Geometric dimension changes with carotid endarterectomy reconstruction

Purpose: The geometry of carotid endarterectomy (CEA) reconstruction is a major determinant of carotid bifurcation hemodynamics that, in turn, may play a significant role in the likelihood of early postoperative thrombosis and early and late restenosis. The purpose of this study was to measure the geometry of various types of CEA reconstructions. Methods: Six carotid artery diameters and lengths were measured during surgery, before and after CEA. Three reconstruction methods were used in 562 CEA procedures: a greater saphenous vein patch in 389, a synthetic patch in 157, and primary closure in 16. Veins 6 mm or more in distended diameter were trimmed before use as a patch. Synthetic patches were 8 to 11 mm in width. Patch reconstruction was used when the length of the arteriotomy required to obtain a complete distal endarterectomy end point extended beyond the internal carotid artery bulb. Saphenous vein patches were used when it was available and adequate. Neither gender nor internal carotid artery diameter was used as a criteria for the selection of the reconstruction method. Results: Before endarterectomy, the 302 male carotid arteries had 7% to 15% greater linear dimensions than the 260 female arteries ( p < 0.001). Both vein and synthetic patch reconstruction produced up to 16% changes in linear dimensions except for almost doubling of the length of the internal carotid bulb. Patching made the elliptical common carotid bulb significantly more round, but the maximum diameter of curvature of the carotid bulb remained unchanged. Primary closure slightly decreased the diameter of the internal carotid bulb. Conclusions: CEA patch reconstruction has two major effects on carotid geometry: an increase in internal carotid bulb length and a more round common carotid bulb. The former allows for a gradual transition from the terminal common carotid bulb to the uniform diameter more distal internal carotid artery. It also separates the two major causes of disturbed flow: the bifurcation and the step-down in internal carotid artery diameter. Primary closure has minimal effect on preoperative geometry. (J Vasc Surg 1997;25:488-98.)