Sequential Versus Individual Saphenous Vein Grafting During Coronary Arterial Bypass Surgery

Long-term results following off-pump coronary-artery bypass grafting in left ventricular dysfunction

Severe left ventricular (LV) dysfunction is an independent risk factor for early and long-term mortality after coronary-artery bypass grafting (CABG). Off-pump CABG (OPCAB) significantly reduces the early incidence of major complications in high-risk patients. Moreover, bilateral internal thoracic artery (BITA) grafting after CABG is associated with improved long-term outcomes. We aimed to evaluate the impact of multivessel OPCAB with BITA grafting for complete revascularization on postoperative and long-term outcomes in patients with low LV ejection fraction (EF). We included 121 patients with EF ≤ 30.0% who underwent isolated multivessel OPCAB (average LVEF, 24.8%) between April 2007 and December 2019. Sixty-six patients received BITA grafts, while 55 had single internal thoracic artery (SITA) grafts. We conducted multivariate analyses to examine the correlation between perioperative data and late mortality rate. The early mortality rate was 1.65%. After excluding in-hospital mortality cases, we performed long-term follow-up of 119 patients. Early postoperative echocardiography showed significant LVEF improvement in 89 (75.2%) patients. However, LVEF remained ≤ 30.0% in 30 (24.8%) patients. We recorded 15 and 30 cases of cardiac death and cardiac events, respectively, during the long-term follow-up period. Postoperative LVEF ≤ 30.0% (P < 0.01) and no use of BITA grafting (P = 0.03) were significant predictors of cardiac death and events; moreover, hemodialysis was a significant predictor of all-cause mortality rather than cardiac death. Multivessel OPCAB in patients with severe LV dysfunction was associated with acceptable in-hospital mortality and early postoperative improvement in LV function. Additionally, OPCAB with BITA grafting may provide long-term benefits with respect to cardiac death and events. However, the long-term benefits were significantly limited in patients without early postoperative improvement in LV function and patients with chronic hemodialysis.Clinical registration number: 5590 (14/5/2020 Tokyo Women's Medical University).

Distal end side-to-side anastomosis of sequential coronary bypass for size mismatched saphenous vein grafts and coronary arteries

INTRODUCTION

The distal end anastomosis is critical to the entire sequential grafts in coronary artery bypass grafting (CABG), but caliber mismatch diminishes the quality of the anastomosis. We aimed to introduce a modified distal end side-to-side (deSTS) anastomosis to handle the size mismatch and compared with classic distal end end-to-side (deETS) anastomosis.

METHODS

From January 2014 to December 2018, 185 patients who underwent off-pump CABG with size mismatched sequential vein grafts (≥3.5 mm) and target coronaries (1.0-1.5 mm) at the distal end anastomoses were included. We retrospectively reviewed the data of the patients, perioperative and follow-up outcomes were analyzed.

RESULTS

The deSTS group (n = 67) showed higher anastomotic flow (19.8 ± 8.0 vs 14.9±6.8 mL/min; p < 0.001) and lower pulsatility index (2.7 ± 0.8 vs 3.2 ± 1.0; p = 0.001) than the deETS group (n = 118). Higher incidence of in-hospital myocardial infarction (MI) was found in the deETS group but without significant difference (9.0% vs. 15.3%; p = 0.220). Kaplan-Meier analysis illustrated a relatively lower MI and major adverse cardiovascular and cerebrovascular events (MACCE) incidence in the deSTS group, and the deSTS group was associated with a reduction in long-term death, MI and MACCE in the adjusted Cox regression model. In addition, relatively higher graft patency was found in the deSTS group.

CONCLUSIONS

The deSTS anastomosis showed superiority in solving size mismatch in sequential CABG, including better intraoperative flow dynamics, ideal long-term graft patency and reduced the incidence of perioperative and follow-up adverse events especially in MI.

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.

Ninety-seven cases of experiences with the left thoracotomy approach for off-pump conventional revascularization: a retrospective cohort study

BACKGROUND

Minimally invasive coronary surgery-coronary artery bypass grafting (MICS CABG) is well adopted in clinical practice. However, this procedure did not really achieve conventional complete revascularization. The present study aimed to explore the feasibility and safety of conventional revascularization via the left thoracotomy (8-10 cm) approach.

METHODS

From January 2020 to March 2022, a total of 97 consecutive patients who needed coronary artery revascularization were operated on using this technique. The patients' preoperative, intraoperative, postoperative, and follow-up data were collected. Perioperative variables were compared between the single graft and non-single graft groups. All patients received dual-source computerized tomographic angiography at 1-week postoperatively to evaluate the graft patency and detect pulmonary embolism and aortic dissection. The patients were followed up for 3-27 months.

RESULTS

The mean age of the entire cohort was 61.5±8.8 years, there were 16 (16.5%) female patients, and 1-4 grafts were performed per patient. There were no conversions to median sternotomy or on-pump CABG. The average number of grafts was 1.9±0.9, and that of the non-single graft group was 2.5±0.6. Among the 97 included patients, one patient in the single graft group suffered from aspiration pneumonia after a stroke and died. The 30-day mortality was 1.0% (one patient), one patient required re-exploration for bleeding (1.1%), and a total of 191 grafts were performed. All grafts were unobstructed except for one graft to the obtuse marginal branch (OM) (0.5%). Follow-up was performed by phone or via outpatient visits and was available for 92 patients (95%). During the follow-up period, 1 (1.1%) patient suffered an acute myocardial infarction and received percutaneous coronary intervention with no redo-surgery. All patients are alive and angina-free.

CONCLUSIONS

Left thoracotomy for conventional revascularization is a safe procedure for appropriately selected patients, with few early complications and good early and mid-term results. More cases are ongoing and long-term results are in observation.

Predictors of vein graft disease progression between one week and one year after surgical coronary revascularization: Impact of secondary prevention medications

OBJECTIVE

This study aimed to detect the predictors of vein graft disease (VGD) progression between 1 week and 1 year after surgery and to evaluate the impact of secondary prevention medications.

METHODS

A total of 218 consecutive patients underwent surgical coronary revascularization were evaluated by coronary computed tomography angiography both at 1-week and 1-year follow-up. Logistic regression analyses were performed to investigate the predictors of VGD progression. A risk score (0-4) was set up to evaluate implementation result of secondary prevention measures according to 1-year follow-up result. Association between VGD progression and the risk score was assessed.

RESULTS

VGD progression occurred in 11.3% of saphenous vein grafts (SVG) and 22.1% of patients. At the patient level, poor vein graft (odds ratio [OR] = 4.25), noncontrolled hyperlipidemia (OR = 3.01), and diabetes mellitus (DM) (OR = 2.96) were predictors, while diameter of SVG (mm, OR = 0.35) was protective factor. At the graft level, DM (OR = 3.52), noncontrolled hyperlipidemia (OR = 2.33), and peripheral artery disease (PAD) (OR = 2.20) were predictors, while number of SVGs (OR = 0.63), diameter of SVG (mm, OR = 0.39), and mean graft flow >25 ml/min (OR = 0.35) were protective factors. VGD progression was significantly associated with the risk score at both the patient (OR = 1.52) and the graft level (OR = 1.38).

CONCLUSIONS

Poor vein graft, noncontrolled hyperlipidemia and DM were predictors of VGD progression between 1 week and 1 year after surgery at the patient level, while larger SVG diameter was a protective factor. DM, PAD and noncontrolled hyperlipidemia were predictors at the graft level, while a number of SVGs, larger SVG diameter, and mean graft flow >25 ml/min were protective factors. Implementation failure of secondary prevention medications was associated with VGD progression from as early as 1 year after surgery.

Patency and adverse outcomes of sequential vs. individual saphenous vein grafts in coronary artery bypass: A meta-analysis

Objectives

To undertake a systematic review and meta-analysis of cohort studies to compare the patency and adverse outcomes of sequential and individual saphenous vein grafts (SVGs) in coronary artery bypass grafting (CABG).

Methods

We searched PubMed, Embase, and the Cochrane Library for cohort studies. Endpoints for vein graft failure, perioperative and follow-up adverse events were extracted as risk ratio (RR) with 95% confidence intervals (95% CI). Statistical heterogeneity across the studies was examined using the I² statistic. Potential of publication bias was evaluated quantitatively by the Egger's test. Sensitivity analysis was also performed to assess the robustness of our outcomes.

Results

The 15 studies were analyzed, including 22,004 patients, 4,580 grafts, and seven different adverse events under individual or sequential CABG. The sequential group had inferior graft failure (RR = 0.68; 95% CI, 0.60–0.77) and long-term mortality (RR = 0.76; 95%CI, 0.61–0.95), but with an increased risk of perioperative repeat revascularization (RR = 1.58; 95%CI, 1.16–2.14) than the individual group.

Conclusion

Taken together, our analysis of the aggregated evidence comparing the sequential and individual saphenous vein grafts for coronary heart disease patients showed that the use of the sequential graft was associated with inferior graft failure and long-term mortality respectively, but with an increased risk of perioperative repeat revascularization. According to our study, both surgical techniques have their own advantages in efficacy and safety, and the selection of surgical techniques should be based on patients and surgeons. Sequential saphenous vein grafts should be more recommended to experienced surgeons in order to both reduce perioperative adverse events and improve long-term patency.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022326992.

No-Touch Sequential Saphenous Venous Harvesting Technique in Off-Pump Bypass Surgery: A Retrospective Study

Background

In the mid-1990s, the Swedish expert team proposed saphenous vein graft (SVG) harvesting with pedicle tissue. The short-term and long-term patency rates of the great saphenous vein obtained by the no-touch (NT) were higher than those obtained by the conventional (CON). In the past, NT harvesting was mainly used in on-pump coronary artery bypass grafting (CABG), and vein grafts were mostly single vein grafts. In this study, we retrospectively analyzed the safety and effectiveness of sequential vein grafts using NT harvesting in off-pump CABG.

Methods

From 2017 to 2019, a total of 505 patients were included in the study. There were 150 patients in the NT group and 355 patients in the CON group. After applying propensity score matching (1:1 matching), 148 patients were included in each group. Baseline data, graft patency, post-operative complications, leg wound complications and 1-year major adverse cardiac and cerebrovascular events (MACCEs) were compared between the two groups.

Results

There was no significant difference in the patency rate of sequential venous grafts between the two groups 1 year after the operation either before [NT: 7.1% (10/141) vs. CON: 11.5% (38/331), p = 0.149) or after matching (NT: 7.1% (10/140) vs. CON: 7.3% (9/124), p = 0.971]. There was no significant difference in the composite clinical endpoint between the two groups either before [NT: 3 (2.3%) vs. CON: 9 (2.8%), p = 1.000] or after matching [NT: 3 (2.3%) vs. CON: 3 (2.5%), p = 1.000]. There were differences in leg wound complications between the two groups both before [NT: 9 (6.9%) vs. CON: 6 (1.9%), p = 0.007] and after matching [NT: 9 (6.9%) vs. CON: 2 (1.7%), p = 0.043].

Conclusions

The application of the NT harvesting in off-pump CABG with sequential vein grafts is safe and effective. NT method has disadvantages in leg wound.

The expansion of no-touch harvesting sequential vein graft after off-pump coronary artery bypass grafting

Background and Aim of the Study

Many studies support that the no‐touch (NT) procedure can improve the patency rate of vein grafts. However, it is not clear that the sequential vein graft early expansion in the NT technique during off‐pump coronary artery bypass grafting (CABG). This study will explore this issue.

Methods

This was a prospective single‐center randomized controlled clinical trial. A total of 100 patients undergoing off‐pump CABG with the sequential saphenous graft were randomly assigned to two groups: the NT and conventional (CON) groups. Perioperative and postoperative data were collected during the hospital stay. The mean diameter of sequential grafts was measured using cardiac computed tomography angiography 3 months after the operation.

Results

There was a significant difference in the average diameter of sequential grafts between the two groups (NT: [2.98 ± 0.42], CON: [3.26 ± 0.51], p = .005). There was no difference in occlusion of sequential venous grafts between the two groups (NT: 4/48 [8.3%], CON: 5/49 [10.2%], p = 1.000). There were differences in surgery time between the two groups (NT: 220 [188,240], CON: 190 [175,230], p = .009).

Conclusions

The sequential graft early expansion in the NT technique is not as pronounced as that in the conventional technique, which may have a long‐term protective effect on the grafts.

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.

Computational Evaluation of Venous Graft Geometries in Coronary Artery Bypass Surgery

Cardiothoracic surgeons are faced with a choice of different revascularization techniques and diameters for saphenous vein grafts (SVG) in coronary artery bypass graft surgery . Using computational simulations, we virtually investigate the effect of SVG geometry on hemodynamics of both venous grafts and the target coronary arteries. We generated patient-specific 3-dimensional anatomic models of coronary artery bypass graft surgery patients and quantified mechanical stimuli. We performed virtual surgery on 3 patient-specific models by modifying the geometry vein grafts to reflect single, Y, and sequential surgical configurations with SVG diameters ranging from 2 mm to 5 mm. Our study demonstrates that the coronary artery runoffs are relatively insensitive to the choice of SVG revascularization geometry. We observe a 10% increase in runoff when the SVG diameter is changed from 2 mm to 5 mm. The wall shear stress of SVG increases dramatically when the diameter drops, following an inverse power scaling with diameter. For a fixed diameter, the average wall shear stress on the vein graft varies in ascending order as single, Y, and sequential graft in the patient cohort. The runoff to the target coronary arteries changes marginally due to the choice of graft configuration or diameter. The shear stress on the vein graft depends on both flow rate and diameter and follows an inverse power scaling consistent with a Poiseuille flow assumption. Given the similarity in runoff with different surgical configurations, choices of SVG geometries can be informed by propensity for graft failure using shear stress evaluations.

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.

Individual Versus Sequential Saphenous Vein Grafts for on-Pump Coronary Artery Bypass Grafting - Does Smaller Coronaries in Indians Affect Graft Choice? - A Mid-Term Patency Comparison Study

Purpose

Although multiarterial grafting or bilateral mammary artery use is being increasingly emphasized for contemporary coronary artery bypass grafting (CABG) practice, saphenous vein graft (SVG) still accounts for 80% of all CABG conduits (Park et al., 2020) [1]. In India, both the individual and sequential saphenous grafting techniques are used arbitrarily, and there has not been a study that compares the mid-term patency of these two. This is specially relevant in view of smaller coronaries in Indians than the Caucasian counterparts. This study aims to compare the patency for on pump CABG's.

Methods

In the present study, 323 patients underwent either sequential (group A, N = 151 grafts, each graft having two anastomoses each) or individual (group B, N = 344 grafts) saphenous vein CABG, between February 2014 and June 2017. The SVG anastomoses were created on obtuse marginal (OM1/OM2) and posterior descending artery (PDA). The graft patency of the vein grafts as well as the left internal mammary artery were assessed by serial coronary angiograms.

Results

Results were evaluated at 6 months, 1, 2 and 3 years post operatively. Group A showed a higher graft patency at 3 years at 80.8%, and group B, 67.1% (P = 0.002). Also, anastomoses on sequential conduits had overall better patency rates at three years (77.2% vs 67.2%, P = 0.005). The groups showed similar results at one year post operatively.

Conclusions

Sequential bypass grafts were associated with superior mid-term patency compared with individual grafts. These findings suggest the more favourable results of sequential bypass grafting to be attributed to the enhanced flow haemodynamics.

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.