Purpose: To compare the efficacy and safety of Super-mini percutaneous nephrolithotomy (SMP, F12-F14) and Miniperc (F18) in the treatment of renal stones of 2-4 cm in size.
Methods: A prospective comparative analysis of outcomes of patients who underwent SMP and Miniperc for treatment of 2-4 cm renal stones was conducted between July 2014 and January 2017. Demographic data, stone criteria, operative technique, complications, blood transfusion, hemoglobin decrease, stone-free rate (SFR) and length of hospital stay were compared between the two groups. Propensity score-matching (PSM) analysis was performed to further compare the outcomes between the two groups.
Results: 79 and 257 patients underwent SMP and Miniperc, respectively. After matching, 73 patients in each group were included. The stone burden was comparable for both groups (3.0 ± 1.1 vs 3.2 ± 0.7 cm, p = 0.577). Mean operation time was not significant different between two groups (p = 0.115), while the hospital stay of SMP was much shorter than Miniperc (2.6 ± 1.4 vs 5.2 ± 1.8, p < 0.0001). Both groups had similar SFRs in postoperative 1 day and at 1 month follow-up (p = 0.326, p = 0.153), while SMP achieved a markedly higher tubeless rate than Miniperc (84.9 vs 47.9%, p < 0.0001). The total complication rate was significantly lower in SMP (16.4 vs 41.1%, p = 0.0001), and the SIRS rate was markedly lower in SMP group (1.4 vs 12.3%, p = 0.009).
Conclusions: SMP is equally effective as Miniperc in the treatment of moderate renal calculi, and has the significant advantage in hospital duration and tubeless rate.
Keywords: Renal stones; Stone-free rate; Super-mini percutaneous nephrolithotomy; Tubeless rate.