Assessment of Renal Artery Fibromuscular Dysplasia: From Diagnosis to Treatment

This is a prospective multicenter study based on the validation of diagnostic criteria and predictive factors of treatment efficacy for renal artery stenosis in renal artery dysplasia. This is considered as a rare disease and patients are usually treated in specialized centers involved in a national network. Marseille is a center specialized in FMD and a member of the network that is very active across the country. In order to rapidly recruit patients the investigators propose a multicenter study. All patients included will benefit from an invasive angiography with trans stenotic gradient assessment at rest. In case of bilateral stenosis the investigators will randomly omit data from one side and consider the data from the contralateral artery for further analysis, to avoid statistical interdependency. Patients who require angioplasty and who have unilateral stenosis (unilateral FMD lesion or bilateral but with one non significant stenosis based on duplex ultrasound European recommendations for atherosclerotic renal artery stenosis) will be included in the second part of the study. These patients will in addition benefit from a trans stenotic pressure assessment under vasodilation and intravascular renal artery ultrasound. Patients with severe bilateral renal artery stenosis will not be included in the analysis to assess predictive criteria for treatment efficacy on hypertension, treatment of these patients will followed the current best clinical practice. These patients will be followed during 6 to 8 month to assess potential complication of the pressure assessment renal artery stenosis, but their data will be included to assess the value of FFR and IVUS to guide the procedure. Patients with unilateral stenosis will be followed up 6 month after angioplasty in order to assess hypertension and to look for potential complications.