Unbalanced atrioventricular septal defect with parachute valve

Restriction of Atrial Septal Defect Leads to Growth of Hypoplastic Ventricle in Patients with Borderline Right or Left Heart

Patients with borderline hypoplastic right or left ventricle and VSD may be candidates for either single ventricle palliation or staged ventricular recruitment (SVR) followed by eventual biventricular conversion. Components of SVR include restriction of atrial septal defects (ASD) without ventricular septal defects (VSD) closure and addition of accessory pulmonary blood flow. This study evaluated the impact of ASD restriction on ventricular growth and function. We retrospectively reviewed patients with borderline ventricular hypoplasia and VSD who underwent a staged ventricular recruitment (SVR) procedure from 2012 to June 2019. Pre- and post-recruitment MRI and echocardiogram data were compared and analyzed. We excluded cases in which we intentionally restricted VSD with simultaneous ASD restriction. Forty-six patients (41 with right-dominant ventricle, 25 with risk factors for Fontan procedure) underwent SVR at a median age of 15.1 months' (interquartile range (IQR), 7.2-37.2 months'). The median indexed ventricular end-diastolic volume, end-systolic volume, and stroke volume according to cardiac MRI significantly increased at median 11.0 months' (IQR:7.8~14.1 months') after recruitment. Among them, except 2 operative mortalities after SVR, 26 patients underwent bi-ventricular repair (56.5% including one and a half ventricle repair) at a median of 8.0 months' (IQR: 6.2-12.2 months') after recruitment. Fifteen patients await biventricular completion, and 3 patients underwent single ventricle palliation. Pulmonary blood flow (Qp) tended to increase after recruitment regardless of type of pulmonary blood flow modification without statistical significance. Six patients died at a median duration of 6.5 months' (IQR: 2.9-11.7) after SVR; 3 patients died after biventricular completion, 2 after recruitment, and 1 after returning to single ventricle palliation. All of them were considered poor Fontan candidates due to severe atrioventricular valve regurgitation, pulmonary hypertension, pulmonary vein stenosis, or airway stenosis. Restriction of the atrial septum leads to the growth of hypoplastic ventricle in patients with ventricular septal defects who undergo SVR regardless of the preoperative characteristics, and eventual biventricular repair can be performed in a subgroup of these patients. Future work is necessary to optimize timing of SVR and method of accessory pulmonary blood flow.

Parachute mitral valve: Morphology and surgical management

Background

This review aims to discuss morphology and surgical management of parachute mitral valve.

Methods

A total of 62 articles in the English language with 330 parachute mitral valve patients were retrieved from the PubMed, HighWire Press, and Cochrane Library databases using specific MeSH terms and keywords between January 2000 and December 2018. In these articles, morphology of parachute mitral valve and surgical treatment options were investigated.

Results

A non-syndromic parachute mitral valve was present in 287 patients (87.0%) and a syndromic parachute mitral valve was present in 43 patients (13.0%). A higher number of patients with a non-syndromic parachute mitral valve presented with congestive heart failure compared to syndromic ones. The patients with a non-syndromic parachute mitral valve often had mitral regurgitation, while syndromic parachute mitral valve patients often had mitral stenosis.

Conclusion

Parachute mitral valves are usually not an isolated lesion and are often characterized by a constellation of pathological changes of the mitral valve leaflets, annulus, commissures, subvalvular apparatus, and supravalvular mitral ring. Therefore, the majority of the patients need one or more surgical operations. The incidence of adverse events such as reintervention, postoperative complete heart block, and mortality is high in these patients.

Unbalanced atrioventricular septal defect: definition and decision making

Unbalanced atrioventricular septal defect is an uncommon lesion with widely varying anatomic manifestations. When unbalance is severe, diagnosis and treatment is straightforward, directed toward single-ventricle palliation. Milder forms, however, pose a challenge to current diagnostic and therapeutic approaches. The transition from anatomies that are capable of sustaining biventricular physiology to those that cannot is obscure, resulting in uneven application of surgical strategy and excess mortality. Imprecise assessments of ventricular competence have dominated clinical decision making in this regard. Malalignment of the atrioventricular junction and its attendant derangement of inflow physiology is a critical factor in determining the feasibility of biventricular repair in the setting of unbalanced atrioventricular septal defect. The atrioventricular valve index accurately identifies unbalanced atrioventricular septal defect and also brings into focus a zone of transition from anatomies that can support a biventricular end state and those that cannot.

Outcomes for patients with unbalanced atrioventricular septal defects

Infants with an unbalanced atrioventricular septal defect (AVSD) frequently present with comorbidities that may have an impact on their medical course and outcome. This study aimed to assess outcomes and explore possible prognostic indicators for patients undergoing surgical palliation for an unbalanced AVSD. The medical records of all infants presenting to the authors' institution with an unbalanced AVSD over a 5-year period were retrospectively reviewed for assessment of outcomes and comorbidities. The study group consisted of 44 patients with an overall survival rate of 51% for the entire follow-up period. The majority of these patients (88%) underwent single-ventricle palliation, with an 83% rate of survival to initial hospital discharge and an overall long-term survival rate of 50%. The midterm outcome was significantly worse than that for a cohort of hypoplastic left heart syndrome patients undergoing single-ventricle palliation during the same period (P = 0.03). In addition, 30% of the patients required either repair or replacement of their systemic atrioventricular valve at initial palliation or during subsequent follow-up evaluation. Of the patients with an unbalanced AVSD, 75% had associated congenital anomalies. In conclusion, infants with an unbalanced AVSD are a high-risk population with diminished midterm survival compared with palliated patients who have more classic forms of hypoplastic heart syndromes. This may be due to the higher incidence of both severe atrioventricular valve regurgitation and important associated congenital anomalies.

Predictive Value of Intraoperative Transesophageal Echocardiography in Complete Atrioventricular Septal Defect

BACKGROUND

Intraoperative transesophageal echocardiography and follow-up transthoracic echocardiography have been useful in assessing cardiac function in complete atrioventricular septal defects. However, it has been suggested that a discrepancy exists between intraoperative and postoperative findings, and that intraoperative findings cannot reliably predict long-term results. This study aims to determine whether this discrepancy exists and to assess whether it is possible to predict follow-up results using intraoperative transesophageal echocardiography.

METHODS

A retrospective analysis was made in 35 patients who underwent biventricular repair by one surgeon between November 1997 and January 2004. All patients received intraoperative transesophageal echocardiography and follow-up transthoracic echocardiography at 19.1 +/- 18.02 months (range, 7 days to 5 years; median, 15.1 months).

RESULTS

In left-sided atrioventricular valve regurgitation, 34.3% (12 of 35) of patients showed discrepancy during follow-up, and 28.6% (10 of 35) showed progression of regurgitation (from grade I to II). In right-sided atrioventricular valve, 11.4% (4 of 35) of patients showed discrepancy, 9.6% (3 of 35) showed progression of regurgitation (from grade I to II).

CONCLUSIONS

In complete atrioventricular septal defects, intraoperative transesophageal echocardiography did not show the same findings as that of follow-up transthoracic echocardiography in some cases. However, this discrepancy is not so great as to require reoperation in early to midterm follow-up. Therefore, intraoperative transesophageal echocardiography may be used as tool to predict durability of surgical results and to decrease the incidence of reoperation in complete atrioventricular septal defects.