Prospective study of the effects of shock wave lithotripsy on renal function: role of post-shock wave lithotripsy obstruction.

摘要

OBJECTIVES: To examine the effects of transient post-shock wave lithotripsy (SWL) obstruction on renal function after SWL application for treatment of renal stones in nonobstructed kidneys. METHODS: One hundred consecutive patients with unilateral renal stones were treated by SWL monotherapy. They had a normal laboratory profile and no or controlled urinary tract infection. The urinary tract was radiologically normal. Technetium-99m mercaptoacetyltriglycine and Doppler ultrasonography were performed for all cases a few days before and 1 week and 3 months after SWL. Renal uptake, time to peak clearance, split renal function, effective renal plasma flow, and resistive index were obtained. Patients were stratified into two groups. Group 1 consisted of patients with normal kidneys before SWL and unobstructed kidneys after SWL (n = 84). Group 2 consisted of patients with normal kidneys before SWL that were obstructed 1 week after SWL (n = 16). RESULTS: In group 1, there was a gradual increase in the effective renal plasma flow that became significant after 3 months, up to 114% of the pretreatment levels (P = 0.008). The glomerular filtration rate was stable 1 week after SWL and had increased significantly after 3 months, up to 110% of the pretreatment levels (P = 0.006). In group 2, there was marked deterioration of the effective renal plasma flow and glomerular flow rate to 50.5% (P = 0.002) and 45.8% (P = 0.001), respectively, of the pretreatment levels. These levels returned to the basal levels after 3 months. No significant changes occurred in the resistive index in both groups. CONCLUSIONS: Extracorporeal shock wave lithotripsy has no deleterious effects on the renal function. Post-SWL obstruction, although transient, has a major effect on the renal function on the treated side and must be managed urgently.