Aortopulmonary communication between the arterial trunks in tetralogy of Fallot with pulmonary atresia

Abstract

We reported a case of a 14-year-old tetralogy of Fallot/pulmonary atresia patient, where a rare tubular aortopulmonary communication between the arterial trunks allowed for well-growth of the pulmonary vasculature. The patient underwent successful one-stage unifocalization, right ventricle-pulmonary artery conduit and ventricular septal defect closure. The tubular communication was considered an aortopulmonary window as opposed to the major aortopulmonary collateral, based on its exclusively intrapericardial course. We highlighted the importance of cross-section imaging in diagnosis and surgical decision-making in such situations.

INTRODUCTION

Tetralogy of Fallot/pulmonary atresia (TOF/PA) is considered the most severe form of TOF, characterized by the absence of connection between the right ventricle (RV) and the main pulmonary artery (MPA). Here, we report a TOF/PA patient with an unusually shaped aortopulmonary communication between the arterial trunks.

CASE REPORT

A 14-year-old boy was referred to our centre due to marked limitation in activity and mild cyanosis (saturation 90%). The transthoracic echocardiography showed an enlarged aorta overriding the interventricular septum and a well-developed MPA connecting with the ascending aorta (Fig. 1 and Video 1). Computed tomography angiography and catheterization (Fig. 2A–C and Video 2) revealed the remnant of a separate atretic pulmonary valve, and the MPA supplied by a tubular communication (*) arising from proximal ascending aorta. Four major aortopulmonary collateral arteries (MAPCAs) were identified feeding left upper (#1), left middle (#2), right upper (#3) and right lower (#4) lung. These findings suggested the diagnosis as TOF/PA/MAPCAs, while the nature of the tubular communication was unclear.

Given the well-developed MPA and normal intrapulmonary arborization, the decision-making was one-stage repair through a median sternotomy including unifocalization and RV–pulmonary artery conduit, with the intraoperative pulmonary flow study for the decision of ventricular septal defect closure. The intraoperative exploration showed a large thin-walled tubular communication (*) that arose from the anterior wall of the right coronary aortic sinus, with an anterior course to the distal MPA (Fig. 2D). The pulmonary valve was absent with a muscular pouch. Exposure to MAPCAs was achieved through the subcarinal space superior to the roof of the left atrium. MAPCAs #1, #3 and #4 were extensively dissected from origin to the distal branches to ensure tension-free reconstruction. The tubular communication (*) and dual-blood-supply MAPCA #2 were ligated. MAPCAs #1, #3 and #4 were anastomosed to the pulmonary artery using 8–0 polypropylene sutures (Ethicon, Inc, Somerville, NJ) after removing the proximal stenotic segments. The flow study showed the mean pulmonary artery pressure of 17 mmHg with the flow of 3.0 l/mm²/min, and the ventricular septal defect was therefore closed. The direct needle pressure measurement after surgery showed that the right and left ventricular systolic pressures were 30 and 100 mmHg, respectively. The postoperative recovery was uneventful, and the patient is in good clinical condition currently after 8 months. The follow-up computed tomography angiography showed patent branch pulmonary arteries with unobstructed unifocalized MAPCAs (Supplementary Material, Fig. S1).

DISCUSSION

The goal of management for TOF/PA/MAPCAs is to create a separated biventricular circulation with the lowest possible pulmonary artery pressure. To achieve this goal, one important requirement is to recruit maximal lung segments by surgical integration of MAPCAs in a newly reconstructed pulmonary circulation in the form of unifocalization. Furthermore, MAPCAs are prone to stenosis or occlusion over time leading to lung segment loss if persistently exposed to the systemic circulation [1]. Although technique challenging, we believed that the unifocalization of 3 MAPCAs in this patient was crucially important in the long-term RV health.

In the current case, the pulmonary blood was largely provided by a tubular aortopulmonary communication. The pulmonary blood supply typically arises from the ductus arteriosus and/or MAPCAs in the setting of TOF/PA. The exclusively intrapericardial course of the tubular communication is sufficient to distinguish it from either a persistent ductus arteriosus, or an MAPCA, since both would, of necessity, be extrapericardial [2]. Moreover, the communication was separated from the right coronary artery, excluding any diagnosis of coronary-to-pulmonary collateral artery. We argued that it was a tubular aortopulmonary window (APW), defined as intrapericardial communications between the aortic and the pulmonary trunks. APW can be associated with other cardiac abnormalities including TOF/PA [3]. However, the shape, different from the typically represented window between the arterial trunks, was unusual. The extensive tubular nature of the APW in the current patient can be explained by the persistence of the initially extensive aortopulmonary foramen observed at the beginning of the separation of the cavities of the intrapericardial arterial trunks [4].

The TOF/PA associated with a tubular APW is rare. The current case highlighted the importance of cross-section imaging in diagnosis and surgical decision-making in such situations.

SUPPLEMENTARY MATERIAL

Supplementary material is available at EJCTS online.

Conflict of interest: none declared.

Data availability statement

The data underlying this article will be shared on reasonable request to the corresponding author.

Reviewer information

European Journal of Cardio-Thoracic Surgery thanks Robert H. Anderson and the other, anonymous reviewer(s) for their contribution to the peer review process of this article.

REFERENCES

Author notes