Comparison of the Comprehensive Complication Index and Clavien-Dindo systems in predicting perioperative outcomes following radical nephroureterectomy

BACKGROUND: Complications can occur following radical nephroureterectomy (RNU) in 20–40% of patients. The Comprehensive Complication Index (CCI) is an alternative grading system to the Clavien-Dindo (CD) grading system that aggregates all complications experienced by a patient on a continuous (as opposed to categorical) scale. We investigate whether the cumulative nature of CCI renders it superior to CD in predicting perioperative course after RNU. METHODS: The records of 596 patents who underwent RNU at 7 academic medical centers from 2005 to 2015 were reviewed. Complications occurring within 30 days of RNU were annotated using both the CD and CCI classification systems. Logistic regression was used to determine associations between CD and CCI with perioperative covariates as well as measures of convalescence [hospital length of stay (LOS) and readmission]. RESULTS: A total of 377 men and 219 women with a median age of 71, BMI of 27, and Charlson comorbidity score of 4 were included. Over half underwent a minimally invasive RNU. Median LOS following RNU was 6.0 days (range, 1–37 days) and readmission within 30-days occurred in 45 (8%) patients. Overall, 136 patients (23%) experienced a post-operative complication with 91 having a single complication and 45 with multiple (range, 2–6); 44 (7%) patients had Clavien III or greater complications, and the median CCI for those patients experiencing a complication was 20.9 (range, 8.7–100). Both the upper quartile of CCI (≥75th %) and major CD complications were associated with higher baseline Charlson score, ECOG ≥2, and CKD stage ≥ III (all P<0.05). However, only the upper quartile of CCI was associated with LOS (8.9 vs. 5.4 days, P<0.01) and hospital readmission (OR 3.2, 95% CI: 1.9–5.6, P=0.02) after RNU. CONCLUSIONS: The CD and CCI classification systems both are associated with similar baseline and perioperative characteristics for RNU patients. However, the cumulative nature of the CCI allows for superior prediction of postoperative course after RNU including LOS and readmission.