Strecker stents in the femoropopliteal arteries: value of duplex ultrasonography in restenosis assessment

PURPOSE

Experience with Strecker stent implantation in the femoropopliteal arteries has been described; however, few of the reports were prospective studies, and none routinely used site-specific assessment methods for follow-up evaluation of stent patency. The purpose of this study was to evaluate 1-year Strecker stent patency using duplex ultrasound imaging to obtain a more precise delineation of stent restenosis than is possible with other noninvasive assessment modalities.

METHODS

A prospective study involved 52 patients with 57 sites treated by angioplasty and Strecker stent deployment in the femoropopliteal arteries. Assessment included clinical evaluation; ankle-brachial index (ABI) measurements at rest and after exercise; and duplex ultrasound imaging preprocedurally and at 3 and 12 months after the intervention.

RESULTS

All 74 stents were deployed successfully in the 35 occluded arteries and 22 stenotic lesions. Acute reocclusion occurred in 6 (10%). At 3 months, primary patency was 81% and secondary patency 84%. Mean ( +/- SD) ABIs increased from 0.64 +/- 0.15 at rest and 0.32 +/- 0.17 after exercise to 0.89 +/- 0.14 and 0.68 +/- 0.23, respectively (p < 0.0001). At 12 months, primary patency was 79%, and secondary patency was 82%. Mean ABIs were 0.82 +/- 0.15 at rest and 0.52 +/- 0.22 after exercise at 12 months (p < 0.0002 compared with preprocedural ABIs). Analysis of the length of lesion treated showed betted results with shorter diseased segments, but this was not statistically significant (p > 0.05). Better outcomes were also obtained when one stent was used rather than two stents at 12 months (p = 0.15), but there was no difference at 3 months (p = 0.3). Thirty-four percent of the stented segments progressed from < 20% stenosis at 3 months to > 50% stenosis at 12 months. Overall, 19 (43%) of 44 segments progressed from < 50% stenosis at 3 months to a > 50% stenosis at 12 months. Restenosis seen at 3 months generally was in the native artery just proximal or distal to the stent, but at 12 months, restenosis was mainly inside the stent.

CONCLUSIONS

Strecker stents at 1-year demonstrated satisfactory patency in the femoropopliteal arteries when deployed for angioplasty salvage or recurrent disease. The 3- and 12-month evaluations obtained with duplex ultrasound provided site-specific hemodynamic data for stent assessment. Resting ankle pressures were a poor index of restenosis.

Initial experience with the Cragg Endopro System 1 for intraluminal treatment of peripheral vascular disease

PURPOSE

To evaluate the safety and efficacy of a new covered stent, the Cragg Endopro System 1, for intraluminal treatment of peripheral vascular disease in the iliac and femoropopliteal arteries.

METHODS

Forty symptomatic patients with predominantly lengthy stenotic (24) or occlusive (13) lesions or aneurysms (3) in the iliac (19), femoral (19), or popliteal (2) arteries were treated percutaneously with balloon angioplasty followed by implantation of the self-expanding nitinol Cragg stent covered by a woven polyester fabric coated with low-molecular-weight heparin. The mean length of femoropopliteal lesions was 13.0 +/- 1.8 cm, as compared to 6.7 +/- 0.8 cm (p < 0.01) for iliac lesions. Mean percent stenosis was 89% +/- 2% with no significant difference between the arterial segments.

RESULTS

With a total of 52 covered stents implanted, technical success was achieved in 98% (39/40 patients). One tortuous femoral artery aneurysm was not satisfactorily excluded to prevent leakage. Clinical success was seen in all patients with demonstrable improvements in the claudication stage and the ankle-brachial index from a mean 0.54 to 0.92. Three local complications (one hematoma, two false aneurysms) required surgical repair. One distal embolism, one acute thrombosis, and three subacute thromboses were encountered and successfully treated by thrombolysis and/or surgery. One patient with two iliac stents developed contralateral common iliac artery occlusion from a stent partially obstructing the aorta; placement of a covered stent in the blocked artery re-established normal flow. Over an 8-month follow-up with arteriographic re-examination, all iliac stents remained patent. At the femoropopliteal level, two stents were occluded at 4 months; one was successfully dilated, but the other required surgical bypass grafting. A third patient developed a stenotic lesion proximal to the stent; dilation restored adequate inflow to the stent.

CONCLUSIONS

The Cragg Endopro System 1 appears to be effective as an "internal bypass" for iliac and femoropopliteal occlusive disease. More complications and restenosis were seen in femoropopliteal implantations; however, a change in postoperative medication may improve these results. Long-term results will determine if the Cragg Endopro System 1 can achieve a patency equal to conventional bypass grafting.