What surgical improvements are needed to prove that anatomic repair is superior to physiologic repair in the majority of patients with corrected transposition of the great arteries?

Contemporary outcomes of the double switch operation for congenitally corrected transposition of the great arteries

OBJECTIVE

To determine the contemporary outcomes of the double switch operation (DSO) (ie, Mustard or Senning + arterial switch).

METHODS

A single-institution, retrospective review of all patients with congenitally corrected transposition of the great arteries undergoing a DSO.

RESULTS

Between 1999 and 2019, 103 patients underwent DSO with a Mustard (n = 93) or Senning (n = 10) procedure. Segmental anatomy was (S, L, L) in 93 patients and (I, D, D) in 6 patients. Eight patients had heterotaxy and 71 patients had a ventricular septal defect. Median age was 2.1 years (range, 1.8 months-40 years), including 34 patients younger than age 1 year (33%). Median weight was 10.9 kg (range, 3.4-64 kg). Sixty-one patients had prior pulmonary artery bands for a median of 1.1 years (range, 14 days-12.9 years; interquartile range, 0.7-3.1 years). Median intensive care unit and hospital lengths of stay were 5 and 10 days, respectively. Median follow-up was 3.4 years (interquartile range, 1-9.8 years) and 5.2 years (interquartile range, 2.3-10.7 years) in 79 patients with >1 year follow-up. At latest follow-up, aortic, mitral, tricuspid valve regurgitation, and left ventricle dysfunction was less than moderate in 96%, 98%, 96%, and 93%, respectively. Seventeen patients underwent reoperation: neoaortic valve intervention (n = 10), baffle revision (n = 5), and ventricular septal defect closure (n = 4). At latest follow-up, 17 patients (17%) had a pacemaker and 27 (26%) had cardiac resynchronization therapy devices. There were 2 deaths and 2 transplants. Transplant-free survival was 94.6% at 5 years. Risk factors for death or transplant included longer cardiopulmonary bypass time and older age at DSO.

CONCLUSIONS

The outcomes of the DSO are promising. Earlier age at operation might favor better outcomes. Progressive neoaortic regurgitation and reinterventions on the neo-aortic valve are anticipated problems.

The Epidemiology of Persons Living with Fontan in 2020 and Projections for 2030: Development of an Epidemiology Model Providing Multinational Estimates

Introduction

Fontan surgery is a palliative procedure performed in children with a functionally univentricular heart. Improvements in surgical technique over the past 30 years have increased life expectancy in this rare population. However, the epidemiology of persons living with Fontan is poorly understood. This study aimed to estimate the 2020 and 2030 prevalence of persons living with a Fontan circulation in 11 countries across the US, Europe, Australia and New Zealand, by procedure type: [atriopulmonary connection (AP), lateral tunnel total cavopulmonary connection (LT-TCPC) or extracardiac total cavopulmonary connection (EC-TCPC)]; and age group: [children (< 12 years), adolescents (12–17 years), and adults (≥ 18 years old)] by building an epidemiologic model.

Methods

The annual number of Fontan surgeries by country in 2010–2020 were extracted from hospital or claims databases, via procedure codes. The epidemiology of persons living with Fontan was modelled by applying these surgery frequencies to mid-year populations from 1972 to 2020 and overlaying an uptake curve. A literature search identified: 30-day mortality rates, long-term survival, and median age at surgery. Averages of these estimates were inputted into the model to project prevalence in 2030.

Results

The number of persons living with Fontan in 2020 across the 11 countries was estimated to be 47,881 [66 people per million (ppm)], rising to 59,777 (79 ppm) by 2030. In 2020, this population was 55% adults, 17% adolescents and 28% children shifting to 64%, 13% and 23%, respectively, in 2030. Among all persons living with Fontan, 74%/18%/9% are estimated to have EC-TCPC/LT-TCPC/AP, respectively, in 2020, and 83%/14%/4% in 2030.

Conclusions

According to this epidemiology model, the Fontan population is growing, partly driven by increased survival rates with the more recent LT-TCPC and EC-TCPC procedures (compared with AP). The 2020/2030 prevalence of persons living with Fontan is 66/79 ppm.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-02002-3.

Anatomic Repair of Corrected Transposition of the Great Arteries: The Double Switch

The long-term outcome of patients with corrected transposition of the great arteries and associated lesions after physiologic repair is uncertain. Anatomic correction, utilizing the morphologic left ventricle as a systemic pumping chamber and the mitral valve as the systemic atrioventricular valve, is considered the preferred method, especially for patients with either tricuspid valve regurgitation, with Ebstein's malformation of the tricuspid valve, or with right ventricular dysfunction. The double switch employs both an atrial switch and arterial switch to "correct" the atrioventricular and ventriculoarterial discordance. Associated lesions are also repaired. The best outcomes with double switch are achieved with patients in the first few years of life even if reconditioning of morphologic left ventricle is required. However, the long-term function of the conduction system, the aortic valve, and the ventricles is variable and requires close surveillance.

Congenitally Corrected Transposition of the Great Arteries: Anatomic, Physiologic Repair, and Palliation

Congenitally corrected transposition of the great arteries (ccTGA) is a lesion that rarely occurs in isolation. The presenting physiology of ccTGA is predominantly secondary to the concurrent cardiac lesions; however, as the child ages, unrepaired ccTGA results in progressive failure of the morphologic right ventricle under the strain of maintaining a systemic pressure. Repair of ccTGA was initially focused on rectification of the underlying physiologic aberrations, but in recent years, the focus of repair has shifted toward anatomic correction to avoid failure of the morphologic right ventricle. This anatomic repair is commonly associated with improved long-term mortality at the cost of increased short-term mortality. Key preoperative considerations such as morphologic left ventricular pressure, tricuspid valve competency, and out flow tract obstructions can assist in determining the optimal repair for individual patients. An alternative, single ventricle, pathway has been proposed for any patient without optimal preoperative anatomy to improve long-term survival. Adjunctive repair options including pulmonary artery banding and one-and-a-half ventricle repairs have also been proposed to augment the survival curves.