Pulmonary stenosis is one of the most common complications in patients with transposition of the great arteries after the arterial switch operation. The reason for this is multifactorial and related to the anterior shift of the pulmonary trunk during the LeCompte manoeuvre, the complex suture line required to fill the gaps after harvesting the coronary arteries, and the need for patch implantation to maintain a tensionless anastomosis.

We reviewed all patients with transposition of the great arteries operated on at our institute between 1991 and 2020 to establish the frequency of pulmonary stenosis during post-operative follow-up, reinterventions, and reoperations related to pulmonary stenosis and its potential risk factors.

During the analysed period, we performed 848 arterial switch operations for simple and complex cases of transposition of the great arteries. The overall early mortality was 6.96%, and the late mortality was 2.53%. Among all study groups, 243 (28.66%) patients developed mild pulmonary stenosis, 43 patients (5.07%) developed moderate, and 45 patients (5.31%) developed severe pulmonary stenosis. During follow-up, 21 patients required interventions related to pulmonary stenosis. Pulmonary reconstruction with patches, aortic arch anomalies, and ventricular septal defects associated with transposition of the great arteries were significant risk factors. Nine patients required reoperation because of pulmonary artery stenosis with patch reconstruction of the pulmonary artery, aortic arch anomalies, and aortic cross-clamping time, increasing the risk of reoperation.

Pulmonary stenosis in patients with transposition of the great arteries after the arterial switch operation is a common complication. If significant, it occurs early after surgery and is the most frequent reason for post-operative interventions and reoperations.