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Objectives: To investigate the variables affecting the long-term outcome of infrainguinal vein bypass grafts that have undergone postoperative surveillance., Design: A retrospective analysis., Patients and Methods: Details of 299 consecutive infrainguinal vein grafts performed in 275 patients from a single university hospital were collected and analysed. All grafts underwent postoperative duplex surveillance. Factors affecting patency, limb salvage and survival rates were examined. These factors were gender, diabetes, hypertension, aspirin, warfarin, ischaemic heart disease, run-off, graft type, early thrombectomy, level of anastomoses and indication for surgery., Results: The 6-year primary, primary assisted and secondary patency rates were 23, 47, and 57%, respectively. Six-year limb salvage and patient survival were 68 and 45%, respectively. Primary patency was adversely influenced by the use of composite vein grafts. Early thrombectomy was the only factor that significantly influenced secondary patency. Limb salvage was worse in diabetic limbs, limbs with poor run-off and in grafts that required early thrombectomy. Postoperative survival was better in males, claudicants and in patients who took aspirin., Conclusions: Although co-morbid factors did not influence graft patency rates, diabetes did adversely effect limb salvage. This study, like others before it, confirms that aspirin significantly reduces long-term mortality in patients undergoing infrainguinal revascularisation.

Objective: Although a number of pharmacologic agents have been shown to reduce intimal hyperplasia in animal models of restenosis, to date no systemic agent has conclusively been shown to be effective in humans. Recently, considerable attention has been directed towards endothelin (ET), a potent vasoconstrictor and a powerful mitogen for vascular smooth muscle cells, as a mediator of intimal hyperplasia. Endothelin-1 has been shown to be mitogenic for human saphenous vein smooth muscle cells, and expression also is elevated in human vein graft stenosis. The aim of this study was the investigation of whether ET receptor antagonists can attenuate neointima formation in a laboratory model of vein graft intimal hyperplasia and the determination of whether the effects are mediated by a specific ET receptor subtype., Methods: We used an organ culture of human saphenous vein, a well-validated model of vein graft intimal hyperplasia. Paired segments of human long saphenous vein were cultured with and without the following antagonists: bosentan, a nonselective ET receptor antagonist; BQ 123, a specific endothelin-A antagonist; or BQ 788, a specific endothelin-B (ETB) antagonist. After 14 days in the culture, the segments were fixed and processed and the sections were immunostained to facilitate the measurements of neointimal thickness with a computerized image analysis system., Results: The nonselective antagonist bosentan and the ETB selective antagonist BQ 788 significantly reduced neointima formation by 70% (P = .001) and 50% (P = .03), respectively, but the ETA antagonist BQ 123 had no significant effect on the reduction of neointima formation (P = 1.0)., Conclusion: The results of this study imply an important role for ET as a mediator of human vein graft intimal hyperplasia and imply further that a specific ETB antagonist may have a therapeutic potential for the prevention of vein graft stenosis.

Objectives: To determine the peak velocity ratio (PVR) threshold at which to intervene and correct duplex detected vein graft stenoses., Design: Prospective study., Materials: Infrainguinal vein grafts in patients attending the vascular studies for routine postoperative surveillance., Methods: Colour duplex detected stenotic vein graft lesions with a peak velocity ratio (PVR) between 2.0 and 2.9 were identified and monitored by serial duplex scans performed monthly for 3 months and then at 3-monthly intervals thereafter. At the end of the study period, the outcome of these lesions were analysed., Results: Thirty-eight lesions were identified from 32 grafts. Of these lesions, sixteen (42%) resolved, 11 (29%) remained stable and 11 (29%) progressed to a PVR of > or = 3.0 and underwent angioplasty. There were no occlusions in any of the grafts during the period of study., Conclusions: Colour duplex detected vein graft stenoses with a PVR of less than 3.0 can be treated expectantly if grafts with stenoses with a PVR 2.0-2.9 are scanned every month for at least 3 months after detection.