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Small-bowel Intestinal Obstruction Caused by an Unusual Internal Hernia
Case Report
Small-bowel Intestinal Obstruction Caused by an Unusual Internal Hernia Jimmy C.M. Li, David W. Chu, Danny W.H. Lee and Angus C.W. Chan, Department of Surgery, North District Hospital, New Territories East Cluster, The Chinese University of Hong Kong, Hong Kong SAR, China.
We report a rare case of transomental small-bowel herniation in a 91-year-old lady who presented with central abdominal pain and mild distension. Urgent abdominal computed tomography (CT) showed a segment of dilated ileum with features suggestive of strangulation. Emergency exploration revealed a segment of congested smallbowel loop herniated through a defect over the greater omentum. Reduction of the bowel loops and division of the omental defect was performed without the need for bowel resection. The patient made an uneventful recovery. We discuss the value of CT scan and highlight the importance of recognizing this rare cause of small-bowel obstruction. [Asian J Surg 2005;28(1):62–4] Key Words: small-bowel obstruction, internal hernia, transomental hernia
Introduction An internal hernia is formed by protrusion of a viscus segment through a peritoneal or mesenteric aperture, leading to its encapsulation within a compartment of the abdominal cavity. Acute small-bowel obstruction is the most common presentation of an incarcerated internal hernia. Of all intestinal obstructions, 4.1% are caused by internal hernia; transomental hernia is extremely rare and accounts for only 1–4% of internal hernias.1 We report a case of small-bowel obstruction caused by a transomental hernia.
Case report A 91-year-old lady presented with severe abdominal pain over the umbilical area for 1 day. The pain was colicky in nature and associated with vomiting. She had no history of abdominal surgery. She could not recall any history of abdominal trauma or significant abdominal infection. She had had a cerebrovas-
cular accident 3 years ago with good recovery. On physical examination, she was afebrile. Her abdomen was slightly distended with mild tenderness over the umbilical area. There was no surgical scar, no abdominal wall hernia and no abdominal mass. The bowel sound was hyperactive. Blood tests showed a normal white cell count and no metabolic acidosis. Abdominal radiography showed a few loops of dilated small bowel. Urgent computed tomography (CT) scan of the abdomen showed dilated, fluid-filled, small-bowel loops. There were some segments of thickened small bowel on the left side of the abdomen. The terminal ileum and large bowel were not dilated. The mesentery showed increased streakiness. There was a trace of free fluid intraperitoneally (Figure 1). Radiologically, the impression was small-bowel obstruction with suspected intestinal strangulation. Emergency laparotomy was performed. The jejunum and proximal ileum were dilated. A segment of mid-ileum, which measured 20 cm in length, was herniated through a 2.5 cm defect over the periphery of the greater omentum (Figure 2).
Address correspondence and reprint requests to Professor Angus C.W. Chan, Department of Surgery, North District Hospital and Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China. E-mail: [email protected] • Date of acceptance: 10 November 2003 © 2005 Elsevier. All rights reserved.
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■ SMALL-BOWEL INTESTINAL OBSTRUCTION ■
A
Figure 1. Computed tomography scan of the abdomen shows dilated, fluid-filled small-bowel loops and a collapsed terminal ileum and large bowel.
B
The segment of ileum looked congested but viable. The rest of the ileum and colon were normal. The affected small bowel was reduced and confirmed to be viable. The omentum was divided and the abdomen was closed. The patient recovered well and was discharged 1 week after the operation.
Discussion Internal herniation can be paraduodenal (30–53%), be due to Winslow’s foramen (8%), be paracaecal (6%) or transmesenteric (5–10%), or involve the broad ligament (4–7%) or sigmoid colon (5%).1 Herniation through a defect over the greater omentum, as in this case, accounts for approximately 1–4% of internal hernias in the literature.1 The hernia orifice is usually a slit-like opening of up to 10 cm located in the greater omentum.2 Most such hernias have a congenital origin, but trauma and inflammation may also produce omental perforation or weak areas.3 The defects can then serve as potential sites for transomental herniation. In the absence of a limiting sac, a considerable length of small intestine may protrude through the defect. Intestinal gangrene may develop if the blood supply is compromised when bowel strangulation occurs. Internal hernias have been diagnosed preoperatively by radiological imaging, i.e. CT scan, and small-bowel follow-through.4,5 Common CT findings are small-bowel obstruction; clustering of the small bowel; stretched, displaced, crowded and engorged mesenteric vessels; and possible displacement of other bowel segments.4 In our case, the radiological finding only suggested small-bowel strangulation but did not define the cause of the obstruction. The small segment of the ileum herniated through the omental defect meant that CT scan was not sensitive enough to detect the exact pathology. Combining the clinical
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Figure 2. (A) Segment of the mid-ileum herniated (‘H’) through an omental defect over the greater omentum; (B) intraoperative photograph shows the defect (‘D’) in the greater omentum (‘O’).
features and radiological findings, we managed to operate early in this case before irreversible bowel ischaemia occurred. High clinical suspicion and appropriate investigations including abdominal radiography and CT scan may aid the diagnosis of bowel strangulation secondary to internal hernia. Surgical treatment remains the mainstay of management when complications, e.g. obstruction, arise from an internal hernia. When CT scan is not readily available or does not show any abnormality, surgery should proceed according to clinical parameters. The possibility of an internal hernia should be considered in cases of acute or intermittent small-bowel obstruction, particularly in the absence of an external hernia or a history of previous abdominal surgery.
References 1. Stern LE, Warner BW. Congenital internal abdominal hernias: incidence and management. In: Robert JF, Gerson G, eds. Nyhus and Condon’s Hernia, 5th edition. Philadelphia: Lippincott Williams & Wilkins, 2002:453–65. 2. Estrada RL. Internal Intra-abdominal Hernias. Austin: RG Landes Co, 1994:168–75.
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3. Mock CJ, Mock HE. Strangulated internal hernia associated with trauma. Arch Surg 1958;77:881–6. 4. Blachar A, Federle MP, Dodson SF. Internal hernia: clinical and imaging findings in 17 patients with emphasis on CT criteria.
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Radiology 2001;218:68–74. 5. Takagi Y, Yasuda K, Nakada T, et al. A case of strangulated transomental hernia diagnosed preoperatively. Am J Gastroenterol 1996;91: 1659–60.
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Small-bowel Intestinal Obstruction Caused by an Unusual Internal Hernia Jimmy C.M. Li, David W. Chu, Danny W.H. Lee and Angus C.W. Chan, Department of Surgery, North District Hospital, New Territories East Cluster, The Chinese University of Hong Kong, Hong Kong SAR, China.
We report a rare case of transomental small-bowel herniation in a 91-year-old lady who presented with central abdominal pain and mild distension. Urgent abdominal computed tomography (CT) showed a segment of dilated ileum with features suggestive of strangulation. Emergency exploration revealed a segment of congested smallbowel loop herniated through a defect over the greater omentum. Reduction of the bowel loops and division of the omental defect was performed without the need for bowel resection. The patient made an uneventful recovery. We discuss the value of CT scan and highlight the importance of recognizing this rare cause of small-bowel obstruction. [Asian J Surg 2005;28(1):62–4] Key Words: small-bowel obstruction, internal hernia, transomental hernia
Introduction An internal hernia is formed by protrusion of a viscus segment through a peritoneal or mesenteric aperture, leading to its encapsulation within a compartment of the abdominal cavity. Acute small-bowel obstruction is the most common presentation of an incarcerated internal hernia. Of all intestinal obstructions, 4.1% are caused by internal hernia; transomental hernia is extremely rare and accounts for only 1–4% of internal hernias.1 We report a case of small-bowel obstruction caused by a transomental hernia.
Case report A 91-year-old lady presented with severe abdominal pain over the umbilical area for 1 day. The pain was colicky in nature and associated with vomiting. She had no history of abdominal surgery. She could not recall any history of abdominal trauma or significant abdominal infection. She had had a cerebrovas-
cular accident 3 years ago with good recovery. On physical examination, she was afebrile. Her abdomen was slightly distended with mild tenderness over the umbilical area. There was no surgical scar, no abdominal wall hernia and no abdominal mass. The bowel sound was hyperactive. Blood tests showed a normal white cell count and no metabolic acidosis. Abdominal radiography showed a few loops of dilated small bowel. Urgent computed tomography (CT) scan of the abdomen showed dilated, fluid-filled, small-bowel loops. There were some segments of thickened small bowel on the left side of the abdomen. The terminal ileum and large bowel were not dilated. The mesentery showed increased streakiness. There was a trace of free fluid intraperitoneally (Figure 1). Radiologically, the impression was small-bowel obstruction with suspected intestinal strangulation. Emergency laparotomy was performed. The jejunum and proximal ileum were dilated. A segment of mid-ileum, which measured 20 cm in length, was herniated through a 2.5 cm defect over the periphery of the greater omentum (Figure 2).
Address correspondence and reprint requests to Professor Angus C.W. Chan, Department of Surgery, North District Hospital and Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China. E-mail: [email protected] • Date of acceptance: 10 November 2003 © 2005 Elsevier. All rights reserved.
62
ASIAN JOURNAL OF SURGERY VOL 28 • NO 1 • JANUARY 2005
070/2001
■ SMALL-BOWEL INTESTINAL OBSTRUCTION ■
A
Figure 1. Computed tomography scan of the abdomen shows dilated, fluid-filled small-bowel loops and a collapsed terminal ileum and large bowel.
B
The segment of ileum looked congested but viable. The rest of the ileum and colon were normal. The affected small bowel was reduced and confirmed to be viable. The omentum was divided and the abdomen was closed. The patient recovered well and was discharged 1 week after the operation.
Discussion Internal herniation can be paraduodenal (30–53%), be due to Winslow’s foramen (8%), be paracaecal (6%) or transmesenteric (5–10%), or involve the broad ligament (4–7%) or sigmoid colon (5%).1 Herniation through a defect over the greater omentum, as in this case, accounts for approximately 1–4% of internal hernias in the literature.1 The hernia orifice is usually a slit-like opening of up to 10 cm located in the greater omentum.2 Most such hernias have a congenital origin, but trauma and inflammation may also produce omental perforation or weak areas.3 The defects can then serve as potential sites for transomental herniation. In the absence of a limiting sac, a considerable length of small intestine may protrude through the defect. Intestinal gangrene may develop if the blood supply is compromised when bowel strangulation occurs. Internal hernias have been diagnosed preoperatively by radiological imaging, i.e. CT scan, and small-bowel follow-through.4,5 Common CT findings are small-bowel obstruction; clustering of the small bowel; stretched, displaced, crowded and engorged mesenteric vessels; and possible displacement of other bowel segments.4 In our case, the radiological finding only suggested small-bowel strangulation but did not define the cause of the obstruction. The small segment of the ileum herniated through the omental defect meant that CT scan was not sensitive enough to detect the exact pathology. Combining the clinical
ASIAN JOURNAL OF SURGERY VOL 28 • NO 1 • JANUARY 2005
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Figure 2. (A) Segment of the mid-ileum herniated (‘H’) through an omental defect over the greater omentum; (B) intraoperative photograph shows the defect (‘D’) in the greater omentum (‘O’).
features and radiological findings, we managed to operate early in this case before irreversible bowel ischaemia occurred. High clinical suspicion and appropriate investigations including abdominal radiography and CT scan may aid the diagnosis of bowel strangulation secondary to internal hernia. Surgical treatment remains the mainstay of management when complications, e.g. obstruction, arise from an internal hernia. When CT scan is not readily available or does not show any abnormality, surgery should proceed according to clinical parameters. The possibility of an internal hernia should be considered in cases of acute or intermittent small-bowel obstruction, particularly in the absence of an external hernia or a history of previous abdominal surgery.
References 1. Stern LE, Warner BW. Congenital internal abdominal hernias: incidence and management. In: Robert JF, Gerson G, eds. Nyhus and Condon’s Hernia, 5th edition. Philadelphia: Lippincott Williams & Wilkins, 2002:453–65. 2. Estrada RL. Internal Intra-abdominal Hernias. Austin: RG Landes Co, 1994:168–75.
63
■ LI et al ■
3. Mock CJ, Mock HE. Strangulated internal hernia associated with trauma. Arch Surg 1958;77:881–6. 4. Blachar A, Federle MP, Dodson SF. Internal hernia: clinical and imaging findings in 17 patients with emphasis on CT criteria.
64
Radiology 2001;218:68–74. 5. Takagi Y, Yasuda K, Nakada T, et al. A case of strangulated transomental hernia diagnosed preoperatively. Am J Gastroenterol 1996;91: 1659–60.
ASIAN JOURNAL OF SURGERY VOL 28 • NO 1 • JANUARY 2005
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