Prognostic impact of severe postoperative complications after curative-intent resection for perihilar cholangiocarcinoma: an international multi-institutional analysis.

INTRODUCTION: We sought to evaluate the impact of severe postoperative complications on recurrence-free survival (RFS) after curative-intent resection for pCCA with particular attention to tumor biology. METHODS: An international multi-institutional database was queried to identify patients who underwent curative-intent liver resection for pCCA between 2000 and 2023. Patients who died within 90 days of surgery were excluded. Severe complications were defined as Clavien-Dindo grade ≥ III. RESULTS: Among 453 patients, the median age was 67 years (IQR, 57-74), 62.3% were male, 29.3% had CA19-9 ≥400 U/mL, and 36.6% experienced severe postoperative complications. Overall, 3-year RFS was worse among patients with severe complications versus those without (26.7% vs 30.7%; p = 0.044). This association was more pronounced among patients with CA19-9 <400 U/mL (25.4% vs 32.9%; p = 0.014), whereas no difference was observed among patients with CA19-9 ≥400 U/mL (28.3% vs 24.9%; p = 0.88). On multivariable analysis, severe complications remained independently associated with worse RFS among patients with CA19-9 <400 U/mL (HR 1.39, 95% CI 1.03-1.88; p = 0.03), but not among individuals with CA19-9 ≥400 U/mL (HR 0.78, 95% CI 0.48-1.28; p = 0.32). On sensitivity analyses using a Fine-Gray competing risk model, severe postoperative complications were not independently associated with recurrence in either subgroup. CONCLUSIONS: The association between severe postoperative complications and long-term outcomes appeared more evident among patients with more favorable tumor biology.