Single-versus multi-tract mini percutaneous nephrolithotomy for renal stones in a solitary kidney: a propensity-matched study

Abstract Background: Mini percutaneous nephrolithotomy (mPNL) is recommended for renal stones in a solitary kidney due to its high stone-free rate (SFR), with acceptable complications. Aimed to compare the effectiveness and the safety of single-tract mPNL (SM) and multi-tract mPNL (MM) in these patients. Methods: 176 patients with a solitary kidney who had undergone SM or MM from January 2013 to December 2020 had been retrospectivelyevaluated. The MM group had tractsranged from 2 to 3. Patient clinical characteristics and demographic information were used for propensity score matching (PSM). Both groups' perioperative outcomes, procedure numbers, and efficacy quotient (EQ) were evaluated. As a more objective indicator for stone removal, EQ was calculated by SFR, retreatment rate, and auxiliary procedure rate. Results: The retreatment rate of the SM group was higher than the MM group (45.2% vs 21.4%, P =0.031). No statistical difference between the two groups in complication rate. The initial SFR of the MM group was significantly higher than that of the SM group in a subgroup with a cumulative stone diameter (CSD) range of 40-70 mm (58.8%vs15.4%, P =0.026). The MM group had a significantly lower retreatment rate than SM (23.5% vs 69.2%, P =0.025), showinga higher EQ (56.5% vs 34.8%) and fewer procedures (1.35±0.49 vs 1.77±0.44, P =0.023). Conclusions: In the CSD 40-70mm subgroups,MM proved better EQ with an acceptable complication rate and fewer procedures. When the CSD ranges from 40-70mm, MM can be used as a preferred procedure for renal stones in a solitary kidney. Trial registration: This study was retrospectively registered and approved by the Ethics Committee of the First Affilated Hospital of Guangzhou Medical University(2020 No.K-41)