Anaortic Off-Pump Coronary Artery Bypass Grafting in the Elderly and Very Elderly

Survival benefit from a second arterial conduit to the circumflex circulation persists in elderly after coronary artery bypass surgery

BACKGROUND

This retrospective propensity matched study investigated the impact of age on the survival benefit from a second arterial conduit to the left-sided circulation.

METHODS

Data for isolated coronary artery bypass surgery were collected from October 2004 to March 2014. All patients with an internal mammary artery graft to left anterior descending artery and additional arterial or venous graft to the circumflex circulation were included. Propensity matching was used to balance co-variates and generate odds of death for each observation. Odds ratios (venous vs. arterial) were charted against age.

RESULTS

The in-hospital mortality rate was 1.12% (arterial) vs. 1.24% (venous) (p = 0.77). The overall 10-year survival was 74.6% (venous) vs. 82.6% (arterial) (p = 0.001). A total of 1226 patients were successfully matched to the venous or arterial (second conduit to circumflex territory after left internal mammary artery to left anterior descending artery) cohorts. Odds ratio for death (venous to arterial) showed a linear decremental overall survival benefit for the second arterial graft to circumflex circulation with increasing age.

CONCLUSIONS

The survival benefit of a second arterial graft persists through all age groups with a gradual decline with increasing age over the decades. Elderly patients should not be denied a second arterial graft to the circumflex circulation based on age criterion alone.

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

Surgical coronary revascularization remains the preferred strategy in a significant portion of patients with coronary artery disease due to superior long-term outcomes. However, there is a significant risk of perioperative neurologic injury that has influenced guideline recommendations. These complications occur in 1%-5% of patients, ranging from overt neurologic deficits with permanent disability, to subtle cerebral defects noted on neuroimaging that may result in slow cognitive and functional decline. The primary mechanism by which these events occur is thromboembolism from manipulation of the ascending aorta. This occurs during cardiopulmonary bypass, aortic cross-clamping, and partial occlusion clamping (side clamp). Elderly patients and patients with aortic atheroma are, therefore, at significantly increased risk. Initial surgical techniques addressed this by aggressively debriding or replacing the ascending aorta during coronary artery bypass grafting (CABG). Strategies then moved toward minimizing aortic manipulation through pump-assisted beating heart surgery and off-pump surgery with partial occlusion clamping or proximal anastomosis devices. Finally, anaortic off-pump CABG aims to avoid all manipulation of the ascending aorta through advanced off-pump grafting techniques combined with in situ and composite grafts. This has been demonstrated to result in the greatest reduction in risk. Establishing successful anaortic off-pump CABG programs requires subspecialization and focused interest groups dedicated to advancing CABG outcomes.

Technical Aspects of the Use of the Radial Artery in Coronary Artery Bypass Surgery

BACKGROUND

The radial artery has been used for coronary artery bypass surgery for more than 25 years. The recent confirmation of the clinical benefits associated with the use of the artery is likely to drive a new interest toward this conduit in the next few years.

METHODS

A group of surgeons with extensive experience in the systematic use of the radial artery summarize here the key technical aspects of the use of the conduit for coronary bypass operations.

RESULTS

Preoperative evaluation of the ulnar collateral circulation and attention to the characteristics of the target vessel are keys for the successful use of the radial artery. Open or endoscopic harvesting can be used, preferentially with the aid of the harmonic scalpel. The use of vasodilatory and antispastic protocols is probably important but poorly supported by the current evidence. The radial artery can be used for multiple grafting strategies with a variable degree of technical complexity.

CONCLUSIONS

With attention to few technical key points, the radial artery is a versatile conduit that can be easily introduced in the everyday practice of coronary artery bypass surgery.

Neural network imaging to characterize brain injury in cardiac procedures: the emerging utility of connectomics

Cognitive dysfunction is a poorly understood but potentially devastating complication of cardiac surgery. Clinically meaningful assessment of cognitive changes after surgery is problematic because of the absence of a means to obtain reproducible, objective, and quantitative measures of the neural disturbances that cause altered brain function. By using both structural and functional connectivity magnetic resonance imaging data to construct a map of the inter-regional connections within the brain, connectomics has the potential to increase the specificity and sensitivity of perioperative neurological assessment, permitting rational individualized assessment and improvement of surgical techniques.

The radial artery in coronary surgery, 2018

It is now 25 years since the radial artery (RA) was reintroduced in coronary surgery. It has evolved into being a significant coronary artery bypass conduit and ranks third in usage after the internal thoracic artery (ITA) and saphenous vein grafts (SVG). Its advantages are that it can be readily and efficiently harvested, is of good length and appropriate size for coronary artery bypass graft (CABG) surgery, is robust and easy to handle, and remains free of atheroma, and there is minimal wound morbidity. The RA must be used judiciously with attention to spasm prophylaxis because of its muscular wall, and by avoiding competitive flow. Its patency is equivalent to the ITAs when placed to similar coronary territories and under similar conditions (stenosis, size, quality) and RA patencies are always superior to those of SVG in both observational and randomized studies-88-90% versus 50-60% at 10 years, and 80-87% versus 25-40% at 20 years. Its use and excellent patencies result in survival results equivalent to bilateral internal thoracic artery (BITA) grafting and always superior to left internal thoracic artery (LITA) +SVG. Typical radial artery multiarterial bypass grafting (RA-MABG) 10-year survivals are 80-90% versus 70-80% for LITA-SVG. In general, for every 100 patients undergoing CABG, 10 more patients will be alive at 10 years post-operatively. The RA also is important in achieving total arterial revascularization, and several reports indicate a further survival advantage for patients having three arterial grafts over two. The RAs are especially useful in diabetic, morbidly obese patients, those with conduit shortage, and leg pathology, and in coronary reoperations. Although the RA has equivalent patencies to the right internal thoracic artery (RITA), it is much more versatile. RAs that have been instrumented by angiography or percutaneous coronary intervention should be avoided. The radial artery has proved to be an excellent arterial conduit, is equivalent to but more versatile than the RITA, and is always superior to SVG. Its use should be part of every coronary surgeon's skill set.

Composite Y Grafts From the Left Internal Mammary Artery: Current Considerations

The use of composite coronary artery bypass grafts from the left internal mammary artery (LIMA) has increased over the last 20 years. Total arterial revascularisation can be achieved with two arterial conduits and is associated with a reduced risk of stroke. However, the traditional coronary bypass graft configurations of the in situ LIMA and aorto-coronary saphenous vein grafts remain as the mainstay of coronary bypass surgery in most centres. Concerns regarding composite Y grafts relate to (1) the adequacy of a single inflow for all coronary bypass grafts; (2) the risk of compromising the LIMA flow to the left anterior descending coronary artery; (3) the effects of competitive flow on graft patency; and (4) the use of sequential coronary anastomoses. The evidence upon which these concerns are based will be discussed along with the evidence relating to the use of the various second conduit options.

Coronary Artery Bypass Grafting With and Without Manipulation of the Ascending Aorta: A Network Meta-Analysis

BACKGROUND

Coronary artery bypass grafting (CABG) remains the standard of treatment for 3-vessel and left main coronary disease, but is associated with an increased risk of post-operative stroke compared to percutaneous coronary intervention. It has been suggested that CABG techniques that eliminate cardiopulmonary bypass and reduce aortic manipulation may reduce the incidence of post-operative stroke.

OBJECTIVES

A network meta-analysis was performed to compare post-operative outcomes between all CABG techniques, including anaortic off-pump CABG (anOPCABG), off-pump with the clampless Heartstring device (OPCABG-HS), off-pump with a partial clamp (OPCABG-PC), and traditional on-pump CABG with aortic cross-clamping.

METHODS

A systematic search of 6 electronic databases was performed to identify all publications reporting the outcomes of the included operations. Studies reporting the primary endpoint, 30-day post-operative stroke rate, were included in a Bayesian network meta-analysis.

RESULTS

There were 13 included studies with 37,720 patients. At baseline, anOPCABG patients had higher previous stroke than did the OPCABG-PC (7.4% vs. 6.5%; p = 0.02) and CABG (7.4% vs. 3.2%; p = 0.001) patients. AnOPCABG was the most effective treatment for decreasing the risk of post-operative stroke (-78% vs. CABG, 95% confidence interval [CI]: 0.14 to 0.33; -66% vs. OPCABG-PC, 95% CI: 0.22 to 0.52; -52% vs. OPCABG-HS, 95% CI: 0.27 to 0.86), mortality (-50% vs. CABG, 95% CI: 0.35 to 0.70; -40% vs. OPCABG-HS, 95% CI: 0.38 to 0.94), renal failure (-53% vs. CABG, 95% CI: 0.31 to 0.68), bleeding complications (-48% vs. OPCABG-HS, 95% CI: 0.31 to 0.87; -36% vs. CABG, 95% CI: 0.42 to 0.95), atrial fibrillation (-34% vs. OPCABG-HS, 95% CI: 0.49 to 0.89; -29% vs. CABG, 95% CI: 0.55 to 0.87; -20% vs. OPCABG-PC, 95% CI: 0.68 to 0.97), and shortening the length of intensive care unit stay (-13.3 h; 95% CI: -19.32 to -7.26; p < 0.0001).

CONCLUSIONS

Avoidance of aortic manipulation in anOPCABG may decrease the risk of post-operative stroke, especially in patients with higher stroke risk. In addition, the elimination of cardiopulmonary bypass may reduce the risk of short-term mortality, renal failure, atrial fibrillation, bleeding, and length of intensive care unit stay.

Cardiac Magnetic Resonance Imaging Predictors of Short-Term Outcomes after High Risk Coronary Surgery

BACKGROUND

The euroSCORE II is a widely used pre-coronary artery bypass graft surgery (CAGS) risk score, but its predictive power lacks the specificity to predict outcomes in high-risk patients (<LVEF 40%) due to changes in cardiac surgery case mix, revascularisation techniques and related outcomes in recent years. We investigated the utility of Cardiac Magnetic Resonance Imaging (CMRI) in predicting immediate and six-week outcomes after CAGS.

METHODS

Fifty-two consecutive patients with high euroSCORE II (>16) and left ventricular (LV) dysfunction (<40%) based on 2D-echocardiography who underwent CAGS and in whom CMRI (1.5T) was performed preoperatively were retrospectively studied. Cardiac magnetic resonance imaging parameters were assessed in patients who either had complications immediately post-surgery (n=35), six weeks post-surgery (n=20) or were uncomplicated.

RESULTS

The average age of patients recruited was 69±5 years with high euroSCORE II (22±4) and low 2D-echocardiography LV ejection fraction (38%±2%). Cardiac magnetic resonance imaging results demonstrated that those with immediate complications had higher LV scar/infarct burden as a proportion of LV mass (17±3% vs 10±3%; p=0.04) with lower circumferential relaxation index (2.5±0.46 vs 2.8±0.56; p=0.05) compared to those with no complications. Early mortality from surgery was 17% (n=9) and was associated with lower RV stroke volume (55±12 vs 68±18; p=0.03) and higher LV infarct scar/burden (18±2% vs 10±2%, p=0.04). Cardiac magnetic resonance imaging showed patients with complications at six weeks post-surgery had higher LV scar/infarct burden (14.5±2% vs 6.8±2%, p=0.03) compared to those without complications.

CONCLUSION

Cardiac magnetic resonance imaging preoperative LV and RV parameters are valuable in assessing the likelihood of successful outcomes from CAGS in high-risk patients with LV dysfunction.