Role of Intraoperative Transesophageal Echocardiography in Patients Having Coronary Artery Bypass Graft Surgery

Surgical Coronary Revascularization in Patients With Underlying Atrial Fibrillation: State-of-the-Art Review

The number of individuals referred for coronary artery bypass grafting (CABG) with preoperative atrial fibrillation (AF) is reported to be 8% to 20%. Atrial fibrillation is a known marker of high-risk patients as it was repeatedly found to negatively influence survival. Therefore, when performing surgical revascularization, consideration should be given to the concomitant treatment of the arrhythmia, the clinical consequences of the arrhythmia itself, and the selection of adequate surgical techniques. This state-of-the-art review aimed to provide a comprehensive analysis of the current understanding of, advancements in, and optimal strategies for CABG in patients with underlying AF. The following topics are considered: stroke prevention, prophylaxis and occurrence of postoperative AF, the role of surgical ablation and left atrial appendage occlusion, and an on-pump vs off-pump strategy. Multiple acute complications can occur in patients with preexisting AF undergoing CABG, each of which can have a significant effect on patient outcomes. Long-term results in these patients and the future perspectives of this scientific area were also addressed. Preoperative arrhythmia should always be considered for surgical ablation because such an approach improves prognosis without increasing perioperative risk. While planning a revascularization strategy, it should be noted that although off-pump coronary artery bypass provides better short-term outcomes, conventional on-pump approach may be beneficial at long-term follow-up. By collecting the current evidence, addressing knowledge gaps, and offering practical recommendations, this state-of-the-art review serves as a valuable resource for clinicians involved in the management of patients with AF undergoing CABG, ultimately contributing to improved outcomes and enhanced patient care.

Perioperative hemodynamic monitoring in cardiac surgery

PURPOSE OF REVIEW

Cardiac surgery has traditionally relied upon invasive hemodynamic monitoring, including regular use of pulmonary artery catheters. More recently, there has been advancement in our understanding as well as broader adoption of less invasive alternatives. This review serves as an outline of the key perioperative hemodynamic monitoring options for cardiac surgery.

RECENT FINDINGS

Recent study has revealed that the use of invasive monitoring such as pulmonary artery catheters or transesophageal echocardiography in low-risk patients undergoing low-risk cardiac surgery is of questionable benefit. Lesser invasive approaches such a pulse contour analysis or ultrasound may provide a useful alternative to assess patient hemodynamics and guide resuscitation therapy. A number of recent studies have been published to support broader indication for these evolving technologies.

SUMMARY

More selective use of indwelling catheters for cardiac surgery has coincided with greater application of less invasive alternatives. Understanding the advantages and limitations of each tool allows the bedside clinician to identify which hemodynamic monitoring modality is most suitable for which patient.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Transesophageal Echocardiography in Patients Undergoing Coronary Artery Bypass Graft Surgery

BACKGROUND

The impact of utilization of intraoperative transesophageal echocardiography (TEE) at the time of isolated coronary artery bypass grafting (CABG) on clinical decision making and associated outcomes is not well understood.

OBJECTIVES

The purpose of this study was to determine the association of TEE with post-CABG mortality and changes to the operative plan.

METHODS

A retrospective cohort study of planned isolated CABG patients from the Society of Thoracic Surgeons Adult Cardiac Surgery Database between January 1, 2011, and June 30, 2019, was performed. The exposure variable of interest was use of intraoperative TEE during CABG compared with no TEE. The primary outcome was operative mortality. The association of TEE with unplanned valve surgery was also assessed.

RESULTS

Of 1,255,860 planned isolated CABG procedures across 1218 centers, 676,803 (53.9%) had intraoperative TEE. The percentage of patients receiving intraoperative TEE increased over time from 39.9% in 2011 to 62.1% in 2019 (p trend <0.0001). CABG patients undergoing intraoperative TEE had lower odds of mortality (adjusted odds ratio: 0.95; 95% confidence interval: 0.91 to 0.99; p = 0.025), with heterogeneity across STS risk groups (p interaction = 0.015). TEE was associated with increased odds of unplanned valve procedure in lieu of planned isolated CABG (adjusted odds ratio: 4.98; 95% confidence interval: 3.98 to 6.22; p < 0.0001).

CONCLUSIONS

Intraoperative TEE usage during planned isolated CABG is associated with lower operative mortality, particularly in higher-risk patients, as well as greater odds of unplanned valve procedure. These findings support usage of TEE to improve outcomes for isolated CABG for high-risk patients.

A rare case report of early myocardial ischemia after coronary artery bypass surgery due to mechanical compression of vein graft by pericardial drainage tube: Role of transesophageal echocardiography

New onset regional wall motion abnormality (RWMA) following coronary artery bypass grafting adversely affects the patient outcome. Early detection and addressing the cause of RWMA improves overall morbidity and mortality of the patient. We report a rare case of early myocardial ischemia detected by intraoperative transesophageal echocardiography due to mechanical compression of a vein graft by a pericardial drain tube.

Cost-effectiveness of routine transoesophageal echocardiography during cardiac surgery: a discrete-event simulation study

BACKGROUND

The aim of this study was to simulate and compare the healthcare and economic outcomes associated with routine use of intraoperative transoesophageal echocardiography (TOE) in patients undergoing cardiac surgery with those associated with a scenario where TOE is not routinely used.

METHODS

The impact of TOE on surgical decision-making was estimated through a systematic literature review. Individual short-term morbidity and mortality estimates were generated by application of the Society of Thoracic Surgeons risk calculator. Long-term event rates, unit costs, and utility weights were sourced from published literature and expert opinion. A discrete-event simulation model was then constructed to simulate both the in-hospital and post-discharge outcomes for patients undergoing cardiac surgery. Robustness of the base case results was examined through deterministic and probabilistic sensitivity analyses. An incremental cost-effectiveness ratio of €30 000 per quality-adjusted life-year gained was assumed to represent acceptable cost-effectiveness.

RESULTS

Routine use of intraoperative TOE was associated with lower costs and higher benefits per patient, which indicates that use of TOE is a dominant strategy. The intervention resulted in the avoidance of 299 cardiac complications, 20 strokes, and 11 all-cause deaths per 10 000 patients. Routine intraoperative TOE was associated with an increased occurrence of bleeding owing to more valvular surgery and subsequent long-term anticoagulation.

CONCLUSIONS

Routine intraoperative TOE is a cost-effective procedure for patients undergoing cardiac surgery, leading to lower overall costs. It was associated with a decrease in long-term complications including stroke, cardiac complications, and death, although there was a slight increase in extracranial bleeding events.

Transesophageal Echocardiography, Acute Kidney Injury, and Length of Hospitalization Among Adults Undergoing Coronary Artery Bypass Graft Surgery

OBJECTIVE

To test the association between transesophageal echocardiography (TEE) and incidence of acute kidney injury and length of hospitalization among United States adults undergoing isolated coronary artery bypass graft (CABG) surgery.

DESIGN

This was an observational, retrospective cohort analysis.

SETTING

This study used a multicenter claims dataset from a commercially insured population undergoing CABG surgery in the United States between 2004 and 2016.

PARTICIPANTS

Adults aged 18 years or older with continuous insurance enrollment and an absence of renal-related diagnoses before the index CABG surgery.

INTERVENTIONS

Receipt of TEE within 1 calendar day of the index CABG surgery date.

MEASUREMENTS AND MAIN RESULTS

Of 51,487 CABG surgeries, 5,361 (10.4%; [95% confidence interval [CI]: 10.1-10.7%]) developed acute kidney injury and the mean length of hospitalization was 8.8 days (95% CI: 8.7-8.8). The TEE group demonstrated a greater absolute risk difference (RD) for acute kidney injury by multiple linear regression, overall, (RD=+1.0; [95% CI: 0.4-1.5%]; p < 0.001) and among a low-risk subgroup (RD=+1.0; [95% CI: 0.4-1.6; p = 0.002), but not by instrumental variable analysis (RD=+0.9 [95% CI: -1.1 to 2.9%]; p = 0.362). The TEE group demonstrated a longer length of hospitalization by multiple linear regression, overall (+2.0%; [95% CI: 1.1-2.9%]; p < 0.001), among a low-risk subgroup (+2.2%; [95% CI: 1.2-3.2%]; p < 0.001), and by instrumental variable analysis (+10.3%; [95% CI: 7.0-13.7%]; p < 0.001).

CONCLUSIONS

TEE monitoring in CABG surgery was not associated with a lower incidence of acute kidney injury or decreased length of hospitalization. These findings highlight the importance of additional work to study the clinical effectiveness of TEE in CABG surgery.

Echocardiographic detection of free-floating thrombus in left ventricle during coronary artery bypass grafting

We report an incident of detection of a free-floating thrombus in the left ventricle (LV) using intraoperative two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE) during proximal coronary artery bypass graft anastomosis. A 58-year-old man presented to us with a 6-month history of chest pain without any history suggestive of myocardial infarction or transient ischemic attacks. His preoperative echocardiography revealed the systolic dysfunction of LV, mild hypokinesia of basal and mid-anterior wall, and the absence of an aneurysm. He was scheduled for on-pump coronary artery bypass surgery. On intraoperative TEE before establishing cardiopulmonary bypass (CPB), a small immobile mass was found attached to LV apical area. After completion of distal coronary artery grafting, when the aortic cross-clamp was removed, the heart was filled partially and beating spontaneously. TEE examination using 2D mode revealed a free-floating mass in the LV, which was suspected to be a thrombus. Additional navigation using biplane and 3D modes confirmed the presence of the thrombus and distinguished it from papillary muscles and artifact. The surgeon opened the left atrium after re-establishing electromechanical quiescence and removed a thrombus measuring 1.5 cm Χ 1 cm from the LV. The LV mass in the apical region was no longer seen after discontinuation of CPB. Accurate TEE-detection and timely removal of the thrombus averted disastrous embolic complications. Intraoperative 2D and recent biplane and 3D echocardiography modes are useful monitoring tools during the conduct of CPB.

Critical importance of unsuspected findings detected by intraoperative transesophageal echocardiography for decision making during cardiac surgery

AIMS

To report the frequency of unsuspected pathologies detected by presurgical and/or postsurgical intraoperative transesophageal echocardiography (IOTEE) and its impact on the extent of cardiac surgery and the number of pathologies remaining unoperated.

METHODS AND RESULTS

In a 2-year study period, 469 patients (male/female = 273/196; age 68.0 ± 11.9 years) with presurgical and/or postsurgical IOTEE out of 2,035 patients submitted for cardiac surgery were analyzed retrospectively. Presurgical IOTEE was performed in all patients referred to valve surgery or suspicious valve disease or valve diseases with open surgical decision. Postsurgical IOTEE was performed in all patients after valve surgery. Pathologies relevant for surgery were defined as valve disease of moderate degree or higher or structural disease like shunt lesions. In 464 patients (98.9 %), a total number of 757 IOTEEs were successfully performed including 351 presurgical and 384 postsurgical studies, 1-s presurgical IOTEE, 20-s postsurgical, and one-third postsurgical IOTEE. Surgically relevant unsuspected findings were detected in 33.0 % of presurgical IOTEE leading to alteration of surgery in 27.6 %. Relevant pathologies detected by postsurgical IOTEE were found in 7.8 % as remnant valvular dysfunction of the operated valve and in 12.3 % related to other structures. Relevant pathologies detected by postsurgical IOTEE finally remained unoperated in 21.2 % of patients with only postsurgical IOTEE versus only 10.7 % (p < 0.05) of patients with both presurgical and postsurgical IOTEE.

CONCLUSION

We found an alarming high number of unsuspected pathologies by IOTEE causing substantial alterations of surgery. Beyond this, whether patients received presurgical IOTEE or not made a significant difference on the number of pathologies left unoperated.

Effect of on-pump versus off-pump coronary bypass surgery on cardiac function assessed by intraoperative transesophageal echocardiography

PURPOSE

To compare cardiac function assessed by intraoperative transesophageal echocardiography in patients undergoing cardiac revascularization with or without cardiopulmonary bypass.

MATERIAL AND METHODS

Forty-one patients scheduled for elective, isolated cardiac revascularization (21 on-pump and 20 off-pump) were prospectively analyzed. Patients were matched for demographic (age and gender), anthropometric (BMI), clinical (co-morbidities, EuroScore) and laboratory variables (blood counts, renal function, left ventricular function). Transesophageal echocardiography was performed after induction of anesthesia, protamine sulfate administration, and chest closure. Left ventricular wall motion score index, end-diastolic area, fractional area change, right ventricular area change and end-diastolic area were assessed. Troponin I and C-reactive protein concentrations were measured.

RESULTS

Regarding echocardiographic parameters of left and right ventricular function no significant differences between on-pump and off-pump groups at any point-of-time measurements were found. Troponin I and C-reactive protein were higher in on-pump as compared to off-pump group (p=0.001 and p=0.002; p=0.003 and p=0.001, respectively).

CONCLUSIONS

In elective patients scheduled for cardiac revascularization there were no difference in cardiac performance assessed by intraoperative echocardiography regardless of surgical method used.

Core review: physician-performed ultrasound: the time has come for routine use in acute care medicine

The use of ultrasound in the acute care specialties of anesthesiology, intensive care, emergency medicine, and surgery has evolved from discrete, office-based echocardiographic examinations to the real-time or point-of-care clinical assessment and interventions. "Goal-focused" transthoracic echocardiography is a limited scope (as compared with comprehensive examination) echocardiographic examination, performed by the treating clinician in acute care medical practice, and is aimed at addressing specific clinical concerns. In the future, the practice of surface ultrasound will be integrated into the everyday clinical practice as ultrasound-assisted examination and ultrasound-guided procedures. This evolution should start at the medical student level and be reinforced throughout specialist training. The key to making ultrasound available to every physician is through education programs designed to facilitate uptake, rather than to prevent access to this technology and education by specialist craft groups. There is evidence that diagnosis is improved with ultrasound examination, yet data showing change in management and improvement in patient outcome are few and an important area for future research.

A Modification of the Trans-Oesophageal Echocardiography Protocol can Reduce Post-Operative Dysphagia following Cardiac Surgery

Use of intra-operative trans-oesophageal echocardiography (TEE) is an independent risk factor for post-operative dysphagia. This study investigated whether modifying the TEE probe-placement protocol could reduce the incidence of post-operative dysphagia. In group I ( n = 100), the TEE probe was inserted after anaesthetic induction and remained in place until the completion of surgery. In group II ( n = 100), the TEE probe was inserted after anaesthetic induction, the heart was examined, then the probe was removed. The probe was inserted again before weaning from cardiopulmonary bypass and then immediately removed after examination. The incidence of dysphagia was significantly higher in group I than in group II patients (51.1% versus 28.6%). Multivariate regression analysis showed that the length of time that the TEE probe was in the oesophagus was an independent predictor of dysphagia. Modification of the TEE protocol in this way can reduce the incidence of post-operative dysphagia in cardiac surgery patients.

Intraoperative echocardiography in valvular heart disease: an evidence-based appraisal

Intraoperative (IO) transesophageal echocardiography (TEE) is widely used for assessing the results of valvular heart disease (VHD) surgery. Epiaortic ultrasonography (EAU) has been recommended for prevention of perioperative strokes. To what extent does high-quality evidence justify the widespread use of these imaging modalities? In March 2009, we searched MEDLINE (PubMed and OVID interfaces) and EMBASE for studies published in English using database-specific controlled vocabulary describing the concepts of IOTEE, cardiac surgery, VHD, and EAU. We found no randomized trials or studies with control groups assessing the impact of IOTEE in VHD surgery. Pooled analysis of 8 observational studies including 15,540 patients showed an average incidence of 11% for prebypass surgical changes and 4% for second pump runs, suggesting that patients undergoing VHD surgery may benefit significantly from IOTEE, particularly from postcardiopulmonary bypass IOTEE in aortic repair and mitral repair and replacement, but less so in isolated aortic replacement. Further available indirect evidence was satisfactory in the test accuracy and surgical quality control aspects, with low complication rates for IOTEE. The data supporting EAU included 12,687 patients in 2 prospective randomized studies and 4 nonrandomized, controlled studies, producing inconsistent outcome-related results. Despite low-quality scientific evidence supporting IOTEE in VHD surgery, we conclude that indirect evidence supporting its use is satisfactory and suggests that IOTEE may offer considerable benefit in valvular repairs and mitral replacements. The value of IOTEE in isolated aortic valve replacement remains less clear. Evidence supporting EAU is scientifically more robust but conflicting. These findings have important clinical policy and research implications.

Meta-analysis of the diagnostic accuracy of transesophageal echocardiography for assessment of atherosclerosis in the ascending aorta in patients undergoing cardiac surgery

BACKGROUND

Stroke after cardiac surgery may be caused by emboli emerging from an atherosclerotic ascending aorta (AA). Epiaortic ultrasound scanning (EUS), the current 'gold' standard for detecting AA atherosclerosis, has not gained widespread use because there is a lack of optimized ultrasound devices, it lengthens the procedure, it endangers sterility, and there is a false belief by many surgeons that palpation is as sensitive as EUS. Furthermore there is no clear evidence proving that the use of epiaortic scanning changes outcome in cardiac surgery. Various researchers investigated the ability of transesophageal echocardiography (TEE) to discriminate between the presence and absence of AA atherosclerosis. It is acknowledged that TEE has limited value in this, but it has never been supported by a meta-analysis estimating the true diagnostic accuracy of TEE based on all quantitative evidence. We aimed to do this using state-of-the-art methodology of diagnostic meta-analyses.

METHODS

We searched multiple databases for studies comparing TEE vs. EUS for detection of atherosclerosis. A random-effects bivariate meta-regression model was used to obtain summary estimates of sensitivity and specificity, incorporating the correlation between sensitivity and specificity as well as covariates to explore heterogeneity across studies.

RESULTS

We extracted six studies with a total of 346 patients, of whom 419 aortic segments were analyzed, including 100 segments with atherosclerosis [median prevalence 25% (range 17-62%)]. Summary estimates of sensitivity and specificity were 21% (95% CI 13-32%) and 99% (96-99%), respectively.

CONCLUSIONS

Because of the low sensitivity of TEE for the detection of AA atherosclerosis, a negative test result requires verification by additional testing using epiaortic scanning. In case of a positive test result, AA atherosclerosis can be considered as present, and less manipulative strategies might be indicated.

Perioperative echocardiography: two-dimensional and three-dimensional applications

Perioperative echocardiography is an essential skill for today's cardiac anesthesiologist and a driving force for innovation and accomplishment for the future of the subspecialty. Real-time three-dimensional transesophageal echocardiography (RT3-D TEE) will dominate the future practice of perioperative echocardiography, but transthoracic echocardiography (TTE) will grow in application, as will contrast echocardiography. Hand-held ultrasonongraphs will rival current machines in capabilities and make it possible for TTE to become the stethoscope of the future for cardiac anesthesiologists.

Severe hypoxaemia after weaning from cardiopulmonary bypass: a case report

Persistence of patent foramen ovale is frequent in adults and usually asymptomatic. We report the case of a patient in whom a patent foramen ovale was diagnosed after weaning from cardiopulmonary bypass and was not recognised preoperatively. Intraoperative transoesophageal echocardiography is pivotal for surgical decision-making and should be performed in all patients undergoing cardiac surgery.

Resolving the blind spot of transoesophageal echocardiography: a new diagnostic device for visualizing the ascending aorta in cardiac surgery

BACKGROUND

Atherosclerosis of the ascending aorta (AA) and stroke after cardiac surgery are related. Knowledge of the location of AA-atherosclerosis pre-sternotomy allows changes in surgical strategy to avoid manipulation of the AA. The gold-standard for assessment of AA-atherosclerosis is intraoperative epiaortic ultrasound scanning (EUS). Transoesophageal echocardiography (TOE) is unable to detect atherosclerosis in the distal AA due to the 'blind spot'. A new method [A-View (Aortic-view) method] using a fluid-filled catheter may enhance the assessment of distal AA-atherosclerosis. The aim of this study was to evaluate whether the A-View method indeed visualizes the distal AA and to assess the safety of this technology.

METHODS

In a cross-sectional diagnostic study, 41 patients undergoing cardiac surgery including sternotomy underwent the same work-up including TOE, the A-View method, EUS, and routine operative monitoring.

RESULTS

With the A-View method, the distal AA was visible in all (100%) patients. There were no clinical important side-effects associated with the use of the A-View catheter; however, in one patient the endotracheal tube was accidentally dislocated leading to a decrease in Sa(O2). Severity of atherosclerosis visualized with the A-View method compared with EUS results showed good agreement between the two methods [Kappa of 0.69 (0.50-0.88)]. The Bland-Altman analysis showed poor agreement in plaque-size measurements (bias 0.05 cm2, limits of agreement - 0.63 to 0.74 cm2).

CONCLUSIONS

The A-View method offers a minimally invasive and safe approach to preoperatively resolving the blind spot of TOE. Compared with EUS, the A-View method yielded satisfactory results in the detection of AA-atherosclerosis. The A-View method seems a promising tool for patients undergoing cardiac surgery to direct surgical management.