Challenging Repair of Common Arterial Trunk Type III
This video highlights innovative surgical strategies for repairing common arterial trunk (CAT) type III. Patients with CAT are predisposed to an early, irreversible increase in pulmonary vascular resistance. Hence, early surgical correction is crucial for improving prognosis (1).
Surgical treatment consists of separating the aortopulmonary connection, creating a new right ventricular (RV) to pulmonary artery (PA) continuity, and closing the ventricular septum defect (VSD). The most used RV-PA conduits are homografts, xenografts, or synthetic grafts. However, they require multiple re-operations due to degeneration or patient-conduit mismatch.
The Patient
The patient is a two-month-old infant presenting with mild cyanosis, dyspnea during feeding, and repeated chest infections. Transthoracic Echocardiography and MSCT revealed common arterial trunk, left pulmonary artery (LPA) branching from the left lateral aspect of the ascending aorta above the sinotubular junction, right pulmonary artery (RPA) branching from the right lateral aspect of the proximal aortic arch, a right-sided aortic arch, and a subarterial VSD.
This presented numerous challenges to the surgical team including creating a new autologous RV-PA conduit and reconstructing a new pulmonary artery bifurcation without compromising the lumens of the PA branches.
To address the first challenge, the team used the surgical technique described by Professor Yacoub and his surgical team at Aswan heart center (2). This technique uses only native arterial tissues to reconstruct a new right ventricular outflow tract (RVOT).
The second challenge was addressed by extensively mobilizing the PA branches, harvesting both branches with wide arterial cuffs, and translocating the RPA in front of the aorta in an orientation similar to the LeCompte maneuver (3).
The Surgery
First, a median sternotomy was performed, followed by initiation of cardiopulmonary bypass with mild hypothermia (32°C). The truncal artery and the PA branches were extensively mobilized. A C-clamp was applied at the proximal aortic arch to allow for good perfusion of the neck vessels while still permitting transection of the RPA. Cardioplegia was administered after snaring both PA branches.
The truncal artery was then transected above the origin of the LPA. Both PA branches were harvested and the truncal artery was transected distally, resulting in a circular segment of arterial wall that was used to reconstruct the anterior wall of the new RVOT. The truncal root and distal ascending aorta were plicated to reduce their diameters before connecting them.
Next, an anterior right ventriculotomy was created below the truncal valve, sparing important epicardial coronary arteries. As the new RVOT orifice, it should not be wider than the size of the distal PA bifurcation to limit the size of the regurgitant orifice area responsible for the degree of pulmonary regurgitation (PR) (2). The VSD was small, so it was widened before closure to prevent left ventricular outflow tract obstruction.
Reconstruction of a new PA bifurcation was the completed by connecting both PA branches in front of the aorta. The RV-PA continuity was established by connecting the posterior walls of the new PA bifurcation and the new RVOT ostium. Finally, the anterior wall was reconstructed using the autologous arterial segment harvested earlier from the main trunk.
Reference(s)
1. Stark J, Gandhi D, De Leval M, Macartney F, Taylor JFN. Surgical treatment of persistent truncus arteriosus in the first year of life. Heart. 1978;40(11):1280–7.
2. Yacoub MH, Hosny H, Afifi A, Nagy M, Mahgoub A, Simry W, et al. Novel concepts and early results of repairing common arterial trunk. Eur J Cardio-thoracic Surg. 2022;61(3):562–71.
3. Lecompte Y, Zannini L, Hazan E, Jarreau MM, Bex JP, Tu T V, et al. Anatomic correction of transposition of the great arteries. J Thorac Cardiovasc Surg. 1981 Oct;82(4):629–31.