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

Carotid Interventions in Patients Undergoing Coronary Artery Bypass Grafting: A Narrative Review

Simultaneous carotid artery stenosis (CS) and coronary artery disease (CAD) is a common condition among patients with several cardiovascular risk factors; however, its optimal management still remains under investigation, such as the assumption that carotid disease is causally related to perioperative stroke and that preventive carotid revascularization decrease the risk of this complication. Synchronous surgical approach to both conditions, performing carotid endarterectomy (CEA) before coronary artery bypass graft (CABG) during the same procedure, should still be considered in selective patients, in order to reduce the risk of perioperative stroke during coronary cardiac surgery. For the same purpose, staged approaches, such as CEA followed by CABG or CABG followed by CEA during the same hospitalization or a few weeks later have been described. Hybrid approach with carotid artery stenting (CAS) and CABG can also be an option in selected cases, offering a minimally invasive procedure to treat CS among patients whom CABG cannot be postponed. When carotid intervention is indicated in patients with concomitant CAD requiring CABG, a personalized and tailored approach is mandatory, especially in asymptomatic patients, in order to define the ideal surgical strategy. The aim of this paper is to summarize the current "state of the art" of the different approaches to carotid artery diseases in patients undergoing CABG.

Outcomes following coronary artery bypass grafting with multiple arterial grafting by pump status in men and women

BACKGROUND

Multiple arterial grafting (MAG) and off-pump surgery are strategies proposed to improve outcomes with coronary artery bypass grafting (CABG). This study was conducted to determine the impact of off-pump surgery on outcomes after CABG with MAG in men and women.

METHODS

This cohort study used population-based data to identify all Ontarians undergoing isolated CABG with MAG between October 2008 and September 2019. The primary outcome was all-cause mortality. Secondary outcomes included major adverse cardiac and cerebrovascular events (MACCE; hospitalization for stroke, myocardial infarction hospitalization or heart failure, or repeat revascularization). Analysis used propensity-score overlap-weighted cause-specific Cox proportional hazard regression.

RESULTS

A total of 2989 women (1188 off-pump, 1801 on-pump) and 16,209 men (6065 off-pump, 10,144 on-pump) underwent MAG with a median follow-up of 5.0 years (interquartile range, 2.7-8.0) years. Compared to the on-pump approach, all-cause mortality was not changed with off-pump status (hazard ratio [HR] in women: 1.25 [95% CI, 0.83-1.88]; in men: 1.08 [95% CI, 0.85-1.37]). In women, the risk of MACCE was significantly higher off-pump (HR, 1.45; 95% CI, 1.04-2.03), with nonsignificantly increased risk observed for all component outcomes.

CONCLUSIONS

In patients undergoing CABG with MAG, this population-based analysis found no association between pump status and survival in either men or women. However, it did suggest that off-pump MAG in women may be associated with an increased risk of MACCE.

Neurologic complications after cardiopulmonary bypass - A narrative review

Neurologic complications, associated with cardiac surgery and cardiopulmonary bypass (CPB) in adults, are common and can be devastating in some cases. This comprehensive review will not only consider the broad categories of stroke and neurocognitive dysfunction, but it also summarises other neurological complications associated with CPB, and it provides an update about risks, prevention and treatment. Where appropriate, we consider the impact of off-pump techniques upon our understanding of the contribution of CPB to adverse outcomes.

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.

Synchronous Carotid Endarterectomy and Anaortic Off-Pump Coronary Artery Bypass Surgery

BACKGROUND

There is ongoing debate regarding the optimal strategy and timing for the surgical management of patients with severe concomitant carotid and coronary artery disease. Anaortic off-pump coronary artery bypass (anOPCAB), which avoids aortic manipulation and cardiopulmonary bypass, has been shown to reduce the risk of perioperative stroke. We present the outcomes of a series of synchronous carotid endarterectomy (CEA) and anOPCAB.

METHODS

A retrospective review was performed. The primary endpoint was stroke at 30 days post-operation. Secondary endpoints included transient ischaemic attack, myocardial infarction and mortality 30 days post-operation.

RESULTS

From 2009 to 2016, 1,041 patients underwent anOPCAB with a 30-day stroke rate of 0.4%. The majority of patients had preoperative carotid-subclavian duplex ultrasound screening and 39 were identified with significant concomitant carotid disease who underwent synchronous CEA-anOPCAB. The mean age was 71±7.5 years. Nine patients (23.1%) had previous neurological events. Thirty (30) patients (76.9%) underwent an urgent operation. For CEA, a conventional longitudinal carotid endarterectomy with patch angioplasty was performed in all patients. For anOPCAB, total arterial revascularisation rate was performed in 84.6% and the mean number of distal anastomoses was 2.9±0.7. In the 30-day postoperative period, there was one stroke (2.63%), two deaths (5.26%), two transient ischemic attacks (TIAs) (5.26%) and no myocardial infarction. Two patients experienced acute kidney injury (5.26%), one of which required haemodialysis (2.63%). Mean length of stay was 11.37±7.9 days.

CONCLUSION

Synchronous CEA and anOPCAB is a safe and effective option for patients' severe concomitant disease. Preoperative carotid-subclavian ultrasound screening allows identification of these patients.

Personalized surgical planning for coronary bypass graft configurations using patient-specific computational modeling to avoid flow competition in arterial grafts

Objectives

Flow competition between coronary artery bypass grafts (CABG) and native coronary arteries is a significant problem affecting arterial graft patency. The objectives of this study were to compare the predictive hemodynamic flow resulting from various total arterial grafting configurations and to evaluate whether the use of computational fluid dynamics (CFD) models capable of predicting flow can assist surgeons to make better decisions for individual patients by avoiding poorly functioning grafts.

Methods

Sixteen cardiac surgeons declared their preferred CABG configuration using bilateral internal mammary and radial arteries for each of 5 patients who had differing degrees of severe triple vessel coronary disease. Surgeons selected both a preferred 'aortic' strategy, with at least one graft arising from the ascending aorta, and a preferred "anaortic" strategy which could be performed as a "no-aortic touch" operation. CT coronary angiograms of the 5 patients were coupled to CFD models using a novel flow solver "COMCAB." Twelve different CABG configurations were compared for each patient of which 4 were "aortic" and 8 were "anaortic." Surgeons then selected their preferred grafting configurations after being shown predictive hemodynamic metrics including functional assessment of stenoses (instantaneous wave-free ratio; fractional flow reserve), transit time flowmetry graft parameters (mean graft flow; pulsatility index) and myocardial perfusion.

Results

A total of 87.5% (7/8) of "anaortic" configurations compared to 25% (1/4) of "aortic" configurations led to unsatisfactory grafts in at least 1 of the 5 patients (P = 0.038). The use of the computational models led to a significant decrease in the selection of unsatisfactory grafting configurations when surgeons employed "anaortic" (21.25% (17/80) vs. 1.25% (1/80), P < 0.001) but not "aortic" techniques (5% (4/80) vs. 0% (0/80), P = 0.64). Similarly, there was an increase in the selection of ideal configurations for "anaortic" (6.25% (5/80) vs. 28.75% (23/80), P < 0.001) but not "aortic" techniques (65% (52/80) vs. 61.25% (49/80), P = 0.74). Furthermore, surgeons who planned to use more than one unique "anaortic" configuration across all 5 patients increased (12.5% (2/16) vs. 87.5% (14/16), P<0.001).

Conclusions

"COMCAB" is a promising tool to improve personalized surgical planning particularly for CABG configurations involving composite or sequential grafts which are used more frequently in anaortic operations.

Concomitant anaortic OPCAB and transfemoral TAVR for high-risk patients: A case series

BACKGROUND

Combined on-pump coronary artery bypass (ONCAB) and surgical aortic valve replacement (SAVR) is the treatment of choice for concomitant severe aortic stenosis and coronary artery disease not amenable to percutaneous coronary intervention. Extensive aortic calcification and atheromatous disease may prohibit cardiopulmonary bypass and aortic cross-clamping. In these cases, anaortic off-pump coronary artery bypass (OPCAB) is a Class I (EACTS 2018) and Class IIA (AHA 2021) indication for surgical coronary revascularization. Transcatheter aortic valve replacement (TAVR) has similar benefits when compared with SAVR for this population (Partner 2 & 3). Herewith we describe a case series of concomitant Anaortic OPCAB and TAVR via the transfemoral approach for patients with coronary artery and valve disease considered too high risk for traditional coronary artery bypass grafting and SAVR due to severe aortic disease.

METHODS/RESULTS

Eight patients underwent anaortic OPCAB and transfemoral TAVR during the same anesthetic in a hybrid operating room. Seven patients with multivessel disease had anaortic OPCAB via a sternotomy using composite grafts, one patient with LAD disease had anaortic OPCAB using a Da Vinci-assisted MIDCAB approach. All patients then had an Edwards Sapien 3 TAVR placed percutaneously via the common femoral artery. There was no 30 mortality or CVA in the series and all patients were discharged to home or a rehabilitation facility on Day 4-13.

CONCLUSIONS

Combined anaortic OPCAB and transfemoral TAVR is a safe and feasible approach to treating concomitant extensive coronary artery disease and severe aortic stenosis. The aortic no-touch technique provides benefits in the elderly high-risk patients by reducing the risk of postoperative myocardial infarction and cerebrovascular stroke.