Long-Term Renal Function after Bilateral Extracorporeal Shock Wave Lithotripsy

Abstract

Our unit has performed bilateral renal extracorporeal shock wave lithotripsy (SWL) on 388 patients, with treatment being given in a single session in 369 (95%). No cases of clinically apparent acute renal failure occurred in the early postoperative period. Long-term (> 6 months) renal function data were available in 94 cases. Among the 77 patients who had normal serum creatinine values (≤1.5 mg/dl) before SWL, only 1 had a significant increase (> 0.5 mg/dl) afterward, and this patient had undergone bilateral SWL twice. In the group as a whole, the mean serum creatinine decreased from 1.10 ± 0.21 (SD) mg/dl to 1.07 ± 0.22 mg/dl, which was not statistically significant by the paired t-test (p = 0.16). In the 17 patients whose serum creatinine concentration was elevated before SWL, there was a statistically significant decline attributable to relief of obstruction in 12 (from 2.22 ± 0.05 mg/dl to 1.45 ± 0.25 mg/dl; p < 0.01) and no change in 2. In three patients, all of whom had chronic renal disease (small scarred kidneys with clubbed calices in two, longstanding severe brittle diabetes in one) with elevated serum creatinine, there were increases after SWL of 0.8 (2.1 to 2.9 mg/dl), 2.1 (2.1 to 4.2 mg/dl), and 9.2 mg/dl (2.7 to 11.9 mg/dl). Simultaneous bilateral SWL appears safe in patients with normal or near-normal renal function if the kidney does not become obstructed by stone debris.