Image of the Month—Diagnosis

Figure 2(axial computed tomography) reveals a right-sided obturator hernia containing the distal ileum. The herniated bowel loop shows prominent wall enhancement consistent with early vascular compromise. A diagnosis of strangulating obturator hernia causing small-bowel obstruction was made, and the patient underwent laparotomy.

The small bowel within the hernia was reduced with gentle traction. An ischemic-looking 2-cm knuckle of bowel was found and resected with 3-cm margins. After lavage of the peritoneal cavity, the mesenteric defect was closed with Vicryl sutures. A composite mesh (Parietex; Covidien, Mansfield, Massachusetts) was then sutured to the pubic symphysis in the midline and to the Cooper ligament laterally. The lateral free edge of the mesh was sutured inferiorly to the round ligament. The lower edge was laid down into the pelvic floor. Our patient had an uneventful postoperative recovery and was discharged home a week later.

Obturator hernia is a rare condition, accounting for approximately 1.5% of all hernias and up to 2% of all cases of mechanical intestinal obstruction. It is associated with the highest mortality rate (up to 40%) of all abdominal hernias. The diagnosis should be suspected in elderly women (male to female ratio, 1:6; mean age, 60 years) presenting with small-bowel obstruction, especially when there is no history of abdominal surgery.¹

The obturator canal is 1 to 2 cm long and 1 cm wide. With significant weight loss as in debilitated individuals, the normal fat pad of the canal disappears and raised intra-abdominal pressure can cause herniation. It is thought to be more common in women owing to a sex-specific larger obturator canal diameter. The hernia compresses the obturator nerve, producing pain and paresthesia of the anterior thigh (the Howship-Romberg sign). Abdominal contents traverse the obturator canal, coming to lie behind the pectineus muscle in the thigh.

The clinical presentation is usually intermittent, with mechanical small-intestinal obstruction followed by pain in the thigh or groin area.

Owing to the lack of obvious external manifestations and the lack of clinical suspicion, the diagnosis of mechanical bowel obstruction secondary to an obturator hernia is often delayed. The often debilitated state of patients with an obturator hernia and the frequent delay in diagnosis combine to produce significant operative morbidity and mortality rates.²

Computed tomographic findings are typical and convincingly exclude other causes of bowel obstruction.³

The usual surgery involves stretching the obturator fascia and reducing the hernia sac into the peritoneal cavity.^4,5Recurrence is prevented by stitching 1 of the uterine ligaments (usually the broad ligament) over the obturator opening. A resection anastomosis is required in cases where the contained bowel is not viable.

Laparoscopic techniques have been successfully applied to diagnose, reduce, and repair these hernias.⁶Laparoscopic repair with intracorporeal bowel resection and anastomosis may be considered in already debilitated patients to minimize the risk of morbidity and mortality.

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Correspondence:Kshitij Mankad, MBBS, MRCP, Department of Radiology, Leeds Teaching Hospitals NHS Trust, Radiology Academy, Clarendon Wing, Leeds General Infirmary, Leeds LS1 3EX, England (drmankad@gmail.com).

Accepted for Publication:December 31, 2006.

Author Contributions:Study concept and design: Mankad and Hoey. Acquisition of data: Hoey. Analysis and interpretation of data: Mankad and Hoey. Drafting of the manuscript: Mankad and Hoey. Critical revision of the manuscript for important intellectual content: Mankad and Hoey. Administrative, technical, and material support: Mankad and Hoey. Study supervision: Mankad and Hoey.

Financial Disclosure:None reported.