OBJECTIVETo analyze the value of fractional flow reserve (FFR) measurement on endovascular therapy for patients with renal artery stenosis.

METHODSClinical data of 9 patients underwent endovascular therapy due to moderate renal artery stenosis (50%-69%) in Anzhen hospital from May to September 2013 were retrospectively analyzed. Fractional flow reserve (FFR) were measured in patients with moderate stenosis in renal artery and abnormal glomerular filtration rate (GFR) or different between renal artery angiography and ultrasound before the procedure. Endovascular therapy was not applied for patients with FFR > 0.90, and the patients were subsequently followed up clinically. Endovascular therapy was applied in patients with FFR less than 0.90 or the pressure difference between the two ends of stenosis was more than 20 mmHg (1 mmHg = 0.133 kPa). Blood pressure, ultrasound and contrast-enhanced ultrasonography data were obtained at 1 and 3 months later, respectively.

RESULTSThere were 6 patients diagnosed as severe renal artery stenosis (≥ 70%) and the other 3 patients diagnosed as moderate renal artery stenosis by renal artery ultrasound before operation. Two patients with FFR > 0.90 were not undertaken the endovascular therapy. Seven patients with FFR < 0.90 underwent endovascular therapy. After renal artery stenting, renal stenosis was relieved immediately and the transstent blood flow was fluency in these 7 patients. There was significant difference in the FFR before and after operation (0.81 ± 0.09 vs.0.94 ± 0.03, P = 0.008). Among the patients underwent endovascular therapy, blood pressure was normal without medication in 2 patients and well controlled with 1 or 2 combined antihypertensive drugs in the rest 5 patients.

CONCLUSIONIn patients with moderate renal artery stenosis, fractional flow reserve measurement could be used as a useful index to guide intervention procedure and to evaluate the efficacy of endovascular therapy.