Ten-year experience with renal artery in-stent stenosis.

BACKGROUND: Atherosclerotic renal artery stenosis (RAS) is the most common cause of secondary hypertension. Renal stenting has become the treatment of choice for RAS in most centers. Primary patency of RAS is well defined, but limited data are available on outcomes of secondary interventions for treatment of in-stent restenosis.
METHODS: This was a retrospective analysis of a 10-year experience with renal artery stenting in patients presenting with recurrent symptomatic stenosis. End points included freedom from tertiary procedures, change in baseline renal function by ≥20% measured by estimated glomerular filtration rate (eGFR), patency confirmed by duplex imaging, long-term hypertension response, freedom from hemodialysis, and survival.
RESULTS: We reviewed 948 patients with 1150 treated renal arteries. Of these, 107 patients (122 renal stents) returned with symptomatic in-stent restenosis and required reintervention (target vessel revascularization [TVR] rate, 10.6%): 97% had recurrent or worsening hypertension, and 67% had worsening renal function. There were 69 women (64%) and 38 men (35%) with an average age of 68.9 years. Mean follow-up was 35.5 months (range, 1.0-104.7 months) for patency and 37.7 months (range, 0.03-100.9 months) for renal function (creatinine). Secondary interventions included 27 percutaneous transluminal angioplasties (PTAs), 10 PTAs with cutting balloon, 77 repeat renal artery stenting, and 8 placements of drug-eluting stents (DES). Twenty-five of the 122 arteries (20%) required tertiary interventions in 23 patients, a significantly higher TVR rate vs de novo interventions (11%; P = .003). Freedom from tertiary interventions at 60 months was similar among treatment groups undergoing PTA (66%), cutting balloon (100%), stent (80%), and DES (75%; P = .348). Seventeen (16%) had an increase of >20%, 50 (47%) had a decrease of >20%, and 30 (28%) had no change in renal function. Ultimately 25 (23%) remained or progressed to renal failure (eGFR < 30%), and 8 required hemodialysis. The survival rate was 73% at 5 years. Mean follow-up for long-term hypertension response was 3.2 years, with 56% improved, 28% with no improvement or deterioration, 16% without long-term data available, and no patients cured.
CONCLUSIONS: Secondary interventions for renal in-stent restenosis had higher TVR vs de novo renal stents in this large series (21% vs 11%; P = .003). Definitive recommendations on the best secondary treatment strategy cannot be made because a medical treatment control group was not available for comparison.