The Failed Bidirectional Glenn Shunt: Risk Factors for Poor Outcomes and the Role of Early Reoperation.

Background: Bidirectional Glenn shunt (BDG) failure carries high morbidity and mortality but the clinical factors associated with failure and the optimal management strategy are understudied. Methods: A total of 217 patients undergoing BDG at our institution between 1989 and 2020 were retrospectively reviewed and categorized as success or failure. Failure was defined as the need for reoperation (BDG takedown, reoperation for correction of cardiac defect, and/or transplantation) at any time postoperatively; operative mortality (death attributable to BDG malfunction occurring during the index hospitalization for BDG or within 30 days of discharge); or late mortality (death directly attributable to BDG malfunction occurring prior to Fontan or next-stage palliation). Univariate and binary logistic regression analyses were performed. Results: BDG failure occurred in 14 (6.5%) patients. Univariate predictors were: hypoplastic left heart syndrome (P = .037), right ventricular (RV) dominance (P = .010), greater pre-BDG pulmonary vascular resistance (PVR) (P = .012), concomitant atrioventricular valve repair (P = .020), prolonged pleural drainage (P = .001), intensive care unit (P<.001) and hospital (P = .002) stays, and extracorporeal membrane oxygenation (ECMO) requirement (P<.001). Multivariate predictors were: RV dominance (P = .002), greater PVR (P = .041), ICU (P<.001) and hospital (P = .020) stays, and need for ECMO (P<.001). As many as 10 of 14 (71%) patients with BDG failure died. Reoperation was performed for 10 patients with BDG failure. Five reoperation patients survived until discharge, with four patients alive at last follow-up (mean 7.9 years). Survivors underwent reoperation earlier than nonsurvivors (36 vs. 94 days). Conclusions: BDG failure carries high mortality, but preoperative predictors and postoperative indicators of failure exist. Early BDG takedown and insertion of aorta-pulmonary shunt may allow survival.

Extracardiac Fontan Fenestration Device Closure with Amplatzer Vascular Plug II and Septal Occluder: Procedure Results and Medium-Term Follow-Up.

The objective of this study was to determine medium-term morbidity and mortality of patients who have undergone device closure of an extracardiac Fontan fenestration with an Amplatzer Vascular Plug II (AVPII) or Septal Occluder (ASO). A secondary objective was to compare medium-term morbidity and mortality between these patients and other fenestrated Fontan patients. A retrospective chart review was performed on patients who underwent an extracardiac fenestrated Fontan procedure between 1992 and 2015 at Cardinal Glennon Children's Medical Center. Procedural and follow-up data were obtained and compared between those who underwent fenestration closure and those who did not. Additional outcome measures included whether the fenestration had spontaneously closed, morbidity and mortality, oxygen saturations, and hemodynamics pre- and post-closure. Fifty-nine of 118 patients (50%) with a fenestrated Fontan underwent 60 device closures of the fenestration. Thirty-two (53%) of these were with the AVPII and 28 (47%) with the ASO. There was one device embolization. At a median follow-up of 3.9 years, five patients suffered morbidity, including 2 with arrhythmias, 1 with plastic bronchitis, 1 with protein losing enteropathy, and 1 with stroke. There were no cardiopulmonary deaths in this group. Twenty-three of 118 patients (19%) had spontaneous closure. There was no difference in morbidity and mortality between patients who underwent percutaneous fenestration closure and those who either had spontaneous closure or a persistently patent fenestration. Device closure of Fontan fenestrations is a safe and effective procedure with minimal morbidity and mortality comparable to other patients with fenestrations.

Rare occurrence of Tetralogy of Fallot in dizygotic twins conceived via in vitro fertilisation.

An increased incidence of CHD has been noted in twin gestations and in infants conceived using assisted reproductive technologies. However, CHD in these populations remains understudied and the mechanisms underlying these phenomena remain unclear. We present the case of twins conceived via in vitro fertilisation both with Tetralogy of Fallot and additional cardiac and extracardiac malformations.

A novel mutation of the MYH7 gene in a patient with hypertrophic cardiomyopathy.

Goel N, Huddleston CB, Fiore AC. A novel mutation of the MYH7 gene in a patient with hypertrophic cardiomyopathy. Turk J Pediatr 2018; 60: 315-318. Hypertrophic cardiomyopathy (HCM) is a genetic disorder characterized by asymmetric cardiac hypertrophy due to inherited mutations in genes that encode sarcomeric proteins. MYH7, which encodes ß-myosin heavy chain, is among the most commonly mutated genes in patients affected by HCM. We aimed to identify the specific mutation responsible for HCM in a six-month old Caucasian patient. NextGen DNA sequencing revealed a novel p.Ala1328Thr (A1328T) mutation of MYH7 in the affected patient as well as his asymptomatic father and asymptomatic brother. The clinical details of this mutation are described for the first time in this report. The genetic variant affects a residue that is highly conserved across species. Theoretical analysis suggests that A1328T is very likely deleterious to ß-myosin heavy chain protein structure and function. Furthermore, this novel mutation was not observed with any significant frequency in approximately 6,500 healthy individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, underlining the potential pathogenicity of this variant.