Strangulated obturator hernia: a case report with literature review

Obturator hernia is rare. It occurs when part of the pelvic contents protrude through the obturator foramen. It is a diagnostic challenge in the emergency department since the signs and symptoms are non-specific. It often occurs in elderly, emaciated and chronically ill women. The clinical picture include intestinal obstruction with abdominal pain, nausea and vomiting. The treatment is only surgical. Delayed diagnosis of this condition usually leads to a high mortality rate. We report the case of an 83-year-old woman with a strangulated obturator hernia. The hernia was discovered early by computed tomography and was treated by emergency laparotomy. We emphasize on the rule of CT scan to establishing a prompt preoperative diagnosis of an obturator hernia, appropriate planning of surgical intervention and thus optimizing the outcome.


Introduction
Obturator hernia is a rare abdominal wall hernia with incidence of 1% [1]. It occur when the intestine protrudes through a defect in the obturator foramen and into the obturator canal [2]. It most commonly presents as non-specific signs of acute intestinal obstruction with contents being small bowel in majority of cases. Obturator hernias are potentially the most lethal of all abdominal wall hernias due to diagnosis delay and complications of this unknown pathology. Various imaging modalities have been applied to establish the diagnosis but the CT scan has superior sensitivity and accuracy [3]. Here we present a case of obturator hernia causing bowel obstruction which was diagnosed by CT scan and was successfully operated in emergency. obstruction. The diagnosis of strangulated small-bowel obstruction secondary to a left obturator hernia was confirmed and the decision was to carry out surgery. At laparotomy, a strangulated centimeter segment of ileum was resected from the right obturator hernia defect and a side-to-side anastomosis was done. The obturator defect was closed with simple sutures. Patient was kept in high intensity care unit for 3 days. She was discharged after 10 days.

Discussion
Obturator hernias are characterised by bowel herniating between the obturator and the pectineus muscles. They are a rare type of abdominal hernia. With the nickname "little old lady's hernia", they are often seen in elderly, chronically ill and thin women [1]. The hernia sac can also contain appendix, Meckels diverticulum, omentum, ovary, fallopian tube and even uterus [4]. Due to non-specific signs and symptoms, the diagnosis and treatment of this condition are usually delayed, which has led to high mortality rate and can be very difficult to diagnose clinically [5]. The obturator foramen of iliac bone is sealed by a thick membrane which drilled by the obturator canal. This 2-3cm tunnel contains the obturator neurovascular bundle. It is through this deficiency that an obturator hernia occurs facilitated by the atrophy and loss of preperitoneal fat around obturator vessels. Multiparity, constipation, ascites, and causes of raised intra-abdominal pressure are the other predisposing factors. These hernias are more common on the right due to the left position of sigmoid colon in the pelvis [6].
The most common clinical presentation of obturator hernia is intestinal obstruction, with nausea, vomiting, abdominal pain, distension and weight loss, but this is nonspecific [7]. The hernia orifice is small, so bowel pinching and strangulation are frequent and mortality remains high (25%-47.6%) [7]. Since the use of CT scan, pre-operative diagnosis rate was improved from 43% to 90% in some reports [2]. The only treatment for obturator hernia is surgery [1,2]. In the emergency setting, the abdominal approach via a low midline incision is favored. Resection of the involved portion of bowel is sometimes required because of gangrenous change or perforation.

Conclusion
An obturator hernia is very rare and difficult to diagnose. It occurs when part of the pelvic contents protrude through the obturator foramen. In elderly and chronically ill women with signs of bowel obstruction, this type of hernia must be considered. Abdominal CT scan is actually the best diagnosis tool.

Competing interests
The authors declare no competing interests.

Authors' contributions
All the authors have read and agreed to the final manuscript.