Objective: The aim of this study was to define robust benchmark values for the surgical
treatment of perihilar cholangiocarcinomas (PHC) to enable unbiased comparisons. Background:
Despite ongoing efforts, postoperative mortality and morbidity remains high after
complex liver surgery for PHC. Benchmark data of best achievable results in surgical
PHC treatment are however still lacking. Methods: This study analyzed consecutive
patients undergoing major liver surgery for PHC in 24 high-volume centers in 3 continents
over the recent 5-year period (2014-2018) with a minimum follow-up of 1 year in each
patient. Benchmark patients were those operated at high-volume centers (>= 50 cases
during the study period) without the need for vascular reconstruction due to tumor
invasion, or the presence of significant co-morbidities such as severe obesity (body
mass index >= 35), diabetes, or cardiovascular diseases. Benchmark cutoff values were
derived from the 75(th) or 25(th) percentile of the median values of all benchmark
centers. Results: Seven hundred eight (39%) of a total of 1829 consecutive patients
qualified as benchmark cases. Benchmark cut-offs included: R0 resection >= 57%, postoperative
liver failure (International Study Group of Liver Surgery): <= 35%; in-hospital and
3-month mortality rates <= 8% and <= 13%, respectively; 3-month grade 3 complications
and the CCI: <= 70% and <= 30.5, respectively; bile leak-rate: <= 47% and 5-year overall
survival of >= 39.7%. Centers operating mostly on complex cases disclosed better outcome
including lower post-operative liver failure rates (4% vs 13%; P = 0.002). Centers
from Asia disclosed better outcomes. Conclusion: Surgery for PHC remains associated
with high morbidity and mortality with now the availability of benchmark values covering
21 outcome parameters, which may serve as key references for comparison in any future
analyses of individuals, group of patients or centers.
