Changes in Renal Function after Extracorporeal Shock Wave Lithotripsy in Patients with Solitary Functioning Kidneys: Long-Term Follow-Up

Nine of twelve consecutive patients with a solitary functioning kidney treated for renal stone by extracorporeal shock wave lithotripsy (SWL) with the modified Dornier HM3 lithotripter were evaluated before and 20 months (range 12-24 months) after treatment by detailed renal cortical and tubular function tests. Urinary excretion of the renal tubular enzymes N-acetyl-β-glucosaminidase (NAG), alkaline phosphatase (ALP), and kallikrein and of albumin and β₂-microglobulin was unchanged. Clearances of creatinine (C_Cr), inulin (C_IN) and para-aminohippuric acid (C_PAH) and filtration fraction (FF) were constant, as were serum levels of creatinine, urea, and β₂-microglobulin. In seven of the nine patients, however, C_IN was decreased at follow-up by a mean of 15% (range 5% to 54%), and C_PAH was decreased by a mean of 30% (range 3% to 58%) in six of the nine patients. Plasma renin activity (PRA) and serum aldosterone were stable, and no patient developed new-onset hypertension.