Clinical significance of intraoperative bile duct margin assessment for hilar cholangiocarcinoma

Background: Frozen section analysis of bile duct margins is often used to guide the extent of surgical resection for hilar cholangiocarcinoma (HCCA), but the usefulness of this practice is unknown. Methods: The association between disease-specific survival (DSS) and pathologic margin status determined during and after surgical resection for HCCA was assessed retrospectively for 101 patients between 1992 and 2005. Final histopathology identified three subgroups on the basis of resection margin status: wide margin (bile duct and specimen margins negative for adenocarcinoma), narrow margin (bile duct margin negative but specimen margins positive), and positive margin (bile duct and specimen margins positive). Results: On the basis of frozen section analysis alone, 90 patients were thought to have a disease-negative bile duct margin intraoperatively. Final histopathology showed that eight patients (9%) had invasive adenocarcinoma in the cuff of bile duct submitted for frozen section analysis. Of the 82 patients with negative final bile duct margins, 54 patients were categorized as having wide margins, and 28 patients had narrow margins. The median DSS for patients with wide margins was 56 months compared with 38 months for patients with narrow margins and 32 months for margin-positive patients (P = .01). Conclusion: Frozen section analysis of the proximal bile duct margin is misleading in 9% of patients. Among patients with HCCA who are determined to have negative duct margins intraoperatively, only 60% will have margins adequately wide enough to be associated with an improvement in DSS.