The Comprehensive Complication Index CCI: A proposed modification to optimize short-term complication reporting after cystectomy and urinary diversion.

Objective: To optimize complication reporting in patients undergoing cystectomy and urinary diversion (UD) using the Comprehensive Complication Index (CCI). The original CCI ranging from 0 (no complications) to 100 (death) integrates all complications weighted by severity over time in a single formula. However, due to the large number of complications after cystectomy and UD, the CCI may exceed the upper limit.

Methods: In an observational single-center cohort, 90-day postoperative complications in 1,313 consecutive patients undergoing cystectomy and UD from 2000 to 2017 were evaluated. Prospectively collected complications were graded according to the Clavien-Dindo classification (CDC). A modified Berne CCI was developed using an exponential function, which transforms the sum of the weights into a value between 0 and 100. The correlation between the Berne and original CCI values was depicted graphically. Finally, original CCI and Berne CCI values for each patient were extracted and compared. Predictive values of CCI scores for mortality or severe complications (CDC ≥IV) within 1 year postoperatively were investigated by use of multiple logistic regression analyses.

Results: Overall complication rate was 82%, with CDC grade I to II in 56% and CDC grade IIIa to V in 27% respectively. Applying the original CCI, the upper limit was exceeded in 8 patients, with a maximal value of 119.1 (median 25.7 [interquartile range: 20.9-37.2]). The maximal value of the Berne CCI was 99.4 (21.2 [14.6-39.3]) for nondeath cases. The Berne CCI predicted the onset of death and severe complications between postoperative day 91 and 365 (both P <0.0001), whereas the original CCI was only predictive in interaction with other variables but not alone (P = 0.2772 and P = 0.0862, respectively).

Conclusion: The optimized Berne CCI depicts postoperative morbidity and burden within 90 days after cystectomy and UD without exceeding the upper index limit. It is specifically suited for longitudinal assessment of complications after cystectomy and UD taking into consideration every single complication and corresponding treatment. As the Berne CCI well predicted the onset of mortality and severe complications within 1 year postoperatively, this may allow a better preoperative patient counselling. It therefore warrants consideration for standardized reporting of complications after cystectomy and UD.