Directional atherectomy in iliac stent failure: clinical technique and histopathologic correlation

To assess the feasibility and efficacy of directional atherectomy in the treatment of iliac stent stenosis or occlusion and to evaluate the histologic composition of excised atherectomy specimens.

Directional atherectomy of six occluded and 10 severely stenosed iliac stents was undertaken in 12 patients at a mean interval of 28 months (range 3-69 months) after stent insertion for occlusive aortoiliac disease. In cases of stent occlusion, atherectomy was preceded by low-dose thrombolysis. In all patients stent clearance with return of femoral pulses was achieved within 24 hr and there were no significant complications. All excised specimens were sent for histologic examination.

Eleven patients (92%) remain symptom free with unlimited walking distance at a mean follow-up interval of 11.5 months (range 3-31 months) after treatment. Histologic examination revealed typical myointimal hyperplasia at three excision sites, intimal fibrosis at three sites, atheroma at four sites and organized thrombus at six sites.

Atherectomy offers an effective treatment in iliac stent occlusion and restenosis with no significant adverse effects. Debulking of these lesions seems to offer a more logical approach than simple balloon angioplasty. Clinical and duplex follow-up confirms satisfactory outcome within the first year but longer-term results are not yet known. The histologic data obtained demonstrate that stent restenosis and occlusion are likely to be multifactorial, and challenge the assumption that myointimal hyperplasia is the sole cause of iliac stent occlusion.