ORIGINAL ARTICLES: CONGENITAL HEART SURGERY CONGENITAL HEART SURGERY: The Annals of Thoracic Surgery CME Program is located online at http://cme.ctsnetjournals.org. To take the CME activity related to this article, you must have either an STS member or an individual non-member subscription to the journal. CONGENITAL HEART Long-Term Outcomes of the Neoaorta After Arterial Switch Operation for Transposition of the Great Arteries Jennifer G. Co-Vu, MD,* Salil Ginde, MD,* Peter J. Bartz, MD, Peter C. Frommelt, MD, James S. Tweddell, MD, and Michael G. Earing, MD Department of Pediatrics, Division of Pediatric Cardiology, and Department of Internal Medicine, Division of Cardiovascular Medicine, and Department of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin Background. After the arterial switch operation (ASO) score increased at an average rate of 0.08 per year over for transposition of the great arteries (TGA), the native time after ASO. Freedom from neoaortic root dilation at pulmonary root and valve function in the systemic posi- 1, 5, 10, and 15 years after ASO was 84%, 67%, 47%, and tion, and the long-term risk for neoaortic root dilation 32%, respectively. Risk factors for root dilation include -pre ,(0.003 ؍ and valve regurgitation is currently undefined. The aim history of double-outlet right ventricle (p and length of ,(0.01 ؍ of this study was to determine the prevalence and pro- vious pulmonary artery banding (p Neoaortic valve regurgitation of at .(0.04 ؍ gression of neoaortic root dilation and neoaortic valve follow-up (p regurgitation in patients with TGA repaired with the least moderate degree was present in 14%. Neoaortic root ASO. dilation was a significant risk factor for neoaortic valve Methods. Measurements of the neoaortic annulus, neo- regurgitation (p < 0.0001). No patient required reinter- aortic root at the level of the sinuses of Valsalva, and the vention on the neoaorta or neoaortic valve during degree of neoaortic regurgitation were assessed by serial follow-up. transthoracic echocardiograms on 124 patients with TGA Conclusions. Progressive neoaortic root dilation is com- at a median follow-up of 7.2 years (range, 1 to 23 years) mon in patients with TGA after the ASO. Continued after the ASO at our institution. surveillance of this population is required. Results. Neoaortic root dilation with z scores of 2.5 or (Ann Thorac Surg 2013;95:1654–9) greater was identified in 66%, and the root diameter z © 2013 by The Society of Thoracic Surgeons ince the arterial switch operation (ASO) was first Dilation of the neoaortic root has been reported in S described by Jatene and colleagues in 1975 [1],ithas more than two-thirds of patients after ASO [6, 7]. The become the surgical procedure of choice for repair of natural history of neoaortic root dilation in this setting is transposition of the great arteries (TGA). Perioperative unclear. Previous studies have demonstrated conflicting mortality has improved in the more recent eras, and data, with reports of the indexed neoaortic root dimen- several case series have described good long-term sur- sions progressively increasing [8, 9], decreasing [10],or vival in patients up to 30 years after the ASO [2–5]. remaining fixed [11] over time. Neoaortic valve regurgi- However, these long-term studies have also revealed tation may also be an important late complication, and important late complications that contribute to late mor- although uncommon, the need for aortic valve repair or bidity and the need for reoperation. These late compli- replacement has now been reported in several series late cations include coronary artery insufficiency, right ven- after ASO [12–14]. We sought to determine the preva- tricular outflow tract obstruction, and problems with the lence of neoaortic root dilation and neoaortic valve re- native pulmonary root and pulmonary valve in the sys- gurgitation in patients with TGA repaired with ASO at temic position functioning as the neoaortic root and the our institution and to determine risk factors for the neoaortic valve, respectively [4–9]. development of these late complications. Accepted for publication Oct 31, 2012. *Drs Ginde and Co-Vu contributed equally to this article. Patients and Methods Address correspondence to Dr Earing, 9000 W Wisconsin Ave, MS 713, This study was approved by the Children’s Hospital of Milwaukee, WI 53226; e-mail: [email protected]. Wisconsin Human Research Review Board and was con- © 2013 by The Society of Thoracic Surgeons 0003-4975/$36.00 Published by Elsevier Inc http://dx.doi.org/10.1016/j.athoracsur.2012.10.081 Ann Thorac Surg CO-VU ET AL 1655 2013;95:1654–9 NEOAORTA AFTER ARTERIAL SWITCH OPERATION Table 1. Potential Risk Factors for Neoaortic Annulus indicated trivial to mild regurgitation, 4 to 6 mm Dilation, Neoaortic Root Dilation, and Neoaortic indicated moderate regurgitation, and greater than 6 Regurgitation After Arterial Switch Operation mm indicated severe regurgitation. Moderate and se- Demographic variables vere regurgitation were also verified by left ventricular Age at ASO dilatation and presence of diastolic flow reversal in the aortic arch or descending aorta. Body surface area was Sex calculated by using the formula of Haycock and col- Weight leagues [17]. Height Coexisting anatomic lesions Data Outcomes and Risk Factors Ventricular septal defect Echocardiographic measurements of neoaortic root di- Double outlet right ventricle mensions and neoaortic valve regurgitation were ana- CONGENITAL HEART Coarctation of the aorta lyzed throughout the entire follow-up. Significant neo- Coronary artery anatomy aortic root dilation was defined as maximum systolic Left ventricular outflow tract obstruction dimension at sinuses of Valsalva (midsinus level) z score Bicommissural pulmonary valve of 2.5 or higher, and significant neoaortic annulus dila- Prior intervention to ASO tion was defined as a measurement z score of 2.5 or Balloon atrial septostomy higher. We chose 2.5 as the cutoff to exclude patients with Coarctation of the aorta repair borderline dilation (z scores of 1.5 to 2.5). Significant Pulmonary artery banding neoaortic valve regurgitation was defined as moderate or Arch reconstruction severe regurgitation. Placement of a Blalock-Taussig shunt Potential risk factors for the development of neoaortic Associated operation with ASO root dilation, annulus dilation, and neoaortic valve regur- Coarctation of the aorta repair gitation were also analyzed (Table 1). Variables that were Subaortic membrane resection evaluated included demographic data, coexisting ana- Left ventricular outflow tract obstruction repair tomic lesions, interventions before ASO, and additional Ventricular septal defect repair operations performed at the time of ASO. Need for reintervention for neoaortic root dilation or neoaortic ASO ϭ arterial switch operation. valve regurgitation, including valve repair or replace- ment, was also evaluated in the patient cohort. ducted in accordance with all human research regulatory Statistical Analysis requirements. Demographic data are described as mean Ϯ standard deviation or median with ranges. The Kaplan-Meier Patients method was used to assess freedom from neoaortic root A total of 247 patients with TGA who underwent ASO at the Children’s Hospital of Wisconsin were identified in the cardiovascular surgical database from January 1984 to Table 2. Patient Demographic and Clinical Characteristics December 2007. Of these patients, 124 had at least one Median available postoperative transthoracic echocardiogram at (range) least 1 year after ASO and were included in the study. Variables or No. (%) Hospital and outpatient records were reviewed to obtain ϭ demographics, describe preoperative anatomy, and iden- Patient characteristics (n 124) tify potential risk factors predictive of progressive neo- Age at time of ASO, months 0.2 (0.1–60) aortic root dilation or neoaortic root regurgitation. Age at last follow-up, years 7.2 (1–23) Female 36 (29) Echocardiographic Measurements Coexisting lesions (n ϭ 74) Retrospective measurements of the neoaortic annulus Ventricular septal defect 36 (49) and root were performed on all available postoperative Nonusual coronary artery pattern 20 (27) transthoracic echocardiograms. Maximum systolic di- Coarctation of the aorta 14 (19) mensions of the neoaortic annulus (measured at the level Double-outlet right ventricle morphology 11 (15) of valve hinge points of the leaflets) and sinuses of Bicommissural pulmonary valve 7 (10) Valsalva (at the midsinus level) were measured from Left ventricular outflow tract obstruction 2 (3) 2-dimensional parasternal long-axis views. Neoaortic an- Previous intervention before ASO (n ϭ 74) nulus and root (sinuses of Valsalva) diameter z scores Balloon atrial septostomy 40 (54) were derived using the data from Children’s Hospital of Coarctation of the aorta repair 12 (16) Boston [15]. The severity of neoaortic valve regurgitation Pulmonary artery banding 11 (15) was graded by assessing the width of the color Doppler Blalock-Taussig shunt 2 (3) jet of regurgitation measured at the level of the valve in parasternal long-axis view [16]. A jet width of 1 to 4 mm ASO ϭ arterial switch operation. 1656 CO-VU ET AL Ann Thorac Surg NEOAORTA AFTER ARTERIAL SWITCH OPERATION 2013;95:1654–9 dilation and neoaortic regurgitation after ASO. The ran- dom coefficient model with linear fit was used to assess neoaortic root dilation and neoaortic annulus dilation CONGENITAL HEART over time. The Cox proportional hazards model was used for multivariate analysis to identify predictors of out- comes. A p value of less than 0.05 was considered statistically significant. Results Table 2 summarizes the demographic and clinical char- acteristics of the patient cohort. Of the 124 patients included in the study, the median age at the time of ASO was 0.2 months (range, 0.1 to 60 months), and median follow-up was 7.2 years (range, 1 to 23 years). Coexisting anatomic lesions existed in 74 patients (60%). The most common coexisting lesion with TGA was a ventricular Fig 2. Neoaortic root measurement after arterial switch operation septal defect (VSD), occurring in 36 patients (49%).