A rare spatial relation of the great arteries in patients with transposition of the great arteries: Posterior aorta and its effect on outcomes.

Background: This study aimed to evaluate patients diagnosed with posterior transposition of the great arteries (TGA) in detail.

Methods: This retrospective study included 192 patients (155 males, 37 females; mean age: 0.4±0.9 month; range, 0.1 to 6 month) with TGA who were followed between August 1, 2016, and August 1, 2022. Patients with ventriculoarterial discordance, normal vessel relationship, and mitral-aortic continuity were considered posterior TGA. Demographic features, clinical findings, echocardiographic data, and surgical results of each patient were recorded.

Results: Posterior TGA was present in 11 (5.7%) of the patients. The median age of patients with posterior TGA at the time of surgery was two months (interquartile range [IQR], 1-3 months), and their median body weight was 6.2 kg (IQR, 5-7.2 kg). The median oxygen saturation of the patients was 85% (IQR, 80-90%). A ventricular septal defect was present in all patients on echocardiography. There was also nonrestrictive atrial septal defect and patent ductus arteriosus in four patients, and one patient had arcus aorta hypoplasia. A coronary anomaly was determined in eight of the patients during surgery. These were 1LRCA2Cx in three cases, 1LRCx in three cases, 1R2LCx in one case, and 1L2RCx in one case. Arterial switch operation and ventricular septal defect closure was performed in 10 patients initially and in one patient after a pulmonary banding operation. The median cardiopulmonary bypass time was 190 min (IQR, 170-210 min). The Lecompte maneuver was not performed in any of the patients. The median stay in the intensive care unit and the hospital was 7 days (IQR, 5-10 days) and 16 days (IQR, 14-18 days), respectively. Two patients died in the early postoperative period.

Conclusion: In patients with suspected congenital heart disease, a segmental echocardiographic evaluation should be performed, and it should be kept in mind that the aorta may be located posteriorly as a rare spatial relationship in patients with TGA.