The long-term outcomes of percutaneous therapy for renal artery fibromuscular dysplasia

Background: Percutaneous intervention for symptomatic renal artery fibromuscular dysplasia (FMD) has replaced surgical therapy as first-line treatment. This study evaluates the factors that impact long-term anatomic and functional outcomes of endovascular therapy for symptomatic renal artery FMD. Methods: Records of patients who underwent renal artery angioplasty for FMD between January 1990 and December 2007 were retrospectively analyzed. Indication for intervention was poorly controlled hypertension (diastolic blood pressure >90 mm Hg or systolic blood pressure >140 mm Hg, or both, taking >2 antihypertensive medications). Twenty-nine women (average age, 45 years [range, 18-80]; 86% with a history of hypertension <8 years) underwent 38 attempted interventions. Sixty-six percent of contralateral kidneys were normal (31% had a <= 60% stenosis), 13% had >60% stenosis, and the remainder were nonfunctioning or absent. Creatinine was >1.5 mg/dL in 4%, 24% had hyperlipidemia, 17% had metabolic syndrome, and 4% were considered diabetic. Outcomes. All interventions were successfully performed. Stent placement was required in 13% for technical failure and flow-limiting dissection. Seventy-three percent of these lesions were in the proximal renal artery, with the remainder in the middle renal artery. Technical success (<30% residual stenosis) was achieved in all vessels. There were no periprocedural or 90-day deaths. The procedurally related complication rate was 8%. Median follow-up was 2 years. All patients were alive at follow-up. Primary and assisted primary patency rates were 66% and 87% at 5 years. Restenosis was considered a 50% reduction in luminal area on angiography during follow-up. The restenosis rate was 28% at 5 years (10 vessels underwent repeat percutaneous intervention). Immediate clinical benefit was seen in hypertension in 72% (improved or cured <= 3 months) and was maintained in 73% at 5 years by life-table analysis. Proportional hazard analysis showed the predictors of long-term clinical benefit were duration of hypertension <8 years, creatinine <1.5 mg/dL, ipsilateral kidney size >9 cm, functional status of the contralateral kidney, a fasting blood glucose <110 mg/dL, triglycerides <150 mg/dL, and high-density lipoprotein >50 mg/dL. Neither age <50 years nor statin administration appeared significant. Conclusions. Percutaneous endovascular intervention for clinically symptomatic FMD in the renal arteries is technically successful, safe, and durable. Most patients have immediate clinical benefit, with continued long-term results out to 5 years. It appears that the presence of existing renal pathology and markers of prediabetic state are associated with recurrence of hypertensive symptoms.