Radial Artery Versus Saphenous Vein Grafts in Coronary Artery Bypass Surgery: a Literature Review

Recent Advances in the Fabrication and Performance Optimization of Polyvinyl Alcohol Based Vascular Grafts

Cardiovascular disease is one of the diseases with the highest morbidity and mortality rates worldwide, and coronary artery bypass grafting (CABG) is a fast and effective treatment. More researchers are investigating in artificial blood vessels due to the limitations of autologous blood vessels. Despite the availability of large-diameter vascular grafts (Ø > 6 mm) for clinical use, small-diameter vascular grafts (Ø < 6 mm) have been a challenge for researchers to overcome in recent years. Vascular grafts made of polyvinyl alcohol (PVA) and PVA-based composites have excellent biocompatibility and mechanical characteristics. In order to gain a clearer and more specific understanding of the progress in PVA vascular graft research, particularly regarding the preparation methods, principles, and functionality of PVA vascular graft, this article discusses the mechanical properties, biocompatibility, blood compatibility, and other properties of PVA vascular graft prepared or enhanced with different blends using various techniques that mimic natural blood vessels. The findings reveal the feasibility and promising potential of PVA or PVA-based composite materials as vascular grafts.

Iatrogenic Dissection of the Left Internal Mammary Artery During Percutaneous Coronary Intervention of Jump Radial Artery Graft Bifurcation Disease: A Case Report

Guide-catheter-induced ostial coronary artery dissection is a feared complication of percutaneous coronary intervention, but thankfully the incidence is low. We describe a case of catheter-induced ostial dissection of the left internal mammary artery (LIMA) with multiple radial jump grafts during percutaneous coronary intervention of radial graft bifurcation disease via the LIMA. The dissection led to loss of flow and profound haemodynamic compromise and cardiac arrest as the LIMA supplied the majority of the myocardium in this patient. Intravascular ultrasound was not immediately available, so an Export AP thrombus aspiration catheter (Medtronic) was used over the coronary wire in place to allow the injection of contrast while simultaneously pulling back on the catheter to delineate the extent of the dissection and guide accurate drug-eluting stent placement. The report is a cautionary tale to the reader to treat the LIMA with respect and think long and hard before considering any interventional procedure that uses the LIMA as a conduit.

A Review of Arterial Grafts Used for Microvascular Arterial Reconstruction

Arterial grafts are sometimes used in microvascular reconstruction and their clinical benefit over standard venous grafts is unknown. To determine arterial graft utilization in clinical microvascular arterial reconstruction, a review of the literature was done. PubMed search resulted with 4,352 finds, and after screening for relevance, 11 articles reporting on 55 arterial grafts were analyzed. All reports were retrospective studies, case reports, and case series, with no randomized controlled trials. Two retrospective series reported better patency of arterial versus venous grafts in upper-limb revascularization for chronic occlusion, but the findings were highly biased. Better patency of arterial grafts did not lead to higher rate of clinical improvement. Antiplatelet and lipid-lowering agents seem to be underused in venous graft recipients and use of no-touch venous grafting has not been reported. Based on the available data, routine use of arterial grafts cannot be recommended. Studies that show better patency of arterial grafts in hand revascularization for chronic vascular insufficiency are retrospective and biased, so a randomized controlled trial is needed.

Comparative Analysis Following Implementation of Two Types of Y-Composite Multiarterial Revascularization Strategies at a Single Academic Institution

Background

We compared early outcomes, at a single academic institution, of implementing full coronary revascularization in coronary artery bypass grafting using multiarterial Y‐composite grafts with multiple sequential anastomoses.

Methods and Results

Clinical records of 425 consecutive patients who underwent coronary artery bypass grafting using Y‐grafting with left internal mammary artery and radial artery (Y‐RA group) or right internal mammary artery (Y‐RIMA group) from 2015 to 2019, were reviewed. These were compared with the institutional experience of isolated coronary artery bypass grafting cases (in situ on pump/off pump) for the same period of time. When comparing the 4 groups, the Y‐RIMA/RA groups revealed a higher number of distal anastomosis than the in situ on‐ or off‐pump groups. When the number of distal arterial anastomosis was analyzed, there was a superiority of using the Y‐configuration compared with the in situ approach. Moreover, there were no significant differences among groups for mortality and/or major adverse cardiac and cerebrovascular events in hospital or at 30‐day follow‐up. A subanalysis comparing the Y‐RIMA group with the Y‐RA group showed that complementary grafts to the Y‐construct were required to accomplish full revascularization more frequently in the Y‐RIMA group. Full‐arterial revascularization was achieved in 92.2% of the Y‐RA group and 72.0% of the Y‐RIMA group (P<0.001). In 82.8% of the Y‐RA group and 30.8% of the Y‐RIMA group, revascularization was completed as an anaortic procedure (P<0.001).

Conclusions

The 2 types of arterial Y‐composite grafting were able to be introduced in the routine practice of our institution showing comparable results to the established institutional practice. This procedure allowed for more arterial distal anastomosis to be performed safely without compromising outcomes.

Conduits' Biology Regulates the Outcomes of Coronary Artery Bypass Grafting

•

Accelerated atherosclerosis is common when SVGs, but not arterial grafts, are used for myocardial revascularization during CABG.

•

This review will provide an overview of the available data on the most commonly used conduits in CABG, highlighting the differences in their cellular biology, mechanical, biochemical, and vasoconstrictive properties.

•

Clinical and scientific evidence support the use of arterial grafts over venous conduits at the time of CABG. These arterial conduits seem to be more protected toward the development of atherosclerosis. Exploring the molecular and cellular mechanisms, of the various cell populations within these conduits, will help unveil the pathways responsible for these protective effects.

Coronary artery bypass graft (CABG) is the gold standard for coronary surgical revascularization. Retrospective, prospective, and meta-analysis studies looking into long-term outcomes of using different conduits have pointed to the superiority of arterial grafts over veins and have placed the internal mammary artery as the standard conduit of choice for CABG. The superiority of the internal mammary artery over other conduits could be attributable to its intrinsic characteristics; however, little is known regarding the features that render some conduits atherosclerosis-prone and others atherosclerosis-resistant. Here, an overview is provided of the available data on the most commonly used conduits in CABG (internal mammary artery, saphenous vein, radial artery, gastroepiploic artery), highlighting the differences in their cellular biology, mechanical, biochemical, and vasoconstrictive properties. This information should help in furthering our understanding of the clinical outcomes observed for each of these conduits.

Coronary Artery Bypass: Review of Surgical Techniques and Impact on Long-Term Revascularization Outcomes

Coronary revascularization for multivessel disease remains a common and costly source of hospitalizations in the United States. Surgical techniques influence outcomes for coronary bypass and also affect the need for percutaneous coronary intervention in the future. As more radial access has been used for coronary angiography, consideration for use of the radial artery as a surgical conduit remains unclear. Saphenous vein grafts are commonly used for coronary bypass, however long-term patency remains suboptimal, and is also associated with a higher risk of adverse events with percutaneous coronary intervention. Thus, understanding the interplay between coronary bypass techniques and percutaneous coronary intervention has become increasingly important.

Upregulation of miR‑423 improves autologous vein graft restenosis via targeting ADAMTS‑7

Coronary artery bypass graft (CABG) is one of the primary methods of treating coronary heart disease (CHD); however, vein graft restenosis is a major limiting factor of the effectiveness of CABG. Emerging evidence has indicated that miR‑423 is associated with vascular diseases. Additionally, upregulation of a disintegrin and metalloproteinase with thrombospondin motifs‑7 (ADAMTS‑7) contributes to neointima formation by promoting the proliferation and migration of vascular smooth muscle cells and inhibiting the proliferation and migration of endothelial cells. The aim of the present study was to examine the effects of miR‑423 target, ADAMTS‑7, on regulating vein graft disease and identify novel biomarkers for use in therapy of vein graft failure (VGF). Aberrant expression of miR‑423 in plasma of patients with CHD prior to and following CABG confirms that miR‑423 may be a suitable target for preventing VGF. Furthermore, a dual‑luciferase reporter gene assay indicated that miR‑423 directly interacted with ADAMTS‑7 and suppressed its expression. Ectopic expression of miR‑423 suppressed ADAMTS‑7, resulting in decreased proliferation and migration rates of human umbilical vein smooth muscle cells by targeting ADAMTS‑7, but resulted in increased proliferation and migration of human umbilical vein endothelial cells in vitro. Overexpression of miR‑423 also enhanced re‑endothelialization and decreased neointimal formation in a rat vein graft model. In conclusion, the results of the present study demonstrated that the miR‑423/ADAMTS‑7 axis may possess potential clinical value for the prevention and treatment of restenosis in patients with CHD following CABG.

The π-Circuit Technique in Coronary Surgery: Analysis of 1359 Consecutive Cases

Coronary artery bypass surgery still has its unique role in the treatment of coronary artery disease. It faces, however, the continuous challenge of becoming even less invasive and more effective as cases become more complex. We here present the results of 1359 cases treated with the π-circuit technique which consists of an off-pump total myocardial revascularization using composite arterial grafts. The results demonstrate that it is a safe technique providing low mortality, stroke, renal failure, wound infection, and other complication rates. We suggest the application of this technique, as well as of other similar techniques regarding similar principles, especially in high-risk patients.