Epicardial Echocardiography in Pediatric and Congenital Heart Surgery

Intraoperative and Intraprocedural Use of 3-Dimensional Transesophageal Echocardiography: An International European Association of Cardiothoracic Anesthesia and Intensive Care Survey of Cardiac Surgical Centers

OBJECTIVE

To assess the intraoperative use of 3-dimensional transesophageal echocardiography (3D TEE) in cardiac surgical centers, the authors created a survey aimed at evaluating the availability of equipment and the use of 3D TEE for specific surgical and interventional procedures and single-image modalities. The respondents were asked to identify the perceived impact on patient management and current limitations to its routine use.

DESIGN

A multiple choice 25-question online survey submitted to the members of the European Association of Cardiothoracic Anesthesia and Intensive Care (EACTAIC) on December 6, 2021, and closed on January 31, 2022.

SETTING

An online survey.

PARTICIPANTS

Registered EACTAIC members in 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 239 respondents from 44 different countries took part in the survey (27% of the total 903 EACTAIC members). Most respondents (59%) were TEE-certified by the National Board of Echocardiography, European Association of Cardiovascular Imaging (EACVI/EACTAIC), or had a national certificate. Of the respondents, 68% had no formal 3D TEE training. Eight percent of respondents had no 3D machines, whereas 40% had one for each operating room, and 33% had only one for the entire operating room block. 3D TEE was performed most frequently in more than 67% of cases for mitral valve surgery, and in more than 54% of cases for mitral and tricuspid clips, aortic valve, tricuspid valve, and aortic surgery.

CONCLUSION

Current guidelines suggest integrating 3D TEE into all comprehensive examinations. The authors' survey reported that intraoperative 3D TEE was used in the majority of mitral valve surgery and only one-half of the other valve surgeries and transcatheter procedures. Its use may be explained by the availability of 3D machines, trained personnel, and limited time to perform TEE in the operating room. Educational initiatives for training in 3D TEE may further increase its routine use.

Contemporary transesophageal echocardiography practice patterns among paediatric cardiology centres in the United States and Canada

OBJECTIVE

To characterise transesophageal echocardiography practice patterns among paediatric cardiac surgical centres in the United States and Canada.

METHODS

A 42-question survey was sent to 80 echocardiography laboratory directors at paediatric cardiology centres with surgical programmes in the United States and Canada. Question domains included transesophageal echocardiography centre characteristics, performance and reporting, equipment use, trainee participation, and quality assurance.

RESULTS

Fifty of the 80 centres (62.5%) responded to the survey. Most settings were academic (86.0%) with 42.0% of centres performing > 350 surgical cases/year. The median number of transesophageal echocardiograms performed/cardiologist/year was 50 (26, 73). Pre-operative transesophageal echocardiography was performed in most surgical cases by 91.7% of centres. Transesophageal echocardiography was always performed by most centres following Norwood, Glenn, and Fontan procedures and by < 10% of centres following coarctation repair. Many centres with a written guideline allowed transesophageal echocardiography transducer use at weights below manufacturer recommendations (50.0 and 61.1% for neonatal and paediatric transducers, respectively). Most centres (36/37, 97.3%) with categorical fellowships had rotations which included transesophageal echocardiography participation. Large surgical centres (>350 cases/year) had higher median number of transesophageal echocardiograms/cardiologist/year (75.5 [53, 86] versus 35 [20, 52], p < 0.001) and more frequently used anaesthesia for diagnostic transesophageal echocardiography ≥ 67% of time (100.0 versus 62.1%, p = 0.001).

CONCLUSIONS

There is significant variability in transesophageal echocardiography practice patterns and training requirements among paediatric cardiology centres in the United States and Canada. Findings may help inform programmatic decisions regarding transesophageal echocardiography expectations, performance and reporting, equipment use, trainee involvement, and quality assurance.

Cardiac dimensions and hemodynamics in healthy juvenile Landrace swine

BACKGROUND

Swine are frequently used as animal model for cardiovascular research, especially in terms of representativity of human anatomy and physiology. Reference values for the most common species used in research are important for planning and execution of animal testing. Transesophageal echocardiography is the gold standard for intraoperative imaging, but can be technically challenging in swine. Its predecessor, epicardial echocardiography (EE), is a simple and fast intraoperative imaging technique, which allows comprehensive and goal-directed assessment. However, there are few echocardiographic studies describing echocardiographic parameters in juvenile swine, none of them using EE. Therefore, in this study, we provide a comprehensive dataset on multiple geometric and functional echocardiographic parameters, as well as basic hemodynamic parameters in swine using EE.

METHODS

The data collection was performed during animal testing in ten female swine (German Landrace, 104.4 ± 13.0 kg) before left ventricular assist device implantation. Hemodynamic data was recorded continuously, before and during EE. The herein described echocardiographic measurements were acquired according to a standardized protocol, encompassing apical, left ventricular short axis and long axis as well as epiaortic windows. In total, 50 echocardiographic parameters and 10 hemodynamic parameters were assessed.

RESULTS

Epicardial echocardiography was successfully performed in all animals, with a median screening time of 14 min (interquartile range 11-18 min). Referring to left ventricular function, ejection fraction was 51.6 ± 5.9% and 51.2 ± 6.2% using the Teichholz and Simpson methods, respectively. Calculated ventricular mass was 301.1 ± 64.0 g, as the left ventricular end-systolic and end-diastolic diameters were 35.3 ± 2.5 mm and 48.2 ± 3.5 mm, respectively. The mean heart rate was 103 ± 28 bpm, mean arterial pressure was 101 ± 20 mmHg and mean flow at the common carotid artery was 627 ± 203 mL/min.

CONCLUSION

Epicardial echocardiography allows comprehensive assessment of most common echocardiographic parameters. Compared to humans, there are important differences in swine with respect to ventricular mass, size and wall thickness, especially in the right heart. Most hemodynamic parameters were comparable between swine and humans. This data supports study planning, animal and device selection, reinforcing the three R principles in animal research.

Considerations of valvular heart disease in children with ventricular assist devices

Ventricular assist devices have become a valuable tool in the treatment of heart failure in children. The use of ventricular assist devices has decreased mortality in children with end-stage heart failure awaiting transplant. It is not uncommon for children with end-stage heart failure associated with cardiomyopathy or congenital heart disease to have significant systemic semilunar and atrioventricular valve regurgitation, which can impact the efficiency and efficacy of hemodynamic support provided by a ventricular assist device. Therefore, implanting clinicians should carefully assess for valve abnormalities that may need repair and impact device selection and cannulation strategy to effectively support this diverse population. The purpose of this review is to provide an overview of this important and relevant topic and to discuss strategies for managing these patients.

Intraoperative epicardial echocardiography or transoesophageal echocardiography in CHD: how much does it matter?

BACKGROUND

Intraoperative imaging determines the integrity of surgical repairs. Transoesophageal echocardiography represents standard care for intraoperative imaging in CHD. However, some conditions preclude its use, and epicardial echocardiography is used alternatively. Minimal literature exists on the impact of epicardial echocardiography versus transoesophageal echocardiography. We aimed to evaluate accuracy between the two modalities and hypothesised higher imaging error rates for epicardial echocardiography.

METHODS

We retrospectively reviewed all epicardial echocardiograms performed over 16 years and compared them to an age- and procedure-matched, randomly selected transoesophageal echocardiography cohort. We detected un- or misidentified cardiac lesions during the intraoperative imaging and evaluated patient outcomes. Data are presented as a median with a range, or a number with percentages, with comparisons by Wilcoxon two-sample test and Fisher's exact test.

RESULTS

Totally, 413 patients comprised the epicardial echocardiography group with 295 transoesophageal echocardiography matches. Rates of imaging discrepancies, re-operation, and incision infection were similar. About 13% of epicardial echocardiography patients had imaging discrepancies versus 16% for transoesophageal (p = 0.2352), the former also had smaller body sizes (p < 0.0001) and more genetic abnormalities (33% versus 19%, p < 0.0001). Death/mechanical support occurred more frequently in epicardial echocardiography patients (16% versus 6%, p < 0.0001), while hospitalisations were longer (25 versus 19 days, p = 0.0003).

CONCLUSIONS

Diagnostic accuracy was similar between patients undergoing epicardial echocardiography and transoesophageal echocardiography, while rates of death and mechanical support were increased in this inherently higher risk patient population. Epicardial echocardiography provides a reasonable alternative when transoesophageal echocardiography is not feasible.

Screening and diagnostic imaging at centres performing congenital heart surgery in middle-income countries

BACKGROUND

Surgical care for CHD is increasingly available in low- and middle-income countries, and efforts to optimise outcomes are growing. This study characterises cardiac imaging and prenatal diagnosis infrastructure in this setting.

METHODS

An infrastructure survey was administered to sites participating in the International Quality Improvement Collaborative for CHD. Questions regarding transthoracic, transesophageal and epicardial echocardiography, cardiac CT, cardiac magnetic resonance, prenatal screening and fetal echocardiography were included. Associations with in-hospital and 30-day mortality were assessed.

RESULTS

Thirty-seven sites in 17 countries responded. Programme size and geography varied considerably: < 250 cases (n = 13), 250-500 cases (n = 9), > 500 cases (n = 15); Americas (n = 13), Asia (n = 18), and Eastern Europe (n = 6). All had access to transthoracic echo. Most reported transesophageal and epicardial echocardiography availability (86 and 89%, respectively). Most (81%) had cardiac CT, but only 54% had cardiac magnetic resonance. A third reported impediments to imaging, including lack of portable machines, age/size-appropriate equipment and advanced cardiac imaging access and training. Only 19% of centres reported universal prenatal CHD screening in their catchment area, and only 46% always performed fetal echocardiography if screening raised concern for CHD. No statistically significant associations were identified between imaging modality availability and surgical outcomes.

CONCLUSIONS

Although access to echocardiography is available in most middle-income countries; advanced imaging modalities (cardiac CT and magnetic resonance) are not always accessible. Prenatal screening for CHD is low, and availability of fetal echocardiography is limited. Imaging infrastructure in low- and middle-income countries and associations with outcomes merits additional study.

A narrative review of modern approach and outcomes evaluation in congenital heart defects

OBJECTIVE

The purpose of this review is to highlight critical advances and innovative approaches to the most challenging clinical situations in congenital heart surgery, to establish a new perspective from which to evaluate current clinical practice patterns and contemporary United States program ranking systems.

BACKGROUND

The past decades have witnessed substantial advances in the treatment of congenital heart defects. New strategies are deeply rooted in calculated risk-taking innovations. Pioneer surgeons developed, improved and refined critical operative skills and techniques to optimize cardiovascular physiology, decrease operative mortality and improve clinical outcomes.

METHODS

Unfortunately, in the modern surgical era, supportive environments to allow surgeons to make similar gains and innovative contributions remain scarce. In the current practice, overall procedure volume is prioritized to safeguard quality metrics, including hospital survival and length of stay, surgical complications, and neurocognitive outcomes. As a result, exceptional surgical results have become translated and defined by public ranking systems such as the US News and World Report Best Children's Hospital National Ranking (USNWR) and the Congenital Heart Surgery Database of the Society for Thoracic Surgeons (CHSD-STS), primary based upon early post-operative mortality. This reality places surgeons in a vulnerable position where pressure to achieve a high clinical ranking contrasts with a surgeon definition of "acceptable" surgical risk. Currently, the most frequently used risk stratification tools do not factor in important differences in strategies, such as staged palliation versus complete repair, or bi-ventricular versus uni-ventricular physiology. This favors hospitals pursuing multistage surgical approaches, even if the result is worse long-term morbidity, mortality and increased resource utilization. This economy of ranking-based decision-making causes surgeons either avoid operating altogether or accept less advantageous multi-staged treatment strategies for patients with elevated expected mortality. Such an environment also might present much farther-reaching negative impacts on the growth and development of junior surgeons and trainees, as well as on the pursuit of new surgical innovations to aid future generations of patients.

CONCLUSIONS

Risk aversive surgical behavior is creating an environment not favorable for the children born with truly complex congenital heart defects.

KEYWORDS

Biventricular conversion; congenital heart surgery; multidisciplinary approach; risk-stratification; surgical outcomes.

A systematic approach to epicardial echocardiography in pediatric cardiac surgery: An important but underutilized intraoperative tool

Intraoperative echocardiography is an integral component of the peri-operative management of pediatric heart disease. It confirms the adequacy of surgery, identifies residual lesions, and can provide useful hemodynamic data. It, therefore, helps to decide on the need for revision of repair and guides the postoperative management strategy. Intraoperative echocardiography is done with the use of either an epicardial probe or a transesophageal probe. Epicardial echocardiography is a simple, useful modality and has the ability to perform imaging in cases where transesophageal echocardiography cannot be easily performed, for example, in low birth weight babies. We attempt to describe in detail the technique of epicardial echocardiography and the various views that we have found useful for a complete postsurgical evaluation. The limitations of the technique are also discussed in detail.