Longterm Outcomes After Percutaneous Therapy For Renal Artery Fibromuscular Dysplasia

Background: Percutaneous intervention (PTA) for symptomatic renal artery fibromuscular dysplasia (FMD) has replaced surgery as first line treatment. This study evaluates the factors that impact long term anatomic and functional outcomes of PTA for renal FMD.
Methods: A retrospective analysis of records from patients who underwent renal PTA for FMD was performed (1990 - 2007). Indication was poorly controlled hypertension (diastolic BP<90mmHg on >3 antihypertensive). Twenty-nine patients (all females, average age 45yrs, range 18-80, 69% under 50yrs, 86% with hypertension <8 yrs) underwent 38 interventions (5 were bilateral). 66% of contralateral kidneys were normal (31% had a <50% stenosis, the remainder were non-functioning or absent). 4% of patients had a creatinine >1.5mg/dl, 24% had hyperlipidemia, 17% had metabolic syndrome and 4% were considered diabetic.
Outcomes: Of the 38 PTAs, all were successful with stent placement in 13%. 73% of lesions were in the proximal renal artery. Technical success (defined by <30% residual stenosis) was achieved in all vessels. There were no periprocedural or 90 day mortalities. The morbidity rate was 8% (all minor). All patients were alive at follow up. Primary and assisted primary patency rates determined by serial duplex imaging were 66±6% and 87±8% at 10 years. The restenosis rate was 28% at 10 years (10 vessels underwent repeat percutaneous intervention). 72% of patients demonstrated immediate clinical benefit (improved or cured hypertension within 3 months). Clinical benefit was maintained in 71% of patients at 10 years by life table analysis. Predictors of longterm clinical benefit were duration of hypertension <8 yrs, creatinine <1.5mg/dl, ipsilateral kidney size, status of the contralateral kidney, a fasting blood sugar <110mg/dl*, Triglycerides <150mg/dl* and HDL >50mg/dl* (* components of metabolic syndrome). Age < 50yrs, presence of metabolic syndrome or administration of statins did not affect outcomes.
Conclusions: While renal PTA for FMD is technically successful, safe and durable, existing renal pathology and markers of metabolic syndrome are associated with recurrence of hypertensive symptoms.