1. Outcomes following simple and complex (Damus- Kaye-Stansel takedown) Ross operations in 62 consecutive pediatric patients Alejandra Bueno MD, David Zurakowski PhD, Vijayakumar Raju MD, Michele J. Borisuk MSN, CPNP, Suyog A. Mokashi MD, Sitaram Emani, MD, Gerald R. Marx MD, Pedro J. del Nido MD, and Christopher W. Baird MD

2. No disclosures

3. Introduction The Ross operation has good outcomes in selected pediatric patients with a biventricular circulation. However, there have been no reports in patients with uni-ventricular circulation who have undergone single ventricle palliation followed by biventricular conversion with Ross operation.

4. Objectives Review outcomes following simple and complex Ross operations including patients undergoing biventricular conversion with Damus-Kaye-Stansel (DKS) takedown. To determine predictors for successful Ross operation based on echocardiographic measurements.

5. Methodology A retrospective review on 62 patients who underwent Ross operations at Boston Children's Hospital from March 2000 and October 2014. Simple (50 pts.) – Ross operation in patients who had a biventricular circulation. Complex (12 pts.) –Patients with pre-operative uni- ventricular circulation with hypoplasia of the left heart structures who then underwent biventricular conversion with DKS takedown and a Ross operation.

6. Data collection Clinical data IRB approval was obtained. Medical records were reviewed. Echocardiography Data was measured independently by a single reviewer and a random sample was reviewed by a second reviewer.

7. Echocardiography Aortic Annulus Ascending Aorta Sinus of Valsalva

8. Measurement of Vena Contracta Aortic regurgitation was estimated from the vena contracta width indexed to the square root of the body surface area.

9. Patient Characteristics Characteristic n, (%) Simple 50 (81%) Complex 12 (19%) P value Male n, (%) 39 (78%)9 (75%)1 Weight kg (median, IQR) 23 (8-46)13 (8-17).07 Age at the Ross procedure years (median, IQR) 5.5 (1-14)2.5 (1-4).05 Age n, (%) Neonate < 1 month Infant < 2 years Children from 2-12 years Adolescents from 13-18 years Adults >18 years 6 (12%) 9 (18%) 19 (38%) 11 (22%) 5 (10 %) 1 (8%) 5 (42%) 6 (50%) 0 (0%) 1.12.52.1.57 Nature of Aortic lesion n, (%) Aortic stenosis Aortic regurgitation AS/AR 10 (20%) 24 (48%) 16 (32%) 4 (33%) 7 (58%) 1 (8%).44.75.15 Aortic valve operative technique n, (%) Aortic root replacement Inclusion Additional root stabilization Aortic root enlargement 49 (98%) 1 (2%) 6 (12%) 29 (47%) 11 (92%) 1 (8%) 8 (67%).35 1.20

10. Follow-up All patients (n=62 patients) Follow-up was available in 54 patients (87%) At a median of 2.7 years (IQR, 8m-5.2 years) Simple group (n=50 patients) Follow-up was available in 45 patients At a median of 42 months (IQR, 8m-66m) Complex group (n=12 patients) Follow-up was available in 11 patients At a median of 18 months (IQR, 9m-41m)

11. Patient Survival

12. Freedom from Neo-aortic Valve Re-intervention

13. Pre-operative Echocardiography Z-scores

14. Aortic annulus Echocardiographic Z-scores

15. Sinus of Valsalva Echocardiographic Z-scores

16. Aortic regurgitation – Vena contracta - Indexed to BSA (mm/m)

17. Lack of correlation between initial pulmonary valve Z-scores and late aortic regurgitation. Pre-operative Pulmonary Valve Z-score

18. Limitations Retrospective Single center study Patient selection bias - as patients with large dilated aortic roots and ascending aortas were generally not operated with a Ross procedure. Complex group of patients with multiple additional lesions.

19. Conclusions The aortic valve complex including the aortic annuli, the sinus of Valsalva and ascending aorta increased in size without development of late aortic regurgitation. Neither pulmonary valve size or native pulmonary and aortic annular size discrepancy should be a contraindication for Ross procedure. The Ross operation should be considered in patients with significant aortic valve disease undergoing biventricular conversion with DKS takedown.

22. No correlation between base line PV Z-score and late follow-up aortic regurgitation.

27. Online table 2. Echo measurements. Echocardiographic Data Z-scores Pre-operative vs. discharge P value Pre-operative vs. late follow-up P value Discharge vs. late follow-up P value Aortic Valve Simple Complex.01.004 <.001.002.02.06 Aortic Root Simple Complex <.001 <.001.008.05 Ascending Aorta Simple Complex.76.22.50.05.74.22 Pulmonary Valve Simple Complex.03.27 <.001.025.020.56 Aortic Regurgitation Simple Complex <.001.022 <.001.05.01.11

28. Online table 3. Late outcomes. Late Outcomes Data n (%) All patients 62 Simple 50 Complex 12 P value Deaths n, (%)2 (3%) 0 (0%) 2 (17%).04 RVOT reintervention n, (%) Surgical Catheterization 13 (21%) 7 6 10 (20%) 5 3 (25%) 2 1.70.61 1 LVOT reintervention n, (%) Surgical Catheterization 2 (3%) 2 0 2 (4%) 2 0 0 (0%) 0 111111 Echocardiography – AR * n, (%) None Mild Moderate Severe 15 (31%) 29 (59%) 4 (8%) 1 (2%) 13 (33%) 24 (60%) 3 (8%) 0 (0%) 2 (22%) 5 (56%) 1 (11%).18

29. Improvement in AA Z-score between discharge and late follow-up

30. P =.27