Pyelolithotomy improves while extracorporeal lithotripsy impairs kidney function

Abstract

Purpose: Extracorporeal shock wave lithotripsy (ESWL) causes acute depression of kidney function, which chronically returns to baseline levels. This sequala could indicate chronic regression of acute lesions or a balance between lesions and relief of obstruction. We compared changes in kidney function 1 week and 3 months after ESWL and pyelolithotomy.

Materials and methods: A group of 17 women and 13 men 28 to 71 years old with 0.6 to 3 cm. stones received 1,800 to 3,200 shock waves by an electromagnetic lithotriptor. Another group of 21 women and 9 men 35 to 76 years old with 2.5 to 3.8 cm. stones underwent Gil-Vernet intra-sinus pyelolithotomy. Split renal plasma flow, glomerular filtration rate and mean parenchymal transit times of nonreabsorbable filtrate solutes were measured by dual gamma camera renography, and plasma clearances of 99mtechnetium diethylenetriaminepentaacetic acid and 131orthoiodohippurate acid.

Results: ESWL caused acute deterioration and chronic restoration of baseline parameters of the treated kidney, and small but sometimes irreversible damage to plasma flow to the untreated kidney, especially in obese patients. In contrast, pyelolithotomy acutely and chronically improved function of the treated kidney, and normalized parenchymal transit times of radiotracers.

Conclusions: ESWL does not achieve substantial improvements in kidney function, which can be achieved by other methods of stone removal.