Inverted Meckel’s diverticulitis manifesting as intussusception: unusual case of intestinal obstruction in adults

Introduction

Meckel’s diverticulum is a small intestinal diverticulum which is a remnant of the vitellointestinal duct and normally obliterates by weeks 5 to 8 of fetal development. Failure of closure of the duct can result in a spectrum of defects including umbilical fecal fistula, umbilical sinus, enterocystoma, fibrotic cord or diverticulum; Meckel’s diverticulum being the most common, accounting for 2% of the population with an equal incidence in males and females among the above- mentioned anomaly. ¹ It is usually located on the antimesenteric border of the ileum 45–60 cm proximal to the ileocecal valve and is 3–5 cm long. As the cell lining of the vitelline duct is pluripotent, it may contain heterotopic gastric mucosa in about 50% of cases, pancreatic mucosa (5%), jejunal, colonic, hepatobiliary tissue which is responsible for complications such as haemorrhage, peptic ulceration and perforation.^2,3 Occasionally, inversion of Meckel’s diverticulum into the lumen may cause intussusception, which can proceed further to obstruction infarction of diverticulum itself or intussuscepted bowel. ⁴ Here we present the case of a young man who presented with obstructed ileo-ileal intussusception with inverting Meckel’s diverticulum being the leading point, which we successfully managed operatively.

Case report

An 18-year old man presented to the emergency room with acute onset abdomen pain in the paraumbilical region for 5 days. Pain was colicky in nature, not relieved by analgesics, and was associated with episodes of bilious vomiting. He also complained of non-passage of flatus and stool for the past 3 days. There was no history of haematochezia or melena. On examination, the patient was conscious, with tachycardia of 102 per minute and blood pressure was 110/70 mmHg, he was dehydrated. Examination of the abdomen revealed mild distension, there was no visible bowel peristalsis, no guarding and rigidity. A few high-pitched bowel sounds were audible on auscultation. Per rectal examination was unremarkable. Laboratory reports showed normal blood cell counts and blood chemistry except for a raised leukocyte count (16,200/mm³). Abdominal X-ray showed dilated small bowel loops (about 4 cm) with a few air-fluid levels. Ultrasonogram demonstrated bowel within bowel configuration in the right iliac fossa, suggestive of ileo-ileal intussusception. Computed tomography (CT) scan demonstrated dilated small bowel loops in the central abdomen and pelvis, with abrupt transition in the terminal ileum with a long segment (9.5 cm) ileoileal intussusception with mesenteric fat as the leading point. There was no abnormal lymph node or soft tissue lesion seen. Mild circumferential mural thickening of the intussuscepted segment was seen (Figure 1).

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Figure 1.

Contrast enhanced computed tomography showing classic target sign (bowel within bowel) in the distal ileum.

On laparotomy, ileo-ileal intussusception was observed approximately 70 cm from the ileocecal junction, the bowel wall was healthy and the proximal bowel was dilated (Figure 2). We did not reduce the segment and went for resection of the intussusception and performed ileo-ileal anastomosis. On examination of the resected segment an elongated Meckel’s diverticulum measuring 10 × 2 cm was seen, with its tip gangrenous and impending perforation at its base (Figure 3). Histopathological examination revealed Meckel’s diverticulitis with necrotic mucosa, without ectopic mucosa or malignancy. Postoperatively, the patient made an uneventful recovery and was discharged on the seventh day.

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Figure 2.

Intra-operative image showing intussuscepted ileo-ileal segment with normal healthy bowel.

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Figure 3.

Resected specimen showing Meckel’s diverticulum with necrosis at the tip after reduction of the intussusception.

Discussion

Intestinal obstruction is the most common presentation seen in adults with Meckel’s diverticulum. ⁴ Intussusception in Meckel’s diverticulum sags into the intestinal lumen and serves as a lead point to allow telescoping of the bowel. ⁵ Inversion of Meckel’s diverticulum is not clearly understood but it has been hypothesised that abnormal peristaltic movement of the diverticulum due to ulceration or ectopic tissue at the base may be a cause. This inversion may lead to a complete intussusception of the bowel causing a compromise in blood flow of the bowel or diverticulum itself.^6,7

Clinical presentation in adult patients is often non-specific and long standing. The most frequent symptom is mild, periodic, intermittent in nature and accounts for the delay in diagnosis. ⁸ Ultrasonography is the first investigation of choice in diagnosing intussusceptions as it shows a classic ‘target’ or ‘doughnut’ appearance. However, it gives limited information in obese and gaseous abdomen. ⁸ However, abdominal CT is considered to be the most sensitive radiological method to confirm intussusception, with an accuracy of 58–100%. ⁹ The characteristic finding on CT scan in the early stages is target lesion in the cross-sectional view and eccentrically located areas of low density. ⁹ In the later stages, vascular compromise may be seen, showing a layering or stratification effect to bowel wall thickening and formation of amorphous mass. ¹⁰

Intraoperatively, the bowel should be examined for ischaemia. In the case of transmural ischaemia, the bowel should be resected along with diverticulum. Attempts at reduction should be made only in benign-appearing enteric intussusception, followed by resection of the lead point or organic lesion. If a suspicion of malignancy or colonic involvement is present, then resection without reduction is recommended. ¹⁰ Intussusception due to Meckel’s diverticulum is considered to be an indication for diverticulum resection. ¹⁰ In conclusion, Intussusception of Meckel’s diverticulum is a rare but important entity in view of the non-specific presenting symptoms. It should be considered and suspected in adult patients presenting with acute abdomen.