The impact of additional epicardial imaging to transesophageal echocardiography on intraoperative detection of residual lesions in congenital heart surgery

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.

A systematic methodology for epicardial and epiaortic echocardiography in swine research models

Background

Perioperative echocardiography is of paramount importance during cardiac surgery. Nonetheless, in the experimental large-animal setting, it might be challenging obtaining optimal imaging when using conventional imaging acquisition techniques, such as transthoracic and transesophageal screenings. Open-chest surgery allows epicardial echocardiographic assessment with direct contact between probe and heart, thus providing superior quality. Standard protocols regarding the use of epicardial ultrasound in swine for research purposes are lacking.

Methods

Epicardial echocardiography was performed in 10 female German Landrace pigs undergoing cardiac surgery. A structured and comprehensive protocol for epicardial echocardiography was elaborated including apical, ventricular long and short axis, as well as epiaortic planes. All experiments were approved by the local board for animal welfare and conducted in accordance with the German animal protection law (TierSchG) and the ARRIVE guidelines.

Conclusions

Systematic protocols using epicardial echocardiography may serve as an additional tool to assess cardiac dimensions and function in experimental scenarios with swine models.

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.

Branch pulmonary artery stenosis after arterial switch operation: The effect of preoperative anatomic factors on reintervention

BACKGROUND

We hypothesized that preoperative patient characteristics and branch pulmonary artery (PA) size might influence the rate of postoperative branch PA reintervention in patients with transposition of the great arteries who undergo the arterial switch operation (ASO).

METHODS

The retrospective single-center study included 262 consecutive (2008-2017) newborns who underwent the ASO. Demographic characteristics, echocardiography, and clinical outcomes were reviewed. Competing risk analysis modeled incidence of branch PA reintervention and cause-specific hazard regression for predictors analyses.

RESULTS

Median age and weight were 7 (range, 5-11) days and 3.4 (range, 3.1-3.8) kg, respectively. Various types of early branch PA reinterventions (concomitant revision or reintervention during the intensive care unit stay) were required in 28 (10.7%) patients. These patients had prolonged ventilation (P < .001), intensive care unit duration (P < .001), worse right ventricular function (P = .043), and high in-hospital mortality (P = .010). Branch PA dimensions significantly decreased immediately after ASO compared with baseline measurements. The median follow-up duration was 20.8 (range, 0.9-44.7) months. Branch PA reintervention was common among survivors without early reinterventions (9.4%), and even more frequent among those with early reinterventions (25%). Subsequent reintervention (all catheter-based) was necessary for more than one-third of patients after initial branch PA reintervention. The multivariable analysis showed preoperative dimension of the left PA (hazard ratio, 0.527 [95% CI, 0.337-0.823]; P = .005), and right PA (hazard ratio, 0.503 [95% CI, 0.318-0.796]; P = .003) were independently associated with late branch PA reinterventions.

CONCLUSIONS

Branch PA reintervention was common and often required surgical or catheter-based reinterventions after ASO. PA branch diameters became significantly smaller after ASO. Smaller preoperative branch PA predicted late branch PA reintervention, indicating a smaller margin of geometrical tolerance to this effect.

Intraoperative echocardiographic coronary artery imaging in congenital and acquired heart disease

Transoesophageal and epicardial echocardiography are indispensible intraoperative imaging modalities to guide paediatric heart disease surgeries and influence surgical decision-making. A less well-described role of intraoperative imaging is its utility in evaluating coronary artery patency and flow. Focused two-dimensional, colour, and spectral Doppler imaging of the coronary arteries should be performed during surgeries involving coronary manipulation or re-implantation, or in cases where there is unexpected ventricular dysfunction or electrographic signs concerning for ischaemia. Intraoperative imaging allows for any anatomical issues to be detected and addressed promptly in the operating room. Imaging of the coronary arteries should identify unobstructed coronary ostia and proximal course without kinking, angulation, narrowing, or significant calibre change to suggest stenosis or extrinsic compression from neighbouring structures. The aim of this review is to highlight the usefulness of transoesophageal and epicardial echocardiography in evaluating coronary artery patency and flow, provide a how-to guide for optimal imaging, and to introduce a practical guideline to achieve best clinical practice.

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.

Epicardial Echocardiography in Pediatric and Congenital Heart Surgery

Epicardial echocardiography (e-echo) is a useful approach to intraoperative imaging for the smallest patients and in those with contraindications to transesophageal echocardiography (TEE). The e-echo has additional advantages that include improved visualization of anterior and vascular structures and three-dimensional capabilities. In this review, we describe the advantages and disadvantages of e-echo versus TEE for pediatric and congenital heart surgery with the goal of enhancing the utility and feasibility of the former among congenital heart surgeons. We also review the technique for performance of an e-echo and provide demonstrations of the images obtained for select lesions.

Intraoperative Completion Angiogram May Be Superior to Transesophageal Echocardiogram for Detection of Pulmonary Artery Residual Lesions in Congenital Heart Surgery

The purpose of this study was to assess the diagnostic capabilities of transesophageal echocardiography (TEE) compared to completion angiography for detection of residual post-operative pulmonary artery lesions. This is a retrospective review of 19 consecutive surgical cases involving the pulmonary arteries that had post-operative TEE and completion angiography from 2014 to 2017. The echocardiograms were reviewed by 2 blinded examiners and categorized as adequate or inadequate visualization of the surgical repair. Based on TEE images, the surgical repair was graded as no revision necessary, residual lesion present requiring revision, or unable to assess. TEE was compared to completion angiography to determine the ability of each method to detect residual pulmonary artery lesions. Fifty-three percent of TEE imaging was graded as inadequate. Based on TEE, surgical revision was indicated in 2 of 19 cases. Completion angiography documented 4 additional residual lesions resulting in surgical revision in 6 of 19 patients. TEE sensitivity for detecting residual pulmonary artery lesions was 40%. One Glenn patient with adequate image quality and repair by TEE had moderate left pulmonary artery stenosis by completion angiography. All other discrepancies occurred in patients with inadequate TEE imaging. No patient with pulmonary artery abnormalities had hemodynamic instability or excessive desaturations. Completion angiography-related complications included three transient arrhythmias with no increased incidence of acute kidney injury. Completion angiography may be more effective than TEE at detecting post-operative pulmonary artery lesions even in patients not manifesting clinical symptoms. Documentation of residual lesions with completion angiography allows immediate surgical revision potentially limiting necessity for future interventions.

The 2017 Seventh World Congress of Pediatric Cardiology & Cardiac Surgery: week in review: imaging

The Imaging Program at the 7th World Congress highlighted the versatility and diagnostic power of the current and upcoming imaging tools in Pediatric Cardiology and Cardiac Surgery. Several experts presented interesting as well as practical data on the use of 2D and 3D Echocardiography, magnetic resonance imaging and computed tomography in the fetus, child, and adult with congenital heart disease. Bridging sessions coupled use of these imaging modalities and screening practices in patients with acquired heart disease. Hot topics included nomenclature of ventricular septal defects, the challenging diagnosis of double outlet right ventricle, cardiac tumors, and imaging of aortapathies. Several talks concentrated on the quantitative assessment of ventricular function and reviewed numerous exciting new modalities that currently serve as research tools. In summary, Imaging Sessions truly represented how far we have advanced the field of Imaging in Pediatric Cardiology and Cardiovascular Surgery.

Utility of a standardized postcardiopulmonary bypass epicardial echocardiography protocol for stage I Norwood palliation

OBJECTIVE

Stage 1 Norwood palliation is one of the highest risk procedures in congenital cardiac surgery. Patients with superior technical performance scores have more favorable outcomes. Intraoperative epicardial echocardiography may allow the surgeon to address residual lesions prior to leaving the operating room, resulting in improved technical performance. The ability of intraoperative epicardial echocardiography to visualize the relevant anatomy and its association with outcomes is not known.

DESIGN

A standardized intraoperative epicardial echocardiography protocol was developed and performed at the conclusion of Stage 1 Norwood palliation. Data pertaining to visualization of relevant anatomy, and comparison of intraoperative echocardiogram findings with other postoperative investigations was performed. Clinical outcomes, including technical performance, were collected. A historical cohort who received either no echocardiogram or a nonstandardized examination was used as a comparison group.

RESULTS

Thirty on-protocol and 30 preprotocol patients, 22 of whom had a nonstandardized intraoperative epicardial echocardiogram, were studied. Compared with preprotocol, visualization of the relevant anatomy was significantly increased for the Damus-Kaye-Stansel anastomosis (93% vs. 68% P = .03) and branch pulmonary arteries (70% vs. 36%, P = .02). One residual lesion requiring immediate operative reintervention was diagnosed in the preprotocol group. There were 5 patients in each cohort with residual lesions during the postoperative hospitalization that were not appreciated on the intraoperative echocardiogram. Technical performance, rates of reintervention and clinical outcomes were not significantly different between the two groups.

CONCLUSIONS

Intraoperative epicardial echocardiography is technically feasible and increases visualization of the relevant anatomy. Larger investigations may be warranted to determine if there is clinical benefit to such an approach.

Impacts of early cardiac catheterization for children with congenital heart disease supported by extracorporeal membrane oxygenation

BACKGROUND

Cardiac catheterization is often required for patients on extracorporeal membranous oxygenation (ECMO) support, though its efficacy remains unclear. This study aimed to assess the impact of catheterization on successful ECMO weaning.

METHODS

This is a single-center retrospective study from 2000 to 2014. Patients with congenital heart disease who underwent cardiac catheterization while on cardiac ECMO support were included. Logistic regression analysis and Kaplan-Meier survival analysis with log-rank test were performed to determine predictors for successful weaning and patient outcome.

RESULTS

Forty-nine catheterizations in 47 patients with the median age of 65 days (range: 1 day-12 years) and the median body weight of 4.2 kg (range: 1.9-32.7 kg) were included. Median duration between ECMO cannulation and catheterization was 1 day (range: 0-11 days). Thirty-three patients (70%) succeeded in decannulation and 24 patients (51%) survived to hospital discharge. Absence of renal (P = 0.045) and respiratory complications (P = 0.031) were significant prognostic factors for successful weaning in multivariate analysis. Patients who received catheterization within 48 hr after ECMO cannulation demonstrated less respiratory complications (P = 0.006) and better survival at 30 days after ECMO initiation (P = 0.039) than those who underwent later catheterization. There was no mortality; however, nine major catheterization-related complications (18%) were detected.

CONCLUSION

Catheterization for pediatric patients on ECMO support can be performed, although this group contained high risk of serious adverse events. The absence of ECMO complications is a predictor for successful weaning. An earlier catheterization appears to be associated with better short-term survival in this cohort. © 2016 Wiley Periodicals, Inc.

Outcomes differ in patients who undergo immediate intraoperative revision versus patients with delayed postoperative revision of residual lesions in congenital heart operations

OBJECTIVES

In a previous study of infants less than 6 month old, we found that delayed revision of residual lesions resulted in worse patient outcomes compared with intraoperative revision. We explored a larger cohort to determine if this finding persisted.

METHODS

A prospective cohort followed from index surgery to discharge from January 2011 to September 2013 were divided into 4 groups: (1) intraoperative revisions (IO) of residual lesions, (2) delayed postoperative revision (PO) of residual lesions during the same hospital stay, (3) both intraoperative and delayed (BOTH) revision of residual lesions, (4) no intraoperative or postoperative revision (NO). Linear and logistic regression analyses were used to compare outcomes of postoperative hospital length of stay, postoperative adverse events (AE), hospital costs, and mortality, after adjusting for age, prematurity, presence of extracardiac anomalies, and RACHS-1 (Risk Adjustment for Congenital Heart Surgery-1) risk category known to affect outcomes.

RESULTS

Of the 2427 patients discharged after a congenital cardiac operation, 1886 were eligible for this study after exclusion of adults, procedures performed off cardiopulmonary bypass, and transplants and assist devices. On multivariable modeling adjusting for other significant patient factors, the NO group fared better than the other 3 groups. The IO group had significantly lower postoperative length of stay, AE rate, and hospital costs compared with the PO and BOTH groups, but showed no significant differences in mortality.

CONCLUSIONS

Intraoperative correction of residual lesions results in shorter length of stay, and lower postoperative AE and costs compared with delayed postoperative revision of residual lesions.

Surgical repair of pulmonary artery branches

Surgical repair of pulmonary artery (PA) branches encompasses many different clinical scenarios and technical challenges. The most common, such as bifurcation and central PA reconstruction, are described, as well as the challenges of complex and peripheral reconstruction.

Accuracy of Intraoperative Epicardial Echocardiography in the Assessment of Surgical Repair of Congenital Heart Defects confirmed

Objective:

To determine the accuracy of epicardial echocardiography in detecting residual lesions after surgical repair of congenital heart defects. To determine the sensitivity, specificity, positive predictive valve, negative predictive valve, and false negative and false positive percentage of the same.

Materials and Methods:

One year hospital-based prospective study of epicardial echocardiography in patients undergoing cardiopulmonary bypass for surgical correction of congenital heart defects in children and adults.

Results:

Epicardial echocardiography was done in 158 patients. Residual lesions were detected in 38 patients by epicardial echocardiography. In 28 of these cases the residual lesions were significant. In 24 of them immediate reoperation was done with good outcome. Epicardial echo has high sensitivity, specificity, positive and negative predictive valve, in detecting residual lesion with congenital heart defects.

Conclusion:

Routine use of intraoperative epicardial echocardiography allows detection of majority of residual defects. It has high accuracy. There were no complications associated with use of epicardial echocardiography. The use of transesophageal echocardiography (TEE) can be avoided in small children and neonates undergoing cardiac surgery.