Vein Cuff Interposition Prevents Juxta-Anastomotic Neointimal Hyperplasia

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Abstract
This study sought to minimize juxta-anastomotic neointimal hyperplasia (JNIH) following the use of polytetrafluorethylene (PTFE) conduits. PTFE anastomoses to canine carotid arteries (noncuff grafts) were compared with grafts with vein cuffs interposed proximally and distally between the graft and native artery. This technique has been suggested clinically for below-knee PTFE femoropopliteal reconstruction. Twelve dogs received aspirin for 1 week before operation, which was continued after each animal received bilateral cuff and noncuff 4-mm PTFE grafts. At sacrifice, after 3-12 weeks, graft patency was assessed and luminal diameters measured with ophthalmic calipers at three sites along the anastomoses and 1 mm proximal or distal to graft toe (A' diameter). Specimens were perfusion fixed at arterial pressure for gross and histologic study; selected arteries were additionally fixed with 4% buffered glutaraldehyde, stored at 4 C, and examined immunochemically using antimyosin antibody immunopurified for smooth muscle. Overall patency of noncuff grafts in 11 long-term surviving dogs was 4 of 11; patency of the cuff grafts was 7 of 11. Regardless of graft thrombosis, antibody positive cellular proliferation occurred mainly at noncuffed PTFE anastomoses. Luminal encroachment was predominantly due to subintimal proliferation of cells highly reactive to smooth muscle derived antibody. JNIH was most prominent 1 mm distal to the graft toe (A' distal diameter). Average A' for noncuff grafts was 1.82 mm +/- 0.97 SEM; average A' diameter for cuff grafts was 3.41 mm +/- 0.74 SEM (p less than 0.001). Vein cuff inhibition of proliferation of smooth muscle or cells derived from smooth muscle possibly relates to wider distribution of kinetic energy (less compliance mismatch) or to interposition of venous endothelium.