Tetralogy of Fallot with absent pulmonary valve syndrome

Tetralogy of Fallot With Absent Pulmonary Valve Syndrome: The Experience of a Tertiary Care Center in a Developing Country

BACKGROUND

Tetralogy of Fallot with an absent pulmonary valve is a very rare variant of tetralogy. It is characterized by absent valve tissue, severe pulmonary regurgitation, and secondary aneurysmal dilatation of the pulmonary arteries.

AIM

In this study, we aim to investigate the clinical presentations, management strategies, and outcomes of patients with tetralogy of Fallot and absent pulmonary valve.

METHODOLOGY

We retrospectively reviewed the charts of all patients who presented to the American University of Beirut Medical Center between January 2010 and December 2020 and who were diagnosed with this anomaly.

RESULTS

A total of 300 cases of tetralogy of Fallot were identified, of which 18 patients had absent pulmonary valves. They were followed up for an average of 8.2 years. Prenatal diagnoses were made in four patients, while 13 patients were identified in the neonatal period, with an average age of 4.5 days. Genetic testing confirmed DiGeorge syndrome in one patient. Five patients underwent surgical intervention in the neonatal period, while the remaining patients were operated on during their early childhood. While overall there were no surgical mortalities nor any need for reinterventions, a variety of morbidities were encountered.

CONCLUSION

This study provides an overview of this rare anomaly and its management in a developing country.

Out of the blue: inflammatory myofibroblastic tumour identified during repair of tetralogy of Fallot with absent pulmonary valve

Inflammatory myofibroblastic tumour of the heart is an exceedingly rare benign neoplasm. While benign, without prompt management its impact can be devastating. Tetralogy of Fallot with absent pulmonary valve is a rare form of CHD. We present the first documented case of inflammatory myofibroblastic tumour of the heart in the presence of tetralogy of Fallot with absent pulmonary valve.

Rare association of absent pulmonary valve syndrome, complete atrioventricular canal defect, double outlet right ventricle, right aortic arch, and aberrant right subclavian artery in a fetal case

Absent pulmonary valve syndrome (APVS) is a rare congenital cardiac anomaly. It is often associated with TOF, but may also be associated with an intact ventricular septum or, more rarely, with tricuspid atresia. It's combination with a complete atrioventricular septal defects and double outlet right ventricle has been reported extremely rare, even in the postnatal period. Herein, we report a 20-week-old fetus with a right aortic arch and an aberrant left subclavian artery with this rare combination. We report a case of a 20-week fetus diagnosed having this rare combination of right aortic arch and aberrant left subclavian artery. The APVS with complete atrioventricular septal defects may represent another type of APVS.

Diagnostic imaging for absent pulmonary valve syndrome: an update with an emphasis on cardiothoracic computed tomography

Absent pulmonary valve syndrome is a rare congenital heart disease characterized by partial or complete absence of pulmonary valve cusps which commonly presents with respiratory difficulty during infancy. Because central airway compression by dilated central pulmonary arteries is a key pathology of this syndrome responsible for clinical presentation, severity, and outcome, cardiothoracic computed tomography (CT) is currently regarded as the imaging modality of choice before and after treatment. In addition, tracheobronchomalacia frequently responsible for persistent respiratory problems can be accurately evaluated with conventional two-dimensional cine CT or four-dimensional CT. In this pictorial review, various diagnostic imaging methods used to evaluate absent pulmonary valve syndrome are comprehensively illustrated with an emphasis on a recently spotlighted role of cardiothoracic CT.

A Genotyped Case of Townes–Brocks Syndrome with Absent Pulmonary Valve Syndrome from Turkey

Townes–Brocks syndrome (TBS) is a rare syndrome characterized by triad of anal, ear, and thumb anomalies. Further malformations/anomalies include congenital heart diseases, foot malformations, sensorineural and/or conductive hearing impairment, genitourinary malformations, and anomalies of eye and nervous system. Definitive diagnosis for TBS is confirmed by molecular analysis for mutations in the SALL1 gene. Only one known case of TBS with absent pulmonary valve syndrome (APVS) has been previously described to our knowledge. Here, we report a newborn diagnosed with TBS with APVS and tetralogy of Fallot (TOF) who was found to carry the most common pathogenic SALL1 gene mutation c.826C > T (p.R276X), with its surgical repair and postoperative follow-up. To our knowledge, this is the first genotyped case of TBS from Turkey to date. TBS should be suspected in the presence of ear, anal, and thumb malformations in a neonate. If a patient with TBS and TOF-APVS needs preoperative ventilation within the first months of life, this implies prolonged postoperative intubation and increased risk of mortality.

Functional characterization of a novel PBX1 de novo missense variant identified in a patient with syndromic congenital heart disease

Pre-B cell leukemia factor 1 (PBX1) is an essential developmental transcription factor, mutations in which have recently been associated with CAKUTHED syndrome, characterized by multiple congenital defects including congenital heart disease (CHD). During analysis of a whole-exome-sequenced cohort of heterogeneous CHD patients, we identified a de novo missense variant, PBX1:c.551G>C p.R184P, in a patient with tetralogy of Fallot with absent pulmonary valve and extra-cardiac phenotypes. Functional analysis of this variant by creating a CRISPR-Cas9 gene-edited mouse model revealed multiple congenital anomalies. Congenital heart defects (persistent truncus arteriosus and ventricular septal defect), hypoplastic lungs, hypoplastic/ectopic kidneys, aplastic adrenal glands and spleen, as well as atretic trachea and palate defects were observed in the homozygous mutant embryos at multiple stages of development. We also observed developmental anomalies in a proportion of heterozygous embryos, suggestive of a dominant mode of inheritance. Analysis of gene expression and protein levels revealed that although Pbx1 transcripts are higher in homozygotes, amounts of PBX1 protein are significantly decreased. Here, we have presented the first functional model of a missense PBX1 variant and provided strong evidence that p.R184P is disease-causal. Our findings also expand the phenotypic spectrum associated with pathogenic PBX1 variants in both humans and mice.

Evaluation of cardiovascular morphology and airway-related abnormalities in tetralogy of fallot with absent pulmonary valve syndrome on multidetector computed tomography angiography

AIM

To evaluate the cardiovascular, tracheobronchial and pulmonary abnormalities associated with tetralogy of Fallot with absent pulmonary valve syndrome (TOF-APVS) on multidetector computed tomograpgy (MDCT) angiography.

MATERIALS AND METHODS

We conducted a retrospective review of our electronic database from January, 2014 to December, 2020 to identify pediatric patients diagnosed with TOF-APVS on MDCT angiography. Pulmonary anatomy, associated tracheobronchial and coronary compression, compression of intrapulmonary bronchi, lung parenchymal changes and other associated cardiovascular abnormalities were evaluated.

RESULTS

Forty-seven patients with TOF-APVS were included in the study. Compression of the airways was observed at multiple levels; 4 (8.5%) patients had carinal compression while right main bronchus and left main bronchus compression was seen in 12 (25.5%) and 16 (34.0%) patients, respectively. Forty-three (91.5%) patients showed abnormal pulmonary arterial branching at the segmental level and compression at the level of intrapulmonary bronchi was seen in 24 (51.1%) patients. Some degree of air trapping was seen in 35 (74.5%) patients whereas atelectasis was observed in 15 (31.9%) patients. Mild coronary arterial compression was seen in 3 (6.4%) patients.

CONCLUSION

TOF-APVS is characterized by aneurysmal dilatation of pulmonary arteries leading to a varying degree of airway compression. However, even in the absence of compression of the trachea and main bronchi, there can be distal bronchial compression secondary to abnormal pulmonary arterial branching resulting in lung abnormalities in the majority of these patients. This study highlights the importance of dedicated airway assessment in addition to cardiovascular morphological assessment by MDCT angiography, before planning surgery.

Unusual association of isolation of right pulmonary artery in absent pulmonary valve syndrome

Absence of arterial duct, a sixth aortic arch derivative, plays an important etiologic role in Tetralogy of Fallot with absent pulmonary valve syndrome. When fetal ductus is absent, the large right ventricular stroke volume dilates the pulmonary trunk leading to pulmonary regurgitation. A proximal extension of the embryonic insult to the entire left sixth arch causes absence of the left pulmonary artery, a common association of absent pulmonary valve syndrome. On the contrary, absence of right pulmonary artery is not reported in absent pulmonary valve syndrome. A rare combination of tetralogy, absent pulmonary valve syndrome and isolation of a hypoplastic right pulmonary artery offered challenges to diagnosis and management.

Surgical outcomes of absent pulmonary valve syndrome: An institutional experience

Background:

Absent pulmonary valve syndrome (APVS) is a variant of tetralogy of Fallot characterized by aneurysmal pulmonary arteries, which compresses the tracheobronchial tree, leading to respiratory symptoms. We report the mid-term outcomes of surgical correction of patients with APVS.

Subject and Methods:

A total of 27 patients underwent surgery between 2001 and 2015, and they were followed up for a mean period of 6.4 ± 4.1 years. Out of the 27 patients, 14 (51.9%) were infants. The median age at repair was 9.8 months. Preoperative intubation was required in six patients (22.2%), and 11 patients (40.7%) had symptoms of respiratory distress. The pulmonary valve was replaced with a valved conduit in 15 patients (55.6%), monocusp valve in 6 patients (22.2%), and a transannular patch in 6 patients (22.2%). Reduction pulmonary arterioplasty was done in all patients.

Results:

The overall 10-year survival was 82.1%. There was 81.1% overall freedom from re-intervention at 10 years. No statistically significant difference was found in 10-year survival (P = 0.464) and reoperation rates (P = 0.129) between valved conduit, monocusp, or transannular patch techniques. Older children had statistically significantly longer survival (P = 0.039) and freedom from re-intervention (P = 0.016) compared to infants. Patients without respiratory complications had 100% 10-year survival and 93.3% freedom from reoperation at 10 years compared to 55.6% and 60.1%, respectively, for patients with respiratory complications.

Conclusion:

There has been improvement in surgical results for APVS over the years. However, it still remains a challenge to manage infants and patients with persistent respiratory problems.

Nakata index above 1500 mm2/m2 predicts death in absent pulmonary valve syndrome

OBJECTIVES

Absent pulmonary valve syndrome is a rare congenital heart disease with severe airway compression due to dilatation of the pulmonary arteries (PAs). We investigated risk factors for death and prolonged mechanical ventilation (>7 days) and a threshold PA size for these outcomes.

METHODS

This retrospective 2-centre cohort study included 68 patients with complete repair between January 1996 and December 2015.

RESULTS

Median age at repair was 3.9 months (1.3-8.7 months), and median weight was 5 kg (4-7 kg). The mortality rate before hospital discharge was 12%, and the mortality rate at last follow-up was 19%. In multivariable analysis, risk factors for death were higher Nakata index [hazard ratio (HR) 1.001, 95% confidence interval (CI) 1.001-1.002; P < 0.001] and lower SpO2 (HR 1.06, 95% CI 1.02-1.09; P = 0.002). The accuracy of the Nakata index to predict death was excellent (area under the curve at 6 months: 0.92; P = 0.010). A Nakata index above 1500 mm2/m2 predicted mortality at 6 months with a sensitivity of 98% and a specificity of 82%. Twenty-five patients (37%) had prolonged mechanical ventilation. The only multivariable risk factor for prolonged ventilation was lower weight at repair (odds ratio 2.9, 95% CI 1.3-6.7; P = 0.008). Neither PA plasty nor the LeCompte manoeuvre had a protective effect on mortality or prolonged ventilation. A Nakata index above 1500 mm2/m2 remained a risk factor for mortality (P = 0.022) in patients who had a PA plasty or the LeCompte manoeuvre.

CONCLUSIONS

In patients with absent pulmonary valve syndrome, the Nakata index predicts mortality with a cut-off of 1500 mm2/m2. Lower weight at repair is the only multivariable risk factor for prolonged ventilation. Neither PA plasty nor the LeCompte manoeuvre had a protective effect on these outcomes.

Transthoracic Echocardiographic Evaluation of Pulmonary Valve Anomalies in Pediatric Patients

The pulmonary valve normally consists of 3 leaflets supported in a semilunar fashion within the sinuses of the pulmonary trunk. Pulmonary leaflet malformations, such as congenital single pulmonary cusp absence, bicuspid pulmonary valve, and quadricuspid pulmonary valve anomalies, as well as pulmonary valve commissural fusion, are seldom identified preoperatively on echocardiography. In this study, we report on 5 children with different types of pulmonary valve malformations diagnosed by transthoracic echocardiography.

Surgical outcome after complete repair of tetralogy of Fallot with absent pulmonary valve: comparison between bovine jugular vein-valved conduit and monocusp-valve patch

BACKGROUND

The prognosis of tetralogy of Fallot with absent pulmonary valve (TOF/APV) without operation is poor. We evaluated the surgical outcome of TOF/APV in a single center.

METHODS

Twenty-two TOF/APV patients underwent complete surgical correction in our hospital. Right ventricular outflow tract reconstruction was performed using bovine jugular vein (BJV)-valved conduit implantation (n = 10), homograft-valved conduit implantation (n = 2), or monocusp-valve patch (n = 10). Health-related quality of life (QOL) was evaluated during follow-up.

RESULTS

The overall survival at 5 and 10 years was 86.4 ± 7.3% (confidence interval 69.4-97.2%). The survival rates were significantly different between patients with and without bronchial stenosis (40 and 100%, P = 0.0003, log-rank test). The survival of patients aged > 6 months was higher than those ≤ 6 months (100 vs. 40%, P = 0.0003, log-rank test). Patients with BJV-valved conduits had higher systolic gradients from the right ventricle to the pulmonary artery (RV-PA) compared to those with monocusp-valve patches. BJV-valved conduit implantation was a risk factor for post-operative pulmonary-valve stenosis. The QOL score for patients with BJV-valved conduits was lower than those with monocusp-valve patches (P < 0.05). No reoperation was performed during follow-up.

CONCLUSIONS

Bronchial stenosis and lower age (≤ 6 months) were the main factors influencing post-operative survival. The use of a BJV-valved conduit was a main reason for RV-PA restenosis; thus, the use of a BJV-valved conduit may increase the need for repeat intervention and decrease the post-operative quality of life.

Perspectives on neonatal and infant tracheostomy

Neonates and infants may need a tracheostomy for many different reasons, ranging from airway obstruction to a requirement for long term mechanical ventilator support. Here, we present the pathophysiology of the many congenital and acquired conditions that might be managed with a tracheostomy. Decisions about tracheostomy demand consideration of not only the benefits, but also the potential side-effects, which may differ in the short and long term and may be attributable to underlying conditions as well as the tracheostomy. Evaluation of potential advantages of tracheostomy will influence decisions about optimal timing. In many cases, an infant may 'graduate' from dependence on a tracheostomy and resume a natural airway, although some will require reconstructive airway surgery.

Perinatal Thoracic Mass Lesions: Pre- and Postnatal Imaging

Chest masses present a common problem in the perinatal period. Advances in prenatal ultrasound, supplemented by fetal magnetic resonance imaging, now allow early detection and detailed characterization of many thoracic lesions in utero. As such, in asymptomatic infants, assessment with postnatal computed tomography or magnetic resonance imaging can often be delayed for several months until the time at which surgery is being contemplated. Bronchopulmonary malformations comprise most of the thoracic masses encountered in clinical practice. However, a variety of other pathologies can mimic their appearances or produce similar effects such as hypoplasia of a lung or both lungs. Understanding of the key differentiating clinical and imaging features can assist in optimizing prognostication and timely management.

Airway compression management in late-presenting absent pulmonary valve syndrome

INTRODUCTION

Patients with absent pulmonary valve syndrome often present early with airway compression from aneurysmal pulmonary arteries. This study reviews our experience in managing absent pulmonary valve syndrome in later presenting children, and techniques used for managing airway compression.

METHODS

This study is a retrospective chart review of all patients who underwent repair of absent pulmonary valve syndrome from 2000 to 2012 at our institution. The primary endpoints were post-operative bronchoscopic and clinical evidence of persistent airway compression and need for reinterventions on the pulmonary arteries.

RESULTS

A total of 19 patients were included during the study period. The mean age at repair was 4.1±3.0 years (range 10 months-11 years). In all, seven patients had pre-operative bronchoscopic evidence of airway compression, which was managed by pulmonary artery reduction plasty in four patients and Lecompte manoeuvre in three patients. There were no peri-operative deaths. In patients with pulmonary artery plasty, two had no post-operative airway compression, one patient had improved compression, and one patient had unchanged compression. In patients managed with a Lecompte manoeuvre, two patients had no or trivial airway compression and one had improved compression. There were six late reinterventions or reoperations on the pulmonary arteries - two out of four in the pulmonary artery plasty group and one out of three in the Lecompte group.

CONCLUSIONS

Most late-presenting patients with absent pulmonary valve syndrome do not have airway compression. Either pulmonary artery reduction plasty or the Lecompte manoeuvre can relieve proximal airway compression, without a significantly different risk of pulmonary artery reintervention between techniques.

Surgery for tetralogy of Fallot - absent pulmonary valve syndrome. Technique of anterior translocation of the pulmonary artery

Patients with absent pulmonary valve syndrome (APVS) and tetralogy of Fallot represent a particular management's challenge. The distinctive feature of APVS is the airway obstruction caused by tracheobronchial compression that results from massive dilatation of the main pulmonary artery (PA) and its first- and second-order branches. Consequential tracheomalacia and bronchomalacia determine the timing and severity of respiratory compromise, as well as the morbidity and mortality of these patients. Although several techniques have been proposed for decompression of the airways, the method of choice is still controversial. Translocation of the PA anterior to the aorta and away from the airways has the potential to reduce or eliminate bronchial compression. Overall, the intermediate-term functional outcomes using this technique have been encouraging, with zero mortality even in the youngest age group of patients and the disappearance of respiratory symptoms in the majority of them. Nevertheless, failure of the treatment could be expected in symptomatic patients in whom the pathology of the airways extends beyond the proximal PAs.

Tetralogy of Fallot With Absent Pulmonary Valve Syndrome, Right Aortic Arch, and Disconnected Left Pulmonary Artery

We present a rare case of a two-week-old infant with tetralogy of Fallot , absent pulmonary valve syndrome , right aortic arch, and disconnected left pulmonary artery (LPA) whose origin was from ductal ligament adjacent to the left subclavian artery. One-stage surgical correction, including closure of ventricular septal defect (VSD), LPA reconstruction and reconnection to the pulmonary trunk, reduction in size of the right pulmonary artery (RPA), and right ventricular outflow tract reconstruction with valved conduit, was successfully performed with good clinical mid-term outcome.

A novel approach to the repair of tetralogy of Fallot with absent pulmonary valve and the reduction of airway compression by the pulmonary artery

Controversy persists regarding the management of patients suffering from tetralogy of Fallot with absent pulmonary valve syndrome. Airway obstruction caused by the dilated pulmonary arteries is the determining factor in the mortality of symptomatic newborns and infants. A number of surgical techniques for the reduction of bronchial obstruction have been proposed, producing variable results. All strategies have focused on plication and reduction of the anterior or posterior wall of the normally positioned pulmonary arteries, with or without pulmonary valve replacement. An alternative approach is to bring the pulmonary arteries anterior to the aorta and away from the trachea and bronchial tree. This technique has the potential to reduce or eliminate bronchial compression by the central pulmonary arteries. Failure of the treatment could be expected in symptomatic patients, where the pathology of the airways extends beyond the proximal pulmonary arteries.

Superior outcomes for repair in infants and neonates with tetralogy of Fallot with absent pulmonary valve syndrome

OBJECTIVE

Primary repair of tetralogy of Fallot with absent pulmonary valve syndrome has been associated with significant mortality, particularly for neonates in respiratory distress. Controversy persists regarding the method of establishing right ventricle-pulmonary artery continuity.

METHODS

Anatomic and demographic parameters were evaluated for patients undergoing repair of tetralogy of Fallot with absent pulmonary valve syndrome from 1990 to 2005, as were perioperative and late postoperative parameters (airway complications, reoperation or catheter-based intervention, and mortality).

RESULTS

Twenty-three patients underwent repair. Median age was 15 days (range 2-1154 days). Patients were followed up for 5.3 +/- 3.9 years. Seventeen (85%) required preoperative ventilatory assistance. One patient died within 24 hours; 1 patient died 8 months postoperatively. Four patients received valved homografts, and the remainder had valveless connections. All patients underwent reduction pulmonary arterioplasty and mobilization, unifocalization (in 3), and ventricular septal defect closure. Valveless connection recipients had a transannular hood. No patient underwent a Lecompte maneuver. Four patients underwent reoperation for conversion to valveless connection (n = 1), reduction arterioplasty (n = 1), and repair of pulmonary stenosis (n = 2). Three patients required catheter-based intervention, with balloon angioplasty (n = 3) and stent placement (n = 1); 2 now demonstrate equal quantitative lung perfusion. No patient has had significant debility from airway compromise. All patients demonstrate free pulmonary insufficiency and good biventricular function.

CONCLUSIONS

We report excellent overall survival (89%) and low postoperative morbidity for neonates and infants undergoing primary repair of tetralogy of Fallot with absent pulmonary valve syndrome. Our recent experience supports the use of a valveless right ventricle-pulmonary artery connection, which, combined with catheter-based intervention, reduces the likelihood of reoperation necessitated by homograft placement.

Repair of tetralogy of Fallot with absent pulmonary valve using a new approach

Although several techniques for the correction of tetralogy of Fallot (TOF) with absent pulmonary valve have been described, the method of choice is controversial. Symptomatic infants, in particular, have a poor prognosis because of severe central pulmonary artery dilatation and bronchial compression. An alternative technique for primary repair of TOF with absent pulmonary valve syndrome is suggested. Apart from correction of TOF, this approach includes translocation of the pulmonary artery anterior to the aorta and away from the airways. This technique has a potential to reduce or eliminate bronchial compression by the pulmonary artery. Insertion of valve homograft with anterior and/or posterior plication of the pulmonary artery is considered especially in symptomatic newborns and infants. The intermediate-term functional outcomes have been encouraging, with zero mortality events even in the youngest age group of patients and with the disappearance of respiratory symptoms in the majority of them.