The role of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS)

To assess the safety and efficacy of super-mini percutaneous nephrolithotomy (SMP) in the treatment of symptomatic lower pole renal stones (LPSs) after the failure of shockwave lithotripsy (SWL) or retrograde intrarenal surgery (RIRS), we retrospectively evaluated 44 patients with symptomatic LPSs with previously failed SWL or RIRS and consequently underwent SMP from October 2014 to March 2016. The percutaneous renal access was performed 12–14F with C-arm fluoroscopy or ultrasonographic guidance. Stone disintegration was performed using either Holmium laser or pneumatic lithotripter. Perioperative parameters along with operations were assessed in detail. A total of 44 patients (mean age 49.1 ± 13.7 years) were included in the study. Stone size was 18.4 ± 6.0 mm (range 9–29), operative time was 63.9 ± 32.7 min (range 14–145) and hospital stay was 2.8 ± 1.2 days (range 1–5). The hemoglobin drop was 12.4 ± 8.8 g/L (range 0–31), and no patients required blood transfusion. Complete stone-free status was achieved in 40 (90.9%) patients. Clinically insignificant residual fragments were observed in three (6.8%) patients and only one (2.3%) patient had a 6 mm residual calculus. A total of three minor complications (urinary tract infection, hemorrhage resolved by hemostatics and renal colic requiring analgesics) were observed postoperatively. For symptomatic LPSs after the failure of SWL or RIRS, SMP is a safe and efficient auxiliary option and even might be an alternative to SWL or RIRS, while further considering the stone-free rates and stone-related events.