Treatment of upper urinary calculi with Chinese minimally invasive percutaneous nephrolithotomy: a single-center experience with 12,482 consecutive patients over 20 years.

The Chinese minimally invasive percutaneous nephrolithotomy (MPCNL) was a modified version of standard PCNL which utilizes smaller tract and sheaths. The aim of this study was to present our experience on its efficacy and safety, and to grade its complications according to the modified Clavien classification. Between 1992 and 2011, 12,482 patients who underwent 13,984 MPCNL procedures entered this study. Data on stone size, access number, operative time, hospital length of stay, stone-free rate (SFR), and complications according to the modified clavien system were evaluated prospectively. Their mean age of patients was 47.6 years (range 0.6-93). The mean stone size was 3.2 ± 0.8 (1.4-7.4) cm. The mean operative time was 83 ± 38 min. Mean hemoglobin drop was 13.5 ± 11.3 g/L. Mean hospital stay was 10.3 ± 6.4 days (2-22 days). The initial SFR after first procedure was 78.6 %. In 14.7 % of cases with a second look, the SFR increase to 89.9 %. At 3 months after auxiliary procedures (re-PCNL, ureterorenoscopy, and shock wave lithotripsy), the overall SFR was achieved to 94.8 %. A total of 3,624 complications (25.92 %) were observed in 2,591 (18.53 %) procedures. There were 2,355 grade I (16.84 %), 706 grade II (5.05 %), 553 grade III (3.95 %), 7 grade IV (0.05 %), and three death of grade V (0.02 %) complications. This large-scale, contemporary analysis confirms MPCNL is still a safe and efficacious treatment option of kidney stones with a high stone-free rate and uncommon rate of high grade complications.