Reversed vein graft stenosis: Early diagnosis and management

Abstract

Conscientious surveillance ofintrainguinal bypass grafts is mandatory to detect vein graft stenoses, which, ifuncorrected, can lead to graft occlusion. It is now widely accepted that noninvasive vascular laboratory studies are the best way to detect these lesions. However, controversy still exists over treatment, specifically whether balloon angioplasty is an acceptable substitute for surgery (patch angioplasty or short jump grafts) in the treatment ofthese lesions. We have always favored balloon angioplasty as primary treatment and have summarized our experience with treating 72 stenotic reversed femoropopliteal and femorotibial vein grafts, which represent 12% of 521 bypass grafts performed at our institution. Prosthetic and in situ grafts are specifically excluded from this report, as well as occluded grafts, found to have stenotic lesions after lytic therapy. The most common stenotic lesion occurred within 4 cm of the proximal anastomosis (29/72 = 40%). The other sites were near the distal anastomosis (7/72 =10%), and in the middle of the graft (15/72 =12%). Eighty-one percent (58/72) ofthe lesions were treated initially by balloon angioplasty with a 31% recurrence. Twenty-nine percent ofthe 14 grafts treated surgically by vein patch angioplasty or short jump grafts experienced recurrence. Overall 61% (44/72) of the stenotic grafts were treated by balloon angioplasty alone. The 5-year life-table assisted primary patency after correction of the stenotic lesion was 61%. The patency of the grafts from the time ofinitial bypass surgery, however, was 80%. Location ofthe stenosis within the graft was a major determinant ofpatency. Lesions in the proximal graft, proximal anastomosis, and distal graft taken as a group had significantly better patency than the midgraft and distal anastomotic lesions (5-year patency, 65% vs 48%, P < 0.001 log rank test). We continue to recommend balloon angioplasty as primary therapy for vein graft stenosis except for those occurring in the midgraft and distal "anastomosis. Fortunately, this group accounts for only 36% oflesions seen with reversed veins. Recurrent stenosis after balloon angioplasty should be repaired surgically. (J VAse SURG 1992;15:130-42).

Ultrastructural Analogies between Intimal Alterations in Veins from Diabetic Patients and Animals with STZ-Induced Diabetes

“…On the basis of these findings we speculate in accordance with Davies et al 20 and Marin et al 10 that diabetes affects venous physiology and may contribute to graft failure. Intimal hyperplasia, 10,14,15 preexisting disease, 18,19 and thick or calcified walls 10 are among the numer- ous factors that increase the risk of intragraft lesions. Our results also validate the usefulness of experimentally induced diabetes in animals as a model for further study to clarify the fate of the diabetic venous wall when used as a graft in patients with peripheral vascular disease.…”

“…Changes in the vascular endothelium occur early in the course of diabetes and have been implicated in the onset of diabetic complications. 11,12 Thirty percent of peripheral bypass grafts develop stenosis within 1 year after implantation 13 and several studies have shown that these lesions are due to intimal hyperplasia, 14,15 which is the consistent response of vein graft inserted into arterial circulation. The cause of this response in diabetic patients is unclear, but it has been suggested that hyperglycemia, through nonenzymatic glycocylation endproducts, which can modulate cellular responses, alters venous structure and vascular responses.…”

Pharmacological characterisation of endothelium-dependent relaxation in human radial artery: comparison with internal thoracic artery

“…While long term patency and tory the distal end was divided and 1-2 cm immediately survival are good for ITA grafts the prognosis for SV placed in physiological salt solution. grafts is less promising [13,14]. This has led to the search The vessel segments were immediately transferred to the for other suitable conduit vessels.…”

In Situ Bioengineering of Arterial Vein Grafts

“…This reduced patency has been largely attributed to compliance mismatch between the AVG and the native artery to which it is grafted [18,232,233]. Veins are inherently less compliant than arteries [234] and become even less compliant upon abruptly exposed arterialization [235].…”