External stenting of vein grafts in coronary artery bypass grating: interim results from a two centers prospective study

External stenting for saphenous vein grafts reduces early postoperative graft failure

OBJECTIVES

Multiple studies have shown that external stenting (ExSt) mitigates the progression of vein graft disease years after coronary artery bypass grafting (CABG). We used computed tomography to evaluate the effect of ExSt on perioperative vein graft patency.

METHODS

This study assessed graft patency rates of saphenous vein grafts (SVG) in consecutive patients with isolated coronary artery bypass grafting (CABG) between 2018 and 2021. Logistic regression analyses were conducted to compare the outcomes of supported and non-supported groups at both patient and graft levels, with age, EuroSCORE II, gender, diabetes and arterial grafts as covariates. Subgroup analyses were performed based on different covariates. The goal of the study was to provide valuable insights into the clinical outcomes of SVG in patients having CABG.

RESULTS

The study examined a total of 357 patients who met the inclusion criteria and evaluated 572 vein grafts. Of these, 150 patients (205 SVGs) received ExSt, whereas 207 patients (337 SVGs) did not receive ExSt. The study results indicated that the likelihood of overall SVG patency at discharge was higher in the stented group than in the non-stented group, both at the level of the grafts [93.8% vs 87.8%, odds ratio (OR) 2.1; 95% confidence interval (CI) 1.0-4.5; P = 0.05] and at the patient level (90.1% vs 83.5%, OR 1.8; 95% CI 0.9-3.6; P = 0.1). It is worth noting that the difference between the stented and non-stented groups was most significant in the subgroup that received 2 arterial grafts (96.5% vs 89.6%, OR 3.2; 95% CI 1.2-8.4; P = 0.02) and in the subgroup with a higher EuroSCORE II (median >1.1) (98.6% vs 88.6%, OR 8.8; 95% CI 1.1-72.7; P = 0.04).

CONCLUSIONS

The ExSt is associated with improved perioperative SVG patency at both the graft and the patient levels. Moreover, SVGs to the right territory and high-risk patients appear to have an advantage using ExSt.

Consensus statement-graft treatment in cardiovascular bypass graft surgery

Coronary artery bypass grafting (CABG) is and continues to be the preferred revascularization strategy in patients with multivessel disease. Graft selection has been shown to influence the outcomes following CABG. During the last almost 60 years saphenous vein grafts (SVG) together with the internal mammary artery have become the standard of care for patients undergoing CABG surgery. While there is little doubt about the benefits, the patency rates are constantly under debate. Despite its acknowledged limitations in terms of long-term patency due to intimal hyperplasia, the saphenous vein is still the most often used graft. Although reendothelialization occurs early postoperatively, the process of intimal hyperplasia remains irreversible. This is due in part to the persistence of high shear forces, the chronic localized inflammatory response, and the partial dysfunctionality of the regenerated endothelium. "No-Touch" harvesting techniques, specific storage solutions, pressure controlled graft flushing and external stenting are important and established methods aiming to overcome the process of intimal hyperplasia at different time levels. Still despite the known evidence these methods are not standard everywhere. The use of arterial grafts is another strategy to address the inferior SVG patency rates and to perform CABG with total arterial revascularization. Composite grafting, pharmacological agents as well as latest minimal invasive techniques aim in the same direction. To give guide and set standards all graft related topics for CABG are presented in this expert opinion document on graft treatment.

Large animal model of vein grafts intimal hyperplasia: A systematic review

Coronary artery bypass grafting remains the treatment of choice for a large cohort of patients with significant coronary disease. Despite the increased use of arterial grafts, the long saphenous vein remains the most commonly used conduit. Long-term graft patency continues to be the Achilles heel of saphenous vein grafts. This is due to the development of intimal hyperplasia, a chronic inflammatory disease that results in the narrowing and occlusion of a significant number of vein grafts. Research models for intimal hyperplasia are essential for a better understanding of pathophysiological processes of this condition. Large animal models resemble human anatomical structures and have been used as a surrogate to study disease development and prevention over the years. In this paper, we systematically review all published studies that utilized large animal models of vein graft disease with a focus on the type of model and any therapeutic intervention, specifically the use of external stents/mesh.

External stenting of saphenous vein grafts for coronary artery bypass: a single-center analysis of clinical outcomes

BACKGROUND

Angiographic studies have shown that external stenting reduces disease progression in saphenous vein grafts (SVG) for coronary artery bypass grafting (CABG). However, reports of clinical outcomes of external SVG stenting are limited.

METHODS

We conducted a retrospective analysis using a prospectively maintained national registry to evaluate clinical outcomes in patients undergoing either isolated CABG or combined (CABG + valve) procedures with use of an external SVG stent between December 2015 and December 2019. Median follow-up was 36.2 months (IQR: 24.4-41.6 months). The primary endpoint was ischemia-driven target vessel revascularization at 1 year. Secondary endpoints included all-cause death, non-fatal myocardial infarction (MI), stroke, and the composite of death, non-fatal MI or stroke at 1 year. Kaplan-Meier rates of survival, freedom from the composite of death, non-fatal MI or stroke and freedom from repeat revascularization were calculated at 3 years.

RESULTS

The study population included 74 patients (isolated CABG, N.=61; combined procedure, N.=13). Mean age was 65.5±9.2 years, and 81% were male. External stenting of one SVG was performed in 63 patients (85%) and external stenting of 2 SVG in 11 patients (15%). External stenting was most frequently performed on an SVG to the right coronary artery (N.=45 patients; 53%). Ischemia-driven target-vessel revascularization occurred in 0% at 1 year. All-cause death, MI, stroke, and the composite of death, MI, or stroke at 1 year occurred in 2.7% (2/74), 0% (0/74), 1.4% (1/74), and 4.1% (3/74), respectively. At 3 years, the rates of survival, freedom from the composite of death, non-fatal MI or stroke, and freedom from repeat revascularization were 89.7% (95% CI: 78.0-95.3), 88.3% (95% CI: 76.5-94.4), and 94.8% (95% CI: 84.6-98.3), respectively.

CONCLUSIONS

Clinical outcomes with external SVG stenting are excellent without ischemia-driven target-vessel revascularization at 1 year, and low rates of repeat revascularization at 3 years. Further follow-up will show whether external stenting reduces SVG failure with a benefit on long-term clinical outcomes.