Safety and Efficacy of Sequential Left Internal Thoracic Artery Grafting to Left Circumflex Area

Bypass Grafting to Circumflex: Left Internal Thoracic Artery versus Saphenous Vein

BACKGROUND

This study aimed to compare the short- and long-term outcomes of saphenous vein grafts (SVGs) and in situ left internal thoracic artery (LITA) grafts to the left circumflex artery (LCX) territory.

METHODS

This study included 678 patients who underwent LITA-left anterior descending (LAD) + SVG-LCX grafts and 286 patients who underwent right internal thoracic artery (RITA)-LAD + in situ LITA-LCX grafts from January 2002 to December 2020. Short-term and long-term clinical outcomes were compared using inverse probability of treatment weighting adjustment to reduce selection bias.

RESULTS

In-hospital mortality was significantly higher for the SVG-LCX group (p = 0.008), whereas deep sternal wound infection was significantly higher in the LITA-LCX group (p = 0.013).Survival rates at 5 and 10 years were 83.12 and 71.45% in the SVG-LCX group, whereas 75.24 and 65.54% in the LITA-LCX group (log-rank p = 0.114). Rates of freedom from cardiac events at 5 and 10 years were 92.82 and 85.24% in the SVG-LCX group, whereas 94.89 and 89.46% in the LITA-LCX group (log-rank p = 0.179).Univariate and multivariate logistic regression analysis showed that proximal severe stenosis was significantly protective against graft dysfunction before discharge (odds ratio, 0.43; 95% confidence interval, 0.23-0.81).

CONCLUSION

Deep sternal wound infection was significantly higher for LITA to LCX bypass whereas in-hospital mortality was higher for SVG to LCX. In situ LITA to LCX bypass grafting exhibited similar long-term outcomes with SVG to LCX bypass grafting in adjusted patient cohorts. Proximal severe stenosis of LCX was protective against graft dysfunction.

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.

Is it safe to perform total arterial grafting in elderly patients lacking vein grafts? A single surgeon comparison

OBJECTIVES

The results of coronary artery bypass graft (CABG) surgery with total arterial revascularisation (TA-CABG) in elderly patients, who may have insufficient vein graft material for conventional CABG (CO-CABG), have not been fully established. We therefore sought to compare the short- and long-term outcomes of patients >70 years old undergoing CO-CABG and TA-CABG.

METHODS

We performed a retrospective observational study analyzing all consecutive adult patients aged >70 years undergoing first-time CABG over the 15-year period from 2004 to 2020 under a single surgeon. Primary outcomes of interest were in-hospital mortality, long-term mortality, and re-intervention rate. Secondary outcomes of interest included operative durations and the incidence of peri-operative complications.

RESULTS

There were 46 patients (age 76 ± 3 SD) in the TA-CABG group and 145 patients (age 76 ± 4 SD) in the CO-CABG group. Cardio-pulmonary bypass and cross-clamp durations were comparable between groups (p = .11 and p = .23, respectively). Stroke occurred in 1.0% undergoing CO-CABG compared to 0% in the TA-CABG group (p = .42). Hospital mortality was 3.0% with CO-CABG (EuroSCORE; mean [SD] 6.81 (5.81)) and 2.0% with TA-CABG (EuroSCORE; mean [SD] 6.38 (6.57)) (p = .93). On long-term follow-up, myocardial infarction occurred in 10.0% of CO-CABG patients compared to 4.0% of TA-CABG patients (p = .25). Re-intervention rates were 7% following CO-CABG, and 2% after TA-CABG (p = .23). There was no significant difference in long-term mortality between patients undergoing CO-CABG and TA-CABG (47% vs. 57%, p = .27). Long-term survival was comparable between grafting techniques (p = .27).

CONCLUSIONS

There were no significant differences in major adverse cardiac and cerebrovascular events, re-intervention rate, hospital or long-term mortality between CO-CABG and TA-CABG. TA-CABG represents a safe and feasible alternative to CO-CABG in elderly patients offering good long-term outcomes.

The patency of graft and anastomoses in sequential and individual coronary artery bypass grafting: A meta-analysis

Objective:

To compare the patency of graft and anastomoses in sequential and individual coronary artery bypass grafting (CABG).

Methods:

Our study used the Cochrane Library database, Excerpta Medica database, Web of Science, and PubMed. Studies comparing the outcomes of graft or anastomosis patency were assessed independently by two reviewers to identify the literature of satisfaction. We used Review Manager and STATA software for statistical analysis.

Results:

Fifteen cohort studies were analyzed, including 10681 patients, 12957 grafts, and 4341 anastomoses, under sequential and individual CABG. Compared with the sequential group, the individual one is statistically significant in the graft patency [risk ratio (RR)=1.07, 95% confidence interval (CI ) 1.01–1.13; p=0.02] and anastomosis patency (RR=1.06, 95% CI 1.01–1.12; p=0.005).

Conclusion:

Our study suggested that the patency of the individual group, in terms of graft and anastomosis patency, is better than that of the sequential one.

THE COMPARISON OF VENOUS SEQUENTIAL AND NORMAL GRAFT PATENCY BASED ON HEMODYNAMICS

Background: In coronary artery bypass grafting (CABG), the patency of venous sequential graft remains controversial. Hemodynamic factors have been proved to be the important factors influencing graft patency. The objective of this study is to compare the patency of sequential grafts and normal grafts by hemodynamic environment. Methods: This study used a patient’s clinical data to construct a 0D/3D coupled multi-scale model, and used this model to calculate graft’s hemodynamics under two grafting methods. Meanwhile, CABG ideal models were constructed based on grafts’ flow data of 60 patients (63 normal grafts, 19 sequential grafts) to calculate grafts’ hemodynamics. Results: Based on the multi-scale model, it was found that the sequential graft flow and time average wall shear stress (TAWSS) were higher than normal graft, which was good for graft patency. But there were a flow separation region, some regions of high oscillatory shear index (OSI) and relative residence time (RRT) in sequential graft, which could lead to intimal hyperplasia. Based on ideal CABG models, it was known that failure rate of sequential and normal grafts were 36.8% and 36.5%, and there were significant differences between them in flow rate, TAWSS and OSI (sequential versus normal: flow rate (ml/min): [Formula: see text] versus [Formula: see text], TAWSS (Pa): [Formula: see text] versus [Formula: see text], OSI: 0.[Formula: see text] versus [Formula: see text]). Conclusion: For saphenous venous graft (SVG), although the normal graft has similar patency with the sequential graft, the hemodynamic mechanism behind it is different. In flow rate and WSS, sequential grafts have an advantage over normal grafts. But there are high OSI and RRT regions in sequential grafts.

Internal mammary harvesting: Techniques and evidence from the literature

Coronary artery bypass graft (CABG) is one of the most commonly performed cardiac surgeries in the world. CABG using the internal mammary artery (IMA) remains the gold standard intervention for myocardial intervention in multivessel coronary artery disease. IMA harvesting can be performed with various techniques and approaches: pedicled vs skeletonized harvesting technique as well as approaches such as conventional sternotomy, robotic and endoscopic approaches. While each technique and approach have their respective advantages and disadvantages, evidence remains varied between cohorts. Traditionally, IMA has been used as an in situ conduit; however, IMA free grafts also provide satisfactory outcomes in certain situations. This literature review aims to explore the efficacy of different techniques and approaches of IMA harvesting and grafting. With evidence compiled, this will provide an overview of the complexity of CABG and locate gaps in current literature to direct future research.

Long-term graft patency after coronary artery bypass grafting: Effects of surgical technique

The aim of the current study was to identify surgical factors associated with long-term patency of grafts used in coronary artery bypass grafting (CABG). The present study analyzed data from 127 patients who underwent CABG at our institute between 2000 and 2006 and presented for ambulatory examination and coronary computed tomography angiography evaluation of graft patency in 2016 (139.78±36.64 months post-CABG). The 127 patients received 340 grafts (2.68 grafts/patient) and 399 distal anastomoses (3.14 anastomoses/patient), 220 (55.14%) with arterial grafts and 179 (44.86%) with saphenous vein grafts. Graft patency varied according to coronary territory, proximal anastomosis type (in situ graft, composite graft, graft anastomosed to the ascending aorta), Y anastomosis angle (47.21° for patent arterial grafts vs. 56° for occluded), and distal anastomosis angle (in sequential anastomoses irrespective to graft type, 48.60° for patent side-to-side anastomosis vs. 53.97° for occluded, 65.12° for patent end-to-side anastomosis vs. 90.80° for occluded; in single end-to-side anastomosis of arterial grafts, 39.46° for patent and 44.94° for occluded). A single end-to-side anastomosis angle 60° or greater was associated with a 5.149 occlusion odds ratio (OR) (P<0.001) for arterial grafts. Venous grafts were not sensitive to single end-to-side anastomosis angle. In conclusion, a small anastomosis angle for proximal Y and distal anastomoses is associated with a higher long-term patency of the free graft. Radial artery grafts registered higher patency rates when anastomosed to the ascending aorta compared with composite grafting with the left internal thoracic artery, whereas in situ right internal thoracic artery (RITA) anastomosed to the right coronary territory is associated with a lower patency rate compared with free RITA used to revascularise the anterolateral or circumflex territory in composite grafting.

Bilateral internal thoracic artery grafting: in situ or composite?

Bilateral internal thoracic artery (BITA) grafting is considered a superior choice for coronary artery bypass grafting (CABG). While the 10-year outcomes of BITA grafting from the recent Arterial Revascularization Trial (ART) are still pending, numerous observational studies have demonstrated the advantages of BITA grafting. These include better long-term graft patency and freedom from arteriosclerosis, in addition to higher survival rate compared to CABG using only the left internal thoracic artery (ITA). The different BITA configurations are in situ and composite-the choice of optimal grafting configuration is challenging. Patient factors such as coronary anatomy, presence of a diseased ascending aorta and the potential need for a future redo sternotomy will influence the choice of the grafting strategy. In situ BITA grafting is associated with excellent clinical outcomes and has been extensively described in the literature. However, uncertainties remain regarding the ideal in situ configuration and design. Composite BITA grafting is the other option that maximizes right ITA (RITA) utilization. In this configuration, the RITA is able to reach the distal circumflex and right coronary artery branches. This approach decreases the need for a third graft conduit.

Single-Centre Experience of Off-Pump Multi-Vessel Coronary Artery Bypass Grafting Using Proximal Suture Device

BACKGROUND

To investigate the results of off-pump coronary artery grafting (OPCAB) with the proximal suture device (PSD) regarding postoperative stroke and graft patency.

METHODS

The PSD was used in 376 patients (32.0%), aorta-no-touch OPCAB was performed in 523 patients (45.2%), on-pump beating coronary artery bypass surgery (CABG) (on-beat group) in 125 patients (10.6%) including 51 conversions (conversion rate: 5.4%), and CABG with aortic clamp use (clamp group) in 152 patients. In the PSD group, Enclose II was used in 267 patients (71.0%).

RESULTS

The hospital mortality rate was 1.95%. There was no early stroke in the OPCAB group, whereas the early-stroke rate was 0.8% in the on-beat group and 2.6% in the clamp group. The incidences of stroke at one month were: PSD group, 1.6%; no-touch group, 1.1%; on-beat group, 1.6%; and clamp group, 4.6% (p=0.014). The rates of complete revascularisation were higher in the PSD and clamp groups (94.7 and 94.0%, respectively) compared with the no-touch and on-beat groups (81.5 and 84.9%, respectively; p<0.001). The vein graft patency rates were comparable between the PSD and clamp groups. In multiple logistic regression analysis, OPCAB using the PSD did not increase the risk of stroke compared with the no-touch group (adjusted odds ratio [AOR]: 1.40; p=0.594) or on-beat group (AOR: 0.99; p=0.206), but reduced the risk of stroke compared with the clamp group (AOR: 0.19; p=0.005).

CONCLUSIONS

Off-pump coronary artery grafting using the PSD was a safe and effective procedure. It led to lower incidences of postoperative stroke and excellent rates of graft patency and complete revascularisation compared with conventional CABG.