The long-term patency of a gastroepiploic artery bypass graft deployed in a semiskeletonized fashion: predictors of patency

Preoperative Computed Tomography of the Right Gastroepiploic Artery for Coronary Artery Bypass Grafting

BACKGROUND

Grafting the right gastroepiploic artery (GEA) to the right coronary artery (RCA) is effective, but preoperative evaluation of arterial conduit availability has not been established. By comparing the midterm graft results, we aimed to assess the efficacy of preoperative evaluation of the GEA using computed tomography (CT).

METHODS AND RESULTS

We retrospectively examined patients who underwent isolated coronary artery bypass grafting surgery between April 2010 and December 2020, and those whose GEA was grafted to the RCA were selected: 55 patients were included in the study analysis. Postoperative evaluations were performed during the early phase, 1 year postoperatively, and at follow-up evaluations. The outer diameter of the proximal GEA was compared with the midterm graft patency grade on CT and patients were classified as Functional (Grade A) or Dysfunctional (Grades O or B). The proximal GEA outer diameters were significantly different between the Functional and Dysfunctional groups (P<0.001). Furthermore, multivariate Cox regression analysis revealed that this diameter was an independent predictor of graft functionality (P<0.001). Patients with outer proximal diameters larger than the cutoff value had superior graft results at 3 years postoperatively. The rate of freedom from a dysfunctional graft at 3 years postoperatively was 95.5% and 45.5% for the Larger and Smaller diameter subgroups, respectively (P<0.001).

CONCLUSIONS

Preoperative evaluation of the outer diameter of the proximal GEA, excluding calcified GEA, using CT is a minimally invasive and useful method, and may improve midterm results of in-situ GEA grafting, even in severe stenotic lesions.

Expert systematic review on the choice of conduits for coronary artery bypass grafting: endorsed by the European Association for Cardio-Thoracic Surgery (EACTS) and The Society of Thoracic Surgeons (STS)

PREAMBLE

The finalized document was endorsed by the EACTS Council and STS Executive Committee before being simultaneously published in the European Journal of Cardio-thoracic Surgery (EJCTS) and The Annals of Thoracic Surgery (The Annals) and the Journal of Thoracic and Cardiovascular Surgery (JTCVS).

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.

Angiographic Outcomes for Arterial and Venous Conduits Used in CABG

Coronary artery bypass grafting is the most commonly performed cardiac surgical procedure. Conduit selection is crucial to achieving early optimal outcomes, with graft patency being likely the main driver to long-term survival. We present a review of current evidence on the patency of arterial and venous bypass conduits and of differences in angiographic outcomes.

Left Internal Mammary Artery as an Endocrine Organ: Insights Into Graft Biology and Long-term Impact Following Coronary Artery Bypass Grafting

The left internal mammary artery (LIMA) is considered the criterion standard vessel for use in coronary artery bypass grafting. In recent decades, countless studies have documented its superiority over other arterial and venous coronary artery bypass grafting conduits, although the full mechanisms for this superiority remain unknown. A growing body of literature has unveiled the importance of extracellular vesicles known as exosomes in cardiovascular signaling and various pathologic states. In this review, we briefly compare the clinical longevity of the LIMA relative to other conduits, explore the effects of varying grafting techniques on clinical and angiographic outcomes, and provide physiologic insights into graft function on a cellular and molecular level. Finally, we explore exosome signaling as it pertains to atherosclerosis in support of the LIMA as an "endocrine organ."

Minimally invasive direct coronary artery bypass to the left anterior descending artery using right gastroepiploic artery graft for a redo case with poor conduits

A 64-year-old Thai woman underwent coronary artery bypass grafting (CABG) using saphenous vein grafts (SVG) for completely occluded left anterior descending artery (LAD) and mitral valve replacement with mechanical valve about a year ago. She presented with unstable angina. Three-dimensional computed tomography angiography (3DCTA) showed occlusion of all the grafts. The left subclavian artery had 99% stenosis. The patient underwent redo CABG via a minimally invasive direct approach. The chest was entered through the left fifth intercostal space. The right gastroepiploic artery (RGEA) and a small length of SVG were harvested. The RGEA was extended using the SVG with an end-to-end anastomosis and used to graft the LAD without cardiopulmonary bypass. The patient's postoperative course was uneventful. Postoperative 3DCTA revealed patent RGEA-SVG graft. Minimally invasive direct coronary artery bypass to LAD with RGEA is a useful alternative approach for redo CABG in patients with not much choice of conduits.

Correlation between Preoperative Coronary Artery Stenosis Severity Measured by Instantaneous Wave-Free Ratio and Intraoperative Transit Time Flow Measurement of Attached Grafts

Background and Objectives: To assess the correlation between the degree of target coronary artery stenosis measured by instantaneous wave-free ratio (iFR) and the intraoperative transit time flow measurement (TTFM) of attached grafts as well as evaluate flow competition between the native coronary artery and the attached graft according to the severity of stenosis. Materials and Methods: In total, 89 grafts were subjected to intraoperative transit time flow measurement after coronary artery bypass grafting (CABG) in 25 patients with multivessel coronary artery disease (CAD). The iFR was evaluated for all coronary arteries with grafts. The coronary artery stenoses were divided into three groups based on the iFR value: iFR < 0.86 (group 1); iFR 0.86-0.90 (group 2); and iFR > 0.90 (group 3). Results: The mean graft flow (MGF) was 46.9 ± 18.4 mL/min for group 1, 45.3 ± 20.9 mL/min for group 2, and 31.3 ± 18.5 mL/min for group 3. A statistically significant difference was confirmed between groups 1 and 3 (p = 0.002) and between groups 2 and 3 (p = 0.025). The pulsatility index (PI) was 2.49 ± 1.20 for group 1, 2.66 ± 2.13 for group 2, and 4.70 ± 3.66 for group 3. A statistically significant difference was found between groups 1 and 3 (p = 0.006) and between groups 2 and 3 (p = 0.032). Backward flow was detected in 7.5% of grafts for group 1, in 16.6% of grafts for group 2, and in 16% of grafts for group 3. A statistically significant difference was found between groups 1 and 2 (p = 0.025) and between groups 1 and 3 (p = 0.029). Conclusions: The iFR is a useful tool for predicting the impact of competitive flow observed between a native artery and an attached graft. The effect of competitive flow significantly increases when the graft is attached to a vessel with mild coronary stenosis. In a coronary artery where the iFR was not hemodynamically significant, the MGF was lower, the PI was higher, and a larger proportion of grafts with backward flow (BF) was detected compared to when there was significant stenosis (iFR < 0.86).

In situ skeletonized gastroepiploic artery grafting in hemodialysis patients

OBJECTIVES

There is no firm treatment strategy of coronary artery bypass grafting in hemodialysis patients. We investigated postoperative outcomes in hemodialysis patients undergoing isolated coronary artery bypass grafting using in situ skeletonized gastroepiploic artery.

METHODS

From January 2002 to December 2019, 143 hemodialysis patients underwent isolated coronary artery bypass grafting in our institution. Among them, 49 consecutive patients with gastroepiploic artery grafting were retrospectively analyzed.

RESULTS

No patient was converted from off-pump to on-pump surgery. The mean distal anastomoses were 3.6 ± 1.0 per patients. Seven patients (14.3%) required proximal anastomosis to aorta. Thirty-day mortality was 4.1% (2 of 49). The early (3-20 days after surgery) patency rate of the gastroepiploic artery was 96.9% (63 of 65 anastomoses). The adjusted rates of survival free from overall death at 1, 5 and 10 years after surgery were 91.7%, 72.6% and 32.5%, respectively. Multivariate Cox proportional hazard regression analysis showed that age (hazard ratio 1.131, 95% confidence interval 1.055-1.212, p < 0.001) and LVEF < 40% (hazard ratio 9.411, 95% confidence interval 1.963-45.919, p = 0.005) were independent predictors of mid-term death from all causes (Table 6).

CONCLUSIONS

Short and mid-term outcomes were acceptable. The use of in situ skeletonized gastroepiploic artery can decrease the time of touching aorta, so gastroepiploic artery grafting may be an important option for coronary artery bypass grafting in hemodialysis patients with limited conduits.