title: Risk factors for neo-aortic root enlargement and aortic regurgitation following arterial switch operation.
abstract: The objectives of this study were to evaluate changes in dimension of the neo-aortic annulus, aortic root, and aortic anastomosis following arterial switch operation (ASO) and to identify risk factors for developing abnormal neo-aortic root enlargement and aortic regurgitation (AR). Prior studies report development of neo-aortic root dilatation and AR in a small subset of patients after ASO. Predisposing factors for neo-aortic root dilatation and development of moderate/severe AR are poorly understood. We performed a retrospective review of all patients with d-transposition of the great arteries (d-TGA) or double-outlet right ventricle with subpulmonary ventricular septal defect (VSD) who underwent ASO from May 1986 to January 2001. Serial echocardiograms were reviewed to measure neo-aortic annulus, root, and anastomosis diameter (z scores) and to determine progression of AR. Potential risk factors were assessed for developing neo-aortic root enlargement and AR. There were 119 patients (44 female and 75 male): 73 patients had simple d-TGA, 36 had d-TGA with ventricular septal defect, and 10 had a Taussig-Bing heart. The median duration of follow-up was 65 months (range, 12-180). The median neo-aortic root (z = 0.55+/-2.2; p < 0.01) and aortic annulus dimensions (z = 1.57+/-1.75; p < 0.01) were significantly increased over the study period. Aortic anastomosis diameter correlated with growth of the ascending aorta (z = 0.55+/-1.24). Development of severe neo-aortic root enlargement was associated with prior pulmonary artery (PA) banding (p < 0.01), the presence of a VSD (p = 0.03), and Taussig-Bing anatomy (p < 0.01) but was independent of coronary arterial anatomy, coronary arterial transfer technique, or associated lesions (p > 0.05). At latest follow-up, there was no or trivial AR in 88 patients, mild AR in 29 patients, and moderate to severe AR in 3 patients. Risk factors for developing mild or worse AR included severe or rapid neo-aortic root dilatation (p < 0.01). Only 3 patients required surgical intervention for AR. Despite the significant prevalence of neo-aortic root enlargement at intermediate follow-up after ASO, there is a low incidence of significant AR. Prior PA banding, the presence of VSD, and Taussig-Bing anatomy are risk factors for severe root enlargement. Surgical intervention for AR was rare (2%), however, serial surveillance of such patients is vital to monitor for neo-aortic root enlargement and potential aortic valve dysfunction.
authors.affiliation: Lillie Frank Abercrombie Division of Pediatric Cardiology, Texas Children's Hospital and Baylor College of Medicine, Houston, TX 77030, USA. cmcmahon@bcm.tmc.edu
authors.forename: C J
authors.initials: CJ
authors.lastname: McMahon
authors.forename: W J
authors.initials: WJ
authors.lastname: Ravekes
authors.forename: E O'Brian
authors.initials: EO
authors.lastname: Smith
authors.forename: S W
authors.initials: SW
authors.lastname: Denfield
authors.forename: R H
authors.initials: RH
authors.lastname: Pignatelli
authors.forename: C A
authors.initials: CA
authors.lastname: Altman
authors.forename: N A
authors.initials: NA
authors.lastname: Ayres
mesh_terms: D000714:Anastomosis, Surgical; D001011:Aorta / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D001022:Aortic Valve Insufficiency / Q000453:epidemiology* / Q000209:etiology*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D003330:Coronary Vessel Anomalies / Q000601:surgery; D004310:Double Outlet Right Ventricle / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006345:Heart Septal Defects, Ventricular / Q000601:surgery; D006801:Humans; D007223:Infant; D007229:Infant Welfare; D007231:Infant, Newborn; D008297:Male; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology*; D011651:Pulmonary Artery / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery; D011664:Pulmonary Valve / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D013781:Texas / Q000453:epidemiology; D014188:Transposition of Great Vessels / Q000601:surgery*; D016896:Treatment Outcome; D014463:Ultrasonography