Comparative outcomes of mini-percutaneous nephrolithotomy in patients with primary and recurrent nephrolithiasis

Introduction. Percutaneous nephrolithotomy (PNL) is one of the recommended treatments for kidney stones exceeding 20 mm in size. A significant proportion of patients with recurrent nephrolithiasis require repeated surgical intervention on the ipsilateral side throughout their lifetime. Objective. To compare the outcomes of primary and repeat mini-PNL procedures performed for recurrent urolithiasis on the ipsilateral side in patients with kidney stones. Materials & methods. The study included two distinct patient groups. Group 1 comprised 124 patients with a primary episode of nephrolithiasis, while Group 2 consisted of 59 patients with a recurrent form of nephrolithiasis who had previously undergone PNL on the side of recurrence. All participants underwent mini-PNL. Preoperative patient characteristics and surgical treatment outcomes were evaluated. Complications were classified according to the Clavien-Dindo classification modifed for PNL. The achievement of stone free rate (SFR) was assessed using multispiral computed tomography (MSCT). Results. The groups exhibited comparable preoperative characteristics. The SFR was 70.2% in Group 1 and 69.5% in Group 2 (p = 0.926). The median surgical duration was shorter in Group 2 at 90 (70.0 – 129.5) minutes compared to 100 (83.6 – 135.0) minutes in Group 1 (p = 0.082). The median postoperative hospital stay was 3 days for both groups (p = 0.246). The overall complication rate was 25.8% (32 patients) in Group 1 and 27.1% (16 patients) in Group 2 (p = 0.909). The median haemoglobin decreases on postoperative day 3 was 8.5 g/L in Group 1 and 8.0 g/L in Group 2 (p = 0.405). Conclusion. Mini-PNL via a single access represents an effective treatment modality for both primary and recurrent forms of nephrolithiasis. The incidence of postoperative complications demonstrates a comparable safety profile for both primary and recurrent PNL procedures.