Sigmoid mesocolon hernia is an uncommon type of internal hernia with only a few cases reported to date. This disease entity can progress rapidly to cause vascular disturbance, necrosis, and perforation of the bowel wall; therefore, early diagnosis and surgical treatment are essential. We describe the case of an intra-mesosigmoid hernia in a 60-year-old man without history of previous abdominal surgery who presented with sudden acute abdominal pain and vomiting. Based on computed tomography, which showed ascites and small bowel obstruction, we diagnosed him as having strangulation of the small intestine caused by a sigmoid mesocolic hernia and performed emergency surgery. Laparotomy revealed small intestinal strangulation, extensive engorgement, and discoloration of bowel loops. Approximately 100 cm of the small intestine extending from the ligament of Treitz had undergone strangulation and herniated into the defect of sigmoid mesocolon, leading to a diagnosis of an intra-mesosigmoid hernia. Because the incarcerated portion of the small intestine was viable, we did not perform intestinal resection and reconstruction but closed the defect in the sigmoid mesocolon. His postoperative course was uneventful.
Keywords: Internal hernia; Intra-mesosigmoid hernia; Strangulation.