How to build a multi-arterial coronary artery bypass programme: a stepwise approach

A Comparative Analysis of Single Versus Multiple Arterial Grafts in Coronary Arterial Bypass Grafting: Initial Experience in Iraq

INTRODUCTION

The global recognition of multiple arterial grafting (MAG) and total arterial grafting (TAG) in coronary artery bypass grafting (CABG) is increasing. However, many centers have not yet adopted these procedures. Our study aims to examine the intraoperative, early postoperative, and two-year follow-up outcomes associated with MAG and TAG in candidates for CABG. The goal is to provide valuable insights into the role of these procedures.

METHODS

A prospective comparative study was conducted at Sulaimani Cardiac Hospital to analyze a cohort of 300 patients who underwent CABG surgery between January 2021 and April 2022. Convenience sampling was used to select participants. Prior to surgery, patients underwent comprehensive pre-operative evaluations, with certain CABG types being excluded. The patients were then categorized into three groups based on their surgical approach: single arterial conduit (SA), two arterial conduits (MA), and total arterial revascularization (TA). The standard bypass procedure was performed for all patients, and they were monitored for 30 days, six months, and two years after the surgery. A range of variables, including bypass and cross-clamp times, as well as postoperative complications such as bleeding and stroke, were recorded and analyzed. Statistical Product and Service Solutions (SPSS, version 25; IBM Corp., Armonk, NY) was used for this analysis, with a predetermined significance threshold of p ≤ 0.05.

RESULTS

The study included 300 participants who underwent CABG. The participants had an average age of 61.19 ± 4.67 years (95% CI: 36-81) and an average BMI of 27.40 ± 8.4 kg/m² (95% CI: 18-45). Diabetes was present in 40.3% of the patients, and the majority of the participants were male (77.7%). The number of vessels involved in the bypass varied, with two vessels in 21% of cases, three vessels in 65%, and four vessels in 14%. The left internal thoracic artery (LITA) was primarily used for arterial revascularization, and additional arterial conduits were used in 30.3% of cases. Statistical analysis showed significant differences in the number of grafts among patient groups (P = 0.042). However, there were no significant differences in bypass duration, cross-clamp duration, stroke incidence, or in-hospital mortality rates among the groups (P > 0.05). The rates of myocardial infarction (MI) approached significance (P = 0.05), and the mortality rates were comparable over a two-year period after CABG (4.7%) and at shorter intervals. These findings highlight the importance of age and the number of grafts in determining outcomes in CABG patients.

CONCLUSION

In a developing nation, the lack of a specialized center for MAG does not hinder the implementation of MAG or TAG. The overall occurrence of complications after CABG is similar across all groups, except for MI. Patients who undergo MAG have higher rates of overall survival compared to those who receive SA and TAG.

Performance of left internal thoracic artery-left anterior descending artery anastomosis by residents versus attendings and coronary artery bypass grafting outcomes

OBJECTIVES

Performance of a technically sound left internal thoracic artery to left anterior descending artery (LITA-LAD) anastomosis during coronary artery bypass grafting (CABG) is critically important. We used prospectively collected data from the multicentre, randomized REGROUP (Randomized Endograft Vein Perspective) trial to investigate CABG outcomes based on whether a resident or an attending surgeon performed the LITA-LAD anastomosis.

METHODS

This was a post hoc subanalysis of the REGROUP trial, which randomized veterans undergoing isolated on-pump CABG to endoscopic versus open vein harvest from 2014 through 2017. The primary end point was major cardiac adverse events, defined as the composite of all-cause deaths, nonfatal myocardial infarctions or repeat revascularizations.

RESULTS

Among 1,084 patients, 344 (31.8%) LITA-LAD anastomoses were performed by residents and 740 (68.2%), by attending surgeons. Residents (compared to attendings) operated on fewer patients with high tercile SYNTAX scores (22.1% vs 37.4%, P < 0.001), performed fewer multiarterial CABGs (5.2% vs 14.6%, P < 0.001) and performed more anastomoses to distal targets with diameters > 2.0 mm (19.0% vs 10.9%, P < 0.001) and non-calcified landing zones (25.1% vs 21.6%, P < 0.001). During a median observation time of 4.7 years (interquartile range 3.84-5.45), major cardiac adverse events occurred in 77 patients (22.4%) in the group treated by residents and 169 patients (22.8%) in the group treated by attendings (unadjusted HR 1.00; 95% confidence interval, 0.76-1.33; P = 0.99). Outcomes persisted on adjusted analyses.

CONCLUSIONS

Based on this REGROUP trial subanalysis, under careful supervision and with appropriate patient selection, LITA-LAD anastomoses performed by the residents yielded clinical outcomes similar to those of the attendings.

Multiple Arterial Graft Use in Coronary Artery Bypass Surgery: Surgeon Perspective vs Practice

BACKGROUND

Despite supportive evidence and guidelines, the use of multiple arterial grafts (MAGs) in coronary artery bypass grafting remains low. We sought to determine surgeon perception of personal MAG use and compare this with actual MAG use.

METHODS

We conducted a statewide surgeon survey of MAG use, presence of a hospital MAG protocol, and barriers for MAG use, with a response rate of 78% (n = 25). Surgeon survey responses were compared with actual Society of Thoracic Surgeons patient data from January 1, 2017, to December 31, 2020 using χ2 or Fisher's exact tests.

RESULTS

Of 5299 patients who had first-time, nonemergent, isolated coronary artery bypass grafting (≥2 grafts) by responding surgeons, 16% received MAG (n = 825). MAG use in patients whose surgeons self-designated as "routine" MAG users was 21% vs 7% for "nonroutine" users. Surgeons with a hospital protocol for MAG use utilized MAG more often (18% vs 14%, P = .001). Surgeons who were unconvinced by the data on the benefits of MAGs used MAGs in 11% vs 22% in surgeons who were convinced. MAG use increased over time, particularly from before to after the survey (13.1% vs 30.5%, P < .001).

CONCLUSIONS

Although MAG use increased over time, barriers to routine use remain. In surgeons who reported routine use, only 21% of their patients received MAGs. Hospital protocols, education, and increased awareness may reduce barriers to use and encourage evidence-based clinical practice.

Defining the Role of Anaortic Coronary Artery Bypass Grafting

As the population ages and co-morbidities become more prevalent, the complexity of patients presenting for coronary artery bypass surgery is increasing. Cardiopulmonary bypass and aortic cross-clamping in these patients carry increased risk and, indeed, in some patients, with ascending aortic disease, the risks are prohibitive. Total-arterial anaortic coronary artery surgery is a technique that provides complete surgical coronary artery revascularization without cardiopulmonary bypass and without manipulating the ascending aorta. The technique essentially eliminates the risk of cerebral embolization of aortic atheroma and aortic injury. Anaortic techniques are an essential skillset for coronary artery surgery centers treating higher-risk patients.

Reconstruction Technique Options for Achieving Total Arterial Revascularization and Multiple Arterial Grafting

Ischemic heart disease is the leading cause of morbidity and mortality worldwide and may require coronary revascularization when more severe or symptomatic. Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure and can be performed with different bypass conduits and anastomotic techniques. Saphenous vein grafts (SVGs) are the most frequently used conduits for CABG, in addition to the left internal thoracic artery. Outcomes with a single internal thoracic artery and SVGs are favorable, and the long-term patency of SVGs may be improved through novel harvesting techniques, preservation methods, and optimal medical therapy. However, increasing evidence points towards the superiority of arterial grafts, especially in the form of multiple arterial grafting (MAG). Nevertheless, the uptake of MAG remains limited and variable, both as a result of technical complexity and a scarcity of conclusive randomized controlled trial evidence. Here, we present an overview of CABG techniques, harvesting methods, and anastomosis types to achieve total arterial revascularization and adopt MAG. We further narratively summarize the available evidence for MAG versus single arterial grafting to date and highlight remaining gaps and questions that require further study to elucidate the role of MAG in CABG.

Comparison of Long-term Clinical Outcomes of Skeletonized vs Pedicled Internal Thoracic Artery Harvesting Techniques in the Arterial Revascularization Trial

Importance

Recent evidence has suggested that skeletonization of the internal thoracic artery (ITA) is associated with worse clinical outcomes in patients undergoing coronary artery bypass surgery (CABG).

Objective

To compare the long-term clinical outcomes of skeletonized and pedicled ITA for CABG.

Design, Setting, and Participants

The Arterial Revascularization Trial (ART) was a 2-group, multicenter trial comparing the use of a bilateral ITA vs a single ITA for CABG at 10 years. Patients in the ART trial were stratified by ITA harvesting technique: skeletonized vs pedicled. Data were collected from June 2004 to December 2017, and data were analyzed from June to July 2021.

Interventions

In this analysis, the 10-year clinical outcomes were compared between patients who received skeletonized vs pedicled ITAs.

Main Outcomes and Measures

The primary outcome was all-cause mortality. The secondary outcomes were a composite of major adverse cardiac events (MACE) including all-cause mortality, myocardial infarction, and repeated revascularization and a composite including MACE and sternal wound complication (SWC). Cox regression and propensity score matching were used.

Results

Of 2161 included patients, 295 (13.7%) were female, and the median (interquartile range) age was 65.0 (58.0-70.0) years. At 10 years, the risk of all-cause mortality was not significantly different between the pedicled and skeletonized groups (hazard ratio [HR], 1.12; 95% CI, 0.92-1.36; P = .27). However, the long-term risks of the secondary outcomes were significantly higher in the skeletonized group compared with the pedicled group (MACE: HR, 1.25; 95% CI, 1.06-1.47; P = .01; MACE and SWC: HR, 1.22; 95% CI, 1.05-1.43; P = .01). The difference was not seen when considering only patients operated on by surgeons who enrolled 51 patients or more in the trial (MACE: HR, 1.07; 95% CI, 0.82-1.39; P = .62; MACE and SWC: HR, 1.04; 95% CI, 0.80-1.34; P = .78).

Conclusions and Relevance

While the long-term survival of patients was not different between groups, the rate of adverse cardiovascular events was consistently higher in the skeletonized group and the difference was associated with surgeon-related factors. Further evidence on the outcome of skeletonized ITA is needed.

Whatever happens, two mammary is better than one

It is well known that the left internal mammary artery (LIMA) should be the first conduit of choice. Similarly, especially in patients younger than 70 years, other conduits should be search among arterial grafts, such as right internal mammary artery (RIMA) or radial artery (RA). If the RA can be harvested in the meanwhile of LIMA harvesting without time consuming, it is well established that former one has to be grafted only on presence of a good run-off. One of the main criticisms moved to the use of RIMA are linked to technical difficulties in its harvesting it.

Toward stroke-free coronary surgery: The role of the anaortic off-pump bypass technique

Surgical coronary revascularization remains the preferred strategy in a significant portion of patients with coronary artery disease due to superior long-term outcomes. However, there is a significant risk of perioperative neurologic injury that has influenced guideline recommendations. These complications occur in 1%-5% of patients, ranging from overt neurologic deficits with permanent disability, to subtle cerebral defects noted on neuroimaging that may result in slow cognitive and functional decline. The primary mechanism by which these events occur is thromboembolism from manipulation of the ascending aorta. This occurs during cardiopulmonary bypass, aortic cross-clamping, and partial occlusion clamping (side clamp). Elderly patients and patients with aortic atheroma are, therefore, at significantly increased risk. Initial surgical techniques addressed this by aggressively debriding or replacing the ascending aorta during coronary artery bypass grafting (CABG). Strategies then moved toward minimizing aortic manipulation through pump-assisted beating heart surgery and off-pump surgery with partial occlusion clamping or proximal anastomosis devices. Finally, anaortic off-pump CABG aims to avoid all manipulation of the ascending aorta through advanced off-pump grafting techniques combined with in situ and composite grafts. This has been demonstrated to result in the greatest reduction in risk. Establishing successful anaortic off-pump CABG programs requires subspecialization and focused interest groups dedicated to advancing CABG outcomes.

Feasibility of bilateral internal thoracic artery harvesting using the da Vinci SP system

PURPOSE

We conducted this study to investigate the feasibility of mobilizing the bilateral internal thoracic arteries (ITAs) using the da Vinci SP through a single intercostal incision and to compare the amount of rib spreading with that required for mini-thoracotomy procedures. We also evaluated the construction of an intrathoracic T-graft anastomosis using existing instrumentation of the SP system.

METHODS

We harvested bilateral ITAs from two male cadavers via a single incision made in the fifth intercostal space using the da Vinci SP. A T-graft end-to-side anastomosis was created in one cadaver.

RESULTS

The bilateral ITAs were harvested in less than 60 min and a T-graft was completed. No additional rib spreading was required. Intraoperative adjustments of the da Vinci SP were necessary to maintain alignment with the surgical targets.

CONCLUSIONS

Bilateral ITA harvest using the da Vinci SP through a single intercostal incision was feasible, with less rib spreading than in mini-thoracotomy procedures. Thus, creating an intrathoracic T-graft with the existing da Vinci SP instruments is possible.