[The influence of percutaneous nephrolithotomy on renal function evaluated by 99m-Tc-DTPA renoscintigram]

The influence of percutaneous nephrolithotomy (PNL) on renal function was evaluated by 99m-Tc-DTPA renoscintigraphy. The renoscintigram was recorded and regions of interest of both kidneys (R) and background (BKG) were settled. Renal uptake ratio was calculated by the following formula. Renal uptake ratio = (formula; see text). The renal uptake ratio of 50 patients were compared before and up to 6 months after PNL. Most cases showed an increase or no change in post-PNL renal uptake ratio in operated kidney. Five cases (10%) showed decreased renal uptake ratio of post-PNL. No risk factors for the renal damage caused by PNL such as age, sex, stone size, number of nephrostomy and course of PNL were detected when compared with increased or no change groups. In cases of complete staghorn calculi in the decreased renal uptake ratio group, compensatory hypertrophy of contralateral kidney PNL course might occur, and the function of the operated kidney might not have recovered. More during cases and longer follow-up is necessary for the recovery of renal function.