A case of an intramesosigmoid hernia.

We report an extremely rare case of an intramesosigmoid hernia with small bowel herniation in a defect on the right (medial) leaf of the mesosigmoid. A 46-year-old man was admitted to the hospital complaining of lower abdominal pain, nausea, and vomiting for 6 days. He had undergone an operation for a right inguinal hernia and an appendectomy during childhood. An abdominal X-ray film obtained at admission showed small bowel gas with niveau formation which was diagnosed as small-bowel obstruction. A decompression tube was immediately inserted, and the symptoms subsided. Enterography revealed two strictures separated by approximately 10 cm. However, the contrast medium flowed smoothly through the anal side of the strictures. After the decompression tube was removed, small-bowel obstruction recurred, and laparotomy was performed on the 18th day after admission. During the operation, small bowel herniation with a 4 x 3-cm defect was found on the right leaf of the mesosigmoid, and intramesosigmoid hernia was finally determined to be the cause of the small-bowel obstruction. The resection of the incarcerated part was necessary because a large amount of scar tissue was present on the surface. The postoperative course was uneventful, and no recurrence was observed after discharge. A review of this case indicated that the diagnosis might have been successfully obtained with enterography. Although we did not choose laparoscopic surgery, this surgical modality may also be an appropriate treatment for this disease.