Bowel obstruction following liver transplantation: Clinical and CT findings in 48 cases with emphasis on internal hernia

PURPOSE: To review the incidence, cause, and radiologic findings of bowel obstruction in patients who have undergone orthotopic liver transplantation (OLT). MATERIALS AND METHODS: Retrospective review of 4,001 cases of OLT revealed 48 cases of bowel obstruction in 44 patients. Seventeen computed tomographic (CT) scans and seven barium-enhanced radiographs were reviewed to determine level and cause. Surgical proof was available in 45 cases, while three had characteristic clinical and radiographic features. RESULTS: Adhesions caused the obstruction in 19 cases in 16 patients; three had bowel ischemia. Internal hernias caused obstruction in 18 patients; all obstructions were transmesenteric or retroanastomotic and occurred with choledochoenteric anastomosis. Seven patients had volvulus; four had bowel ischemia. CT signs of internal hernia included mesenteric vascular abnormalities and clusters of dilated small-bowel segments that displaced the colon away from the abdominal wall. Prospective diagnosis of internal hernia was made in only one case. Incisional or inguinal hernia caused obstruction in seven patients; CT was used just once. Four patients had neoplastic bowel obstruction, three due to posttransplantation lymphoprotiferative disorder and one due to colon carcinoma. CONCLUSION: Liver transplantation was complicated by bowel obstruction in 48 (1.2%) of 4,001 cases. While adhesions and incisional hernias are common and well recognized, other causes are more challenging to diagnose. The CT findings reported here may allow more accurate diagnosis of internal hernia.