Purpose: To evaluate the angiographic and clinical results of percutaneously implanted renal artery endoprostheses (stents) for the treatment of patients with ischemic nephropathy.
Materials and methods: During a 52-month period, 45 patients with azotemia (serum creatinine > or = 1.5 mg/dL) and atheromatous renal artery stenosis untreatable by, or recurrent after, balloon angioplasty were treated by percutaneous placement of Palmaz stents. Stent implantation was unilateral in 32 cases and bilateral in 11 cases. Clinical results were determined by measurements of serum creatinine and follow-up angiography. Clinical benefit was defined as stabilization or improvement in serum creatinine level. Angiographic patency was defined as less than 50% diameter recurrent arterial stenosis.
Results: Stent placement was technically successful in 51 of 54 (94%) renal arteries. Technical failures were stent misdeployment requiring percutaneous stent retrieval (n = 2) and inadvertent placement distal to the desired position (n = 1). Complications included acute stent thrombosis (n = 1) and early initiation of hemodialysis (within 30 days; n = 1). There were two periprocedural deaths. With use of life-table analysis, clinical benefit was seen in 78% of patients at 6 months (n = 36), 72% at 1 year (n = 24), 62% at 2 years (n = 12), and 54% at 3 years (n = 3). In patients with clinical benefit, average creatinine level was reduced from 2.21 mg/dL +/- 0.91 before treatment to 2.05 mg/dL +/- 1.05 after treatment (P = .018). Lower initial serum creatinine level was associated with a better chance of clinical benefit (P = .05). No other variables affected outcome, including patient age, sex, diabetes, implanted stent diameter, unilateral versus bilateral stent placement, or ostial versus nonostial stent positioning. Conventional catheter angiography or spiral computed tomographic (CT) angiography performed in 19 patients (28 stents) at a mean interval of 12.5 months demonstrated primary patency in 75%. Maintained stent patency appeared to correlate with renal functional benefit.
Conclusions: Percutaneous renal artery stent placement for angioplasty failures or restenoses provides clinical benefit in most patients with ischemic nephropathy.