CUMULATIVE MORBIDITY ASSESSMENT AFTER PERCUTANEOUS NEPHROLITHOTOMY: A PROSPECTIVE MULTICENTER REGISTRY COMPARISON OF THE CLAVIEN-DINDO CLASSIFICATION AND COMPREHENSIVE COMPLICATION INDEX.

Objective

To compare noncumulative Clavien-Dindo Classification (ncCDC) and cumulative Comprehensive Complication Index (cCCI) for assessing postoperative morbidity after percutaneous nephrolithotomy (PCNL), with emphasis on cumulative complication burden and postoperative recovery.

Methods

This multicenter analysis included 1,328 consecutive patients who underwent PCNL between May 2023 and December 2025 and were identified from a prospectively maintained national registry involving 16 urology clinics in Türkiye. Postoperative complications were graded using the Clavien-Dindo Classification, with the highest grade per patient recorded as ncCDC. cCCI was calculated by incorporating all postoperative complications. Associations with length of hospital stay (LOS), multivariable factors, and the discriminatory performance of cCCI for concurrent major complications (ncCDC ≥III) were evaluated.

Results

Overall, 1,016 patients had no complications, 290 had ncCDC grade I-II complications, and 22 had ncCDC grade ≥III complications. Median LOS was 3 days. LOS correlated more strongly with cCCI than with ncCDC (r=0.229 vs 0.204; both p<0.001). Hydronephrosis grade, STONE score, preoperative JJ stenting, and LOS were independently associated with cCCI. cCCI discriminated concurrent major complications with an AUC of 0.867 and an optimal postoperative threshold of ≥27.3. It also discriminated LOS >3 days with an AUC of 0.849.

Conclusions

cCCI provides a more comprehensive representation of postoperative morbidity after PCNL by capturing the cumulative burden of multiple complications beyond the single highest-grade event recorded by ncCDC. Its association with LOS and ability to classify concurrent major complications support its use as a complementary reporting measure alongside ncCDC in PCNL outcome assessment and multicenter benchmarking.