Achieving biventricular circulation in patients with moderate hypoplastic right ventricle in pulmonary atresia intact ventricular septum after transcatheter pulmonary valve perforation

Borderline Ventricles: From Evaluation to Treatment

A heart with a borderline ventricle refers to a situation where there is uncertainty about whether the left or right underdeveloped ventricle can effectively support the systemic or pulmonary circulation with appropriate filling pressures and sufficient physiological reserve. Pediatric cardiologists often deal with congenital heart diseases (CHDs) associated with various degrees of hypoplasia of the left or right ventricles. To date, no specific guidelines exist, and surgical management may be extremely variable in different centers and sometimes even in the same center at different times. Thus, the choice between the single-ventricle or biventricular approach is always controversial. The aim of this review is to better define when "small is too small and large is large enough" in order to help clinicians make the decision that could potentially affect the patient's entire life.

Current status of transcatheter intervention for complex right ventricular outflow tract abnormalities

Various transcatheter interventions for the right ventricular outflow tract (RVOT) have been introduced and developed in recent decades. Transcatheter pulmonary valve perforation was first introduced in the 1990s. Radiofrequency wire perforation has been the approach of choice for membranous pulmonary atresia in newborns, with high success rates, although complication rates remain relatively common. Stenting of the RVOT is a novel palliative treatment that may improve hemodynamics in neonatal patients with reduced pulmonary blood flow and RVOT obstruction. Whether this option is superior to other surgical palliative strategies or early primary repair of tetralogy of Fallot remains unclear. Transcatheter pulmonary valve replacement has been one of the biggest innovations in the last two decades. With the success of the Melody and SAPIEN valves, this technique has evolved into the gold standard therapy for RVOT abnormalities with excellent procedural safety and efficacy. Challenges remain in managing the wide heterogeneity of postoperative lesions seen in RVOT, and various technical modifications, such as pre-stenting, valve ring modification, or development of self-expanding systems, have been made. Recent large studies have revealed outcomes comparable to those of surgery, with less morbidity. Further experience and multicenter studies and registries to compare the outcomes of various strategies are necessary, with the ultimate goal of a single-step, minimally invasive approach offering the best longer-term anatomical and physiological results.

Echocardiographic Parameters for Risk Prediction in Borderline Right Ventricle: Review with Special Emphasis on Pulmonary Atresia with Intact Ventricular Septum and Critical Pulmonary Stenosis

The aim of the present review is to highlight the strengths and limitations of echocardiographic parameters and scores employed to predict favorable outcome in complex congenital heart diseases (CHDs) with borderline right ventricle (RV), with a focus on pulmonary atresia with intact ventricular septum and critical pulmonary stenosis (PAIVS/CPS). A systematic search in the National Library of Medicine using Medical Subject Headings and free-text terms including echocardiography, CHD, and scores, was performed. The search was refined by adding keywords "PAIVS/CPS", Ebstein's anomaly, and unbalanced atrioventricular septal defect with left dominance. A total of 22 studies were selected for final analysis; 12 of them were focused on parameters to predict biventricular repair (BVR)/pulmonary blood flow augmentation in PAIVS/CPS. All of these studies presented numerical (the limited sample size) and methodological limitations (retrospective design, poor definition of inclusion/exclusion criteria, variability in the definition of outcomes, differences in adopted surgical and interventional strategies). There was heterogeneity in the echocardiographic parameters employed and cut-off values proposed, with difficultly in establishing which one should be recommended. Easy scores such as TV/MV (tricuspid/mitral valve) and RV/LV (right/left ventricle) ratios were proven to have a good prognostic accuracy; however, the data were very limited (only two studies with <40 subjects). In larger studies, RV end-diastolic area and a higher degree of tricuspid regurgitation were also proven as accurate predictors of successful BVR. These measures, however, may be either operator and/or load/pressure dependent. TV Z-scores have been proposed by several authors, but old and heterogenous nomograms sources have been employed, thus producing discordant results. In summary, we provide a review of the currently available echocardiographic parameters for risk prediction in CHDs with a diminutive RV that may serve as a guide for use in clinical practice.

Prediction of postnatal circulation in pulmonary atresia/critical stenosis with intact ventricular septum: systematic review and external validation of models

OBJECTIVE

A favorable postnatal prognosis in cases of pulmonary atresia/critical stenosis with intact ventricular septum (PA/CS-IVS) is generally equated with the possibility of achieving biventricular (BV) repair. Identification of fetuses that will have postnatal univentricular (UV) circulation is key for prenatal counseling, optimization of perinatal care and decision-making regarding fetal therapy. We aimed to evaluate the accuracy of published models for predicting postnatal circulation in PA/CS-IVS using a large internationally derived validation cohort.

METHODS

This was a systematic review of published uni- and multiparametric models for the prediction of postnatal circulation based on echocardiographic findings at between 20 and 28 weeks of gestation. Models were externally validated using data from the International Fetal Cardiac Intervention Registry. Sensitivity, specificity, predictive values, area under the receiver-operating-characteristics curves (AUCs) and proportion of cases with true vs predicted outcome were calculated.

RESULTS

Eleven published studies that reported prognostic parameters of postnatal circulation were identified. Models varied widely in terms of the main outcome (UV (n = 3), non-BV (n = 3), BV (n = 3), right-ventricle-dependent coronary circulation (n = 1) or tricuspid valve size at birth (n = 1)) and in terms of the included predictors (single parameters only (n = 6), multiparametric score (n = 4) or both (n = 1)), and were developed on small sample sizes (range, 15-38). Nine models were validated externally given the availability of the required parameters in the validation cohort. Tricuspid valve diameter Z-score, tricuspid regurgitation, ratios between right and left cardiac structures and the presence of ventriculocoronary connections (VCC) were the most commonly evaluated parameters. Multiparametric models including up to four variables (ratios between right and left structures, right ventricular inflow duration, presence of VCC and tricuspid regurgitation) had the best performance (AUC, 0.80-0.89). Overall, the risk of UV outcome was underestimated and that of BV outcome was overestimated by most models.

CONCLUSIONS

Current prenatal models for the prediction of postnatal outcome in PA/CS-IVS are heterogeneous. Multiparametric models for predicting UV and non-BV circulation perform well in identifying BV patients but have low sensitivity, underestimating the rate of fetuses that will ultimately have UV circulation. Until better discrimination can be achieved, fetal interventions may need to be limited to only those cases in which non-BV postnatal circulation is certain. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Type I and II pulmonary atresia with intact ventricular septum in infants: a 10-year experience in initial surgery at one center

Background

To explore the effect of initial surgery for type I and II pulmonary atresia with intact ventricular septum (PA/IVS).

Methods

50 children with type I PA/IVS and 50 with type II PA/IVS who had undergone initial surgery were enrolled. Children with Type I were divided into groups A (n = 25) and B (n = 25). Group A had received BT shunt combined with PDA ligation and balloon dilatation of pulmonary valve, whereas group B had undergone BT shunt combined with PDA ligation and pulmonary valve incision. Children with type II were divided into groups C (n = 25) and D (n = 25). Group C had received BT shunt combined with PDA ligation, right ventricular outflow tract (RVOT) incision and transannular patch. Group D had undergone BT shunt combined with PDA ligation, RVOT incision, transannular patch and artificial pulmonary valve implantation. The differences in mechanical ventilation time, length of ICU stay, mortality rate, tricuspid Z value, tricuspid regurgitation, oxygen saturation, pulmonary regurgitation, McGoon ratio, pulmonary artery transvalvular pressure, survival rate were compared between groups A and B, between groups C and D respectively.

Results

The ventilator assistance time and length of ICU stay were greater in group C than in group D (80.96 ± 8.42 h vs. 65.16 ± 4.85 h, P = 0.045; 222.00 ± 11.72 h vs. 162.48 ± 7.91 h, P = 0.048). The pulmonary artery transvalvular pressure was significantly higher in group A than in group B at 3, 6, 12, 24 and 36 months after surgery (64.86 ± 4.13 mmHg vs. 53.04 ± 5.64 mmHg, P = 0.045; 69.47 ± 1.93 mmHg vs. 55.95 ± 4.04 mmHg, P = 0.005; 80.16 ± 3.76 mmHg vs. 73.24 ± 2.34 mmHg, P = 0.035; 62.95 ± 5.64 mmHg vs. 48.47 ± 7.44 mmHg, P = 0.04; 53.69 ± 4.89 vs. 45.77 ± 3.26, P = 0.02). Furthermore, the tricuspid Z value was significantly greater in group B than in group A at 3 and 24 months after surgery (− (1.37 ± 0.04) vs. − (1.43 ± 0.06), P = 0.03; − (0.41 ± 0.06) vs. − (0.51 ± 0.11), P = 0.02).

Conclusions

The effect of BT shunt combined with PDA ligation and pulmonary valve incision is superior to BT shunt combined with PDA ligation and balloon dilatation of pulmonary valve, and the effect of BT shunt combined with PDA ligation, RVOT incision, transannular patch and artificial pulmonary valve implantation is superior to BT shunt combined with PDA ligation, RVOT incision and transannular patch.

Risk analysis for patients with a functionally univentricular heart after systemic-to-pulmonary shunt placement

OBJECTIVES

To investigate risk factors for mortality after systemic-to-pulmonary (SP) shunt procedures in patients with a functionally univentricular heart using the Japan Cardiovascular Surgery Database registry.

METHODS

Clinical data from 75 domestic institutions were collected. Overall, 812 patients with a functionally univentricular heart who underwent initial SP shunt palliation were eligible for analysis. Patients with pulmonary atresia with an intact ventricular septum and patients with a SP shunt as part of the Norwood procedure were excluded. Risk factors for 30- and 90-day mortalities were analysed using a logistic regression model.

RESULTS

Median age and body weight at SP shunt placement were 41 days and 3.6 kg, respectively. Modified Blalock-Taussig shunt, central shunt and other types of SP shunts were applied in 689 (84.9%), 94 (11.8%) and 30 (3.7%) patients, respectively. Cardiopulmonary bypass was utilized in 410 patients (51%) for 128 min (median, 19-561). There were 411 isolated SP shunt procedures. Median hospital stay was 27 days, and 742 (91.4%) patients were discharged. The 30- and 90-day mortality rates were 3.4% and 6.0%, respectively. Placement of a central shunt was identified as a risk factor for 30-day mortality, while lower body weight, preoperative ventilator support, right atrial isomerism and coexistence of major aortopulmonary collateral arteries and an unbalanced atrioventricular septal defect were identified as risk factors for 90-day mortality.

CONCLUSIONS

SP shunt carries a high mortality rate in patients with a functionally univentricular heart when it is performed in smaller patients with complex cardiac anomalies.

The Use of Chronic Total Occlusion (CTO) Wires for Perforation of Atretic Pulmonary Valve; Two Centers Experience

Pulmonary valve atresia with intact ventricular septum (PA-IVS) can be treated either surgically or transcatheterly for eligible patients. Perforation of pulmonary valves using chronic total occlusion (CTO) guidewires has been reported as an alternative to radiofrequency (RF) perforation. We sought to report our experience with CTO guidewires for perforation of atretic pulmonary valves and subsequent balloon dilatation (with or without patent ductus arteriosus stenting) in patients with PA-IVS from two centers. A retrospective study was carried out on PA-IVS patients who underwent intervention between March 2014 and September 2019, in which CTO guidewire was employed for pulmonary valve perforation. A total of 26 patients were identified. The median age and weight of the patients were 5.2 days (range 1-21 days) and 3.1 kg (range 2.2-3.8 kg), respectively. All patients were situs solitus, except one patient with left atrial isomerism. The right ventricle (RV) morphology was bipartite in 22/26 patients and tripartite in 4/26 patients. Before the procedure, the mean saturation was 76% (range 70-86%) while the patients were under prostaglandin infusion. The pulmonary valve perforation attempt was performed with the Asahi Conquest Pro 9 CTO wire (n = 6) or Asahi Pro 12 CTO wire (n = 18) and/or Asahi Miracle CTO wire (n = 2). The procedure was successful in 20/26 (77%) patients using CTO wires. We analyzed the efficiency of CTO wire based on the subtypes: Conquest Pro 9 in 6/6 (100%) patients, Conquest Pro 12 in 12/18 (67%) patients, and Miracle in 2/2 (100%) patients. Before CTO wire usage in 3 patients, radiofrequency (RF) perforation was unsuccessful. Among these 3 patients, pulmonary valve perforation was successful in 2 patients with CTO wire; hence, in the remaining patient, perforation was also unsuccessful with CTO wire. After CTO wire perforation was unsuccessful in 6 patients, RF perforation was attempted in 3 patients (2 successful attempts and 1 unsuccessful attempts), and one patient as referred to surgery. Desaturation was persistent in 19 cases, which necessitated ductus arteriosus stenting. Early procedural complication was observed in 3/26 (11%) patients. Two of these patients had vascular complications due to the sheath, which was treated with heparin infusion and streptokinase, and the remaining patient had sudden bradycardia and cardiac arrest during the procedure and did not respond to cardiac resuscitation. CTO wires should be keep in mind for atretic pulmonary valve perforation as a first choice or when RF perforation is unsuccessful.

Is there a transcatheter solution for a sick neonate with hypoplastic right heart syndrome?: Pulmonary valve perforation in a neonate with hypoplastic right ventricle with pulmonary atresia, restrictive VSD-a case report

BACKGROUND

Hypoplastic right heart syndrome with pulmonary atresia is a rare cyanotic heart disease with poor prognosis requiring urgent intervention to establish the pulmonary blood flow. Pulmonary blood flow is achieved by BT shunt or percutaneous techniques like PDA stenting or pulmonary valve perforation. Various series have shown that early surgical intervention causes high mortality in these patients. Pulmonary valve perforation is a suitable, physiological alternative to surgical techniques in selected patients.

CASE PRESENTATION

We report a case of hypoplastic right heart syndrome with pulmonary atresia and restrictive VSD presenting with cyanosis from birth and underwent pulmonary valve perforation successfully.

CONCLUSION

Duct-dependent pulmonary circulation is a pediatric emergency, palliative procedure for establishing adequate pulmonary blood flow is essential early in the life. In the management of duct-dependent pulmonary circulation, RVOT perforation is an effective and safe option in suitable high-risk subgroups. The induced pulmonary regurgitation along with established physiological antegrade flow would be beneficial in the remodeling of tripartite/hypertrophied small RV.

Quantification of Initial Right Ventricular Dimensions by Computed Tomography in Infants with Congenital Heart Disease and a Hypoplastic Right Ventricle

OBJECTIVE

To demonstrate the feasibility of using cardiothoracic CT for quantification of the initial right ventricle (RV) dimensions in infants with congenital heart disease (CHD) and a hypoplastic RV and to compare these measurements with those obtained in a control group with CHD without a hypoplastic RV.

MATERIALS AND METHODS

Initial RV dimensions, including RV volumes, RV/left ventricle (LV) volume ratios, atrioventricular valve annulus diameter ratios, and RV/LV length ratios based on CT data, were collected from 57 infants with CHD and a hypoplastic RV (hypoplastic RV group; age range, 1 day to 6 months) and 33 infants with tetralogy of Fallot (control group; age range, 1 day to 6 months) and compared between the 2 groups. The type of final surgery was also evaluated in the hypoplastic RV group over a follow-up period of 3-8 years.

RESULTS

The RV and LV volumes and lengths were successfully quantified in all 90 patients. The tricuspid valve annulus diameter could not be measured in cases showing muscular tricuspid atresia and double-inlet LV. The initial RV dimensions quantified by CT were significantly lower for the hypoplastic RV group than for the control group (p < 0.001). The types of final surgery performed in the hypoplastic RV group were univentricular repair in 46 patients, biventricular repair in 4 patients, or an indeterminate surgery in 7 patients.

CONCLUSION

Initial RV dimensions in infants with CHD and a hypoplastic RV can be quantified by CT and are substantially smaller than those in infants with tetralogy of Fallot.

Transcatheter radiofrequency pulmonary valve perforation in newborns with pulmonary atresia/intact ventricular septum: Echocardiographic predictors of biventricular circulation

OBJECTIVE

We report a single-institute experience of neonatal transvenous radiofrequency pulmonary valve perforation for pulmonary atresia/intact ventricular septum, with echocardiographic predictors of biventricular circulation.

METHODS

Data were reviewed retrospectively for all neonates who underwent primary transvenous pulmonary valve perforation for pulmonary atresia/intact ventricular septum between January 2008 and November 2018 at our institution. We compared patients who need systemic-to-pulmonary shunt or ductal stenting with patients who did not need.

RESULTS

During the study period, 31 patients with pulmonary atresia/intact ventricular septum underwent successful radiofrequency pulmonary valve perforation and balloon dilation of the pulmonary valve. There was no procedure-related mortality. Sixteen patients (52%) needed systemic-to-pulmonary shunt or ductal stenting after initial procedure. Among the survivors (follow-up time of 1 to 11.5 years), 15 patients had a biventricular circulation and 6 patients had 1 and 1⁄2 ventricular circulation. Two patients are awaiting for Fontan operation. Both the TV/MV annulus ratio (>0.85) and tricuspid valve z-score (>-1) were found to be a good predictor of a biventricular outcome in our cohort.

CONCLUSIONS

Percutaneous radiofrequency pulmonary valve perforation and balloon valvotomy is an effective and safe primary treatment strategy for neonates with pulmonary atresia/intact ventricular septum. Ductal stenting or systemic-to-pulmonary shunt may be required in the majority of patients who had smaller right heart components. Preselection of patients according to tricuspid valve z-score and TV/MV annulus ratio allows predicting biventricular circulation.

Neonatal Pulmonary Atresia With Intact Ventricular Septum-8-Year Surgical Experience at One Center

BACKGROUND

Surgical treatment of pulmonary atresia with intact ventricular septum (PA/IVS) in neonates is challenging because of the broad variations of right ventricular (RV) malformations. In this retrospective study, we summarized our 8-y experience in surgical management for neonatal PA/IVS patients.

METHODS

Thirty-four neonates with PA/IVS between July 1, 2006 and June 30, 2014, were reviewed. Patients were categorized into three groups: mild, moderate, and severe RV hypoplasia according to RV morphology and development. Patients were on regular follow-up for at least 5 y. Overall survival, complications, reinterventions, risk factors for mortality, and health status were evaluated.

RESULTS

21 patients (61.8%) were treated with biventricular repair, eight patients (23.5%) with Fontan procedure, and one patient (2.9%) with bidirectional Glenn procedure. There were four postprocedural mortalities and one late death. The 5-y survival rates after final surgical repair for mild, moderate, and severe RV hypoplasia groups were 100%, 100%, and 88.9%, respectively. The reintervention rates were 0% (0/4), 21.4% (3/14), and 55.6% (5/9) for the subgroups, respectively. At the latest follow-up, most patients had a status characterized as New York Heart Association class I (88.9%, 24/27).

CONCLUSIONS

Surgical management for PA/IVS in neonates should be individualized. Favorable early and long-term outcomes can be achieved in neonatal PA/IVS patients by individualized surgical strategies, regardless of the degree of RV hypoplasia. In spite of potential RV catch-up development, the degree of RV hypoplasia is a factor of paramount importance to assess PA/IVS in neonates.