Minimally invasive percutaneous nephrolithotomy: an alternative to retrograde intrarenal surgery and shockwave lithotripsy

Abstract

There is a lack of studies comparing shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) in renal stone treatment. This study compared treatment outcome, stone-free rate (SFR) and stone-free survival (SFS) with regard to stone size and localization. This analysis included 482 first-time-treated patients in the period 2001-2007. Detailed clinical information, stone analysis and metabolic evaluation were evaluated retrospectively. Outcome, SFR and SFS were analyzed with regard to size (<1 vs. ≥1cm) and localization (lower vs. non-lower pole). Higher SFRs in lower and non-lower pole stones ≥1cm were confirmed for RIRS and MIP (p<0.0001). A regression model confirmed a higher risk of non-lower pole stone persistence for SWL versus RIRS (OR: 2.27, p=0.034, SWL vs. 3.23, p=0.009) and larger stone burden ≥1 versus <1cm (OR: 2.43, p=0.006). In accordance, a higher risk of residual stones was found in the lower pole for SWL versus RIRS (OR: 2.67, p=0.009), SWL versus 4.75, p<0.0001) and stones ≥1cm versus <1cm (OR: 3.02, p=0.0006). In RIRS and MIP patients, more complications, stenting, prolonged disability, need/duration of hospitalization and analgesia were noticed (p<0.05). Overall SFS increased from SWL, RIRS, to MIP (p<0.001). SWL showed lower SFS for non-lower pole (p=0.006) and lower pole stones (p=0.007). RIRS and MIP were shown to have higher stone-free rates and SFS compared to SWL. The price for better outcome was higher, considering tolerable complication rates. Despite larger preoperative stone burden, MIP achieved high and long-term treatment success.