Low-profile stent placement with the monorail technique for treatment of renal artery stenosis:: Midterm results of a prospective trial

PURPOSE: To determine feasibility, safety, and midterm patency of a monorail balloon stent device for the treatment of renal artery stenosis (RAS). MATERIALS AND METHODS: During a period of 30 months, 47 patients (with severe hypertension, n = 45; renal insufficiency, n = 20) with 50 cases of RAS and indications for stent implantation (calcified ostial lesion, n = 41; insufficient percutaneous transluminal angioplasty, n = 6; dissection, n = 3) were enrolled into the prospective evaluation. After predilation, 59 stents (Rx-Herculink 4 rum, n = 2; 5 mm, n = 19; 6 mm, n = 35; 7 rum, n = 3) were implanted under manometer control with use of the long-sheath technique (5 F; 6 F for 7-mm stents) via a femoral (n = 44) or transbrachial approach (n = 6). Parameters of hypertension and renal insufficiency were determined before and after the procedure and for a maximum of 18 months. Restenosis rate was determined with color duplex ultrasonography. RESULTS: Renal artery stent placement (mean diameter, 5.7 mm; mean length, 16 mm) was technically successful in all cases (100%). Mean blood pressure and serum creatinine level decreased from 177/93 rum Hg to 145/78 rum Hg and from 1.8 mg/dL to 1.5 mg/dL, respectively. Within 48 hours after the implantation, acute occlusions occurred in two patients, supposedly triggered by cholesterol embolization. Primary and primary assisted patency rates were 87% and 92% at 6 months and 75% and 84% at 18 months. CONCLUSIONS: Renal artery stent placement with the rapid-exchange monorail system is a safe procedure with promising patency rates. In combination with the long-sheath technique, adequate control of stent deployment is guaranteed during the entire intervention. The low profile of the device facilitates the use of small sheaths (5 F) to minimize access-site complications.