Retrograde intrarenal surgery for urinary stone disease in patients with solitary kidney: A retrospective analysis of the efficacy and safety

Objectives: To compare outcomes of retrograde intrarenal surgery for urolithiasis between patients with solitary kidneys and patients who have single-side urolithiasis with bilateral kidneys. Methods: We retrospectively analyzed outcomes of retrograde intrarenal surgery in solitary kidney patients (group A) carried out during 2007-2014, and in patients with bilateral kidneys with comparable stone burdens (group B). Stone-free status was defined as no residual fragment on computed tomography 1 month later. Results: There were 19 patients in group A (mean age 62.5 +/- 18.4 years, range 14-76 years). The mean stone diameter and burden were 6.0 mm (range 3-24 mm) and 10.42 +/- 6.92 mm, respectively. The stone-free rate was 94.7%, and no repeat procedure was required. The glomerular filtration rate tended to rise post-surgery (postoperative day 1: 48.67 +/- 15.92 mL/min, 100.2%, P = 0.940; postoperative month 1: 51.32 +/- 16.90 mL/min, 105.7%, P = 0.101) compared with preoperative rates. The stone-free rate and surgery time were not significantly different between the two groups, although post-surgical hospitalization time was longer for group A (4.05 vs 3.08 days, P = 0.037). The change in glomerular filtration rate was not significantly different between groups A and B (postoperative day 1: +0.101 vs +0.547 mL/min, respectively, P = 0.857; postoperative month 1: +2.749 vs 3.161 mL/min, respectively, P = 0.882). No significant difference was found in terms of complication rate. Conclusions: Retrograde intrarenal surgery in solitary kidney patients is as safe and effective as in bilateral kidney patients.