Truncus repair with a valveless conduit in neonates

Conduits for Right Ventricular Outflow Tract Reconstruction in Infants and Young Children

Purpose of Review: Right ventricular outflow tract (RVOT) reconstruction remains a challenge due to the lack of an ideal conduit. Data and experience are accumulating with each passing day. Therefore, it is necessary to review this topic from time to time. This is a 2021 update review focused on the history, evolution, and current situation of small-sized conduits (≤ 16 mm) for RVOT reconstruction in infants and young children.

Recent Findings: Currently, the available small-sized (≤16 mm) conduits can meet most clinical needs. Homograft is still a reliable choice for infants and young children validated by a half-century clinical experience. As an alternative material, bovine jugular vein conduit (BJVC) has at least comparable durability with that of homograft. The performance of expanded polytetrafluoroethylene (ePTFE) is amazing in RVOT position according to limited published data. The past century has witnessed much progress in the materials for RVOT reconstruction. However, lack of growth potential is the dilemma for small-sized conduits. Tissue-engineering based on cell-free scaffolds is the most promising technology to obtain the ideal conduit.

Summary: No conduit has proved to have lifelong durability in RVOT position. We are far from the ideal, but we are not in a state of emergency. In-depth clinical research as well as innovation in material science are needed to help improve the durability of the conduits used in infants and young children.

Clarifying the anatomy of common arterial trunk: a clinical study of 70 patients

Aims

Anatomic variations in hearts with common arterial trunk are well-known, although there is no large study of living patients. Detailed knowledge of the origins of the pulmonary and coronary arteries is vital for surgical management. We sought to clarify the variations using computed tomography.

Methods and results

We prospectively studied 70 consecutive patients using echocardiography and computed tomography. In 63 (90%) patients, there was aortic dominance, while 7 (10%) had dominance of the pulmonary component. In 27 (43%) patients with aortic dominance, part of the pulmonary segment arose from a truncal valvar sinus. A long confluent pulmonary channel was more common in patients with sinusal origin compared to those with non-sinusal origin of the pulmonary segment (19 vs. 0; P = 0.0005). Close proximity between the orifices of the coronary arteries and the pulmonary component was also more frequent with sinusal origin (21 vs. 6; P < 0.001) with 5 (19%) patients having pulmonary flow obstructed by a truncal valvar leaflet.

Conclusion

Sinusal origin of the pulmonary component is common with aortic dominance, frequently in association with a long confluent pulmonary segment, which may be in close proximity to the origin of a coronary artery. One-fifth of patients with sinusal origin of pulmonary component have a truncal valvar leaflet obstructing the pulmonary orifice. These morpho-anatomic findings have important implications for management.

Surgery for truncus arteriosus

Truncus arteriosus (TA) is a congenital heart defect in which a common arterial trunk supplies systemic, pulmonary and coronary circulation. Associated cardiac anomalies are common. Without surgical treatment, most patients die within infancy. Various operative techniques have evolved over the past 50 years. More recently, many centres have adopted primary repair in the neonatal period or early infancy. The objective of this paper is to describe anatomy, diagnosis, natural history and the technique of operation of TA.

Surgery for common arterial trunk

Surgery for common arterial trunk has evolved over the past 30 years. Current management involves total repair during the neonatal period with excellent expected results. The presence of truncal valve insufficiency or interrupted aortic arch may increase the surgical risk for morbidity and mortality. Current therapy and management continues to evolve.

Mid-term results after correction of type I and type II persistent truncus arteriosus in older patients

OBJECTIVE

This study aims to analyze long-term results after correction of type I and type II truncus arteriosus in older patients operated in one institution over five years.

METHODS

Between 2006 and 2010, 12 patients, median age 4 years, underwent repair of truncus arteriosus. Repair with reconstruction of the right ventricular to pulmonary artery continuity was performed using a valved conduit in 12 patients.

RESULTS

There was no early mortality. All patients are alive with their original conduit 0.6 to 5 years after correction. No patients required reoperations for conduit dysfunction. Recent clinical examination was undertaken in all patients and they are in good condition.

CONCLUSIONS

Though mean age at operation was higher in this study than published results, the operation should be performed if the pulmonary vascular resistance is under 8 units.m(2) before operation.

Long-term clinical and hemodynamic evaluation of porcine valved conduits implanted from the right ventricle to the pulmonary artery

OBJECTIVE

This retrospective study was initiated to evaluate the long-term results of valved prosthetic conduits implanted in the right ventricular outflow tract in patients with complex ventricular-pulmonary discontinuity.

METHODS

A cohort of 103 patients out of 127 (24 early deaths, 19%) operated on between 1973 and 1996 with porcine valved conduits was available for evaluation, with a follow-up ranging from 1 to 21.6 years (mean follow-up 8.4 +/- 6 years). A total of 74 hemodynamic studies were performed after the operation, 50 patients having undergone at least 1 cardiac catheterization during the follow-up period.

RESULTS

There were 16 late deaths, and the actuarial survivals, including early mortality, were 72.9% +/- 4% at 5 years, 63.1% +/- 5% at 10 years, and 58.2% +/- 5% at 15 years, at which time 20 patients were still available for review and exposed to the risk of dying. The mean peak systolic gradient across the right ventricular outflow tract was plotted as a function of time, showing a gradual increase and a significant step-up after the eighth year, from 43 +/- 36 to 69 +/- 19 mm Hg (P < .005). Reoperation was required for progressive conduit obstruction between 1.1 and 17.7 years after implantation (mean 7.4 +/- 4.8 years) in 25 patients (24%, 70% CL 15%-33%), with generally very few symptoms, or for residual ventricular septal defect in 3 patients. Freedom from reoperation was 79.5% +/- 5% at 10 years and 65.8% +/- 7% at 15 years.

CONCLUSIONS

Porcine conduits may represent a valuable alternative to biologic substitutes with similar long-term results. Given the few symptoms, progressive conduit stenosis after the eighth postoperative year imposes a yearly noninvasive patient evaluation during the follow-up.