Comparison of outcomes of percutaneous nephrolithotomy on patients with normal and malformed kidneys

Abstract

Aim: To compare outcomes (stone-free rates, complications) of percutaneous nephrolithotomy (PCNL) in patients with kidney malformations and normal subjects having similar stone characteristics(surface area, configuration). Materials and Methods: Data of 170 patients who underwent PCNL were analyzed. Stone burden was 100-1564 mm2, stone configuration was pure pelvic, pure caliceal or complex (pelvic + caliceal) in Group 1 with renal anomalies (n = 18, 19 renal units, 20 sessions). Patients with similar stone characteristics without any renal anomaly comprised Group 2 (n = 152, 158 renal units, 161 sessions). Groups were compared regarding therapy success, outcomes, and complications. Stones ≤ 4 mm were considered as clinically insignificant. Results: Group 1 comprised: 9 horseshoe kidneys, 1 pelvic kidney, 1 ptotic kidney, 1 polycystic kidney, 3 duplex renal system, 2 malrotated kidneys, and 2 with a prior history of open partial nephrectomy. No significant differences were detected in terms of stone-free rates, clinical insignificant residual stone rates, residual stone rates, mean operation times, fluoroscopy times, and complications between the 2 groups (P > 0.05). Although no significant differences were detected regarding pure caliceal and complex stones concerning above parameters between the 2 groups, lower stone-free and higher residual stone rates were detected in Group 1 having pure pelvic stones compared to normal subjects (P = 0.028). Conclusions: PCNL is a safe and effective procedure in patients with kidney malformations. Patients with anomalous kidneys bearing pure pelvic stones might have lower stone-free and higher residual stone rates compared to normal subjects after PCNL in this preliminary study. © TÜBİTAK.