Risk factors for mortality in patients with pulmonary atresia undergoing modified Blalock–Taussig shunt

Background
Pulmonary atresia (PA) is one of the most difficult pathologies to manage, and the surgical procedures related are associated with high mortality and morbidity. A single approach is impractical because of the wide spectrum of right morphology which makes a uniform surgical approach impossible. Anatomical criteria, such as the degree of tricuspid valve or right ventricular hypoplasia or whether a right ventricular infundibulum is present, have been used to assign the infants to single-ventricular or biventricular repair tracks. Palliative procedure to provide a more stable source of pulmonary blood flow is often required before undergoing a more definitive palliation or repair. Despite its widespread use, modified Blalock–Taussig shunt (MBTS) has been associated with high morbidity and mortality.
Aims
The aim of the study was to specify the risk factors for mortality in patients with PA undergoing MBTS operation.
Patients and methods
A prospective nonrandomized study was conducted on 32 patients with PA who underwent MBTS operation between August 2019 and January 2022. Data including demographic data, preoperative status, and morphological factors were correlated to the outcome. Surgery was performed through a posterolateral thoracotomy or sternotomy according to surgeon preference. Nonstretchable ringed Gore-Tex grafts were used to create MBTS between the subclavian artery or innominate artery and the right or left pulmonary artery. Hospital mortality and related risk factors were studied.
Results
The mean age at operation was 13.32 ± 8.36 months. The study involved 17 (53.1%) males and 15 (46.9%) females. Mean weight was 6.86 ± 2.71 kg. Posterolateral thoracotomy was done in 19 (59.4%) patients. Patent ductus arteriosus (PDA) was ligated on 12 (37.5%) patients. The mean total hospital stay was 11 ± 5.94 days. Hospital mortality was seven (21.9%) patients. Isolated risk factor for hospital mortality showed that weight at the time of operation was a statistically significant risk factor (=0.02). Complications were statistically significant in relation to mortality in patients who had reoperations of the MBTS and low cardiac output.
Conclusions
MBTS for patients with PA had a high mortality especially in smaller weights. PDA stenting should be studied as an alternative option in selected cases.