Clinical impact of intraoperative histological examination of the ductal resection margin in extrahepatic cholangiocarcinoma

Background: Although ductal resection margin status in extrahepatic cholangiocarcinoma is evaluated by intraoperative histological examination of frozen sections, its clinical relevance remains controversial. Methods: Material taken from patients who underwent RO or Rl resection for extrahepatic cholangiocarcinoma with intraoperative histological examination of the final ductal resection margins between 1994 and 2003 were reviewed. The following histological classification was used: insufficient, negative for malignancy (NM), undetermined lesion (UDL) or positive for malignancy (PM). Multivariable analyses of overall survival and anastomotic recurrence in relation to ductal margin status were perforied. Results: Resection material from 363 patients was identified. For the proximal ductal margin, only PM in intramural lesions was significantly associated with poor survival (hazard ratio (HR) 1-72, 95 per cent confidence interval (ci.) 1-06 to 2-74) and anastomotic recurrence (HR 6-39, 95 percent c.i. 1-89 to 21-62) compared with NM. In analysis of overall survival according to distal ductal margin status, the HRs for UDL and PM lesions in comparison with NM were not significant. Conclusion: PM in intramural lesions found during intraoperative histological examination of the proximal ductal resection margin was related to clinical outcome. This finding favours additional resection of the bile duct. A similar association was not found for histology results of the distal resection margin.