Applicability of the Clavien-Dindo grading system for assessing the postoperative complications of endoscopic surgery for nephrolithiasis: a critical review.

OBJECTIVE Adaptation of the Clavien-Dindo classification for assessing the severity of complications following the endoscopic treatment of nephrolithiasis and evaluation of its versatility and objectivity. MATERIAL AND METHODS We retrospectively reviewed the medical records of 1027 patients who presented stones located in upper urinary tract (597 males, 58.1% and 430 females, 41.9%), mean age 38.9±15.6 (range, 4 to 84) years. The age ranged from 4 to 15 years in 46 (4.5%) of the patients. The mean size of the stones was 30.3±0.6 (range, 3 to 150) mm. Percutaneous nephrolithotomy (PNL) and ureteroscopy (URS) were performed by three experienced surgeons, PNL with the patients in the prone position. Fragmentation of stones was carried out using a pneumatic lithotripter. The outcomes were compared using Fisher's exact test and Student's t-test. The Clavien-Dindo grading system was used. RESULTS We observed 195 (19.0%) patients who presented a total of 250 complications during the postoperative period. Additional interventions have been performed to eliminate 74 complications: 41 under general anesthesia and 33 without it. "Stone free status" was reached in 879 (85.6%) patients. Postoperative complications were assessed using Clavien grading system: Grade I for 64 complications (6.2%); Grade II for 111 (10.8%); Grade IIIa for 33 (3.2%); Grade IIIb for 39 (3.8%); Grade IVa for 3 (0.3%); Grade IVb for 0; and Grade V for 0. CONCLUSION There is no ideal classification system for assessing the severity of surgical complications. The Clavien-Dindo classification can be adapted to assess the severity of postoperative complications following endoscopic procedures for nephrolithiasis if certain corrections are made.