Predictors for Biventricular Repair in Pulmonary Atresia with Intact Ventricular Septum

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.

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.

Long-Term Outcomes After an Individualized Strategy in Patients with Pulmonary Atresia and Intact Ventricular Septum

This retrospective cohort study aimed to explore the long-term outcomes of an individualized strategy in patients with pulmonary atresia and intact ventricular septum (PAIVS). We analyzed survival and reintervention rates and identified risk factors for outcomes in patients with PAIVS treated based on individual right heart structures between 1979 and 2019. Ninety-five patients were included in this study. The z-scores of the pulmonary annulus, tricuspid annulus, and right ventricular end-diastolic volume were - 3.30 (- 15.15 to 1.83), - 0.70 (- 4.65 to 2.33), and - 1.51 (- 6.35 to 1.18), respectively. Right ventricular-dependent coronary circulation occurred in 15% of the patients. Among the 63 patients attempting biventricular strategy at first, 55 patients achieved biventricular circulation, 3 patients had one-and-a-half circulation, and 4 patients died perioperatively. Among the 33 patients attempting univentricular strategy at first, 10 patients died before the completion of Fontan operation, 17 patients (48%) accomplished Fontan operation, and 5 patients waited for Fontan operation. In one patient, conversion to biventricular circulation occurred. During the follow-up period of 720 person-years, the 20-year survival rate was significantly higher in patients with biventricular circulation than in those patients with univentricular circulation (93% vs. 67%, P < 0.001). Freedom from reintervention rates at 20 years was significantly lower in patients with biventricular circulation than in those patients with univentricular circulation (29% vs. 72%, P < 0.001). The pulmonary annulus z-score was an independent risk factor for reintervention in patients with biventricular circulation. Patients with biventricular circulation had an acceptable survival rate, but a high reintervention rate. Meanwhile, patients with univentricular circulation had high mortality before the completion of Fontan operation, although the reintervention rate was relatively low.

Infants with pulmonary atresia intact ventricular septum who require balloon atrial septostomy have significantly higher 18-month mortality

INTRODUCTION

Many newborns with pulmonary atresia/intact ventricular septum require intervention to establish pulmonary flow and sufficient cardiac output. The resulting haemodynamic changes are not well characterised and may have unintended consequences.

METHODS

This is a 30-year (1988-2018) retrospective study of patients with pulmonary atresia intact ventricular septum.

RESULTS

Eighty-nine patients were included, and median follow-up was 8 years. Fifty-five per cent had coronary sinusoids and 27% had right ventricular-dependent coronary circulation. Most patients were managed with surgical aortopulmonary or modified Blalock-Taussig shunt (73%), and 12 patients underwent balloon atrial septostomy before surgical intervention. The remaining patients (27%) underwent only transcatheter interventions; 7 required an atrial septostomy and 17 required ductal stentings. All-cause mortality was 10%, most deaths (89%) occurred before 18 months of age. Of these early deaths, 87% required a balloon atrial septostomy and 85% had right ventricular-dependent coronary sinusoids. Eighteen-month mortality was significantly higher for patients who required a balloon atrial septostomy compared to those who did not (36% versus 1.4% p < 0.0001).

DISCUSSION

Patients with pulmonary atresia/intact ventricular septum who require balloon atrial septostomy in the newborn period have significantly higher 18-month mortality. Quantifying the mortality difference may help guide prognostication and expectation setting. Infants who had septostomy and a surgical shunt in the newborn period fared better than those who only underwent septostomy (even when accompanied by ductal stenting). For infants with right ventricular-dependent circulation, atrial septostomy should only be performed on an urgent or emergent basis and these patients should be considered for early surgical intervention and neonatal transplant.

[Percutaneous management of pulmonary atresia with intact ventricular septum and critical pulmonary stenosis]

INTRODUCTION

Pulmonary atresia with intact ventricular septum and critical pulmonary stenosis in newborns encompasses a wide spectrum of disease, including cases with significant right ventricular hypoplasia and coronary artery to right ventricle fistulae, which may be considered a contraindication for decompression of the right ventricle. The aim of this study was to review the middle- and long-term outcomes of these patients over 20 years and identify differential factors between both groups, including patients with coronary artery fistulae.

PATIENTS AND METHODS

We performed a descriptive retrospective study by identifying all patients that received a diagnosis of pulmonary atresia with intact ventricular septum and critical pulmonary stenosis between January 1996 and January 2018. We collected and analysed data regarding right ventricular morphology, surgical management, percutaneous intervention and medium- and long-term outcomes.

RESULTS

51 patients were admitted. A total of 9 patients (17.6%) died during the followup. None of the deceased patients had coronary artery to right ventricle fistulae. The median length of follow up in the 42 survivors was 8.9 years (1-16). The functional class based on the latest revision of the New York Heart Association classification was 1.2 for the overall sample. Survivors of critical pulmonary stenosis had a functional class of 1.1, and survivors of pulmonary atresia with intact ventricular septum a functional class of 1.6. There were no differences based on the presence or absence of coronary artery to right ventricle fistulae.

CONCLUSIONS

Coronary artery to right ventricle fistulae may not be a contraindication for biventricular strategy. Patients with critical pulmonary stenosis had better outcomes compared to patients with pulmonary atresia with intact ventricular septum. The aggressive strategy of opening the pulmonary valve early on was associated with a good overall survival and correlated to a good functional class.

Echocardiographic parameters associated with biventricular circulation and right ventricular growth following right ventricular decompression in patients with pulmonary atresia and intact ventricular septum: Results from a multicenter study

BACKGROUND

In patients with pulmonary atresia, intact ventricular septum (PA/IVS) following right ventricular (RV) decompression, RV size and morphology drive clinical outcome. Our objectives were to (1) identify baseline and postdecompression echocardiographic parameters associated with 2V circulation, (2) identify echocardiographic parameters associated with RV growth and (3) describe changes in measures of RV size and changes in RV loading conditions.

METHODS

We performed a retrospective analysis of patients who underwent RV decompression for PA/IVS at four centers. We analyzed echocardiograms at baseline, postdecompression, and at follow up (closest to 1-year or prior to Glenn circulation).

RESULTS

Eighty-one patients were included. At last follow-up, 70 (86%) patients had 2V circulations, 7 (9%) had 1.5 ventricle circulations, and 4 (5%) had single ventricle circulations. Follow-up echocardiograms were available in 43 (53%) patients. The majority of patients had improved RV systolic function, less tricuspid regurgitation (TR), and more left-to-right atrial shunting at a median of 350 days after decompression. Multivariable analysis demonstrated that larger baseline tricuspid valve (TV) z-score (P = .017), ≥ moderate baseline TR (P = .045) and smaller baseline RV area (P < .001) were associated with larger increases in RV area. Baseline RV area ≥6 cm² /m² had 93% sensitivity and 80% specificity for identifying patients who ultimately achieved 2V circulation. All patients with RV area ≥8 cm² /m² at follow up achieved 2V circulation. This finding was confirmed in a validation cohort from a separate center (N = 25). Factors associated with achieving RV area ≥8 cm² /m² included larger TV z-score (P = .004), ≥ moderate baseline TR (P = .031), and ≥ moderate postdecompression pulmonary regurgitation (P = .002).

CONCLUSIONS

Patients with PA/IVS and smaller TV annuli are at risk for poor RV growth. Volume-loading conditions signal increased capacity for growth sufficient for 2V circulation.

Pulmonary Atresia With an Intact Ventricular Septum: Preoperative Physiology, Imaging, and Management

Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare complex cyanotic congenital heart disease with heterogeneous morphological variation. Prenatal diagnosis allows for developing a safe plan for delivery and postnatal management. While transthoracic echocardiography allows for detailed delineation of the cardiac anatomy, additional imaging modalities such as computed tomography, magnetic resonance imaging, and catheterization may be necessary to further outline features of the cardiac anatomy, specifically coronary artery anatomy. The size of the tricuspid valve and right ventricular cavity as well as the presence of right ventricle–dependent coronary circulation help to dichotomize between biventricular repair versus univentricular palliation or heart transplantation, as well as predicting the expected survival. The delineation and understanding of these features help to dictate both medical and surgical management.

Prenatal Echocardiographic Predictors of Postnatal Management Strategy in the Fetus with Right Ventricle Hypoplasia and Pulmonary Atresia or Stenosis

Fetuses with pulmonary atresia or pulmonary stenosis with intact ventricular septum manifest variable degrees of right ventricle hypoplasia and inadequacy. We studied the relationship between prenatal echocardiographic parameters and their progression through gestation as potential predictors of postnatal single-ventricle or two-ventricle care strategy. Serial fetal echocardiograms of pulmonary atresia (n = 28) or severe pulmonary stenosis (n = 8) and intact ventricular septum were reviewed. Measurements included tricuspid valve and mitral valve diameter and Z scores, degree of tricuspid regurgitation, presence of subaortic stenosis, presence of coronary artery fistulae, and Doppler pulsatility indices in middle cerebral and umbilical artery. Data were compared between first and last fetal studies. Subjects were divided based on postnatal course of single- or two-ventricle repair. Tricuspid valve size of those destined for single ventricle is smaller than of those destined for a two-ventricle repair at first study (26w, Z score -4.22 v -1.83, p < 0.001) and at final study (35w, -4.94 v -1.42, p < 0.001). Tricuspid valve and right ventricle grow in those destined for two ventricle, but not single-ventricle palliation. Tricuspid valve Z score = -3 at first or last study discriminated between single- or two-ventricle repair, except in two unusual cases with significant subaortic stenosis. Tricuspid valve Doppler-derived parameters of middle cerebral artery and umbilical artery did not distinguish between groups. In the fetus with pulmonary atresia or stenosis and intact ventricular septum, tricuspid valve Z score ≥-3, presence of important tricuspid regurgitation, absence of coronary fistulae, and absence of subaortic stenosis are associated with a two-ventricle postnatal strategy.

Predictors of Mortality in Children with Pulmonary Atresia with Intact Ventricular Septum

Pulmonary atresia with intact ventricular septum (PA/IVS) is a rare cardiac congenital lesion characterized by imperforate pulmonary valve, intact ventricular septum, and atrial level shunt. Although different management strategies to establish a source of non-ductal dependent pulmonary blood flow have been described, studies have not assessed the relationship between the therapeutic approach, patient characteristics, and outcomes. The purpose of this study was to identify predictors of mortality for patients with PA/IVS. Neonates and children with PA/IVS were identified through analysis of the 2012 Kids' Inpatient Database of the Healthcare Cost and Utilization Project. Hospital admissions that included a cardiac catheterization and/or surgical procedure were analyzed to identify demographics, co-morbidities, and outcomes. We identified 508 patients with PA/IVS with hospital admissions that included cardiac catheterization (n = 165), surgical procedures (n = 273), or both (n = 70). The incidence of mortality in this cohort was 6.69% (34/508). Univariable analysis demonstrated that age less than 12 months (p < 0.001), non-elective admission (p < 0.001), AKI (p = 0.001), sepsis (p = 0.002), and the use of ECMO (p < 0.001) were associated with an increased risk of mortality, while no difference was observed for the type of therapeutic approach (p = 0.498). These variables were used in a multivariable logistic regression analysis to develop the predictive model for mortality. Age less than 12 months, non-elective admission, and the use of ECMO in children with PA/IVS were predictors for mortality. Interestingly, the type of therapeutic approach did not influence mortality, which suggests that patient characteristics other than the method chosen to provide pulmonary blood flow determine mortality.

Perioperative and Anesthetic Considerations in Pulmonary Atresia With Intact Ventricular Septum

Pulmonary atresia with intact ventricular septum (PA/IVS) is a rare right-heart obstructive lesion with a wide anatomic and physiologic spectrum of disease, ranging from simple membranous pulmonary valve atresia with a fully developed right ventricle (RV) to a severely hypoplastic RV and ventriculocoronary (RV-coronary) fistulas. Affected neonates are dependent on prostaglandin for adequate pulmonary blood flow. Depending on the severity of disease, treatment options range from transcatheter pulmonary valve perforation and ultimate biventricular repair to staged single-ventricle palliation. Cardiac transplantation is recommended in the most severe cases. This review will discuss the perioperative and anesthetic management of patients with PA/IVS and highlight the challenges in management.

Optimal Z-Score Use in Surgical Decision-Making in Pulmonary Atresia With Intact Ventricular Septum

Objectives:

In the surgical treatment of pulmonary atresia with intact ventricular septum, the size of the tricuspid valve annulus (as measured by z-scores) has emerged as a significant factor in deciding which repair to perform. Various tricuspid valve annulus z-scores are reported as “cutoffs” for successful biventricular repair. We aimed to determine whether the use of different z-score data sets contributed to the gross variation in “cutoffs” for successful biventricular repair reported in the literature.

Methods:

A single search was made of PubMed using the “advanced” setting with the following search terms: pulmonary, atresia, intact, septum, z, and score. The filters “title” and “title/abstract” were used for the first four and last two terms, respectively; the instruction “AND” combined all terms. Articles that identified which z-score data set was used in patients with biventricular repairs were included.

Results:

From 13 articles, 1,392 patients were studied, 410 (29.5%) of which achieved biventricular repair. Three z-score data sets were quoted; mean tricuspid valve annulus z-scores in biventricular repair patients ranged between −0.53 and −5.1. After correcting for discrepancies between z-score data sets, no study reported a mean tricuspid valve annulus z-score <−2.8 in biventricular repair patients and 83.3% reported mean tricuspid valve annuli z-scores >−1.7.

Conclusion:

The use of varied tricuspid valve annuli z-score data sets may have contributed to gross variations in reported “cutoffs” for successful biventricular repair. This could lead to inappropriate surgical pathway allocation.

Biventricular repair versus uni-ventricular repair for pulmonary atresia with intact ventrical septum: A systematic review

The management of pulmonary atresia with intact ventricular septum (PA/IVS) remains controversial. The goal of separating systematic and pulmonary circulation can be achieved by biventricular or uni-ventricular (Fontan or one and a half ventricle repair) strategies. Although outcomes have been improved, these surgical procedures are still associated with high mortality and morbidity. An optimal strategy for definitive repair has yet to be defined. We searched databases for genetically randomized controlled trials (RCTs) comparing biventricular with uni-ventricular repair for patient with PA/IVS. Data extraction and quality assessment were performed following the guidelines of the Cochrane Collaboration. Primary outcome measures were overall survival, and secondary criteria included exercise function, arrhythmia-free survival and treatment-related mortality. A total number of 669 primary citations were screened for relevant studies. Detailed analysis revealed that no RCTs were found to adequately address the research question and no systematic meta-analysis would have been carried out. Nevertheless, several retrospective analyses and case series addressed the question of finding right balance between biventricular and uni-ventricular repair for patient with PA/IVS. In this review, we will discuss the currently available data.