Revisitation of Double-Inlet Left Ventricle or Tricuspid Atresia With Transposed Great Arteries

Association of Bulboventricular Foramen Size and Need for Early Intervention in Infants with Tricuspid Atresia or Double-Inlet Left Ventricle with Normally Related Great Arteries

BACKGROUND

The association of bulboventricular foramen (BVF) size and systemic outflow adequacy has been studied in patients with tricuspid atresia (TA) or double-inlet left ventricle (DILV) with transposed great arteries. The aim of this study was to determine the relationship between initial BVF size and risk for progressive pulmonary outflow obstruction requiring intervention to increase pulmonary blood flow in patients with TA or DILV with normally related great arteries.

METHODS

Patients with TA or DILV with normally related great arteries were identified by retrospective chart review at a single center from 2005 to 2021. Patients were stratified by indexed BVF area (iBVFA) to determine the relationship of iBVFA size and the need for intervention before the Glenn operation to establish supplemental pulmonary blood flow with either a Blalock-Taussig-Thomas shunt (BTTS) or patent ductus arteriosus (PDA) stent. Patients were followed through the time of their Glenn operations. Logistic regression analysis was performed to determine optimal iBVFA cut points.

RESULTS

Thirty-seven patients with TA or DILV with normally related great arteries were included. Sixteen had iBVFA < 1 cm²/m², with all 16 (100%) requiring either a BTTS or PDA stent to increase pulmonary blood flow before the Glenn operation. Seventeen had iBVFAs of 1 to 2 cm²/m², with 10 (59%) requiring either a BTTS or PDA stent. Nine of those 10 demonstrated flow acceleration across the BVF and/or pulmonary outflow tract. Four had iBVFA > 2 cm²/m², with only one patient (25%) requiring a BTTS. Among our cohort, an iBVFA of <1.8 cm²/m² provided sensitivity of 96% with good positive and negative predictive values (81% and 80%, respectively) for requiring intervention with a BTTS or PDA stent before the Glenn operation.

CONCLUSIONS

An iBVFA of ≤1.8 cm²/m² on initial postnatal echocardiography is associated with the development of subpulmonary obstruction requiring intervention with a BTTS or PDA stent before the Glenn operation, with the highest risk noted in those with iBVFA of ≤1 cm²/m². Factors such as BVF flow acceleration or pulmonary outflow tract narrowing should also be considered in the decision to augment pulmonary blood flow.

Delving into the Molecular World of Single Ventricle Congenital Heart Disease

PURPOSE OF REVIEW

Given a general lack of emphasis on the molecular underpinnings of single ventricle (SV) congenital heart diseases (CHD), our review highlights and summarizes recent advances in uncovering the genetic and molecular mechanisms in SV CHD etiology.

RECENT FINDINGS

While common SV-associated genetic mutations were found in key cardiac transcription factors, other mutations were sporadic. With advances in genetic sequencing technologies and animal models, more disease-associated factors have been identified to act in critical cardiac signaling pathways such as NOTCH, Wnt, and TGF signaling. Recent studies have also revealed that different cardiac lineages play different roles in disease pathogenesis. SV defects are attributed to complex combinations of genetic mutations, indicating that sophisticated spatiotemporal regulation of gene transcription networks and functional cellular pathways govern disease progression. Future studies will warrant in-depth investigations into better understanding how different genetic factors converge to influence common downstream cellular pathways, resulting in SV abnormalities.

The choice of palliative arterial switch operation as an alternative for selected cases in a single center: Experience and mid term results

INTRODUCTION AND OBJECTIVE

There are various management options for newborns with single ventricle physiology, ventriculoarterial discordance and subaortic stenosis, classically involving the early pulmonary banding and aortic arch repair, the restricted bulboventriculer foramen enlargement or the Norwood and the Damus-Kaye-Stansel procedures. The aim of this study is to evaluate our preferred technique and comment on the midterm results of our clinical experience with palliative arterial switch operation (pASO) for a certain subset of patients.

METHOD

We hereby retrospectively evaluate the charts of patients who went through pASO, as initial palliation through Fontan pathway, starting from 2014 till today.

RESULTS

Ten patients underwent an initial palliative arterial switch procedure. Eight of 10 patients survived the operation and discharged. Seven of 10 patients completed Stage II and 1 patient reached the Fontan completion stage and the other six of ten (6/10) patients are doing well and waiting for the next stage of palliation. There are two mortalities in the series (2/10) and one patient lost to follow-up (1/10).

CONCLUSION

In our opinion, the pASO can be considered as an alternative palliation option for patients with single ventricle physiology, transposition of the great arteries and systemic outflow tract obstruction despite longer cross clamp times compared to other methods, but It not only preserves systolic and diastolic ventricular function, but also provides a superior anatomic arrangement for following stages.

Modified Damus-Kaye-Stansel Connection for Systemic Outflow Tract Obstruction After Fontan Operation

Late systemic outflow tract obstruction following completion of the Fontan palliation is rarely seen and is a difficult problem to treat. Absence of the main pulmonary trunk and pulmonary valve at this stage makes a conventional Damus-Kaye-Stansel connection difficult to achieve. We report the case of a 37-year-old female who underwent Fontan completion as an adult and subsequently presented with systemic outflow tract obstruction. A valved conduit was interposed between the native pulmonary annulus and the ascending aorta to create a modified Damus-Kaye-Stansel type connection.