Abstract:Objective To evaluate the Clavien-Dindo Classification System (CDCS) in assessment of perioperative complications in minimally-invasive percutaneous nephrolithotomy (MPCNL). Methods Clinical data of 377 patients with upper urinary stones who underwent MPCNL from January 2013 to October 2015 were retrospectively analyzed. Complications were recorded and graded using CDCS. The patients were divided into three groups according to kidney anatomy, stone burden and underlying diseases. The complications were recorded in the three groups and analyzed using the CDCS. Results Of the 377 patients 85 (22.5%) cases had perioperative complications; evaluated by CDCS, gradⅠ, Ⅱ, Ⅲa, Ⅲb, Ⅳa, Ⅳb and Ⅴ complications occurred in 23 cases (6.1%), 38 cases (10.1%), 14 cases (3.7%), 5 cases (1.3%), 2 cases (0.5%), 2 cases (0.5%) and 1 cases (0.3%), respectively. According to CDCS, the incidences of grade Ⅰ, Ⅱ, Ⅲ and Ⅳ complications in the abnormal anatomy group were significantly higher than those in the normal anatomy group (P < 0.05). The incidences of grade Ⅱ and Ⅲ complications were significantly higher in the complex stone group than in the simple stone group (P < 0.05). The incidences of grade Ⅰ and Ⅱ complications were significantly higher in the underlying disease group than in the group without underlying disease (P < 0.05). Conclusions The Clavien-Dindo Classification System can not only standardize evaluation of perioperative complications but also be applied to surgical risk assessment.