Management of Late Complications After the Arterial Switch Procedure

Objective 

The arterial switch operation has now largely replaced the atrial switch procedures developed by Mustard and Senning in the management of d-transposition of the great arteries (D-TGA) (1, 2). Currently, most patients who undergo the arterial switch operation survive into adulthood, with a 20-year survival rate of nearly 90 percent (3). However, pathologies of the neoaortic root requiring surgical intervention following the arterial switch operation are being increasingly recognized. Complications include neoaortic valve regurgitation and neoaortic root dilation, particularly if there is a size discrepancy between the great arteries (4). Freedom from severe regurgitation (Grade IV, III, and II) at 23 years post-surgery was 90.2 percent plus or minus 6.6 percent, 70.9 percent plus or minus 9.6 percent, and 20.3 percent plus or minus 5.5 percent, respectively (3). 

Procedure 

In this video, the authors present a case of an unusual late complication involving narrowing of the ascending aorta in addition to neoaortic root dilation and detail the surgical management. A 17-year-old boy with a history of prosthetic aortic valve stenosis and ascending aorta narrowing, as well as dilation of the aortic root, presented with dyspnea on exertion. He had undergone arterial switch surgery with a LeCompte maneuver at one week of age for D-TGA. At 15 years old, he required aortic valve replacement with a tissue valve due to neoaortic valve regurgitation, which included placing a 14 mm ringed graft from the pulmonary confluence to the right pulmonary artery and reconstructing the ascending aorta using bovine pericardium. Subsequently, he developed narrowing of the ascending aorta, leading to an increased gradient across the affected segment. This was initially managed with stenting of the ascending aorta. However, over the next two years, the gradient progressed, and the tissue valve degenerated, causing prosthetic valve stenosis. 

During surgery, the authors replaced the aortic root and ascending aorta with a mechanical valve conduit and performed a hemiarch replacement under circulatory arrest with retrograde cerebral perfusion. Additionally, the pulmonary artery was reconstructed using a 16 mm ringed ePTFE graft, optimized to lie anterior to the aorta in a T configuration. The postoperative period was challenging, as the patient exhibited signs of acute respiratory distress syndrome and vasoplegia. He was extubated on postoperative day four and was eventually discharged with good valve and heart function on postoperative day eight. A postoperative CT scan confirmed a patent pulmonary artery and successful hemiarch reconstruction. At the one-year follow-up, the patient was doing well, classified as NYHA Class II, with an NT-proBNP level of 98 pg/mL. He continues to attend regular follow-ups every six months. 

For this case, the decision to proceed with a tissue valve was made following thorough discussions with the patient and his family. The primary factor influencing this choice was the patient's unwillingness to pursue long-term anticoagulation at that time. 

Neoaortic root pathology post-arterial switch surgery with LeCompte maneuver requiring surgical intervention is a challenging surgery wherein meticulous dissection and realization of relevant anatomy is of paramount importance. Reconstruction of pulmonary arteries merit special attention and care to avoid supravalvular pulmonary stenosis or narrowing of the ascending aorta. Additionally, progressive root degeneration post-arterial switch surgery may be observed during follow-up, highlighting the potential need for future root replacement, which could ultimately become the only option. 

References

1. MUSTARD WT. SUCCESSFUL TWO-STAGE CORRECTION OF TRANSPOSITION OF THE GREAT VESSELS. Surgery. 1964 Mar;55:469-72.
2. SENNING A. Surgical correction of transposition of the great vessels. Surgery. 1959 Jun;45(6):966-80.
3. Villafañe J, Lantin-Hermoso MR, Bhatt AB, Tweddell JS, Geva T, Nathan M et al. American College of Cardiology’s Adult Congenital and Pediatric Cardiology Council. D-transposition of the great arteries: the current era of the arterial switch operation. J Am Coll Cardiol. 2014 Aug 5;64(5):498-511.
4. Lim HG, Kim WH, Lee JR, Kim YJ. Long-term results of the arterial switch operation for ventriculo-arterial discordance. Eur J Cardiothorac Surg. 2013 Feb;43(2):325-34.

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