Percutaneous nephrolithotomy in solitary kidneys: effective, safe and improves renal functions.

Background: To evaluate success and complication rates of endourological stone treatments and to evaluate effects of percutaneous nephrolithotomy (PCNL) on renal functions, in patients with solitary kidneys.

Methods: In our center, 3150 patients underwent PCNL between 2003 and 2017 and 142 patients underwent retrograd intrarenal surgery (RIRS) between 2013 and 2017. We retrospectively analysed the data of 82 patients with solitary kidney who underwent PCNL and of 8 patients with solitary kidney who underwent RIRS. Complications were classified according to Clavien-Dindo Classification system. Serum creatinin was measured before the procedure, on the early postoperative period and at sixth month follow-up in PCNL group. The estimated glomerular filtration rate (eGFR) was calculated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula. The 5-stage classification of chronic kidney disease (CKD) was used according to the National Kidney Foundation guideline.

Results: In the PCNL group, the initial stone-free and success rates were 82.9% and 95.1%, respectively. Complications occured in 18 (22%) patients. Transfusion was the most common complication (15.5%). One patient required JJ stenting. The stone-free rates of the patients who required multiple accesses were statistically lower than the patients who required single access (P=0.01). Transfusion rates were statistically higher in patients who required multiple accesses and who had complex stones (P=0.01 and P=0.02, respectively). GFRs calculated preoperatively, in the early and in the late period were 65.03, 62.85 (P=0.224) and 70.63 mL/min/1.73 m2 (P<0.001), respectively. At the postoperative 6th month, GFR was stable in CKD stage 1 patients and improved in CKD stage 2-4 patients (P<0.001, P<0.001 and P=0.012 respectively). In the RIRS group, 5 patients (62.5%) were stone free and the success rate was 75% (6 patients) after single procedure. Any complication did not occur in the RIRS group.

Conclusions: PCNL in solitary kidney is a safe method with acceptable complication rates. Renal functions are preserved in patients with normal functioning kidney and improved in patients with renal insufficiency. RIRS may be an alternative method in selected patients with solitary kidney.