Oncological outcome of R1 vascular margin for mass-forming cholangiocarcinoma. A single center observational cohort analysis

BackgroundRecent studies validated the possibility to detach colorectal liver metastases from vessels (R1vasc) featuring R1vasc equivalent to R0 and superior to tumor exposure along the transection plane (R1par). To clarify the outcome of R1 surgery (margin <1 mm) in patients with intrahepatic cholangiocarcinoma (MFCCC), distinguishing R1par and R1vasc resections.MethodsPatients undergoing resection for MFCCC between 2008 and 2016 were considered. Tumor detachment from 1st/2nd-order Glissonean pedicles or hepatic veins was performed in advanced diseases. R0, R1par, and R1vasc were compared.ResultsThe study included 84 resection areas in 59 patients (17 R1vasc). R1vasc group had local recurrence risk similar to R1par group (per-patient analysis 29% vs. 36%; per-resection area analysis 29% vs. 32%), higher than R0 group (3% and 2%, p = 0.003 and p = 0.0003). R1vasc and R1par groups had similar overall and recurrence-free survival (median OS 30 vs. 30 months; RFS 10 vs. 8 months), lower than R0 group (70 and 39 months, p = 0.066 and p = 0.007).ConclusionIn MFCCC patients, R1vasc resection is not an adequate treatment. Local disease control and survival after R1vasc resection are lower than after R0 resection and similar to R1par resection. R1vasc resection could be exclusively considered to achieve resectability in otherwise unresectable patients.