG and, occasionally, LDH, it does not secrete CA-125, as do other ovarian malignancies. The tumor is bilateral in 10% to 15% of patients and is a relatively low-grade malignancy.

In this case, the old standard is still the best, with greater than 96% sensitivity and specificity. The most effective scintigraphic study is 

I-MIBG scanning. The plasma determinations are not specific, averaging only about 60% to 70%; thus, there are a number of false positives. Forty percent of pheochromocytomas are diagnosed by chemical studies in normotensive patients with adrenal incidentalomas. The usual provocative tests, when needed to establish the diagnosis, are glucagon infusion and clonidine suppression tests.

Bound bilirubin dissociates from albumin within the liver and is incorporated into hepatocytes, where conjugation goes on (not in the gallbladder). The conjugate is excreted into bile against concentration gradients in an energy-requiring process. Intestinal bacteria convert bilirubin to urobilinogen, not enterocytes. Eighty percent of bilirubin is produced by destruction of late phase, senescent erythrocytes.

While air can migrate from one serous cavity to another, it requires pressure. Spontaneous pneumothorax is not associated with increased pressure (at least until it becomes tension pneumothorax), so migration into the mediastinum is rare. Barotrauma, croup, and asthma all have elements of bronchoconstriction resulting in increased airway pressure, and migration of air into the mediastinum is fairly common. In Boerhaave?s syndrome, the esophagus can rupture into the mediastinum, causing pneumomediastinum.

Most patients with thoracic aneurisms are asymptomatic, and the vascular lesion is found incidentally on a chest radiograph. Back pain is generally unrelated to the aorta and is almost invariably muscular in origin. The other manifestations do occur, although uncommonly. 

There are three scenarios by which diaphragmatic hernias present. The first and worst is with immediate respiratory failure; next is when symptoms appear within minutes to a couple of hours; the third scenario, and clearly the best, is when symptoms occur only after 24 or more hours, at which time, the infants have difficulty in feeding, intestinal obstruction, or pneumonia, but not respiratory failure. Despite much research and clinical trials including high-frequency oscillation ventilation, use of nitric oxide, early operation, etc, the average mortality rate for diaphragmatic hernia (60%?70%) has not changed. The major determinant of success or mortality is the extent of pulmonary hypertension.

American Board of Surgery Recerti%uFB01cation Examination

	Small bowel volvulus is a rare condition that can become life-threatening very quickly. The exact cause remains unknown, but dietary habits or the presence of small bowel diverticula may contribute. The symptoms are usually nonspecific, and the surgeon must quickly diagnose and treat the condition to prevent intestinal damage secondary to vascular compromise. Although no gold standard exists for diagnosing small bowel volvulus, computed tomography (CT) scanning is the most reliable diagnostic tool to date. Treatment is almost always surgical and must be performed immediately to ensure an optimal outcome. We report a case of small bowel volvulus that developed independently of the patient's embolic and thrombotic risk factors for mesenteric ischemia.

	A 52-year-old, thin, muscular, Hispanic man presented to our institution with a 4-hour history of severe, constant, and diffuse abdominal pain. The pain had woken him in the middle of the night and was accompanied by nausea, vomiting, and two episodes of nonbloody diarrhea. There appeared to be no alleviating or exacerbating factors, and he reported no other recent episodes of abdominal pain. The patient had undergone no prior surgery, but his medical history was significant for coronary artery disease with an ejection fraction of 20%, atrial fibrillation, and gout. His medications included digoxin, warfarin, furosemide, colchicine, lisinopril, celecoxib, and allopurinol. His social history was significant for a 15-pack-year history of smoking.

	On physical examination, the patient was afebrile and normotensive but exhibited sinus tachycardia at 110 beats per minute. Pulses were palpable in all four extremities. His abdomen was soft and nondistended, and the abdominal pain was not exacerbated by palpation. There was no evidence of peritonitis. A rectal examination was unremarkable and negative for occult blood. The patient was in obvious distress, but his symptoms seemed out of proportion to the physical examination findings.

	Laboratory tests were unrevealing. A CT angiogram demonstrated a widely patent celiac trunk and superior mesenteric artery. An abdominal CT scan showed a swirling of the mesentery distal to the take-off of these vessels, with disruption of arterial blood flow and venous congestion of the distal small bowel (Figure). These findings were thought to be consistent with small bowel volvulus.

	The patient underwent emergency laparotomy. On entering the abdomen, no ascites were seen. Most of the small bowel was well-perfused, but there was a 3-ft segment of dusky-appearing ileum. The mesentery of this segment was twisted on itself. Detorsion of the mesentery restored immediate reperfusion of the bowel, and the ischemia rapidly reversed. A thorough examination of the abdomen did not reveal any other anatomical abnormalities, such as internal hernias or malrotation.

	The patient had an uneventful recovery and was discharged to home on postoperative day 5. He was readmitted to the hospital 1 week later due to a complete small bowel obstruction, which required adhesiolysis. The patient made a full recovery after this procedure.

	Small bowel volvulus refers to the abnormal twisting of a loop of bowel around the axis of its own mesentery.

 This twisting may produce mechanical obstruction, vascular compromise, or both. When small bowel volvulus produces torsional strain around the mesenteric vasculature, it can lead to bowel ischemia and ultimately gangrene. In strangulating obstructions, venous obstruction is usually the initiating factor, which can lead to arterial occlusion and result in rapid ischemia of the bowel wall. Although small bowel volvulus is rare, it has a mortality rate between 9% and 35%, depending on whether underlying necrosis is present.

	One of the most interesting details of small bowel volvulus is its increased proclivity for certain ethnic groups. In North America and Western Europe, the annual incidence is 1.7 to 5.7 cases per 100,000, but much higher rates of 24 to 60 cases per 100,000 have been observed in Africa, Asia, the Middle East, and India.

 The increased rate in these populations has been attributed to regional dietary habits. The ingestion of large volumes of fiberrich foods after periods of prolonged fasting may play a role. For example, the incidence of small bowel volvulus is higher during the month of Ramadan, when Muslims fast during the day and then ingest a large meal after sunset.

 In Ethiopia, the typical patient with primary volvulus of the small intestine is a young adult male from a rural area whose diet is bulky and consists mainly of cereals.

 A study that examined 235 patients of Southern Ethiopian descent found that 98 (41.7%) of those undergoing surgery to address acute intestinal obstruction had small bowel volvulus.

 This condition occurred most often in farmers, who are known to consume fiber-rich foods.

	A large diverticulum of the small bowel also has been proposed to cause small bowel volvulus.

 The incidence of small bowel diverticula in one study of patients with small bowel volvulus was 35%, which is significantly higher than the rate of 1% observed in the control group (

 The diverticulum may serve as a lead point, causing torsion around the mesentery.

	Our patient's clinical presentation and history of atrial fibrillation and smoking led to the presumed diagnosis of mesenteric ischemia from an embolic or thrombotic event. In addition, he was taking digoxin, which is known to induce intestinal ischemia by vasoconstriction of the splanchnic circulation.

 This patient's mesenteric ischemia, however, was not caused by any of these etiologies.

	Diagnosing small bowel volvulus is challenging, because its chief symptoms—abdominal pain, nausea, and vomiting&mdash;are nonspecific.

 The degree of abdominal pain depends directly on the duration of vascular compromise and not on the degree of underlying intestinal obstruction.

 The laboratory values are equally nonspecific, and abnormalities occur inconsistently.

	While it is possible to rely on conventional radiographs to obtain a diagnosis of small bowel obstruction, it is insufficient for establishing a diagnosis of small bowel volvulus. CT scanning is more effective, because it shows the twisting of the mesenteric artery and vein from their normal proximal location to a reversed distal orientation. Often, a "whorl sign" can be visualized where the mesenteric folds and bowel encircle the superior mesenteric vein.

 The whorl sign is useful in making decisions about the need for surgery, in conjunction with other clues, such as bowel ischemia, which is suggested by bowel wall thickening or pneumatosis.

	Various medical treatments are available to manage intrapelvic endometriosis, all of which depend primarily on creating a hypoestrogenic environment that deprives the endometriosis of nourishing hormonal stimulation. Low-dose estrogen oral contraceptives are often used to alleviate pain from endometriosis and limit the extent of cell growth. Medical treatment for extrapelvic endometrioma, however, has generally been found to be ineffective.

 This was true for our patient, who was taking oral contraceptive pills but still experienced tumor growth and symptoms. Since medical treatment is ineffective, surgical excision remains the treatment of choice. Surgery is curative for extrapelvic endometrioma in the vast majority of cases.

	A plain abdominal radiograph is not sufficient for determining when conservative management is warranted for a bowel obstruction or when operative management becomes necessary. To date, the most reliable diagnostic tool is CT scanning, and the surgeon must diagnose the condition quickly to prevent bowel necrosis.

 Immediate surgery is the treatment of choice to prevent progression to irreversible ischemia.

	Although small bowel volvulus is a rare diagnosis, the condition is life-threatening and generally requires emergency surgical treatment to prevent serious morbidity or mortality. The development of small bowel volvulus has been associated with diverticula and eating fiber-rich foods. Patients often present with nonspecific symptoms that include abdominal pain, nausea, and vomiting. Laboratory test results may vary and are rarely conclusive. In cases of bowel obstruction, CT scanning is the most effective imaging modality to help diagnose the condition and suggest appropriate treatment. Often a whorl sign will be present, where the mesenteric folds and bowel encircle the superior mesenteric vein. When the diagnosis is small bowel volvulus, immediate surgery is advisable to prevent serious complications, such as ischemia and necrosis.

		Katis PG, Dias SM. Volvulus: a rare twist on small-bowel obstruction. 

		Roggo A, Ottinger LW. Acute small bowel volvulus in adults. A sporadic form of strangulating intestinal obstruction. 

		Iwuagwu O, Deans GT. Small bowel volvulus: a review. 

		Ghebrat K. Trend of small intestinal volvulus in Northwestern Ethiopia. 

		Demissie M. Small intestinal volvulus in Southern Ethiopia. 

		Chou CK, Mark CW, Wu RH, et al. Large diverticulum and volvulus of the small bowel in adults. 

		Bernstein SM, Russ PD. Midgut volvulus: a rare cause of acute abdomen in an adult patient. 

		Thomson ABR, Par? P, Fedorak RN. Small intestine. In: 

First Principles of Gastroenterology: The Basis of Disease and an Approach to Management

www.gastroresource.com/GITextbook/En/Chapter7/Default.htm

		Fujimoto K, Nakamura K, Nishio H, et al. Whirl sign as CT finding in small-bowel volvulus. 

Matthew A. Wert, Surgical Resident, Orthopedic Surgery, Kingsbrook Jewish Medical Center, Brooklyn, NY, St. Vincent's Hospital, New York, NY; Umut Sarpel, Surgical Oncology Fellow, Department of Surgery, The Mount Sinai Medical Center, New York, NY; Celia M. Divino, Chief, Division of General Surgery, Department of Surgery, The Mount Sinai Medical Center, New York, NY

Small bowel volvulus: Time is of the essence

					Complications of laparoscopic operations can be difficult to recognize. This report emphasizes the importance of prevention and early recognition and treatment when such injuries occur. Port sites pose a low incidence of complications such as herniation, and any sites measuring 10 mm or larger are closed to prevent such complications. Although cannulas and trocars are designed to be atraumatic, a defect is made in the fascia and muscle layers, and this defect can become a potential source of weakness and herniation. In general, any cannula site that is 10 mm or larger should be closed with sutures to prevent a hernia. Another lesson to be learned from this report is that any bulge in a port site should be assumed to be a hernia and immediate exploration should be undertaken. In this case, recognition and treatment were delayed. This resulted in strangulation of the incarcerated small bowel, which required resection. Early recognition and treatment may have allowed simple reduction of the hernia and closure of the defect.

	With the advent of laparoscopy came the unique issue of creating openings for instruments to be inserted into the abdominal cavity. Nearly half of all major complications in laparoscopic surgery are thought to be related to the site and procedure used to access the abdominal cavity.

 Despite advances in laparoscopic equipment over the past decade, access-related complications continue to occur, such as incisional hernias and damage to major blood vessels, the bladder, and intestines. Serious access-related complications appear to be rare but can lead to increased morbidity when they do occur. Herniation of the bowel through port sites is uncommon and can be difficult to diagnose. Often the diagnosis is delayed, resulting in infarction of the involved bowel segment. We report a case of small bowel herniation that presented as a lump in the right lateral port site.

	A fit 84-year-old man was admitted to the hospital for a planned laparoscopic herniorrhaphy to treat a recurrent right inguinal hernia. Under general anesthesia, the patient was placed in the supine position and a urinary catheter was inserted after intravenous (IV) Ringer's lactate was administered. A 1-cm skin incision was made below the umbilicus, and a 12-mm nonbladed trocar cannula with a laparoscope was inserted into the intraperitoneal cavity using a Hasson open technique to create a closed pneumoperitoneum.

 After preliminary laparoscopy, two additional 10-mm ports were inserted in the left and right flanks, lateral to the infraumbilical port site, using videoscopic guidance.

	The right inguinal hernia was reduced, and a preperitoneal space was established. Polypropylene mesh was placed across the defect and secured with staples. Fascial closure of the 12-mm port site was performed using polyglactin 0 sutures, but the lateral port sites were not closed. All skin incisions were closed using 3-0 polyglactin 910 sutures.

	In the immediate postoperative period, the patient experienced acute urinary retention after removal of the urethral catheter, and it was reinserted. On postoperative day 1, the patient started vomiting and reported lower abdominal pain associated with a painful lump on the right lateral port site. Although he had passed flatus earlier that day, he had had no bowel movements since the operation.

	On physical examination, he was febrile with a temperature of 101.5°F. He was hemodynamically stable, with a blood pressure of 148/88 mm Hg and a pulse rate of 86 beats per minute. Abdominal examination found an approximately 5-cm, tender, nonreducible lump overlying the right lateral port site. A biochemical profile revealed moderate dehydration and a white blood cell count that was marginally elevated at 13 x 10

/L). A supine radiograph of the abdomen revealed distended small bowel loops (Figure).

	The patient was treated using nasogastric tube suctioning, IV rehydration, and IV administration of the antibiotics metronidazole and cefuroxime. His urine output was strictly monitored. When the patient's condition did not improve despite these measures, he underwent emergency laparotomy via a tranverse incision joining all three port sites. During the operation, about 6 inches of gangrenous small bowel was found to have herniated through the right lateral port site. A limited small bowel resection and a stapled side-to-side anastomosis were performed. The peritoneal cavity was thoroughly irrigated with 2 L of warm normal saline. The abdominal wound was closed with loop polydioxanone using mass closure. The patient had an unremarkable recovery and was discharged home on postoperative day 10. At 2- and 6-week follow-up visits, the patient was in satisfactory condition and was discharged from further follow-up.

	Laparoscopic procedures have many benefits compared with open ones, but access-related complications, such as intestinal herniation, bleeding, and injury to the viscus, can occur. These require early recognition and prompt intervention. Although the reported incidence of incisional hernia is low (less than 0.17%), its actual incidence is likely much higher, because many patients are asymptomatic or do not return to their primary surgeon for follow-up care.

	Several factors contribute to the development of incisional hernias. Most laparoscopic surgeons agree that the diameter of the cannula or port is the single most common cause of incisional or port-site hernias. Emerging evidence suggests that transmuscular placement of a port, the use of small trocars with conical obturators, and the evacuation of air from the peritoneal cavity before the removal of a port serve to significantly decrease the incidence of incisional hernias.

 The location of the port site also may influence the risk for herniation. Epigastric ports tend to place patients at lower risk for developing incisional hernias due to the difference in pressure gradients across the abdominal wall and the gravitational pull when the patient is standing.

	In our patient, who was physically fit, the lateral ports were inserted transmuscularly in a Z-fashion. We chose this approach because we thought that the abdominal musculature and normal fascial elasticity would inhibit herniation by acting as a shutter mechanism over the defect. It is possible that the herniation developed secondary to the partial vacuum effect created when the trocars were withdrawn. As a result of this case, we have changed our practice to include removal of all trocars under videoscopic guidance and ensure closure of all port sites under direct vision.

	Although the risk of incisional hernia is much higher in cases where large trocars are used, there have been reports of incisional hernias occurring in 5-mm port sites.

 Carson and colleagues advocate a nonclosure policy for fascial defects created with nonbladed trocars.

 We disagree with this recommendation. Although nonbladed trocars bluntly displace tissue and muscle fibers laterally, thereby causing less tissue damage than cutting trocars, the risk for incisional hernia remains. It is possible that laterally displaced muscle fibers do not return to their original state, allowing omentum and bowel to herniate through such a defect. It is for this reason that we concur with the recommendations of clinicians who advocate closing any port sites larger than 5 mm.

	Reissman and associates reported a case of an incarcerated hernia at a lateral port site and advised routine fascial repair of lateral port sites measuring 10 mm or more in diameter, especially in elderly patients.

 Patterson and colleagues reported three cases of an incarcerated hernia at a port site and recommended that all port sites with a diameter of 10 mm or more be repaired in obese patients.

	We no longer think that port sites should be closed blindly, because there are reported incidences of port-site herniation following such closures. We recommend closing these sites under laparoscopic videoscope control, and the last port should be closed by picking up the fascia with Kocher clamps and repairing the defect under direct vision.

	If the cannula or port site is 10 mm or larger in diameter, hernias can occur, despite preventative measures such as entering in a Z-fashion or using a noncutting trocar. Recognition and early treatment of port-site hernias avoids strangulation of an incarcerated hernia and the need for bowel resection. Although port site hernias after laparoscopic surgery are uncommon, they remain a significant cause of postoperative morbidity and require prompt intervention if extensive bowel resection is to be avoided. A bulge at a trocar site should alert a surgeon to this complication.

	Most surgeons do not routinely close lateral port sites because it is commonly thought that the fascial and muscular composition of these sites pose such little risk of herniation that the extra time and effort required to repair them is not justified. We report a case where a strangulated port hernia revealed itself as a tender bulge on the lateral port site on the first postoperative day. This report underscores the significance of performing meticulous closure of all trocar sites that are 10 mm or greater under videoscopic guidance. Because there have been reports of incisional hernias occurring in 5-mm port sites, we also advise giving consideration to closing any port site 5 mm or larger.

		Bittner R. Trocars and other devices for access. 

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		Jones DB, Callery MP, Soper NJ. Strangulated incisional hernia at trocar site. 

		Plaus WJ. Laparoscopic trocar site hernias. 

		Schmedt CG, Leibi BJ, Daubler P, et al. Access-related complications? an analysis of 6,023 consecutive laparoscopic hernia repairs. 

		Reardon PR, Preciado A, Scarborough T, et al. Hernia at 5-mm laparoscopic port site presenting as early postoperative small bowel obstruction. 

		Liu CD, McFadden DW. Laparoscopic port sites do not require fascial closure when nonbladed trocars are used. 

		Eltabbakh GH. Small bowel obstruction secondary to herniation through a 5-mm laparoscopic trocar site following laparoscopic lymphadenectomy. 

		Wegener ME, Chung D, Crans C, et al. Small bowel obstruction secondary to incarcerated Richter's hernia from laparoscopic hernia repair. 

Strangulated lateral port-site hernia: Lessons to be learned

Pancreas divisum is the most common congenital variant of pancreatic ductal development. In symptomatic cases, the underlying mechanism is thought to be a relative outflow obstruction at the site of the minor papilla. Therapeutic interventions for symptomatic pancreas divisum aim to relieve obstruction of the minor papilla by improving pancreatic drainage. The authors report a case of symptomatic pancreas divisum that was successfully treated using a combined approach.

	Pancreas divisum occurs when the ventral and dorsal ducts of the embryonic pancreas fail to fuse. It is the most common congenital variant of pancreatic ductal development.

 A minority of patients with this condition become symptomatic, experiencing recurrent acute pancreatitis, chronic pancreatitis, or chronic abdominal pain.

 The underlying mechanism in these symptomatic cases is thought to be a relative outflow obstruction at the site of the minor papilla.

 We report a case of symptomatic pancreas divisum that was treated using the combined approach of endoscopic sphincterotomy, surgical transduodenal sphincteroplasty, and repeated stenting of the minor papilla over a 5-year period.

	A 33-year-old woman was admitted to the hospital for gallstone pancreatitis, which was treated without complication using laparoscopic cholecystectomy. Postoperatively, the patient's pain never resolved and her pancreatitis continued. An endoscopic retrograde cholangiopancreatography (ERCP) performed 1 month later showed pancreatic divisum and duodenitis around the area of the minor papilla, which itself could not be identified (Figure 1). The patient's condition worsened; she was unable to tolerate a regular diet and required large amounts of narcotics for pain control. She was started on long-term total parenteral nutrition (TPN), and a Hickman catheter was placed.

	Approximately 1 month later, our institution tried and failed to perform an endoscopic minor papilla sphincterotomy. The minor papilla could not be cannulated because of the swelling and inflammation surrounding it. The patient continued to require considerable narcotics and was losing weight despite home TPN. She eventually went to a regional tertiary referral center and underwent successful endoscopic sphincterotomy and stent placement in her minor papilla. The regional center was able to cannulate the minor papilla only after using methylene blue dye spray followed by an injection of secretin.

	This procedure relieved the patient's symptoms for 2 months, after which she returned to our institution due to an occluded stent, recurrent pancreatitis, and a scarred papilla. The stent was removed, and the patient underwent a surgical transduodenal minor papilla sphincteroplasty a few months later. Free pancreatic juice from the papilla was noted at the completion of the procedure.

	The patient's symptoms resolved completely for 208 days following this procedure. After she returned to the hospital with recurrent pancreatitis and diet intolerance, an ERCP showed scarring at the previous minor papilla sphincterotomy site but a normal-sized dorsal duct (Figure 2). Another sphincterotomy and stent placement were performed endoscopically. The patient did well for the following 6 months, and the stent was removed. Over the next 2 years, however, the patient required six hospital admissions. During each admission, she was allowed nothing by mouth for a few days, after which her symptoms improved and she was discharged to home on a regular diet. Her longest hospitalization during this time was for 7 days.

	Approximately 3 months after her last stent was removed, the patient returned to our institution reporting that she was moving to another state. Although she was asymptomatic, a repeat ERCP was performed at her request, and a new No. 7 French stent was placed. The minor papilla was not stenosed at the time and the dorsal pancreatic duct was larger than it had been 5 years earlier.

	Pancreatic divisum is often an incidental finding and typically does not cause symptoms, although it may be responsible for up to 25% of unexplained recurrent pancreatitis cases.

 ERCP is the gold standard test for diagnosing pancreas divisum. Cannulation of the major papilla reveals a short ventral duct (1 to 4 cm in length) that does not cross the midline. There generally is prompt drainage of contrast, and the morphology of the duct, including ductal branches, appears normal.

 Therapeutic interventions for symptomatic pancreas divisum aim to relieve obstruction of the minor papilla by improving pancreatic drainage. Warshaw and associates found that patients with symptomatic pancreas divisum and acute recurrent pancreatitis benefited the most from surgical sphincteroplasty.

 In this study, the mean followup period was 53 months, and the intraoperative identification of a stenotic papilla was associated with an 85% improvement rate after sphincteroplasty.

	In a study evaluating endoscopic minor papillotomy, Gerke and colleagues noted immediate improvement in 60% of patients after this procedure; however, 53% of patients had recurrent symptoms after 6 months.

 The long-term response rate to endoscopic minor papillotomy was only 33% after a median follow-up time of 29 months. The authors reported that endoscopic minor papillotomy was most successful in patients with symptomatic pancreatic divisum and acute recurrent pancreatitis. They suggested that prolonged stenting of the dorsal pancreatic duct can produce irreversible ductal damage and should be avoided.

	A retrospective study by Lehman and colleagues showed a 43% improvement in 51 patients with symptomatic pancreatic divisum following minor papillotomy over a dorsal duct stent after a mean follow-up of 20 months.

David A. Edelman, Surgical Resident; Choichi Sugawa, Professor of Surgery; Hiromi Ono, Endoscopy Fellow; James Tyburski, Associate Professor and Residency Program Director, Department of Surgery, Wayne State University, Detroit, MI

August 2007

August Challenge: What is the likely cause of this radiographic abnormality?

Umbilical hernia and endometriosis: A diagnostic consideration

American Board of Surgery Recerti%uFB01cation Examination

Small bowel volvulus: Time is of the essence

Strangulated lateral port-site hernia: Lessons to be learned

Treating pancreas divisum with a combined approach

Abdominal scar endometrioma mimicking incisional hernia

Stercoral perforation of the colon

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