Follow-up of vascular lesions in fibromuscular dysplasia. no evidence for progression yet

Objective: It is currently unknown whether the vascular lesions in patients with fibromuscular dysplasia (FMD) are progressive in time. Therefore, repeat CT-angiography (CTA) is often necessary to evaluate possible evolution of the abnormalites. It would be unjustified to frequently expose patients to this diagnostic modality with its drawbacks (radiation, contrast material) if the vascular lesions turn out to be stable. The aim of our study was to explore whether vascular FMD lesions (unifocal or multifocal, with or without aneurysms) change in terms of extensiveness or localization over a period of a few years. Design and method: To qualify for the present study, patients had to be diagnosed with FMD in any vascular bed and both the diagnostic and the follow-up CTA had to be performed at the same institution using the same imaging protocol. Patients who had been referred by other hospitals and were followed in our own clinic were excluded from the analysis. On both the basal and the follow-up CTA, we assessed the number of lesions, the site of lesions, and the presence or absence of aneurysms. Results: A total of 161 patients had both a diagnostic and a follow-up CTA at our own clinic. Their mean age at diagnosis was 49 + 11 years (range 19-76) and 63% of the patients had been detected during a work-up for hypertension. On average, FMD was diagnosed nine years after the initial diagnosis of hypertension had been made. In the remainder of the patients, FMD was diagnosed after the patient had experienced a dissection (coronary, carotid). Follow-up CTA after two years was available in 111 patients and after three years in 50 patients. In only three patients we found new vascular lesions after a period of two years. In all the others, the pattern of lesions remained constant. Conclusions: Over a period of two to three years, vascular FMD lesions do not seem to progress in most patients. If repeat CTA scanning is considered, one should respect at least this time period.