Does Percutaneous Nephrolithotripsy (PCNL) affect renal function: Assessment with quantitative spect of TC 99M-DMSA (QDMSA) renal scintigraphy

Purpose: The study aimed to quantitatively investigate the effect of PCNL on global and regional function using quantitative single photon emission computerized tomography (SPECT) measurement of Tc-dimercaptosuccinic acid (DMSA) uptake by the kidneys (QDMSA). Methods: Seventy nine patients with nephrolithiasis undergoing PCNL were studied by sequential QDMSA examination. There were 42 (53%) males and 37 (47%) females with mean age of 4716 years. The initial study was conducted before PCNL procedure and the follow-up studies were performed 1.5-24 months after PCNL. Among 60 of the 79 (76%) patients, in whom PCNL was performed using upper or lower pole access, regional renal function of affected and non-affected pole of operated kidney was calculated separately. Results: There was no statistically significant difference between the uptake of treated kidney before and after PCNL procedure (11.9% 5% vs 11.6% 5% t=0.9, p=0.368). The total renal functional volume of treated kidney was to be slightly decreased from 235cc 62cc to 224cc 59cc (t=2.7 p=0.011). The percent of injected dose per ml. of renal tissue of treated kidney was not affected statistically (0.051 0.02 vs 0.0530.02 t=0.86, p=0.296). In the assessment of the regional renal function of treated kidney, a statistically significant decrease in the functional renal volume was revealed at the part which underwent PCNL procedure (91cc 30cc vs 82cc 27cc t=2.64, P=0.013). Regarding percent of injected dose per ml. of renal tissue, no statistically significant difference was found between the part of treated kidney, which underwent PCNL and non-affected area of the same kidney (0.049 0.02 vs 0.05 0.02 t=0.693, p=0.494). The function of contralateral kidney remained unchanged (13.4% 5.2% vs 13.6% 4.8% t=0.68, p=0.5). Function volume, neither total percent uptake, nor percent of injected dose per ml. of renal tissue were reduced significantly. Further studies with long term follow-up of treated kidney are required.