Meckel’s diverticulum is the most prevalent congenital defect of the gastrointestinal tract present in 2-4% of population due to persistence of the yolk sac during embryogenesis. The most common presentations include ulceration (54%), bleeding, diverticulitis, perforation and small bowel obstruction due to intussusception or a fibrous band that leads to internal hernia (14-53%)^1,2.

The foramen of Winslow is the space between the portal vein and the inferior vena cava. It is a virtual communication between the greater peritoneal cavity and the lesser sac, which becomes a real communication because of increased intra-abdominal pressure and generates an internal hernia³. Exceptionally, the presence of a fibrous band attached to the Meckel’s diverticulum may be the cause.

We present the case of a 68-year-old female patient, a heavy smoker with a history of overweight, chronic obstructive pulmonary disease (COPD) and conventional appendectomy, who consulted the emergency department for abdominal pain in the epigastrium associated with abdominal bloating and bilious vomiting for the last 72 hours. On physical examination the abdomen was distended and tender. Pain intensity was 7/10 and there was rebound tenderness. A computed tomography scan of the abdomen and pelvis with intravenous contrast agent showed jejuno-ileal loops with a maximum diameter of up to 40 mm associated with a change in caliber in the right hypochondrium. The proximal portion of the portal vein presented focal dilatation and a swirling appearance with distal narrowing at the level of the hepatic hilum, which showed extrinsic compression by a small bowel loop (Fig. 1). The differential diagnoses considered were internal right paraduodenal hernia or a lesser sac hernia (foramen of Winslow hernia), transmesenteric or transomental hernia, portal vein thrombosis associated with portal vein dilatation, or a tumor at the level of the hepatic hilum. As the clinical picture was interpreted as acute abdomen due to small bowel obstruction, surgery was decided.

Figure 1 Ileal loop compressing the portal vein (black arrow), proximal portal vein dilation (black arrowhead) and dilated jejuno-ileal loops with a maximum diameter no longer than 40 mm (long black arrow). 

An exploratory laparotomy was performed. The bowel loops with macroscopic evidence of ischemia were exteriorized. There was an internal hernia in the right hypochondrium with an incarcerated ileal loop in the foramen of Winslow that produced compression of the portal vein. After the hernia was reduced, a Meckel’s diverticulum was seen at the herniated ileal loop (Fig. 2), 30 cm from the ileocecal valve and measuring 10 cm in length. The necrotic bowel loops of approximately 80 cm long and the Meckel’s diverticulum were resected and an isoiperistaltic stapled side-to-side anastomosis was created.

Figure 2 Giant Meckel’s diverticulum 30 cm from the ileocecal valve (short black arrow) and distal bowel loop (black arrowhead). 

The patient had favorable postoperative outcome and was discharge on postoperative day 7. The postoperative pathology examination reported small bowel wall with extensive areas of edema, hemorrhage and thrombi in the submucosal layer. The normal histology of the surgical margins was preserved.

Eight percent of internal hernias occur in the foramen of Winslow which presents a mean opening between 4.5-9 cm in diameter⁴. A reduction in its diameter due to abnormalities during embryogenesis may promote the development of an internal hernia. Other congenital defects, as a Meckel’s diverticulum with a persistent fibrous band connecting to the umbilicus, may promote hernia incarceration^2,5. Meckels’ diverticulum is located 7 to 200 cm proximal to the ileocecal valve, may have heterotopic gastric or pancreatic tissue and is approximately 2-3 cm long. It may be found incidentally during a surgical procedure or produce symptoms in 4 to 9% of patients^2,6,3. The treatment of choice is surgical excision of the diverticulum through small bowel resection and anastomosis or diverticulectomy^1.2.

The peculiarity of the case presented is the subhepatic location of the diverticulum directed towards the foramen of Winslow and with partial compression of the portal vein. The diverticulum length was 10 cm, longer than the mean size; the pathology examination did not report heterotopic tissue, and thus falls into the 50% of cases with normal tissue⁶.

We found a similar case in the literature, reporting an internal hernia within the foramen of Winslow caused by a Meckel’s diverticulum. On this occasion, a laparoscopic approach was used, and the diverticulum was smaller and without associated vascular involvement³. The identification and diagnosis of an incarcerated internal hernia and the decision for immediate surgical intervention are essential to avoid complications.