Defining the Morbidity of Robot-Assisted Radical Cystectomy with Intracorporeal Urinary Diversion: Adoption of the Comprehensive Complication Index

The Clavien-Dindo Classification (CDC) only reports the postoperative complication of highest grade. It is thus of limited value for radical cystectomy, after which patients usually experience multiple complications. The Comprehensive Complication Index (CCI) is a novel scoring system, which incorporates all postoperative events in one single value. The study aimed to adopt the CCI for the evaluation of complications in patients undergoing robot-assisted radical cystectomy (RARC) with intracorporeal urinary diversion (ICUD) and explore its advantages in the analysis of the morbidity of RARC with ICUD. A multicentric cohort of 959 patients undergoing RARC+ICUD between 2015 and 2020, whose complications are encoded in local prospective registries. Postoperative complications at 30 days were assessed using both the CDC and CCI. The CCI was calculated using an online tool (assessurgery.com). Risk factors for overall, major complications (CDC ≥III), and CCI were evaluated using uni- and multivariable logistic and linear regressions. To analyze the potential advantage of using the CCI in clinical trials, a sample size calculation of a hypothetic clinical trial was performed using as endpoint reduction of morbidity with either the CDC or CCI. Overall, 885 postoperative complications were reported in 507 patients (53%). The CCI improved the definition of postoperative morbidity in 22.6% of patients. Male sex and neobladder were associated with major complications and to a significant increase in CCI on adjusted regressions. In a hypothetical clinical trial, 80 patients would be needed to demonstrate a ten-point reduction in CCI, compared with 186 needed to demonstrate an absolute risk reduction of 20% in overall morbidity using the CDC. CCI improves the evaluation of postoperative morbidity by considering the cumulative aspect of complications compared with the CDC. Implementing the CCI for radical cystectomy would help reducing sample sizes in clinical trials. Clinical Trial Registration number: NCT03049410.