Hidden pulmonary arteries in tetralogy of Fallot and pulmonary artery pressure in patients operated with a pulmonary artery

Abstract

Introduction The absence of a pulmonary artery is a rare congenital anomaly that occurs isolated or with other congenital cardiac disorders, particularly tetralogy of Fallot (TOF); meanwhile, a hidden pulmonary artery might exist and originate from a closed ductus arteriosus (DA), which can be stented to reach the artery. Material and methods This prospective study describes cardiac catheterization of nine TOF patients diagnosed with the absence of the left pulmonary artery before the operation. The patients were stratified into three groups: group one, whose closed DA was found and connected to the hidden pulmonary artery with a stent; group two, whose hidden pulmonary arteries were found via the pulmonary vein angiography; and group three, for whom we could not find the remnant of the DA, or our attempt to stent the DA to the hidden pulmonary artery was not successful. We also evaluated outcomes of six other surgically-corrected TOF patients who were operated with the absent left pulmonary artery. Results The first group included the patients aged 1, 24, and 30 months, whose CT angiography 6–9 months after stenting showed acceptable left pulmonary artery diameter for surgical correction, and the pulmonary vein angiography of the second group showed a hidden left pulmonary artery with a suitable diameter for surgical correction. However, we were unable to find or stent the DA of group three patients, aged 12, 38, 60, and 63 months. Earlier Angiography might have increased the chance of access to the hidden vessel. Apart from these three groups, follow-ups of six other patients previously corrected with only the right pulmonary artery revealed pulmonary artery hypertension in all patients. Conclusion The concealed pulmonary artery might be found, and stenting of the closed DA to it might be performed to improve the diameter of the diminutive pulmonary artery. This procedure may allow TOF total surgical correction with two pulmonary arteries. Besides, pulmonary vein angiography can reveal the hidden pulmonary artery.

Tetralogy of Fallot With Absent Left Pulmonary Artery in a Patient Who Passed Critical Congenital Heart Disease Screening

“…TOF combines four key features: VSD, pulmonary stenosis, right ventricular hypertrophy, and a dextro-positional aorta causing an override of the ventricular septum by the aortic root. In addition to being an anatomic anomaly, TOF also seems to be a complicated genetic disorder associated with other anomalies such as absent pulmonary valves, absent/hidden pulmonary arteries, and extracardiac anomalies [ 3 ].…”

“…The main pulmonary artery might be small, and various degrees of branch pulmonary artery stenosis may be present. The degree of right ventricular outflow tract (RVOT) obstruction determines the age of presentation, with the most extreme being TOF with pulmonary atresia or critical RVOT obstruction (these would be ductal dependent) to very mild or no RVOT obstruction ("pink" tet) [ 2 , 3 ].…”

“…Unilateral absence of the left pulmonary artery (LPA) is five to eight times more frequent than the right pulmonary artery [ 3 ]. Some patients with the impression of an absent pulmonary artery might have a concealed pulmonary artery (normal size or small) with a closed communication between the ductus arteriosus and pulmonary artery [ 2 , 3 ]. The initial treatment of TOF varies depending on the RVOT obstruction.…”

“…This is provided by the intravenous administration of prostaglandin E1 (PGE1), which relaxes smooth muscles, dilates ductus arteriosus, and provides pulmonary blood flow. Surgical treatment is either palliative (Blalock-Taussig-Thomas shunt) or corrective surgical therapy [ 3 , 4 ].…”