Converting the Fontan Circulation: Challenges and Evolution.

The Fontan operation, the final palliative step after a series of complex operations in patients with univentricular hearts, has undergone multiple modifications throughout the last decades, with the goal of finding the method which combines the optimal hemodynamic effects of the Fontan circulation with minimal long term side effects. An understanding of the operative evolution and subsequent side effects, as well as the management thereof seems imperative. Since its inception by Francis Fontan the, now obsolete, initial atriopulmonary connection has passed through several milestones into having now reached the era of total cavopulmonary connection. However, recently published results bring to light the new option of biventricular conversion which comes to challenge the management of Fontan patients as we know it. Currently, there is no consensus as to whether to continue with palliation in this challenging group of patients or proceed with heart transplantation. In this collective review, we provide a historic overview of the Fontan evolution as well as future insights, discussing the perspectives of options for patients with failing Fontan, including the latest addition of biventricular correction.

Long-term outcome after neonatal intervention for congenital critical aortic stenosis.

BACKGROUND: This study explored long-term outcome and functional status of patients born with critical aortic stenosis (CAS) following neonatal surgical or catheter interventions. METHODS: A 40-year retrospective review of all consecutive patients within a large, single-center referral unit who required neonatal (<30 days) intervention for CAS. Additional detailed evaluation of surviving patients >7 years age was performed, with clinical assessment, objective cardiopulmonary exercise testing and state-of-the-art characterization of myocardial function (advanced echocardiography and cardiac MRI). RESULTS: Between 1970 and 2010, ninety-six neonates underwent CAS intervention (mean age 9 ± 7.5 days). Early death occurred in 19 (19.8%) and late death in 10 patients. Overall survival at 10 and 30 years was 70.1% and 68.5%, freedom from reintervention was 41.8% and 32.9% respectively. Among the 25 long-term survivors available for detailed assessment (median age 15.7 ± 6.4 years), 55% exhibited impaired peak oxygen uptake. Mean left ventricle (LV) ejection fraction was 65 ± 11.2%, with a mean LV end-diastolic volume z-score of 0.02 ± 1.4. Mean LV outflow tract Vmax was 2.3 ± 1.02 m/s. CAS patients had reduced LV longitudinal and increased radial strain (p = 0.003, p < 0.001 respectively). Five patients had severe LV diastolic dysfunction associated with endocardial fibroelastosis (EFE) (p = 0.0014). CONCLUSION: Despite high early mortality rate, long-term survival of patients with CAS is reasonable at the expense of high reintervention rate. With successful intervention, there remained long-term clinical and subclinical LV myocardial impairment, of which EFE was one marker. Long-term follow-up of all CAS patients is crucial, involving detailed myocardial functional assessment to help elucidate physiology and optimise management.

Striving for physiologic coaptation: An experimental and innovative approach towards designing and implanting aortic neo-leaflets.

Aortic valve repair has emerged as the treatment of choice for congenital aortic valvular disease, avoiding the need for a reoperation associated with stented prosthesis overgrowth. The introduction of a leaflet implant represents a recent advancement in a field that originated early techniques, such as simple commissurotomies. In our experimental approach, we assessed two established leaflet-sizing techniques by analysing their resultant coaptation areas. Although both techniques produced competent valves, the large coaptation areas differed significantly from the native aortic valve. This observation prompted us to revisit the functional anatomy of the aortic valve, our goal being to refine leaflet design and implantation for enhanced efficacy and longevity in neo-leaflet procedures. We designed a novel aortic valvar neo-leaflet, utilizing porcine pericardium as our primary source material, and we implanted four tri-leaflet valves in four porcine hearts. All tri-leaflet valves were competent and closely resembled the coaptation area of the native aortic valve. This study serves as a pilot for further experimental aortic valve repair surgery using neo-leaflet implants.

Obstructive left heart disease in neonates with a "borderline" left ventricle: diagnostic challenges to choosing the best outcome.

In most newborns with left heart obstruction, the choice between a single-ventricle or biventricular management pathway is clear. However, in some neonates with a "borderline" left ventricle, this decision is difficult. Existing criteria do not reliably identify neonates who will have a good long-term outlook after biventricular repair (BVR). The objective of this study was prospective assessment of the outcome after BVR for newborns in whom the left ventricle (LV) was considered "borderline" by an expert group. This study was a prospective follow-up evaluation of neonates with obstructive left heart disease related to a "borderline" LV who underwent biventricular management between January 2005 and April 2011. Of 154 neonates who required intervention for left heart obstruction, 13 (7.8 %) met the echocardiographic (echo) inclusion criteria. At the first and last echo, the z-scores were respectively -1.76 ± 1.37 and -0.66 ± 1.47 (p = 0.013) for the mitral valve, -1.02 ± 1.57 and -0.23 ± 1.78 (p = 0.056) for the aortic valve, and 13.77 ± 5.8 and 20.85 ± 8.9 ml/m(2) (p = 0.006) for the LV end-diastolic volume. At this writing, all 12 survivors are clinically well. However, LV diastolic dysfunction and pulmonary artery hypertension was present in 5 (36 %) of 12 patients. Endocardial fibroelastosis (EFE) was detected in five patients at the last follow-up echo, but only in two patients preoperatively. Cardiac magnetic resonance imaging did not confirm EFE in any of assessed patients. The study authors could not reliably predict the outcome after BVR for neonates with left heart obstruction and a "borderline" LV. The presence of EFE with consequent diastolic dysfunction is more important than LV volume in determining the outcome. Prospective identification of EFE remains challenging.

Aortic arch thrombectomy in a 2.8 kilogram neonate--a case report and review of the literature.

Aortic arch thrombus is a rare occurrence in neonates. In the few described cases, this has mainly been associated with sepsis or early postnatal interventions, such as insertion of umbilical arterial line. We describe a case of occlusive aortic arch thrombus in a neonate who presented with signs of critical coarctation and successfully underwent surgical thrombectomy on deep hypothermic circulatory arrest. We also present a review of the most recently published cases of aortic arch thrombus in neonates and the treatment options employed.

Impact of Tracheal Arborization and Lung Hypoplasia in Repair of Pulmonary Artery Sling in Combination With Long-Segment Tracheal Stenosis.

Background: Reimplantation of the left pulmonary artery (LPA) and slide tracheoplasty has been our standard approach of care for patients with pulmonary artery sling (PAS) and tracheal stenosis. We present our experience, with emphasis on tracheal arborization and hypoplastic lungs; and their impact on long-term outcome of children with PAS and tracheal stenosis. Methods: It is a retrospective comparative study. Data were classified and analyzed based on the type of tracheobronchial arborization and normal versus hypoplastic lungs. Results: Seventy-five children operated between January 1994 and December 2019 (67 with normal lungs and 8 with lung hypoplasia/agenesis) were included. Patients with hypoplastic lungs had higher rates of preoperative ventilation (87.5%), postoperative ventilation (10 vs 8 days, P = .621), and mortality (50% vs 9%, P = .009) compared with those with normal lungs. Nineteen patients had tracheal bronchus (TB) variety and 30 patients had congenital long-segment tracheal stenosis (CLSTS) variety of tracheobronchial arborization. Endoscopic intervention was needed in 47.4% of patients with TB type and 60% with CLSTS type. CLSTS patients had higher rates of preoperative ventilation (60% vs 47.4%, P = .386), longer periods of postoperative ventilation (13 vs 6.5 days, P = .006), and ICU stay (15 vs 11 days, P = .714) compared with TB type. Conclusion: Surgical repair of PAS with tracheal stenosis has good long-term outcomes. All variations of tracheal anatomy can be managed with slide tracheoplasty. Persistence of airway problems requires intervention during follow-up as tracheal stenosis continues to be the Achilles heel.

Arterial Switch for Transposition of the Great Arteries: Treatment Timing, Late Outcomes, and Risk Factors.

Background: Reports of long-term mortality and reintervention after transposition of the great arteries with intact ventricular septum treatment, although favorable, are mostly limited to single-center studies. Even less is known about hospital resource utilization (days at hospital) and the impact of treatment choices and timing on outcomes. Objectives: The purpose of this study was to describe survival, reintervention and hospital resource utilization after arterial switch operation (ASO) in a national dataset. Methods: Follow-up and life status data for all patients undergoing ASO between 2000 and 2017 in England and Wales were collected and explored using multivariable regressions and matching. Results: A total of 1,772 patients were identified, with median ASO age of 9.5 days (IQR: 6.5-14.5 days). Mortality and cardiac reintervention at 10 years after ASO were 3.2% (95% CI: 2.5%-4.2%) and 10.7% (95% CI: 9.1%-12.2%), respectively. The median time spent in hospital during the ASO spell was 19 days (IQR: 14, 24). Over the first year after the ASO patients spent 7 days (IQR: 4-10 days) in hospital in total, decreasing to 1 outpatient day/year beyond the fifth year. In a subgroup with complete risk factor data (n = 652), ASO age, and balloon atrial septostomy (BAS) use were not associated with late mortality and reintervention, but cardiac or congenital comorbidities, low weight, and circulatory/renal support at ASO were. After matching for patient characteristics, BAS followed by ASO and ASO as first procedure, performed within the first 3 weeks of life, had comparable early and late outcomes, including hospital resource utilization. Conclusions: Mortality and hospital resource utilization are low, while reintervention remains relatively frequent. Early ASO and individualized use of BAS allows for flexibility in treatment choices and a focus on at-risk patients.

Formal consensus study on surgery to replace the aortic valve in adults aged 18-60 years.

OBJECTIVE: There is uncertainty about surgical procedures for adult patients aged 18-60 years undergoing aortic valve replacement (AVR). Options include conventional AVR (mechanical, mAVR; tissue, tAVR), the pulmonary autograft (Ross) and aortic valve neocuspidisation (Ozaki). Transcatheter treatment may be an option for selected patients. We used formal consensus methodology to make recommendations about the suitability of each procedure. METHODS: A working group, supported by a patient advisory group, developed a list of clinical scenarios across seven domains (anatomy, presentation, cardiac/non-cardiac comorbidities, concurrent treatments, lifestyle, preferences). A consensus group of 12 clinicians rated the appropriateness of each surgical procedure for each scenario on a 9-point Likert scale on two separate occasions (before and after a 1-day meeting). RESULTS: There was a consensus that each procedure was appropriate (A) or inappropriate (I) for all clinical scenarios as follows: mAVR: total 76% (57% A, 19% I); tAVR: total 68% (68% A, 0% I); Ross: total 66% (39% A, 27% I); Ozaki: total 31% (3% A, 28% I). The remainder of percentages to 100% reflects the degree of uncertainty. There was a consensus that transcatheter aortic valve implantation is appropriate for 5 of 68 (7%) of all clinical scenarios (including frailty, prohibitive surgical risk and very limited life span). CONCLUSIONS: Evidence-based expert opinion emerging from a formal consensus process indicates that besides conventional AVR options, there is a high degree of certainty about the suitability of the Ross procedure in patients aged 18-60 years. Future clinical guidelines should include the option of the Ross procedure in aortic prosthetic valve selection.

Bartonella henselae endocarditis of percutaneously implanted pulmonary valve.

Percutaneous pulmonary valve implantation (PPVI) has revolutionized the management of right ventricular outflow tract dysfunction after repaired congenital heart disease. Although the technology is considered to be safe with a relatively low complication rate, infection is a described complication, with five cases of culture-positive infective endocarditis of percutaneously implanted pulmonary valve having been reported to date worldwide. Herein is reported the first ever case of culture-negative endocarditis following PPVI, caused by Bartonella henselae, diagnosed five years after implantation in a 15-year-old patient with a repaired truncus arteriosus.

Ductal arch decoded: the use of its spatial fingerprint to design a Norwood type of patch.

Reconstruction of the aortic arch for the Norwood procedure remains a focus of attention in terms of the management of the distal anastomosis [1,2], patch design and material [3,4], and fashioning the Damus-Kaye-Stansel itself [5]. The reconstructed aorta supplies the coronaries and the head and neck vessels and directs flow to the descending aorta. As the fetus develops, the right ventricle shunts to the aorta through the ductal arch, supporting a great percentage of the systemic and the placental circulation. We have developed a method of designing a Norwood patch by decoding the 3-dimensional geometry of the arterial duct and its arch.

Aortic Arch Phenotypes in Double Outlet Right Ventricle (DORV)-Implications for Surgery and Multi-Modal Imaging.

Abnormal aortic arches (AAAs) cover a spectrum of malformations, including abnormal laterality, branching patterns, and flow-limiting narrowing, which themselves vary from tubular hypoplasia, through discrete coarctation, to complete interruption of the arch. Neonatal surgery within the first days of life is necessary for most of these morphologies. Patch aortoplasty is widely used as it can offer a good haemodynamic result, being tailored to each combination of presenting pathologies. Our study hypothesis was that arch malformations are frequent in DORV and exhibit a plethora of phenotypes. We reviewed 54 post-mortem heart specimens from the UCL Cardiac Archive, analysing morphological features that would potentially influence the surgical repair, and taking relevant measurements of surgical importance. AAAs were found in half of the specimens, including 22.2% with aortic arch narrowing. In total, 70% and 30% of narrow arches had a subpulmonary and subaortic interventricular defect, respectively. Z-scores were significantly negative for all cases with tubular hypoplasia. We concluded that arch malformations are a common finding among hearts with DORV. Surgery on the neonatal aortic arch in DORV, performed in conjunction with other interventions that aim to balance pulmonary to systemic flow (Qp/Qs), should be anticipated and form an important part of multi-modal imaging.

Quantification of Pulmonary Artery Configuration after the Arterial Switch Operation: A Pilot Study.

BACKGROUND: The arterial switch operation (ASO) is the preferred treatment for d-transposition of the great arteries (TGA). Freedom from reintervention is mainly determined by the performance of the arterial outflow tracts, with variable incidence of pulmonary artery stenosis (PAS), possibly related to aspects of surgical technique. This pilot study attempts to describe pulmonary artery (PA) configuration through several measurements using three-dimensional data from cardiac magnetic resonance (CMR) imaging and assesses whether PA configuration is associated with PAS. METHODS: A retrospective, single-centre analysis of paediatric patients undergoing CMR after ASO. The geometry of the pulmonary arteries was compared between patients with and without PAS as judged by the CMR report. RESULTS: Among all patients (n = 612) after ASO, 45 patients underwent CMR at a median age of 10 years (3.5-13). Twenty-two (57.9%) had PAS, categorized as mild (n = 1), moderate (n = 19) or severe (n = 2). Eighteen had stenosis on PA branches. Four had MPA stenosis. Comparison between groups with and without PAS revealed no significant differences in neo-aortic to pulmonary angle, MPA to LPA/RPA angle, or bifurcation angle. There was a significant difference in cranial displacement, with more cranial displacement in the group without PAS. However, this group was older, 10.8 (7.3-14.3) years compared to those with PAS, 6.8 (1.5-12.1). CONCLUSIONS: The spectrum of PAS after ASO is heterogenous. This study shows the feasibility of measuring PA configuration in three planes on CMR. There is no correlation between PA configuration and PAS. Therefore, other mechanisms are probably responsible for the occurrence of PAS, rather than the configuration on itself. Further multicentric studies are warranted to confirm the suggested measuring method and assessing the associations with PAS, to eventually advise surgical methodology.

Use of virtual reality in complex double outlet right ventricle cases.

Virtual reality has been incorporated into clinical practice for planning complex congenital cardiac operations at the Great Ormond Street Hospital for Children since 2018 [1]. Virtual reality allows for 3-dimensional exploration of patient-specific models, created through the segmentation of 3-dimensional imaging data sets. Along with 3-dimensional printed models and 3-dimensional PDFs, this technology has enabled a new approach in planning and reviewing surgical interventions. It is particularly important in intracardiac repairs involving ventricular septal defects [2] and double outlet right ventricle cases presenting with various phenotypes of interventricular communication [3,4]. We present the virtual reality environment of two complex cases of double outlet right ventricle, illustrating the potential of virtual reality as a clinical tool to aid anatomical understanding and surgical planning of complex congenital heart disease.

Reappraisal of lung manifestations in the setting of Fontan circulation.

Fontan circulation is a well-established palliation in patients with functional single ventricles. Absence of a sub-pulmonary pumping chamber creates a unique physiology in which blood flow is mainly guided by negative intrathoracic and elevated central venous pressures. Various pulmonary anatomic or pathophysiologic changes can jeopardize optimal Fontan circulation. Long-term survival of patients who have undergone the contemporary total cavopulmonary connection is satisfactory. Thorough literature review in conjunction with accumulated clinical experience can lead clinicians to extract conclusions regarding Fontan and lung interactions indicating the purpose of this review.

Aortic root translocation and en bloc rotation of the outflow tracts surgery for complex forms of transposition of the great arteries and double outlet right ventricle: A multicenter study.

OBJECTIVE: There are several choices for the correction of complex transposition of the great arteries and double outlet right ventricle not amenable to the Rastelli-type surgery, but outcome data are limited to small series. This study aims to report results after the aortic root translocation and en bloc rotation of the outflow tract procedures. METHODS: This is a retrospective, multicentric, observational study. Clinical, anatomy, procedural, and detailed follow-up data (median, 4.43 years) were collected. RESULTS: A total of 70 patients (62.9% male; median age, 1 year; range 4 days to 12.4 years) were included: n = 43 in the aortic root translocation group and n = 27 in the en bloc rotation group. Those in the aortic root translocation group were older (P = .01) and more likely to have had previous procedures (P < .0001), but cardiac anatomy was similar in both groups. Aortic root translocation and en bloc rotation early mortality (30 days) was similar (4.7% vs 3.7%, P = .8). Late survival and freedom from any cardiac reintervention were 92.7% and 16.9% at 15 years overall, respectively. Freedom from right ventricular outflow tract/conduit reintervention was better in the en bloc rotation group than in the aortic root translocation group (100% vs 24.5%, P = .0003), but more patients in the en bloc rotation group had moderate (or worse) aortic valve regurgitation during follow-up (16% vs 2.6%, P = .07). CONCLUSIONS: Both aortic root translocation and en bloc rotation are valuable surgical options for the treatment of complex transposition of the great arteries and double outlet right ventricle. In the en bloc rotation group, there was better freedom from right ventricular outflow tract reinterventions, but a higher probability of aortic valve regurgitation. Identifying the main driving forces for these observed differences requires further study of these procedures.

Pediatric heart transplantation following donation after circulatory death, distant procurement, and ex-situ perfusion.

BACKGROUND: Limited availability of suitable donor hearts remains a challenge to pediatric heart transplantation, contributing to waitlist mortality. Controlled donation after circulatory death (DCD) has demonstrated success in adults. Early series of pediatric DCD heart transplantation using cold storage alone reported significant early mortality. We report a collaboration between 2 centers in the United Kingdom, combining expertise in adult DCD organ retrieval and pediatric transplantation. METHODS: This retrospective series comprises 6 children (4 male, all >20 kg) undergoing DCD heart transplantation at Great Ormond Street Hospital between 1 February and 30 September 2020, following retrieval with direct procurement and perfusion using portable normothermic machine perfusion by the Royal Papworth Hospital service. Baseline characteristics and 1-year follow-up were compared to 9 children who underwent donation after brain death (DBD) transplants contemporaneously. RESULTS: Mean DCD donor age was 24.67 years and mean DCD recipient age was 13.83 years. Mean functional warm ischemic time was 28.5 minutes and ex-situ heart perfusion time was 280 minutes. Median ICU and hospital stay were 9 and 17 days, respectively. All children survived to 1-year post-transplant. Survival and ICU and hospital stay were similar between the DCD and DBD cohorts. Performing DCD transplants resulted in a 66.7% increase in transplants for children >20 kg at GOSH during the study. CONCLUSIONS: This series demonstrates that DCD heart transplant can be performed safely with excellent short-term survival in children. Although the cohort is small, there was no significant difference in major outcomes compared to a DBD cohort.

Bartonella henselae endocarditis of percutaneously implanted pulmonary valve: a case report.

Percutaneous pulmonary valve implantation (PPVI) has revolutionized the management of right ventricular outflow tract dysfunction after repaired congenital heart disease. The technology is considered to be safe, with a relatively low complication rate. Infection is one of the described complications of PPVI, and to date five cases of culture-positive infective endocarditis of percutaneously implanted pulmonary valve have been reported worldwide. Herein is reported the first ever case of culture-negative endocarditis of a percutaneously implanted pulmonary valve, caused by Bartonella henselae, five years after implantation in a 15-year-old patient with a repaired truncus arteriosus.

Lessons from inter-stage cardiac magnetic resonance imaging in predicting survival for patients with hypoplastic left heart syndrome.

UNLABELLED: This study describes single-unit experience and explores risk stratification, with protocolised inter-stage cardiac magnetic resonance imaging for infants with hypoplastic left heart syndrome. Survival was retrospectively analysed among the cohort of locally followed survivors of Norwood Stage I procedure, who underwent magnetic resonance imaging under general anaesthesia from 2003 to 2008. This included 32 patients: 17 with Sano conduit and 15 with arterio-pulmonary shunt. The median (inter-quartile range) age and weight at scan were 3.1 (2.6-4.6) months and 5.0 (4.5-5.3) kilograms, respectively. Using morphologic definitions, the median coarctation index was 0.71 (0.57-0.83). The degree of proximal right and left pulmonary artery narrowing was 25% (14-44%) and 25% (11-50%), respectively. The median right ventricular ejection fraction was 54% (48-59%). The ejection fraction was not related to the coarctation index or to pulmonary artery narrowing. Patients were followed up for a median of 19.2 (10.8-46.0) months, during which 13 (41%) had an intervention in addition to routine Norwood Stage II surgery and seven died. Risk of death was related to reduced right ventricular ejection fraction, with a hazard ratio of 0.91 (95% confidence interval 0.85-0.98, p = 0.02), and the cumulative number of focal stenoses of neo-aortic arch and pulmonary arteries (hazard ratio 2.71, 95% confidence interval 1.14-6.44, p = 0.02). CONCLUSIONS: In addition to comprehensive three-dimensional morphologic imaging, inter-stage cardiac magnetic resonance imaging provides a ventricular functional index that may predict outcome in patients with hypoplastic left heart syndrome. Measures to preserve right ventricular systolic function and relieve stenoses are paramount within the complex management strategies for these patients.

Enhanced 3D visualization for planning biventricular repair of double outlet right ventricle: a pilot study on the advantages of virtual reality.

Aims: We aim to determine any additional benefit of virtual reality (VR) experience if compared to conventional cross-sectional imaging and standard three-dimensional (3D) modelling when deciding on surgical strategy in patients with complex double outlet right ventricle (DORV). Methods and results: We retrospectively selected 10 consecutive patients with DORV and complex interventricular communications, who underwent biventricular repair. An arterial switch operation (ASO) was part of the repair in three of those. Computed tomography (CT) or cardiac magnetic resonance imaging images were used to reconstruct patient-specific 3D anatomies, which were then presented using different visualization modalities: 3D pdf, 3D printed models, and VR models. Two experienced paediatric cardiac surgeons, blinded to repair performed, reviewed each case evaluating the suitability of repair following assessment of each visualization modalities. In addition, they had to identify those who had ASO as part of the procedure. Answers of the two surgeons were compared to the actual operations performed. There was no mortality during the follow-up (mean = 2.5 years). Two patients required reoperations. After review of CT/cardiac magnetic resonance images, the evaluators identified the surgical strategy in accordance with the actual surgical plan in 75% of the cases. When using 3D pdf this reached only 70%. Accordance improved to 85% after revision of 3D printed models and to 95% after VR. Use of 3D printed models and VR facilitated the identification of patients who required ASO. Conclusion: Virtual reality can enhance understanding of suitability for biventricular repair in patients with complex DORV if compared to cross-sectional images and other 3D modelling techniques.

Need for comprehensive vascular assessment before surgical repair of aortic coarctation in PHACES syndrome.

Children with PHACES syndrome commonly present with aortic coarctation and abnormalities of the supra-aortic and intracranial arteries. We describe a case of complex aortic coarctation in the context of PHACES syndrome, where preoperative detection of abnormalities in supra-aortic and intracranial arteries led to modification of the surgical technique adopted, in order to avoid potential neurological damage.