Neoaortic Valve Function 10 to 18 Years After Arterial Switch Operation

Abstract

Anatomical correction is a procedure of choice for transposition of the great arteries (TGA) in neonates. During surgery, the aorta and pulmonary artery are switched-the native pulmonary valve becomes the neoaortic valve. The fate of this valve remains uncertain. Many reports suggest that its ability to function worsens with time after surgery. Of 519 patients with TGA operated on between 1991 and 2008, 161 met inclusion criteria for this retrospective study and were followed 10 years or more to assess neoaortic valve regurgitation (NeoAR) occurrence and development and to estimate potential risk factors. The subjects were divided into 2 groups: group 1 (simple TGA) and group 2 (TGA + ventricle septal defect). Within the analyzed group, the frequency of significant regurgitation increased from 9% 1 year after the operation to 47% at the most recent follow-up. No severe regurgitation necessitating reoperation was observed. Analysis of potential risk factors revealed that pulmonary/aortic valve diameter discrepancy and nonfacing commissures were associated with increased risk of development of neoaortic insufficiency. NeoAR arises and develops over time after correction of the defect. No hemodynamic repercussions necessitating cardiac surgical interventions were observed. The majority of insufficiencies are detected between 2 and 6 years after surgery. The degree of incompetence is usually mild and increases during follow-up by about 0.5 or 1 degree. The risk factors for NeoAR appearance are pulmonary artery/aortic annulus discrepancy and nonfacing commissures.

Neoaortic Regurgitation Detected by Echocardiography After Arterial Switch Operation

“…Our initial search yielded 344 unique citations ( Supplemental Table 1 ); among these, 30 fulfilled our eligibility criteria ( Figure 1 ). 4 , 5 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 Characteristics of each study and their participants are shown in Table 1 . The 30 included studies comprised a total of 6,169 patients and were conducted in 13 different countries across 3 continents.…”

Is slim better than paunchy?

“…Hypotheses have been made about histomorphological differences between the great vessels in TGA, the position of the pulmonary valve in the systemic circulation, surgical injury to the vasa vasorum and ischemic lesions to the arterial wall and geometrical factors of arterial root anastomosis and leaflet coaptation, as well as primary root dilatation followed by somatic growth. [6][7][8][9][10][11] In our experience in the mid-and long-term follow-up, a common finding in patients who developed moderate to important neoaortic root dilatation and neoaortic valve regurgitation was the presence of APM observed during ASO, especially in patients with complex variants of TGA. We believe that APM plays an important role in the mechanism of neoaortic root dilatation and valve regurgitation by altering the geometry of the great vessel root and affecting fluid dynamics in this structure, leading to changes in the wall shear stress, promoting vascular remodeling and susceptibility to dilatation.…”

“…Nevertheless pathophysiological mechanisms for neoaortic root dilatation and development of moderate‐to‐severe neoaortic valve regurgitation are probably multifactorial and not completely elucidated. Hypotheses have been made about histomorphological differences between the great vessels in TGA, the position of the pulmonary valve in the systemic circulation, surgical injury to the vasa vasorum and ischemic lesions to the arterial wall and geometrical factors of arterial root anastomosis and leaflet coaptation, as well as primary root dilatation followed by somatic growth 6–11 …”

Fate of Neoaortic Valve in Patients undergoing Arterial Switch Operation for Transposition of Great Arteries

“…Michalak, et al followed 519 for 10 years and observed that the frequency of significant regurgitation increased from 9% 1 year after the operation to 47% at the most recent follow-up [23]. No severe regurgitation necessitating reoperation was observed.…”