Severely Impaired Renal Function in Unilateral Atherosclerotic Renal Artery Stenosis Indicated by Renal Slow Perfusion

PURPOSE: Renal artery stenosis leads to ischemic renal insufficiency, but methods for assessing renal perfusion are limited. This study aimed to evaluate the association between renal slow perfusion and impaired renal function in atherosclerotic renal artery stenosis (ARAS). PATIENTS AND METHODS: A total of 79 consecutive patients with uncontrolled hypertension who underwent renal angiography and renal dynamic scintigraphy for suspected ARAS were enrolled in the retrospective descriptive study. Based on the status of renal artery stenosis and renal perfusion, participants were divided into three groups: the control group (n=26), the unilateral ARAS with renal normal perfusion group (RNP, n=30), and the unilateral ARAS with renal slow perfusion group (RSP, n=23). RSP was defined as renal blush grade (RBG) ≤1, while RBG>1 belonged to RNP. Split renal function (SRF) was achieved from 99mTc-DTPA renal scintigraphy. The value of the difference in split renal function (DSRF) is contralateral SRF minus impaired SRF of paired kidneys in ARAS. We compared the SRF and DSRF between different groups to identify the association between renal slow perfusion and renal impairment in ARAS. RESULTS: We analyzed SRF for paired kidneys and found the following: (1) The SRF of the paired kidney was similar in the RNP group (24.3 ± 10.2 mL/min vs 27.5 ± 8.4 mL/min; P = 0.19); however, the impaired SRF was obviously decreased compared with the contralateral SRF in the RSP group (13.5 ± 8.6 mL/min vs 36.7 ± 16.9 mL/min; P < 0.001); and (2) The difference in SRF in the RSP group was significantly higher than that in the control and RNP groups (19.8 ± 11.9 mL/min vs 4.8 ± 8.1 mL/min; 19.8 ± 11.9 mL/min vs 4.6±3.7 mL/min; P < 0.05). CONCLUSION: As an angiographic phenomenon, renal slow perfusion might be an indicator of severely impaired renal function.