Early Prediction of a Serious Postoperative Course in Perihilar Cholangiocarcinoma: Trajectory Analysis of the Comprehensive Complication Index.

OBJECTIVE:The aim of this study was to visualize the postoperative clinical course using the comprehensive complication index (CCI) and to propose an early alarming sign for subsequent serious outcomes in perihilar cholangiocarcinoma. BACKGROUND:Surgery for this disease carries a high risk of morbidity and mortality. The developmental course of the overall morbidity burden and its clinical utility are unknown. METHODS:Patients who underwent major hepatectomy for perihilar cholan-giocarcinoma between 2010 and 2019 were reviewed retrospectively. All postoperative complications were evaluated according to the Clavien-Dindo classification (CDC), and the CCI was calculated on a daily basis until postoperative day 14 to construct an accumulating graph as a trajectory. Group-based trajectory modeling was conducted to categorize the trajectory into clinically distinct patterns and the predictive power of early CCI for a subsequent serious course was assessed. RESULTS:A total of 4230 complications occurred in the 484 study patients (CDC grade I, n = 27; II, n = 132; IlIa, n = 290; IIIb, n = 4; IVa, n = 21; IVb, n = 1; and V, n = 9). The trajectory was categorized into 3 patterns: mild (n = 209), moderate (n = 235), and severe (n = 40) morbidity courses. The 90-day mortality rate significantly differed among the courses: 0%, 0.9%, and 17.5%, respectively (P<0.001). The cutoff values of the CCI on postoperative days 1, 4, and 7 for predicting a severe morbidity course were 15.0, 28.5, and 40.6 with areas under the curves of 0.780, 0.924, and 0.984, respectively. CONCLUSIONS:The CCI could depict the chronological increase in the overall morbidity burden, categorized into 3 patterns. Early CCI potentially predicted sequential progression to serious outcomes.