Controversy. On pump or off pump: what will I do when I grow up? A narrative systematic review

The transition from the second to the third millennium happened to be a turning point in the history of myocardial revascularization on a beating heart, which moved from technical development to critical evaluation. This article describes how the initial acceptance and spread of off-pump coronary artery bypass grafting (OPCABG) was followed by the general perception that the technique could not fulfill the expectations placed in it and provides some insight on what should we do with the know-how of OPCABG in the present and the future of coronary surgical revascularization.

Assessing the benefits of anaortic off-pump coronary artery bypass grafting

Introduction

The procedure called the "aorta no-touch" (NT) or anaortic technique in off-pump coronary artery bypass grafting (OPCAB) is designed to reduce the perioperative risk of stroke. We have observed an increased frequency of anaortic OPCAB procedures at our institution. The main purpose of the present study is to investigate the effectiveness of anaortic OPCAB in reducing the perioperative risk of stroke.

Methods

From April 2011 to July 2023, a total of 2,236 patients underwent isolated OPCAB at our single center. The patients were divided into the anaortic group (NT, n = 762) and the aortic group (A, n = 1,474). The NT group was propensity score-matched (PSM) with the A group at a 1:1 ratio (NT n = 640; A n = 640), and matching was performed based on 26 covariates with preoperative clinical characteristics.

Results

In both the unmatched and matched cohorts of the NT and A groups, there were no significant differences observed in new stroke rates (NT vs. A; unmatched, 1.0% vs. 1.2%, p = 0.624; matched, 0.9% vs. 1.3%, p = 0.789). The univariable logistic analysis did not identify the anaortic technique as an independent factor negatively associated with new stroke events (OR = 0.81, 95% CI = 0.35-1.86, p = 0.624).

Conclusion

The present study did not find the anaortic technique to reduce the perioperative risk of stroke in OPCAB. Hence, further large studies are needed to identify patient cohorts in which anaortic OPCAB is significantly beneficial.

Off-pump coronary artery bypass grafting with clampless aortic anastomosis devices: Aortic sealing devices versus automated anastomosis punching

Objectives

Clampless aortic anastomosis devices aim to lower stroke risk in off-pump coronary artery bypass grafting. Two main strategies for clampless anastomosis devices emerged with automated anastomosis punching and aortic sealing devices, prompting the question of perioperative outcome differences.

Methods

All consecutive patients undergoing elective off-pump coronary artery bypass grafting with a clampless aortic anastomosis device between September 2014 and December 2021 in 2 centers were retrospectively included. Cohorts were divided by the use of an automated anastomosis punching device or an aortic sealing device to achieve proximal anastomosis on the ascending aorta. To reach group comparability propensity score matching was performed. The primary end point was defined as a composite of all-cause mortality, stroke and rethoracotomy. Secondary end points were perioperative outcome parameters.

Results

A total of 3703 patients were enrolled of whom 575 and 3128 were included in the automated anastomosis punching and the aortic sealing device group, respectively. By propensity score matching a total of 1150 patients were included with 575 in each group. The primary composite endpoint showed no significant difference with 6.3% versus 5.9% events (odds ratio, 0.9; 95% confidence interval, 0.58-1.53, P = .81). All-cause mortality (P = .36), stroke (P = .81), and rethoracotomy (P = .89) also exhibit no disparity. Operation time was significantly longer in the aortic sealing device cohort with 220.0 ± 50.8 minutes and 204.6 ± 53.8 minutes (P < .01).

Conclusions

Clampless aortic anastomosis strategies aortic sealing device and automated anastomosis punching did not differ in perioperative outcome parameters, whereas the implementation of aortic sealing devices were associated with a prolonged operation time without inducing any inferior clinical outcome.

Prognosis and Clinical Results after Coronary Artery Bypass Operation in Young Patients Aged <45 Years: Chances and Limitations of a New Therapy Option

Coronary artery bypass grafting (CABG) is the recommended type of revascularization procedure in patients with left main or three-vessel disease and is considered an alternative when percutaneous coronary intervention is not feasible. We evaluated registry data to obtain long-term outcome data.All patients ≤45 years in whom CABG was performed between 2009 and 2019 were selected from the Heart and Diabetes Center NRW, Germany. Cox regression analysis was applied to estimate the incidence risk of events after surgery.A total of 209 patients (81.8% male) were included. Mean (standard deviation) follow-up duration was 5.8 (3.1) years. The combined outcome of death, stroke, myocardial infarction, or repeated revascularization occurred in 31 patients (14.8%). Estimated mean time to event was 8.5 (standard error: 0.22) years. By the end of the follow-up period, 8 patients (3.8%) had died, among whom 2 (1.0%) died within 1 month after surgery, 1 (0.5%) within 1 year, 1 (0.5%) within 2 years, and 4 (1.9%) after 2 years.Risk factors independently associated with postsurgery events were angina pectoris CCS (Canadian Cardiovascular Society) class IV (adjusted hazard ratio [HR]: 4.954; 95% confidence interval [CI]: 1.322-18.563; p = 0.018) and STS (Society of Thoracic Surgeons) score (adjusted HR: 1.152 per scoring point; 95% CI: 1.040-1.276; p = 0.007).After performing CABG in patients ≤45 years, event-free long-term outcomes were observed in the majority of patients. Presence of angina pectoris CCS class IV and higher STS scores were independently associated with adverse postsurgery events.

Device Use for Proximal Anastomosis on Ascending Aorta in Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

We recently reported early postoperative results comparing the use of an anastomosis-assist device with a side-biting clamp for ascending aorta during coronary artery bypass grafting (CABG). Transient neurological complications occurred less often with the device. Here, we evaluated the perioperative safety of the device compared with the aorta no-touch technique (no-touch).

METHODS

We evaluated patients listed in the Japan Adult Cardiovascular Surgery Database who received isolated off-pump CABG with either the device or the no-touch approach from 2014 to 2016. We performed a one-to-one matched analysis based on a propensity score modeled from patient demographics, comorbidities, cardiac conditions, and procedural characteristics. We compared early outcomes in both groups using Pearson's chi-square or Wilcoxon rank sum test as appropriate; P less than .05 was statistically significant.

RESULTS

Among 9546 device and 6890 no-touch patients, we found 5012 patient matches for each group. The device operation time was significantly longer (293 versus 281 minutes; P < .001) and homologous transfusion was significantly greater (56.9% versus 51.0%; P < .001) than with no-touch. Thirty-day operative mortality (1.5% versus 1.7%; P = .34), morbidity and mortality (6.8% versus 7.5%; P = .17), and stroke (0.9% versus 1.1%; P = .36) were similar in both groups. New-onset atrial fibrillation (11.9% versus 10.3%; P = .01) occurred significantly more often with the device. Newly initiated dialysis (1.4% versus 1.9%; P = .051) was more frequent with no-touch whereas reoperation for graft occlusion was more frequent with the device (1.0% versus 0.6%; P = .06) but was not significant for either outcome.

CONCLUSIONS

The clinical safety of use of the device in CABG was comparable to no-touch for mortality and morbidity. Hemostasis may be a key issue for accomplishing higher-level quality control when devices are used in proximal anastomosis of CABG.

Minimally invasive coronary bypass surgery with bilateral internal thoracic arteries: Early outcomes and angiographic patency

OBJECTIVE

Multivessel minimally invasive coronary artery bypass grafting, performed chiefly with left internal thoracic artery and saphenous vein grafts through a left anterolateral thoracotomy, has recently emerged as an alternative to conventional coronary artery bypass grafting. The present study involves our initial experience with respect to early postoperative and angiographic outcomes after total arterial multivessel off-pump minimally invasive coronary artery bypass grafting with bilateral internal thoracic arteries.

METHODS

A total of 88 consecutive patients undergoing total arterial off-pump minimally invasive coronary artery bypass grafting with bilateral internal thoracic arteries without ascending aortic manipulation were included in this study. Bilateral internal thoracic arteries were harvested under direct vision through a left anterolateral thoracotomy and used as Y or in situ grafts. Multivessel grafting was performed off pump. Postoperative graft assessment was performed in 51 patients.

RESULTS

The mean age of patients was 67.1 ± 7.2 years, and 79 patients (89.8%) were male. The mean body mass index and ejection fraction were 26.7 ± 2.7 kg/m² and 57.6% ± 6.6%, respectively, and 40 patients (45.5%) had left main disease. No intraoperative conversions to cardiopulmonary bypass or sternotomy occurred. A total of 209 distal anastomoses (mean 2.4 ± 0.5) were performed, with 57 patients undergoing double, 29 patients undergoing triple, and 2 patients undergoing quadruple coronary artery bypass grafting. There was no in-hospital mortality, and 5 patients underwent reexploration for bleeding. No patient had stroke or chest wound infections. Predischarge coronary angiography revealed an overall graft patency rate of 96.8%.

CONCLUSIONS

Off-pump minimally invasive coronary artery bypass grafting using total arterial revascularization with bilateral internal thoracic arteries is a feasible and safe operation that is associated with excellent short-term outcomes and early graft patency. Future studies should focus on improving the generalizability and reproducibility of this technique.

Tranexamic acid and convulsive seizures after off-pump coronary artery bypass surgery: the role of renal insufficiency

There is evidence that, in adult cardiac surgical patients undergoing on-pump procedures, tranexamic acid (TXA) dose-dependently increases the risk of convulsive seizure (CS). We aimed to investigate whether a single TXA bolus of 1 g influences the risk of CS in patients who were operated on without the use of cardiopulmonary bypass. In 2249 propensity-score-matched pairs who underwent off-pump coronary artery bypass grafting with or without TXA administration, the risk of CS was 0.5% and 0.3% in the TXA and non-TXA groups, respectively (P = 0.36). In the subgroups of patients with estimated glomerular filtration rates <30, 30-60 and >60 ml/min/1.73 m2, the risk of CS in the TXA group was 2.8%, 1.2% and 0.4%, respectively (P = 0.002), and in the non-TXA group 0.0%, 0.0% and 0.3%, respectively (P = 0.36). The risk of stroke, in-hospital mortality and 30-day mortality did not differ significantly between study groups (P-value >0.05). Our data indicate that in patients undergoing off-pump coronary artery bypass grafting, a single TXA bolus of 1 g generally does not increase the risk of CS. However, the presence and extent of renal insufficiency have a very significant impact on the incidence of CS even after single-dose TXA.

A Clampless Aortoprosthetic End to Side Anastomotic Device with Large Diameter Aortic Puncher

Introduction

To facilitate safe anastomosis of a vascular prosthesis onto the proximal ascending aorta without side clamping, a clampless anastomotic device with large diameter aortic puncher was developed.

Report

First, a vascular prosthesis is anastomosed onto the aorta without making a hole, then the aortic wall within the prosthesis is punched out using the device.

Discussion

After further refinement of the present device, endovascular surgery with debranching could be performed more safely and quickly.

Long-term survival following on-pump and off-pump coronary artery bypass graft surgery: a propensity score-matched analysis

OBJECTIVES

Recent studies have once again brought into focus the long-term survival following off-pump coronary artery bypass grafting (OPCAB) compared with conventional on-pump coronary artery bypass grafting surgery (ONCAB). The aim of this study was to compare the long-term risk-adjusted survival rates in patients undergoing coronary artery bypass grafting (CABG) using these 2 techniques.

METHODS

We undertook a propensity score-matched analysis of 10 293 patients who underwent CABG at our single institution between 2000 and 2016. A logistic regression model was fitted using 14 covariates and their 2-way interactions to calculate an estimated propensity score [area under curve (AUC) 0.69], from which 1:1 nearest neighbour matching was performed. Patient survival was assessed using the Kaplan-Meier method and log-rank test.

RESULTS

Of the total cohort, 8319 patients had ONCAB and 1974 had OPCAB. Prior to matching, the OPCAB group had marginally higher EuroSCORE [3.7 ± 2.7 vs 3.5 ± 3, median (interquartile range) 3 (2-5) vs 3 (2-5), P = 0.016] and significantly lower average number of grafts per patient (2.39 ± 0.72 vs 2.75 ± 0.48, P < 0.001). Post-matching distributions between OPCAB and ONCAB showed a substantial improvement in balance in preoperative patient characteristics. The 2 surgery groups differed significantly in survival (P < 0.001). OPCAB demonstrated improved long-term survival at 10 years [84.8%, 95% confidence interval (CI) (82.7-86.9%) vs 75.8%, 95% CI (73.4-78.2%)] and 15 years [65.4%, 95% CI (61.4-69.6%) vs 58.5%, 95% CI (54.9-62.3%)]. Results of sensitivity analysis for 1:2 and 1:3 matched data were in concordance with these findings of survival.

CONCLUSION

At our institution, selected patients who underwent OPCAB had lower in-hospital morbidity and improved long-term survival when compared with a matched population of ONCAB patients.

Off-pump coronary artery bypass surgery with bilateral internal thoracic arteries: the Leipzig experience

Background

Contrasting results of recent randomized controlled trials (RCTs) comparing off-pump and on-pump coronary artery bypass graft (CABG) surgery, as well as the lack of evidence for any survival benefit of bilateral internal thoracic artery (ITA) grafting over single ITA use, has intensified the debate about the role of the off-pump technique and bilateral ITA use in CABG surgery. We therefore investigated our 15-year experience in off-pump CABG with bilateral ITA grafting and evaluated temporal trends in preoperative characteristics and postoperative outcomes.

Methods

Demographic, intra-operative, and outcome data of 1,199 consecutive patients undergoing off-pump CABG with bilateral ITA grafting was prospectively collected in a computerized database. Patients who underwent on-pump cardiac procedures and other extra-cardiac procedures were excluded from this study. Assessment of changes in perioperative characteristics and parameters with time was performed by dividing the whole cohort into three groups (2003-2007, 2008-2012, and 2013-2017) based on the year of surgery.

Results

The overall 30-day mortality was 0.6%, with no differences observed between the three time cohorts (0.6%, 0.7%, 0.5%; P=0.8). The perioperative stroke rate for whole cohort was 0.6% and demonstrated a significant reduction in the last two time cohorts (1%, 0.5%, 0.5%; P<0.0001). The overall incidence of deep sternal wound infections was 0.7%, but was marginally higher in the last time-cohort (0.6%, 0.5%, 0.9%; P=0.7). Overall survival for the entire cohort was 92.9%±1% and 78.9%±4% at 5 and 10 years follow-up, respectively. Older age at surgery and presence of peripheral vascular disease were the only predictors of late mortality.

Conclusions

Off-pump CABG with bilateral skeletonized ITAs is a safe operation and is associated with a low mortality and morbidity, which can be maintained in high volume center unit over a long period of time. The long-term survival of patients undergoing such an operation is excellent.

Cardiac surgery 2017 reviewed

For the year 2017, more than 21,000 published references can be found in PubMed when entering the search term "cardiac surgery". This review focusses on conventional cardiac surgery, considering the new interventional techniques only if they were directly compared to classic techniques but also entails aspects of perioperative intensive care management. The publications last year provided a plethora of new and interesting information that helped to quantify classic surgical treatment effects and provided new guidelines for the management of structural heart disease, which made comparisons to interventional techniques easier. The field of coronary bypass surgery was primarily filled with confirmatory evidence for the beneficial role of coronary artery bypass grafting for complex coronary disease and equal outcomes for percutaneous coronary intervention for less complex disease including main stem lesions. For aortic valve treatment, the new guidelines provide an equal recommendation for surgical and transcatheter aortic valve replacement for high and intermediate risk giving specific check lists to individualize decision-making by the heart team. For low-risk aortic stenosis, surgical valve replacement remains the primary indication. For the mitral valve, the importance of surgical experience of the individual surgeon on short- and long-term outcome was presented and the prognostic impact of mitral repair for primary mitral regurgitation was emphasized. In addition, there were many relevant and interesting other contributions from the purely operative arena in the fields of tricuspid disease as well as terminal heart failure (i.e., transplantation and ventricular assist devices). While this article attempts to summarize the most pertinent publications, it does not have the expectation of being complete and cannot be free of individual interpretation. As in recent years, it provides a condensed summary that is intended to give the reader "solid ground" for up-to-date decision-making in cardiac surgery.