Goetz M. Richter

BACKGROUND: Stent implantation for obstructive femoropopliteal artery disease has been associated with poor long-term outcomes. This study evaluated the effectiveness of shape memory alloy recoverable technology (SMART) nitinol self-expanding stents coated with a polymer impregnated with sirolimus (rapamycin) versus uncoated SMART stents in superficial femoral artery obstructions. METHODS AND RESULTS: Thirty-six patients were recruited for this double-blind, randomized, prospective trial. All patients had chronic limb ischemia and femoral artery occlusions (57%) or stenoses (average lesion length, 85+/-57 mm). Patients were eligible for randomization after successful guidewire passage across the lesion. Eighteen patients received sirolimus-eluting SMART stents and 18 patients received uncoated SMART stents. The primary end point of the study was the in-stent mean percent diameter stenosis, as measured by quantitative angiography at 6 months. The in-stent mean percent diameter stenosis was 22.6% in the sirolimus-eluting stent group versus 30.9% in the uncoated stent group (P=0.294). The in-stent mean lumen diameter was significantly larger in the sirolimus-eluting stent group (4.95 mm versus 4.31 mm in the uncoated stent group; P=0.047). No serious adverse events (death or prolonged hospitalization) were reported. CONCLUSIONS: The use of sirolimus-eluting SMART stents for superficial femoral artery occlusion is feasible, with a trend toward reducing late loss compared with uncoated stents. The coated stent also proved to be safe and was not associated with any serious adverse events.

Palmaz balloon-expandable stents were placed in 28 hypertensive patients with atherosclerosis involving the ostia of the renal arteries. Stents were placed to treat elastic recoil immediately after conventional angioplasty in 20 patients and restenosis after percutaneous transluminal angioplasty in eight patients. Technical success (greater than 30% residual stenosis) was achieved in 27 patients. Complications occurred in five patients. At follow-up (1-25 months), hypertension was cured in three patients and improved in 15 patients, with a cumulative cure or improvement of 64% at 6 months. Of 14 patients with a serum creatinine level of 1.5 mg/dL (132.6 mumol/L) or greater before the placement of stents, five demonstrated improved renal function, five showed stabilization of their condition, and four demonstrated deterioration. Follow-up angiography (2-18 months) was performed in 18 patients. Restenosis was present in seven patients and was accompanied by a relapse of hypertension in only three patients. Of the other four patients with restenosis, two had no initial improvement and two had an initial response without a relapse of hypertension. In this preliminary study, renal stents were beneficial in many patients with poor results from conventional angioplasty for ostial atheroma.

A percutaneous transjugular, intrahepatic portacaval shunt was created by means of a combined jugular and transhepatic approach. In the hepatic tissue track joining the portal and hepatic veins balloon-expandable stents were placed. Two of three patients with life-threatening variceal bleeding and Child C liver cirrhosis benefited from the procedure. One patient in severe hepatorenal failure prior to the procedure died 11 days after the shunt procedure of pulmonary complications. This procedure may be a promising alternative to current therapy in high-risk patients with esophageal bleeding.

Fifteen patients with symptomatic iliac artery stenosis were treated with intraluminal placement of balloon-expandable stents. Before treatment, 14 patients had intermittent claudication, and one had a limb at risk for amputation. One patient had diabetes mellitus, nine had hypertension, and all were long-term smokers. Two patients had surgical placement of the stent; in one patient this was part of a combined revascularization procedure. All other stents were placed percutaneously. The transstenotic gradient after injection of vasodilating drugs distal to the lesion decreased from a mean of 32.3 mm Hg +/- 16.7 to 3.1 mm Hg +/- 4.2 after stent placement. Ankle-arm Doppler systolic pressure index increased from a mean of 0.68 +/- 0.22 to 0.96 +/- 0.24 after the procedure. The treatment eliminated intermittent claudication in 14 patients and increased exercise tolerance to 500 m in the patient with a limb at risk for amputation before the procedure. The improved condition persisted in all patients during the follow-up of 6-12 months. Stent placement may be a valuable adjunct in the management of iliac artery disease.

Balloon-expandable intraluminal stents were used to treat iliac artery stenoses or occlusions that failed to respond to conventional balloon angioplasty. One hundred seventy-one procedures were performed in 154 patients, of whom 48 had a limb at risk for amputation. Thirty-six had severe and 70 had moderate intermittent claudication. At the latest follow-up examination (average, 6 months; range, 1-24 months), 137 patients demonstrated clinical benefit, 113 of whom had become asymptomatic. Eleven patients showed no initial benefit, and six improved initially but later developed new vascular symptoms. Complications occurred in 18 patients. In three patients, complications were directly related to the device. Two occlusions were successfully recanalized, and an intramural collection of contrast material secondary to balloon perforation evolved favorably. The remaining patients had groin hematoma (n = 6), distal embolization (n = 4), extravasation (n = 2), transient renal failure (n = 1), pseudoaneurysm at the puncture site (n = 1), or subintimal dissection (n = 1). All stents have remained patent to the latest follow-up examination without evidence of migration or aneurysm formation.