Optimal Stenting Strategy During Chemotherapy: Impact of Time to First Reintervention on Survival in Malignant Hilar Biliary Obstruction.

Advances in chemotherapy have increased survival in biliary tract cancer patients, and reports of the effectiveness of neoadjuvant therapy are emerging. Accordingly, developing optimal drainage strategies under chemotherapy is important. We aimed to clarify suitable drainage methods and assess the prognostic value of the time to first reintervention (TTFR) following chemotherapy induction. We retrospectively analyzed 81 patients with malignant hilar biliary obstruction (MHBO) who underwent biliary stenting followed by chemotherapy between April 2012 and October 2023. TTFR following chemotherapy induction and drainage- and survival-related factors were evaluated. The median follow-up, survival, and TTFR were 425, 479, and 167 days, respectively. TTFR was correlated with overall survival (r = 0.60, p < 0.01). Univariable analyses identified prechemotherapy cholangitis and stenting above the sphincter of Oddi (SO) as factors associated with shorter TTFR, whereas multivariable analysis revealed stenting above the SO as the only independent factor (hazard ratio [HR] 0.44, p = 0.01). Among 52 non-endoscopic sphincterotomy (EST) patients, prechemotherapy cholangitis (HR 2.05, p = 0.04), stenting above the SO (HR 0.47, p = 0.04), and multiple drainage segments (HR 0.42, p = 0.04) influenced TTFR in univariable analyses. No significant factor was detected among 28 patients undergoing EST. The TTFR was comparable between above- and across-SO placement groups up to 2 months, but superior in the above-SO group at 6 months (69%-73% vs. 27%-42%). TTFR following chemotherapy induction is a prognostic factor in MHBO patients. Stenting above the SO may prolong TTFR, particularly in those without prior EST or expected to continue chemotherapy beyond 2 months. Trial Registration: N/A.