Hepatic resection for metastatic colon cancer in patients with situs inversus totalis complicated by multiple anomalies of the hepatobiliary system: the first case report.

BACKGROUND: Situs inversus totalis is a rare condition characterized by a mirror-image transposition of the abdominal and thoracic viscera. In order to develop safe techniques for hepatic resection, it is important to report surgical outcomes in cases complicated by situs inversus totalis and other anomalies. CASE: The patient was a 64-year-old man with situs inversus totalis who had previously undergone sigmoidectomy with regional lymphadenectomy for sigmoid colon cancer at age 62. Despite postoperative adjuvant chemotherapy, tumor markers increased and multiple liver metastases were detected on abdominal ultrasonography. Enhanced computed tomography revealed not only liver metastases but also hepatobiliary anomalies associated with situs inversus totalis as follows: (1) portal vein located anterior to the common bile duct or hepatic artery, (2) proper hepatic artery arising from the superior mesenteric artery, (3) "left" (right in normal population)-sided umbilical portion of the portal vein and total ramification of intrahepatic portal branches from that point, (4) hepatic vein directly communicating to the "left" atrium. For the treatment of hepatic metastases from sigmoid colon cancer in a patient with situs inversus totalis, "left" hepatic lobectomy, partial hepatectomy, and radiofrequency ablation therapy were performed. The postoperative course was uneventful. Adjuvant chemotherapy has been continued for 2 years after the second operation and the patient is doing well without recurrence.
CONCLUSION: Since situs inversus totalis is occasionally accompanied by multiple hepatobiliary anomalies, careful evaluation of the related anatomy using modern imaging modalities is crucial for safe hepatic resection.