Restenosis After Carotid Endarterectomy in Patients with Paired Vein and Dacron Patch Reconstruction

Abstract

This is an analysis of restenosis after bilateral carotid endarterectomy (CEA) with saphenous vein patch reconstruction on one side and Dacron patch reconstruction on the other. The possibility that differences in reconstruction geometry between vein and Dacron patched sides effected restenosis outcomes was evaluated as was the value of serial common carotid wall thickness measurements in predicting restenosis. Between 1990 and 1997, 33 bilateral CEA were performed within one year on 22 men and 11 women using a greater saphenous vein patch on one side and a knitted Dacron patch on the other. Interoperative post-CEA geometry was measured. Follow-up was by duplex scans that included wall thickness measurements in the endarterectomized common carotid bulb. Over a mean follow-up of 43 months 10 (30%) Dacron patched and one (3%) vein patched CEA developed?25% restenosis (p=0.001), seven (21%) Dacron patched and no vein patched CEA developed >50% restenosis (p=0.01) and four (12%) Dacron patched and no vein patched CEA developed >70% restenosis (p =0.1 1). The Kaplan-Meier cumulative >25% restenosis rates for Dacron and vein patched CEA were 22% and 0% at 2 years and 41% and 5% at 5 years respectively (p=0.002). The cumulative >50% restenosis rates for Dacron and vein patched CEA were 16% and 0% at 2 years and 34% and 0% at 5 years respectively (p = 0.003). The cumulative?70% restenosis rates for Dacron and vein patched CEA were 8% and 0% at 2 years and 20% and 0% at 5 years respectively (p = 0.02). For both patients with and without recurrent stenosis the mean within patient between sides differences of the diameters of the internal carotid, internal carotid bulb, common carotid bulb, and common carotid arteries and the lengths of the internal carotid and total patch segments were not significantly different and all were less than 5%. Common carotid bulb wall thickness measured at the time of identification of the nine unilateral Dacron patched CEA restenosis was 1.5 ±0.5 mm compared to 1.4 +0.4 mm (m ± 1 SD) for the contralateral vein patched CEA (p = 0.45 by paired t test). Dacron patched CEA have a significantly higher incidence of mild, moderate and severe restenosis than do saphenous vein patched CEA independent of systemic risk factors. The within patient equality of Dacron and vein patched carotid reconstruction geometry in patients with unilateral restenosis indicates that patch material is the major local risk factor, not adverse hemodynamics produced by variance in geometry. Common carotid bulb wall thickness measurements after CEA are not predictors or indicators of recurrent stenosis.