Internal herniation of the right colon through the foramen of Winslow: A case report

Introduction and importance: Herniation through the Foramen of Winslow, also known as the epiploic foramen, is an extremely rare phenomenon with less than 200 cases reported in medical literature. Internal hernias account for less than 1% of all hernias and roughly 8% of all internal hernias occur through the foramen of Winslow. We present a case of a foramen of Winslow hernia that was not detected until direct visualization with laparoscopy.Presentation of case: A 52 year-old healthy female with a surgical history of a Caesarean section presented to the ER with severe epigastric pain radiating to her back. Physical exam was positive for abdominal tenderness and guarding. Vital signs were within normal limits. Murphy's sign and Rovsing's sign were negative. Initial imaging studies, including a CT scan of the abdomen, and laboratory findings were unremarkable. A hepatobiliary iminodiacetic acid (HIDA) scan was performed and demonstrated non-visualization of the gallbladder suggestive of acute vs. chronic cholecystitis. Following these results the patient elected to undergo exploratory laparoscopy with potential cholecystectomy. Intra-operatively, the colon was noted to be herniated through the foramen of Winslow. The procedure was converted to an open laparotomy. The hernia was manually reduced, and a right hemicolectomy was performed to prevent recurrence of the hernia.Discussion: Reports list an enlarged foramen of Winslow, excessive viscera mobility (i.e., persistent ascending mesocolon or long small bowel mesentery), and an increase in intra-abdominal pressure as potential risk factors for this particular hernia. In our case, the patient was noted to have excessive mobility of the viscera with the presence of persistent ascending mesocolon and an abnormally long right mesentery. Physical exam is usually nonspecific and laboratory findings are typically unremarkable, posing a diagnostic challenge. Additionally, radiological findings indicating presence of an internal hernia were missed in the initial CT scan read by the radiologist. Internal hernias need to be managed surgically as there is a risk of strangulation with bowel ischemia.Conclusion: This rare radiographic phenomenon is difficult to diagnose radiographically and warrants further workup due to the potential risk of bowel strangulation despite negative clinical and laboratory findings.