Hellenic Journal of Surgery 86 Congenital Mesenteric Defect – A Rare Cause of Internal Herniation in Adults Avijit Roy, Anadi Nath Acharya, Nemai Nath Hellenic Journal of Surgery (2014) 86:6, 391-393 Dr. Avijit Roy, MS, RMO cum Clinical Tutor, Dept of Surgery, Murshidabad Medical College & Hospital, Berhampore,West Bengal. Prof. (Dr.) Anadi Nath Acharya, MS, DNB, FRCS Professor, Dept of Surgery, Murshidabad Medical College & Hospital. Berhampore, West Bengal. Prof. (Dr.) Nemai Nath, MS Professor and Head, Dept of Surgery, Murshidabad Medical College & Hospital. Berhampore, West Bengal Corresponding author: Dr. Avijit Roy, MS, RMO 80/10 Ukilabad Road, P.O. Berhampore, District- Murshidabad, West Bengal, India, Pin-742101, Tel.: +91 9434135081 e-mail: dravijitroy@gmail.com, Received 26 July 2014; Accepted 11 Sept 2014 CASE REPORT Abstract Background: Mesenteric defect, congenital or acquired, is a rare cause of internal hernia. Most documented cases of internal hernias caused by congenital mesenteric defects are described in the paediatric population; its incidence is very rare in adults. Case report: We present the case of a previously asymptomatic 65-year-old man with a defect involving the mesentery of the terminal ileum. Almost the entire ileum had herniated through it twice in a complex manner and had become strangulated. The residual mesenteric defect was closed after relieving the obstruction, resecting the gangrenous part of ileum, and performing an end-to-side ileotransverse anastomosis. Results: The recovery was uneventful and the patient was discharged on the eleventh postoperative day. Conclusion: Reports of strangulated congenital mesenteric hernia at this age are scarce. Severe unexplained abdominal pain in adults with a virgin abdomen can be due to mesenteric hernia. A high index of suspicion and early surgical intervention can prevent a potential catastrophe. Key words: Congenital internal hernia, mesenteric hernia, small bowel obstruction, strangulation, adult Introduction Congenital internal hernia as a result of mesenteric de- fect is a rare cause of bowel obstruction in adults and often presents with complications. A high index of suspicion, occasionally aided by appropriate radiological imaging, should prompt early surgical intervention and thus reduce morbidity and mortality. Case report A 65-year-old man presented with acute intestinal obstruction with peritonitis. Hernial orifices were normal and he had no history of abdominal trauma or surgery. An abdominal X-ray suggested small bowel obstruction. On exploration, the entire ileum was found to be herni- ated through a three centimetre gap in the mesentery of the terminal ileum. Part of the loop was wrapped around itself like an ileal knot and was gangrenous. The obstruction was relieved, the gangrenous gut re- sected, the terminal ileum closed and a primary end-to-side ileotransverse anastomosis was made. The residual mesen- teric defect was repaired. Following peritoneal toileting and the placement of a tube drain in the pelvis, the abdomen was closed en mass. Discussion Internal herniation accounts for only 0.2% to 0.9% of all cases of small bowel obstruction [1,2]. It can be congenital or acquired. Common presentations of internal hernias include paraduodenal (50%), supra and/or perivesical, intersigmoid, through the foramen of Winslow, omental defect and postoperative, post traumatic and congenital mesenteric defects [3]. Mesenteric defects are an established cause of internal herniation even in non-operated abdomens and provide a potential site for intestinal incarceration or strangulation. Congenital mesenteric defects most often occur in the small bowel mesentery and less commonly in the colonic mesentery. The vast majority of these cases have been re- ported in infants or children, often with an associated intra-