Late Pulmonary Autograft Dilation: Can We Make a Good Operation Great? The Supported Ross.

The Ross procedure is an excellent option for aortic valve replacement resulting in outstanding hemodynamic performance and the ability to avoid systemic anticoagulation. The long-term durability of the autograft is generally good but concerns for later aortic root dilation with ensuing neoaortic insufficiency have prompted efforts to stabilize the autograft, root, sinuses and Sino-tubular junction in order to delay or entirely avoid late reinterventions on the neoaortic root. We have employed an inclusion technique, supporting the Auto-graft in a Terumo Gelweave™ Valsalva graft. We performed a retrospective study of all 129 patients undergoing the Ross procedure from 1992 to 2019 at Children's Wisconsin. Fifty-one underwent the supported Ross (SR) and 78 underwent unsupported Ross (UR). Structured clinical data was collected and echocardiograms were reviewed. Median follow-up was 4.9 years (up to 22.6 years) for UR patients and 3.6 years (up to 11.4 years) for SR patients. In order to provide a fair comparison, we sub -analyzed patients aged 10 to 18 years who underwent the Ross procedure, 16 who underwent the UR and 18 patients who underwent the SR. Change in aortic annulus diameter (P = 0.002), aortic sinus diameter (P = 0.001) change in left ventricular function (P = 0.039) and change in aortic insufficiency (P = 0.008) were all worse in UR. The SR is simple, reproducible, and predictable. It seems to prevent change in annulus diameter, sinus diameter and to reduce late neoaortic insufficiency. Longer follow-up with a larger group of patients is required to draw definitive conclusions.

A Novel Diastolic Doppler Index Less Affected by Aortic Arch Anomalies Co-existing with Coarctation.

Severity assessment for coarctation of the aorta (CoA) is challenging due to concomitant morphological anomalies (complex CoA) and inaccurate Doppler-based indices. Promising diagnostic performance has been reported for the continuous flow pressure gradient (CFPG), but it has not been studied in complex CoA. Our objective was to characterize the effect of complex CoA and associated hemodynamics on CFPG in a clinical cohort. Retrospective analysis identified discrete juxtaductal (n = 25) and complex CoA (n = 43; transverse arch and/or isthmus hypoplasia) patients with arm-leg systolic blood pressure gradients (BPG) within 24 h of echocardiography for comparison to BPG by conventional Doppler indices (simplified Bernoulli equation and modified forms correcting for proximal kinetic energy and/or recovered pressure). Results were interpreted using the current CoA guideline (BPG ≥ 20 mmHg) to compare diagnostic performance indicators including receiver operating characteristic curves, sensitivity, specificity, and diagnostic accuracy, among others. Echocardiography Z-scored aortic diameters were applied with computational simulations from a preclinical CoA model to understand aspects of the CFPG driving performance differences. Diagnostic performance was substantially reduced from discrete to complex CoA for conventional Doppler indices calculated from patient data, and by hypoplasia and/or long segment stenosis in simulations. In contrast, diagnostic indicators for the CFPG only modestly dropped for complex vs discrete CoA. Simulations revealed differences in performance due to inclusion of the Doppler velocity index and diastolic pressure half-time in the CFPG calculation. CFPG is less affected by aortic arch anomalies co-existing with CoA when compared to conventional Doppler indices.

Conal Septal Hypoplasia in Tetralogy of Fallot-Impact on Clinical Course, Treatment Strategies, and Outcomes After Surgical Intervention.

We sought to characterize the clinical course and outcomes of intervention for Tetralogy of Fallot (TOF) with associated conal septal hypoplasia (CSH) compared to those with identifiable conal septum on initial newborn echocardiogram. We performed a retrospective, 1:2 case-control study of children with TOF anatomy, 33 with CSH and 66 with typical TOF, who underwent surgical repair from 1991-2019 at Children's Wisconsin. Data on echocardiographic anatomic features, systemic oxygen saturations, medical therapies, admissions, palliative interventions, operative strategies, and long-term follow-up were compared. The CSH group had fewer hypercyanotic spells (6% vs 42%, p < 0.001), beta-blockers prescribed (12% vs 41%, p = 0.005), and hospital admissions for cyanosis (12% vs 44%; p = 0.001) prior to any intervention. Of 14 who required palliative intervention, 8 had balloon pulmonary valvuloplasty (BPV) (7 from the CSH group and 1 from the control group), and 6 had systemic-to-pulmonary artery shunts (all from the control group). Definitive repair was performed at a significantly older age in the CSH group (10.2 ± 10 vs 5.6 ± 5.9 months, p = 0.011), with less subpulmonary muscle resection (57.6% in vs 92.4%, p < 0.001) and higher use of a transannular patch (84.8% vs 65.2%, p = 0.040). The average time to surgical reintervention was similar in both groups (9.7 ± 5.9 vs 8.6 ± 6.4 years in controls). We conclude that infants with TOF and CSH have a milder preoperative clinical course with fewer hypercyanotic spells or need for medical therapy. They also respond well to palliative BPV and can safely undergo later definitive repair compared to typical TOF with a well-developed conal septum.

Clinical Variables Associated with Pre-Fontan Aortopulmonary Collateral Burden.

Aortopulmonary collaterals (APCs) develop universally, but to varying degrees, in patients with single ventricle congenital heart disease (CHD). Despite their ubiquitous presence, APCs remain poorly understood. We sought to evaluate the association between APC burden and common non-invasive clinical variables. We conducted a single center, retrospective study of patients with single ventricle CHD and previous Glenn palliation who underwent pre-Fontan cardiac magnetic resonance (CMR) imaging from 3/2018 to 3/2021. CMR was used to quantify APC flow, which was normalized to aortic (APC/QAo) and pulmonary vein (APC/QPV) blood flow. Univariate, multivariable, and classification and regression tree (CART) analyses were done to investigate the potential relationship between CMR-quantified APC burden and clinical variables. A total of 29 patients were included, all of whom had increased APC flow (APC/QAo: 26.9, [22.0, 39.1]%; APC/QPV: 39.4 [33.3, 46.9]%), but to varying degrees (APC/QAo: range 11.9-44.4%; APC/QPV: range 17.7-60.0%). Pulmonary artery size (Nakata index, at pre-Fontan CMR) was the only variable associated with APC flow on multivariable analysis (APC/QAo: p = 0.020, R2 = 0.19; APC/QPV: p = 0.0006, R2 = 0.36) and was the most important variable associated with APC burden identified by CART analysis (size inversely related to APC flow). APC flow is universally increased but highly variable in patients with single ventricle CHD and Glenn circulation. Small branch pulmonary artery size is a key factor associated with increased APC burden; however, the pathogenesis of APCs is likely multifactorial. Further research is needed to better understand APC pathogenesis, including predisposing and mitigating factors.

Is native aortic valvuloplasty at time of Norwood operation in infants with hypoplastic left heart syndrome and aortic stenosis safe?

In hypoplastic left heart syndrome, the size and function of the left ventricle vary and are dependent on the patency of the aortic valve. A patent native aortic valve, permitting left ventricular ejection, can augment cardiac output. We performed a retrospective chart review of patients with hypoplastic left heart syndrome and a stenotic aortic valve who underwent native aortic valvuloplasty at the time of Norwood and found that none of the eight patients identified had clinically significant aortic insufficiency. This case series suggests that surgical aortic valvuloplasty at Norwood is associated with aortic valve patency/augmented systemic cardiac output without the development of clinically significant aortic regurgitation at intermediate follow-up in a limited cohort.

Innominate Vein Turn-down Procedure for Failing Fontan Circulation.

After the Fontan, systemic venous hypertension induces pathophysiologic changes in the lymphatic system that can result in complications of pleural effusion, ascites, plastic bronchitis, and protein losing enteropathy. Advances in medical therapy and novel interventional approaches have not substantially improved the poor prognosis of these complications. A more physiological approach has been developed by decompression of the thoracic duct to the lower pressure common atrium with a concomitant increase of preload. Diverting the innominate vein to the common atrium increases the transport capacity of the thoracic duct, which in most patients enters the circulation at the left subclavian-jugular vein junction. Contrary to the fenestrated Fontan circulation, in which the thoracic duct is drained into the high pressure Fontan circulation, turn down of the innominate vein to the common atrium effectively decompresses the thoracic duct to the lower pressure system with "diastolic suctioning" of lymph. Innominate vein turn-down may be considered for medical-refractory post-Fontan lymphatic complications of persistent chylothorax, plastic bronchitis, and protein losing enteropathy. Prophylactic innominate vein turn-down may also be considered at time of the Fontan operation for patients that are higher risk for lymphatic complications.

Brain death interval and relationship to outcomes of pediatric cardiac transplantation.

BACKGROUND: We sought to analyze brain death interval and outcomes of pediatric cardiac transplantation using national registry data. METHODS: We retrospectively evaluated a pediatric cohort from the UNOS registry from 2005 to 2014. We restricted the donor cohort to those with a primary central nervous system event as the cause of hospitalization. Brain death interval (BDI) was defined as the time between hospital admission and organ procurement. Primary outcomes were recipient and graft survival time. Logistical regression modeling was used for multivariable analysis. RESULTS: The donor cohort included 2565 cases. Multivariable analysis demonstrated no relationship between BDI and recipient or graft survival time. For patient survival time, the lowest HR was 0.94 (0.63-1.39), P = 0.531; for graft survival time, the lowest HR was 0.89 (0.53-1.49), P = 0.563. We obtained similar results using a non-restricted donor cohort. CONCLUSIONS: There was no clear relationship between BDI and recipient or graft survival after pediatric cardiac transplantation.

Anatomic Repair of Corrected Transposition of the Great Arteries: The Double Switch.

The long-term outcome of patients with corrected transposition of the great arteries and associated lesions after physiologic repair is uncertain. Anatomic correction, utilizing the morphologic left ventricle as a systemic pumping chamber and the mitral valve as the systemic atrioventricular valve, is considered the preferred method, especially for patients with either tricuspid valve regurgitation, with Ebstein's malformation of the tricuspid valve, or with right ventricular dysfunction. The double switch employs both an atrial switch and arterial switch to "correct" the atrioventricular and ventriculoarterial discordance. Associated lesions are also repaired. The best outcomes with double switch are achieved with patients in the first few years of life even if reconditioning of morphologic left ventricle is required. However, the long-term function of the conduction system, the aortic valve, and the ventricles is variable and requires close surveillance.

Central ECMO for circulatory failure following pediatric liver transplantation.

We describe the case of a 4-year-old male with a past medical history significant for nephrotic syndrome, short-bowel syndrome and fulminant hepatic failure status post (s/p) liver transplant (LT) who developed early post-transplant allograft dysfunction (hyperbilirubinemia, coagulopathy) and septic shock requiring central extracorporeal membrane oxygenation (ECMO). He remained on ECMO for 85 hours before he was decannulated without event and later underwent repeat LT. This case highlights the potential of central ECMO to provide the circulatory output necessary to reverse distributive shock physiology in patients with sepsis and hepatic dysfunction following LT. Furthermore, this is the first documented example of central ECMO as a bridge to recovery for repeat LT.

HeartWare Ventricular Assist Device Implantation in Patients With Fontan Physiology.

We aim to describe the clinical course of a series of patients with hypoplastic left heart syndrome and refractory systolic heart failure supported with a HeartWare ventricular assist device (HVAD) following Fontan palliation. This is a retrospective review of three consecutive patients supported with a HVAD following Fontan palliation through February 2016. Data include patient characteristics, operative variables, postimplantation hemodynamic/device parameters, event outcomes, and duration of HVAD support. Patient ages were 11.7, 13.5, and 17.5 years, respectively, at the time of HVAD implant. The duration of HVAD support was 148, 272, and 271 days, respectively, of which 86, 222, and 211 were outpatient days. Inflow cannula position was the morphologic right ventricle with depth adjustment and manipulation of the tricuspid subvalvar apparatus to ensure good inflow. Echocardiographic, hemodynamic, and noninvasive oximetric monitoring resulted in high RPM settings for all patients. Despite various complications, all patients were successfully transplanted and discharged home alive. We present three patients bridged to transplantation using the HVAD following Fontan palliation. We demonstrate potential for durable support with transition to outpatient care while awaiting heart transplantation in a subset of patients status post Fontan surgery.

Mechanical Circulatory Support of the Fontan Patient.

Because of the inadequacies inherent to a circulation supported by a single ventricle, many Fontan patients will experience failure of their circulation. To date, there is no medical regimen that reliably and consistently restores circulatory function in these patients. Because of the shortage of donor organs and the fact that many of these patients present with features that either preclude or render heart transplantation a high risk, there is an intense need to better understand how mechanical circulatory support (MCS) may benefit these patients. In this report, we share our experience of successful MCS and transplantation of three patients. Our experience and that of others is very encouraging, but also preliminary. In general, a systemic ventricular assist device, with or without a Fontan fenestration, is a reasonable consideration for a patient presenting with predominantly systolic dysfunction. A pulmonary/systemic venous assist device may be sufficient for the patient with preserved systolic function and failure of the systemic venous/lymphatic system; however, this remains speculative. The more comprehensive approach of a total artificial heart or bilateral support is attractive in theory, but beset by the need for a more complex operation. In all scenarios, early referral, before organ failure, is paramount to successful MCS.

Complete Repair of Tetralogy of Fallot in the Neonatal Versus Non-neonatal Period: A Meta-analysis.

It is unclear if neonatal tetralogy of Fallot repair offers better outcomes compared to repair later in infancy. We therefore conducted a meta-analysis comparing outcomes of neonatal and non-neonatal repair. Manuscripts were identified and reviewed for quality and bias with favorably scored manuscripts being included in the final meta-analysis. Several perioperative and postoperative variables were compared. A total of 8 studies with 3858 patients were included in the analysis. Of these patients, 19% underwent neonatal repair. Neonatal repair was associated with increased mortality, longer intensive care unit stays, and longer total hospital length of stay.

Anatomic Repair of Congenitally Corrected Transposition of the Great Arteries: Single-Center Intermediate-Term Experience.

We present our experience for patients who have undergone an anatomic repair (AR) for congenitally corrected transposition of the great arteries (CCTGA) at the Children's Hospital of Wisconsin. A retrospective chart review of patients who underwent AR for CCTGA from 2001 to 2015 was performed. The cohort consisted of 15 patients (74% male). Median age of anatomic repair was 15 months (range 4.5-45.6 months). Four patients had a bidirectional Glenn (BDG) prior to AR. At the time of AR,-9 (60%) underwent Senning/Rastelli procedure, 4 (26.6%) had double switch operation, and 2 (13.3%) underwent only Senning with VSD closure. Median duration of follow-up was 5.5 years (0.05-14 years). Reoperations prior to discharge included BDG, revision of pulmonary venous baffle, closure of residual VSD, and pacemaker placement. Late reoperations included left ventricular outflow tract obstruction repair, conduit replacement, melody valve placement, and pacemaker implantation. At their most recent follow-up, no patient had heart failure symptoms and only 1 had severely diminished function that improved with cardiac resynchronization therapy. Moderate mitral regurgitation was noted in 15% (2/13), and severe in 7% (1/13). Moderate tricuspid regurgitation was noted in 15% (2/13). One patient, 7% (1/13), developed moderate aortic insufficiency. There was a 100% survival at the time of the most recent follow-up. Patients with CCTGA who have undergone AR have excellent functional status and mid-term survival but reinterventions are common. Longer term studies are needed to determine both the extent and spectrum of reinterventions as well as long term survival.

Ventricular Assist Device in Single-Ventricle Heart Disease and a Superior Cavopulmonary Anastomosis.

Our objective is to describe the use of a ventricular assist device (VAD) in single-ventricle patients with circulatory failure following superior cavopulmonary anastomosis (SCPA). We performed a retrospective chart review of all single-ventricle patients supported with a VAD following SCPA. Implantation techniques, physiologic parameters while supported, medical and surgical interventions postimplant, and outcomes were reviewed. Four patients were supported with an EXCOR Pediatric (Berlin Heart Inc., The Woodlands, TX, USA) following SCPA for a median duration of 10.5 days (range 9-312 days). Selective excision of trabeculae and chords facilitated apical cannulation in all patients without inflow obstruction. There were two pump exchanges in the one patient supported for 312 days. Two patients were evaluated by cardiac catheterization while supported. Three of four patients were successfully bridged to transplantation. One patient died while supported. All patients had significant bleeding at the time of transplantation, and one required posttransplant extracorporeal membrane oxygenation with subsequent full recovery. VAD support can provide a successful bridge to transplantation in patients with single-ventricle circulation following SCPA. A thorough understanding of the challenges encountered during this support is necessary for successful outcomes.

A case series of patients with cor triatriatum dexter: unique cause of neonatal cyanosis.

Cor triatriatum dexter is a rare congenital heart defect that can lead to cyanosis in a newborn with an otherwise normal exam. The initial evaluation of these patients typically focuses on searching for a pulmonary etiology for arterial desaturation, which often leads to a negative work up. When cardiac evaluation is performed, it may be challenging because the heart lesion can be difficult to visualize on an echocardiogram. The diagnosis requires a high index of suspicion and thorough echocardiographic imaging. Once diagnosed, surgical repair can alleviate the shunt created by the defect. This case series describes all patients (3) with cor triatriatum dexter seen at Children's Hospital of Wisconsin from 2000 to 2013.

Significant response to oral Etoposide in the treatment of an unresectable cardiac sarcoma.

Primary cardiac sarcomas are rare and carry a poor prognosis. The standard of care is complete resection. Outcomes for patients without complete resection are dismal, and the benefit of adjuvant therapy is uncertain. A 9-year-old girl presented with a large right-sided cardiac mass. After biopsy, the tumor was classified as an undifferentiated sarcoma. Resection was not feasible due to apparent invasion of the right ventricle and atrioventricular groove. Treatment with oral etoposide resulted in a 97% reduction in tumor volume and allowed for complete resection of residual tumor. She is alive with no evidence of disease 25 months from diagnosis.

Incidence and outcome of pediatric patients with intracranial hemorrhage while supported on ventricular assist devices.

Pediatric patients supported on ventricular assist devices (VADs) require systemic anticoagulation and are at risk for intracranial hemorrhage (ICH). Little is known about the incidence or outcomes of pediatric patients with ICH while supported on a VAD. A retrospective chart review of all patients receiving VAD support was completed. Patients diagnosed with ICH while supported on a VAD were identified. Significant factors prior to diagnosis of ICH, medical/surgical treatment of ICH, and patient outcomes were assessed. Five of 30 (17%) patients supported on a VAD from January 2000 to November 2012 were diagnosed with an ICH. Four patients had an identified cerebral thromboembolic injury prior to the ICH. Four patients required interruption in their anticoagulation regimen due to other bleeding concerns prior to ICH. Neurosurgical intervention consisted of evacuation of hemorrhage in one, whereas two others required management of hydrocephalus with external ventricular drainage. Three of the five patients died on VAD support. Two deaths were directly related to ICH, whereas the third was unrelated. Two patients were successfully transplanted; one remains with a significant neurological impairment, and the other has recovered with minimal residual impairment following neurosurgical evacuation of a large subdural hematoma. ICH is a devastating complication of VAD support. Prior ischemic infarcts and interruptions to anticoagulation may put a patient at risk for ICH. Prompt neurosurgical evaluation/intervention can result in positive outcomes.

Coarctation duration and severity predict risk of hypertension precursors in a preclinical model and hypertensive status among patients.

Background: Coarctation of the aorta (CoA) often leads to hypertension (HTN) post-treatment. Evidence is lacking for the current >20 mmHg peak-to-peak blood pressure gradient (BPGpp) guideline, which can cause aortic thickening, stiffening and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model, and test if predictors translate to HTN status in CoA patients. Methods: Rabbits (N=75; 5-12/group) were exposed to mild, intermediate or severe CoA (≤12, 13-19, ≥20 mmHg BPGpp) for ~1, 3 or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction and endothelial function evaluated via multivariate regression. Relevance to CoA patients (N=239; age=0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) vs follow-up HTN status. Results: CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and HTN in CoA patients. Interaction between patient age and BPGpp at surgery contributed significantly to HTN, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that pre-operative BPGpp and surgical age predict risk of HTN along with residual post-operative BPGpp. Conclusions: These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of HTN.

Coarctation Duration and Severity Predict Risk of Hypertension Precursors in a Preclinical Model and Hypertensive Status Among Patients.

BACKGROUND: Coarctation of the aorta (CoA) often leads to hypertension posttreatment. Evidence is lacking for the current >20 mm Hg peak-to-peak blood pressure (BP) gradient (BPGpp) guideline, which can cause aortic thickening, stiffening, and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model and test if predictors translate to hypertension status in patients with CoA. METHODS: Rabbits (n=75; 5-12/group) were exposed to mild, intermediate, or severe CoA (≤12, 13-19, ≥20 mm Hg BPGpp) for ≈1, 3, or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction, and endothelial function evaluated via multivariate regression. Relevance to patients with CoA (n=239; age, 0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) versus follow-up hypertension status. RESULTS: CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and hypertension in patients with CoA. Interaction between patient age and BPGpp at surgery contributed significantly to hypertension, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that preoperative BPGpp and surgical age predict risk of hypertension along with residual postoperative BPGpp. CONCLUSIONS: These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of hypertension.

Consistency of the continuous flow pressure gradient despite aortic arch anomalies co-existing with coarctation.

Aims: Severity assessment for coarctation of the aorta (CoA) is challenging due to concomitant morphological anomalies (complex CoA) and inaccurate Doppler-based indices. Promising diagnostic performance has been reported for the continuous flow pressure gradient (CFPG), but it has not been studied in complex CoA. Our objective was to characterize the effect of complex CoA and associated hemodynamics on CFPG in a clinical cohort. Methods and Results: Retrospective analysis identified discrete juxtaductal (n=25) and complex CoA (n=43; transverse arch and/or isthmus hypoplasia) patients with arm-leg systolic blood pressure gradients (BPG) within 24 hours of echocardiography for comparison to BPG by conventional Doppler indices (simplified Bernoulli equation and modified forms correcting for proximal kinetic energy and/or recovered pressure). Results were interpreted using the current CoA guideline (BPG ≥20 mmHg) to compare diagnostic performance indicators including receiver operating characteristic curves, sensitivity, specificity, and diagnostic accuracy, among others. Echocardiography Z-scored aortic diameters were applied with computational stimulations from a preclinical CoA model to understand aspects of the CFPG driving performance differences.Diagnostic performance was substantially reduced from discrete to complex CoA for conventional Doppler indices calculated from patient data, and by hypoplasia and/or long segment stenosis in simulations. In contrast, diagnostic indicators for the CFPG only modestly dropped for complex vs discrete CoA. Simulations revealed differences in performance due to inclusion of the Doppler velocity index and diastolic pressure half-time in the CFPG calculation. Conclusion: CFPG is less affected by aortic arch anomalies co-existing with CoA when compared to conventional Doppler indices.