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Axial torsion of Meckel's diverticulum

A 44-year-old man presented to the emergency department with central umbilical and right iliac fossa pain for 1 day. On examination, he was tender over the umbilical region with localized guarding. Apyretic and haemodynamically stable, he had slight leucocytosis (12.1 × 10/L) and raised C-reactive protein (304 mg/L). Contrastenhanced computed tomography (CECT) of the abdomen showed a 10 × 5.2 cm blind-ending, distended, tubular structure in the right iliac fossa, extending and crossing the midline (Fig. 1a). The stalk was twisted on itself in the mid portion (Fig. 1b). The wall was thickened with patchy mural enhancement. The first impression was of a distended appendix, but on closer inspection, the base of this structure was noted to be in close relation to the anti-mesenteric border of the terminal ileum. Furthermore, the appendix was seen separately arising from the caecum and normal in appearance. Findings were compatible with Meckel’s diverticulitis with torsion. Subsequent, exploratory laparotomy revealed axial torsion, an infarction (Fig. 2) of Meckel’s diverticulum (MD) with omental adhesions. The proximal diverticulum, near its base, showed fibrous narrowing. A resection of MD with limited terminal ileum resection was performed without difficulty. The postoperative recovery was uneventful, and the patient was discharged after 1 week. The histopathological examination showed variable infarction of the wall with ischaemic necrosis. MD is the most common congenital anomaly of the gastrointestinal tract, first described by Johann Friedrick Meckel (1809). It is commonly found incidentally and has a total lifetime rate of complications of 4%. An often quoted memory aide is the rule of 2s; the diverticulum is usually 2 in long, 2 ft from the ileocecal valve, is found in 2% of the population and twice more frequently in males (2:1). It is the only true diverticulum of small intestine containing all the layers of small bowel. It is invariably located along the anti-mesenteric border of the ileum. The common complications of MD include rectal bleeding, intestinal obstruction, diverticulitis and perforation. The rare complications are perforation due to foreign bodies, primary neoplasms, strangulation or vesicodiverticular fistulae. Axial torsion of MD is an extremely rare complication, reported only in 11 studies in the literature, likely resulting from axial twisting of the MD around its base. Torsion causes decreased perfusion, eventually leading to ischaemia and gangrene. Risk factors attributing to axial torsion include benign or malignant neoplasms of MD, such as leiomyoma, fibroma, lipoma, carcinoid tumour, adenocarcinoma, leiomyosarcoma, etc. Other reported risk factors include fibrous vitelline bands connecting MD to the abdominal wall. The anatomical configuration of the MD also plays some role, with the disproportion between the length and the base diameter an important contributory factor. In our case, the diverticulum was 10 cm long and 2 cm wide, indicating that its long length may have predisposed to torsion. Patients with torsed MD present with abdominal pain, frequently localized to the right lower quadrant, closely mimicking conditions such as acute appendicitis, as in our case. Hence, it can be frequently misdiagnosed clinically.