Aortic Arch Reconstruction Using Nonvalved Femoral Vein Homograft in High-Risk Neonates.

Aortic arch obstruction is often present with complex concomitant congenital heart defects (CHDs). The use of nonvalved femoral vein homograft (FVH) to reconstruct the aortic arch has distinct surgical advantages, including simplified reconstruction. We present an intraoperative video of a Yasui procedure utilizing FVH for aortic reconstruction in a 12-day-old (2.2 kg) neonate with right ventricular outflow tract obstruction, malalignment ventricular septal defect, aortic valve atresia, aortic arch hypoplasia, atrial septal defect, and ductal dependent systemic circulation. Further, we report outcomes for a series of three additional neonatal patients with complex CHD and aortic arch obstruction who underwent FVH arch reconstruction.

Narrative review of single ventricle: where are we after 40 years?

Background and Objective: Key medical and surgical advances have been made in the longitudinal management of patients with "functionally" single ventricle physiology, with the principles of Fontan circulation applied to other complex congenital heart defects. The purpose of this article is to review all of the innovations, starting from fetal life, that led to a change of strategy for single ventricle. Methods: Our literature review included all full articles published in English language on the Cochrane, MedLine, and Embase with references to "single ventricle" and "univentricular hearts", including the initial history of the treatments for this congenital heart defects as well as the innovations reported within the last decades. Key Content and Findings: All innovations introduced have been analyzed, including: (I) fetal diagnosis and interventions, in particular to prevent or reduce brain damages; (II) neonatal care; (III) post-natal diagnosis; (IV) interventional cardiology procedures; (V) surgical procedures, including neonatal palliations, hybrid procedures, bidirectional Glenn and variations, Fontan completion, biventricular repair; (VI) peri-operative management; (VII) Fontan failure, with Fontan take-down and conversion, and mechanical circulatory support; (VIII) transplantation, including heart, heart and lung, heart and liver; (IX) exercise; (X) pregnancy; (XI) adolescents and adults without Fontan completion; (XII) future studies, including experimental studies on animals, computational studies, genetics, stem cells and bioengineering. Conclusions: These last 40 years have certainly changed the course of natural history for children born with any form of "functionally" single ventricle, thanks to the improvement in diagnostic and treatment techniques, and particularly to the increased knowledge of the morphology and function of these complex hearts, from fetal to adult life. There is still much left unexplored and room for improvement, and all efforts should be concentrated in collaborations among different institutions and specialties, focused on the same matter.

Aortic valve leaflets are asymmetric and correlated with the origin of coronary arteries.

Background: Asymmetry of the aortic valve leaflets has been known since Leonardo Da Vinci, but the relationship between size and shape and origin of the coronary arteries has never been examined. Our aim was to evaluate this anatomy in a population of pediatric patients using a cross-sectional study design. Methods: Consecutive pediatric patients with trans-esophageal echocardiography (TEE), with or without trans-thoracic echocardiography (TTE), were included in our study. Exclusion criteria: (I) bicuspid aortic valve; (II) aortic valve stenosis; (III) hypoplasia of aortic valve annulus, or aortic root; (IV) truncal valve; (V) coronary artery atresia; (VI) previous surgery on aortic valve and/or coronary arteries. In pre-operative TTE and intra-operative TEE inter-commissural distance and length of aortic valve leaflets were measured in short axis view in the isovolumic phase of systole. Echocardiography investigations, anonymized and randomly coded, were independently reviewed by at least two readers. Echocardiography, angiography, cardiac computed tomography (CT) scan and magnetic resonance imaging (MRI), and operative notes were reviewed to identify origin of coronary arteries. Results: Two hundred sixty-one pediatric patients were identified, 93 excluded per our criteria, leaving 168 patients, age 2.6±4.3 years, weight 12.87±17.34 kg, 128 (76%) with normal and 40 (24%) with abnormal coronary arteries. In TTE and TEE measurements the non-coronary leaflet had larger area (P<0.001), while the right and left had equal areas, but different shape, with the left leaflet longer (P<0.001) and narrower (P=0.005) than the right. With the major source of blood flow from the right coronary sinus, the non-coronary leaflet was still the longest. However, there was no statically significant difference between the size and shape previously observed between the right and left leaflets. Conclusions: Our study showed asymmetry of size and shape among aortic valve leaflets, and a relationship with coronary artery origin. The complex aortic root anatomy must be approximated to optimize function of any surgical repair. These findings also may prove useful in the pre-operative definition of coronary artery anatomy and in the recognition of coronary artery anomalies.

Impact on clinical outcomes from transcatheter closure of the Fontan fenestration: A systematic review and meta-analysis.

Background: Meta-analysis of the impact on clinical outcome from transcatheter closure of Fontan fenestration. Methods: Cochrane, Embase, MEDLINE, and Open-Gray were searched. Parameters such as changes in oxygen saturation, cavo-pulmonary pressure, maximum heart rate during exercise, exercise duration, and oxygen saturation after fenestration closure were pooled and statistical analysis performed. Results: Among 922 publications, 12 retrospective observational studies were included. The included studies involved 610 patients, of which 552 patients (90.5%) had a fenestration. Of those patients, 505 patients (91.5%) underwent attempt at trans-catheter closure. When it could be estimated, the pooled overall mean age at trans-catheter fenestration closure was 6.6 ± 7.4 years, and the mean follow-up time was 34.4 ± 10.7 months. There were 32 minor (6.3%) and 20 major (4.0%) complications during or after trans-catheter Fontan fenestration closure. The forest plots demonstrate that following fenestration closure, there was a significant increase in the mean arterial oxygen saturation of 7.9% (95% CI 6.4-9.4%, p < 0.01). There was also a significant increase in the mean cavo-pulmonary pressure of 1.4 mmHg (95% CI 1.0-1.8 mmHg, p < 0.01) following fenestration closure. The exercise parameters reported in 3 studies also favored closing the fenestration as well, yet the exercise duration increase of 1.7 min (95% CI 0.7-2.8 min, p < 0.01) after fenestration closure is probably clinically insignificant. Conclusion: Late closure of a Fontan fenestration has the impact of improving resting oxygen saturation, exercise oxygen saturation, and a modest improvement of exercise duration. These clinical benefits, however, may be at the expense of tolerating slightly higher cavo-pulmonary mean pressures.

Anesthesia for Echocardiography and Magnetic Resonance Imaging in the African Clawed Frog (Xenopus laevis).

This report describes an anesthesia technique that we used to study cardiovascular anatomy and physiology with echocardiography and cardiac magnetic resonance (CMR) in 46 African clawed frogs (Xenopus laevis) (n = 24 for electrocardiography and n = 22 for CMR). For administration of anesthesia, 3 holding tanks, one each for transportation, sedation, and recovery, were filled with filtered water, with 0.05% buffered tricaine methasulfonate solution (MS-222) added into the sedation tank. Fifteen minutes after the frog was placed in the sedation tank, a paper towel was soaked in MS-222 solution, and the frog was placed in a supine position and rolled 3 to 4 times in the soaked paper with the head and legs exposed. Vital signs were monitored and recorded throughout the procedure. After imagining, frogs were unrolled from the paper towel, placed in the recovery tank, and later returned to their home tank. Monitoring was discontinued when the frogs resumed typical activity. No mortality or complications were observed in frogs that underwent this procedure. Mean duration ±1 SD of anesthesia induction was 12 ± 5 min in the echocardiography group and 14 ± 6 min in the CMR group. The mean duration of anesthesia maintenance was 60 ± 18 min in the echocardiography group and 118 ± 37 min in the CMR group. An additional dose of anesthesia was necessary during maintenance for 9 of 24 (37%) frogs in the echocardiography group and 6 of 22 (27%) frogs in the CMR group. At the end of the procedure, the mean oxygen saturation was 66 ± 9% in the echocardiography group and 85 ± 6% in the CMR group, and heart rate was 48 ± 13 beats/min in the echocardiography group and 42 ± 7 beats/min in the CMR group. We conclude that the anesthesia technique of immersion in MS-222 is suitable for performing echocardiography and CMR imaging in this species without complications.

Biventricular Conversion for Hypoplastic Left Heart Variants: An Update.

Ongoing concerns with single-ventricle palliation morbidity and poor outcomes from primary biventricular strategies for neonates with borderline left heart structures have led some centers to attempt alternative strategies to obviate the need for ultimate Fontan palliation and limit the risk to the child during the vulnerable neonatal period. In certain patients who are traditionally palliated toward single-ventricle circulation, biventricular circulation is possible. This review aims to delineate the current knowledge regarding converting certain patients with borderline left heart structures from single-ventricle palliation toward biventricular circulation.

Ebstein's Anomaly: From Fetus to Adult-Literature Review and Pathway for Patient Care.

Ebstein's anomaly, first described in 1866 by Dr William Ebstein, accounts for 0.3-0.5% of congenital heart defects and represents 40% of congenital tricuspid valve abnormalities. Ebstein's anomaly affects the development of the tricuspid valve with widely varying morphology and, therefore, clinical presentation. Associated congenital cardiac lesions tend to be found more often in younger patients and may even be the reason for presentation. Presentation can vary from the most extreme form in fetal life, to asymptomatic diagnosis late in adult life. The most symptomatic patients need intensive care support in the neonatal period. This article summarizes and analyzes the literature on Ebstein's anomaly and provides a framework for the investigation, management, and follow-up of these patients, whether they present via fetal detection or late in adult life. For each age group, the clinical presentation, required diagnostic investigations, natural history, and management are described. The surgical options available for patients with Ebstein's anomaly are detailed and analyzed, starting from the initial mono-leaflet repairs to the most recent cone repair and its modifications. The review also assesses the effects of pregnancy on the Ebstein's circulation, and vice versa, the effects of Ebstein's on pregnancy outcomes. Finally, two attached appendices are provided for a structured echocardiogram protocol and key information useful for comprehensive Multi-Disciplinary Team discussion.

Essential role of cardiac computed tomography for surgical decision making in children with total anomalous pulmonary venous connection and single ventricle.

BACKGROUND: Total anomalous pulmonary venous connection (TAPVC) is a major risk factor in infants with single ventricle (SV). Exact definition of TAPVC anatomy is crucial for surgical planning. AIM: To evaluate the role of cardiac computed tomography (CT) in this setting. METHODS: Retrospective review of 13 infants who underwent TAPVC repair associated with SV from May 2016 to October 2021. Anatomy, incidence, and mechanisms of pulmonary venous obstruction (PVO) were described. Cardiac CT diagnostic yield was compared to echocardiography (echo). RESULTS: Of 13 infants, median age and weight were 24 days (range 2-303 days) and 3.2 (range 2.6-9.1) kg, 8 (62%) were male, 4 (31%) premature, and 11 (85%) had heterotaxy syndrome. All infants had pre- and postoperative echo; 13 had preoperative and 8 (62%) had postoperative cardiac CT. Type of TAPVC: six (46%) supracardiac, two (15%) intracardiac, one (8%) infracardiac, and four (31%) mixed, with pulmonary veins draining in >1 confluence in nine (69%). PVO was present in 6/13 (46%) preoperatively and 5/13 (31%) postoperatively. Mechanisms of PVO: 9/11 (82%) stenosis, 1/9 (9%) membrane formation, and 1/9 (9%) external compression. The sensitivity to diagnose PVO was 45.5% for echo and 100% for cardiac CT, the specificity was 100% for both. No discrepancy was found between cardiac CT and intraoperative findings, but echo had a complete preoperative diagnosis in 1/13 (8%) (p < .00001, Fisher exact test). CONCLUSIONS: Cardiac CT is essential to evaluate pre- and postoperative TAPVC in SV for surgical decision making and long term follow up.

The Secrets of the Frogs Heart.

The heart of the African clawed frog has a double-inlet and single-outlet ventricle supporting systemic and pulmonary circulations via a truncus, and a lifespan of 25-30 years. We sought to understand the unique cardiac anatomic and physiologic characteristics, with balanced circulation and low metabolic rate, by comparing the basic anatomy structures with focused echocardiography and cardiac magnetic resonance imaging. Twenty-four adult female African clawed frogs were randomly subjected to anatomic dissection (n = 4), echocardiography (n = 10), and cardiac magnetic resonance (n = 10). All anatomical features were confirmed and compared with echocardiography and cardiac magnetic resonance imaging. The main characteristics of the cardiovascular circulation in frogs are the following: Intact interatrial septum, with two separate atrio-ventricular valves, preventing atrial mixing of oxygenated and desaturated blood. Single spongiform ventricular cavity, non-conducive for homogeneous mixing. Single outlet with a valve-like mobile spiral structure, actively streaming into systemic and pulmonary arteries. Intact interatrial septum, spongiform ventricle, and valve-like spiral in the conus arteriosus are likely responsible for balanced systemic and pulmonary circulation in frogs, in spite of double-inlet and single-outlet ventricle.

Virtual Simulated Implantation of an Adult-Sized Left Ventricular Assist Device in a Pediatric Patient.

There is very limited experience with simulated virtual implantation of left ventricular assist devices (LVADs) to assess device fitness in pediatric patients. In this clinical vignette, we report the case of a 9-year-old male patient with dilated cardiomyopathy who underwent successful placement of an LVAD after virtual simulated implantation was performed. (Level of Difficulty: Advanced.).

Absorbable sutures for cardiopulmonary bypass purse strings in pediatric heart surgery.

BACKGROUND: Absorbable sutures, commonly used in general surgery, are not routinely used as purse strings for arterial and venous cannulation for cardiopulmonary bypass in pediatric heart surgery. The general concern is absorbable sutures could predispose to immediate postoperative bleeding; this safety concern has been evaluated in this retrospective study. MATERIALS AND METHODS: A single center, retrospective study, was conducted with criteria for inclusion patient <18 years of age, operation on with cardiopulmonary bypass for heart surgery from July 1, 2018 to June 30, 2020, with purse strings for cannulation performed with absorbable sutures. Data collection included demographics at the time of surgery, site of arterial and venous cannulation with absorbable purse strings, bleeding, required reoperation, related hospital mortality, and complications. RESULTS: One hundred and ninety-eight patients, mean ± standard deviation (SD) age of 1597 ± 3021 days, mean ± SD body weight of 15.9 ± 18.8 kg, were operated on using absorbable sutures for purse strings for arterial and venous cannulation: No bleeding was reported, either intraoperative or in the immediate postoperative period, related to the type of sutures used for purse strings for cannulation. No hospital deaths or complications related to the type of sutures were observed. CONCLUSIONS: Based on the results of our analysis, we can conclude that the utilization of purse strings absorbable sutures for arterial and venous cannulation for cardio-pulmonary bypass in children is safe in relationship to the intraoperative and immediate postoperative period. No complications related to the use of absorbable sutures have been observed in a large pediatric patient population.

Pre- and post-operative cardiovascular CT in Stage I single ventricle palliation.

OBJECTIVES: The aim of this study is to describe clinical utility of low dose cardiac computed tomography (CT) in the evaluation of single ventricle physiology before and after Stage I palliation. BACKGROUND: Despite the increased utilization of CT imaging and advancement of CT technology, there are limited studies describing the routine clinical use of cardiac CT and radiation dose parameters in the single ventricle Stage I palliation. METHODS: This single center, retrospective study included 57 infants with single ventricle physiology who underwent cardiac CT scans between January 1, 2016 and November 30, 2020. Patients' demographic information, diagnosis, indication, total dose length product (DLP), computed tomographic dose index volume (CTDIvol), cardiac CT findings and intraoperative or intraprocedural findings were reviewed. Estimated effective radiation dose was calculated using a previously published conversion rate. RESULTS: The studies were performed using different generations of CT scanners over the 4 years period: Somatom AS 128, Somatom definition edge, Somatom Force (Siemens Medical Solutions). The studies performed with dual source scanner with prospective gated technique have lower radiation dose exposure with median effective radiation dose of 0.32 mSv. CONCLUSION: Pre- and post-operative cardiovascular CT in Stage I single ventricle palliation using newer generation scanners with prospective gated technique can be done with minimal radiation exposure and good image quality. Cardiac CT is a powerful imaging modality for better management planning in this group of patients.

Modern advances regarding interatrial communication in congenital heart defects.

BACKGROUND: The interatrial communication, one of the most frequent congenital heart defects, represents an important intracardiac shunt between systemic and pulmonary circulations. Direction and magnitude of the interatrial shunting depends upon several features, including defect size, shape and location, pressure difference between right and left atrium, and difference in right and left ventricular compliance. METHODS: In this review article, the presence or absence of interatrial communication, and its role, have been analyzed, as they can have a critical impact on the cardiovascular physiopathology, and the interatrial communication can prove to be either clinically harmful, useful or indispensable. Accordingly, the utility and role of the interatrial communication in modern congenital, pediatric and adult, disease has evolved, with modification of the indications to close, maintain patency, or create an interatrial communication. RESULTS: The interatrial communication and shunting can be manipulated to maximize the oxygen delivery to the tissues, accordingly with the underlying congenital heart defect. While not always relevant to patients with bi-ventricular circulations, this becomes extremely important in children and adults with complex congenital heart defects. CONCLUSIONS: With improving long-term survival for the vast majority of congenital heart patients, an advanced understanding of the role and utility of the interatrial communication, and of all the possibilities of its manipulation, is essential to improve the patient outcomes.

Surgical approach for anomalous aortic origin of a coronary artery: A comparison of two techniques.

BACKGROUND: Un-roofing is the most common technique utilized for repair of anomalous aortic origin of a coronary artery (AAOCA). There are very few publications directly comparing un-roofing to another surgical technique, like reimplantation. METHODS: The prospectively collected Children's Memorial Hermann Heart Institute Society of Thoracic Surgeon's Database was retrospectively reviewed from 2007 to 2021. Surgical patients were included if they underwent un-roofing or reimplantation of the AAOCA. The primary outcomes of this study were operative characteristics and postoperative outcomes. Secondary outcomes included angiographic outcomes, aortic regurgitation incidence, ventricular function, and symptom relief. RESULTS: From 2007 to 2021, there were 12 patients who underwent either a reimplantation (n = 9, 73%) or un-roofing (n = 3, 27%) for an AAOCA. The hospital length of stay was a median of 1.8 days longer for reimplantation compared to un-roofing. The last follow-up echocardiogram was a median of 52.2 days later in the reimplantation group. There was one patient (11%) in the reimplantation group that had more than or equal to mild aortic regurgitation and mild systolic ventricular dysfunction. Outpatient follow-up was incomplete and there was no postoperative computed tomographic angiography in the un-roofing cohort. CONCLUSIONS: Coronary artery reimplantation is a valuable alternative surgical technique to un-roofing for the repair of AAOCA. There are still some concerns with the creation of aortic regurgitation or incomplete symptom relief with any surgical technique. Longer-term follow-up and prospective studies will be needed to show an effective reduction of myocardial ischemia and risk of sudden cardiac death.

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.

Development of a biventricular conversion program: A new paradigm.

BACKGROUND: Borderline small ventricular size or technical issues precluding the use of both ventricles may lead to single ventricle palliation. Fontan complications have led some centers to look for alternatives to the traditional pathway. The objective of this study is to evaluate the essential philosophy and outcomes of a new biventricular (BiV) conversion program. METHODS: The prospectively collected Children's Memorial Hermann Heart Institute Society of Thoracic Surgeon's Database was retrospectively reviewed between July 2017 and July 2020. RESULTS: Thirteen patients met inclusion criteria and underwent BiV conversion during that time. The most frequent diagnosis was malposed great arteries and a ventricular septal defect (VSD) in 4 (31%) patients. Seven (54%) patients were in the first interstage, and 1 (8%) patient had already undergone a Fontan operation before their BiV conversion operation. One or more risk factors for single ventricle palliation (genetic syndrome ≥ moderate atrioventricular valve regurgitation ≥ moderate ventricular dysfunction, presence of signs of Fontan failure) were present in 3 (23%) patients. The median left ventricular end diastolic pressure increased from 5.5 mmHg (4-10 mmHg) to 10 mmHg (6-20 mmHg) postoperatively (p < .05). The right ventricular pressure (RVP) was estimated as less than half systemic in all six patients who were able to be estimated. At a median follow-up of 22.6 months (0.3-36.4 months), 12 (92%) patients are alive. CONCLUSIONS: BiV conversion is feasible with reasonable short-term clinical outcomes. Mortality risk is low, but as seen in other studies, the risk of reintervention is high.