Split renal function in patients with unilateral atherosclerotic renal artery stenosis-effect of renal angioplasty

Abstract

Objective: To evaluate the effect of percutaneous transluminal renal angioplasty (PTRA) on split renal function (SRF) in patients with unilateral atherosclerotic renal artery stenosis (ARAS). Methods: We performed a retrospective analysis of all consecutively examined patients at our centre with significant ARAS undergoing PTRA during 2002-07. A significant ARAS was defined as a lesion with a trans-stenotic mean arterial pressure gradient of at least 10mmHg or a diameter stenosis >50% on angiography. Ambulatory (24 h) systolic and diastolic blood pressure (ASBP and ADBP, respectively) and calculated SRF using 99mTc-DTPA renal scintigraphy were evaluated before (baseline) and 4 weeks after PTRA. Results: ASBP and ADBP were significantly lower 4 weeks after PTRA compared with baseline levels. Although total estimated glomerular filtration rate (EGFR; four-variable Modification of Diet in Renal Disease equation) had not changed by PTRA, analysis of SRF showed significantly increased EGFR in stenotic kidneys and a comparable reduction in EGFR in nonstenotic kidneys 4 weeks after PTRA. Conclusions: In patients with unilateral ARAS, PTRA significantly improved EGFR in stenotic kidneys and decreased filtration in contralateral, non-stenotic kidneys. These potentially beneficial effects may not be apparent when total renal function remains stable. The clinical significance of these findings needs to be evaluated further.