Original article
Adult cardiac
A Randomized Trial of External Stenting for Saphenous Vein Grafts in Coronary Artery Bypass Grafting

https://doi.org/10.1016/j.athoracsur.2015.01.060Get rights and content

Background

External stents inhibit saphenous vein graft (SVG) intimal hyperplasia in animal studies. We investigated whether external stenting inhibits SVG diffuse intimal hyperplasia 1 year after coronary artery bypass graft surgery.

Methods

Thirty patients with multivessel disease undergoing coronary artery bypass graft surgery were enrolled. In addition to an internal mammary artery graft, each patient received one external stent to a single SVG randomly allocated to either the right or left coronary territories; and one or more nonstented SVG served as the control. Graft patency was confirmed at the end of surgery in all patients. The primary endpoint was SVG intimal hyperplasia (mean area) assessed by intravascular ultrasonography at 1 year. Secondary endpoints were SVG failure, ectasia (>50% initial diameter), and overall uniformity as judged by Fitzgibbon classification.

Results

One-year follow-up angiography was completed in 29 patients (96.6%). All internal mammary artery grafts were patent. Overall SVG failure rates did not differ significantly between the two groups (30% stented versus 28.2% nonstented SVG, p = 0.55). The SVG mean intimal hyperplasia area, assessed in 43 SVGs, was significantly reduced in the stented group (4.37 ± 1.40 mm2) versus nonstented group (5.12 ± 1.35 mm2, p = 0.04). In addition, stented SVGs demonstrated marginally significant improvement in lumen uniformity (p = 0.08) and less ectasia (6.7% versus 28.2%, p = 0.05). There was some evidence that ligation of side branches with metallic clips increased SVG failure in the stented group.

Conclusions

External stenting has the potential to improve SVG lumen uniformity and reduce diffuse intimal hyperplasia 1 year after coronary artery bypass graft surgery.

Section snippets

Study Design and Population

The VEST trial, conducted from October 2011 to September 2013, was a prospective, multicenter, randomized and self-controlled study. The study was approved by a UK Research Ethics Committee, and all subjects gave informed consent. Patients were eligible if they were scheduled for on-pump multivessel CABG including a left internal mammary artery to the left anterior descending coronary artery and SVGs to right and circumflex territories. Eligibility required a target vessel diameter of 1.5 mm or

Patients, Procedure, and Follow-Up

Thirty-five patients were enrolled, and 30 were randomly assigned to the VEST trial between October 2011 and September 2012. Demographic characteristics for the randomized patients are shown in Table 1. During surgery, 4 patients were deemed ineligible due either to inadequate vein quality or target coronary artery calcification, and 1 patient was not randomized for administrative reasons. Thirty grafts, 1 per patient, were successfully stented with the study device and compared with 39

Comment

The key finding in the current study is that a mechanical external stent has the potential to reduce the process of diffuse intimal hyperplasia in SVG 1 year after CABG. External stenting of SVG resulted in a statistically significant reduction of this area by approximately 15% (p = 0.04). Several studies have previously reported comparable plaque areas in SVG 12 months after implantation 9, 22, and to date, only statins and beta-blockers have been shown to reduce the process [10].

A particular

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