1. THOMAS L. SPRAY, MD THOMAS L. SPRAY, MD Chief, Cardiothoracic Surgery Chief, Cardiothoracic Surgery Alice Langdon Warner Endowed Chair Alice Langdon Warner Endowed Chair The Children’s Hospital of Philadelphia The Children’s Hospital of Philadelphia Professor of Surgery Professor of Surgery The University of Pennsylvania The University of Pennsylvania THE BORDERLINE LEFT VENTRICLE: Where to draw the line The Cardiac Center at The Children’s Hospital of Philadelphia NO DISCLOSURES

2. ANATOMY OF VENTRICULAR HYPOPLASIA LV Hypoplasia: Aortic Stenosis AS/ Mitral Stenosis Coarctation of Aorta TAPVR IAA/VSD TGA Unbalanced AVSD

3. CAN VENTRICULAR GROWTH BE STIMULATED AFTER BIRTH? What Are The Signals For Ventricular Growth? Positive: Flow (Volume, Shear Stress) Preload (Compliance) Negative: Afterload (Hypertrophy)

4. CAN YOU VARY PRELOAD TO LV? Adjustable ASD Leave Vertical Vein Open In TAPVR: Left-to-Right Shunt Volume Re- Presented To LV ? Capacitance of Functional LA

5. LV “GROWTH” DEMONSTRATED WITH REPAIR Septal Shift, Volume Loading of LV, Volume Unloading of RV Relief of Afterload on LV/RV

6. LIMITATIONS TO BVR IN LV HYPOPLASIA: “Fixed” Structural Lesions Endomyocardial Fibroelastosis MV Stenosis Straddling AV Valves Anatomically Abnormal AV Valves Residual Outflow Obstructive Lesions

7. LV GROWTH IN CRITICAL AORTIC STENOSIS Criteria for BVR Ross-Konno Resection of EFE Ross-Konno-MVR if MS PHTN Late Complication

8. Predictors of BVR in Critical AS: New “Rhodes” Score 12.16 (BSA) + 0.59 (aortic valve annulus z-score) +5.73 (LAR) – 7.02 Discriminant cutoff of 0.46 accurately predicts 91% of survivors and 80% events (death) From: Colan, SD et al.JACC2006;47:1858-65

9. Predictors of BVR in Critical AS

10. From: Colan, SD et al.JACC2006;47:1858-65 CHSS Formula for BVR vs. SVR in AS

11. SURVIVAL BASED ON MANAGEMENT From: Hickey, EJ, et al. JTCVS 2007;134:1429-37

12. LV GROWTH IN “HLH COMPLEX” / CoA Repair Coarctation ? ASD Restriction/ Closure ? PA Band If VSD When is BVR Failing And Requires Conversion To SVR?

13. From: Serraf, A et al. JACC 1999;33:827-34 HLHC Survival and Reoperation-Free Survival

14. LV GROWTH IN TAPVR Is The LV Ever Too Small? Should The Vertical Vein/ ASD Be Left Open?

15. UNBALANCED AV CANAL 10% Of All Common Atrioventricular Canal Right Dominant More Common Than Left Dominant Forms Right Dominant Associated With SubAS, CoA, Arch Hypoplasia High Morbidity And Mortality Not Usually Associated With Down Syndrome Few Published Reports BACKGROUND

16. RV Volume > LV Volume In “Balanced” AV CanalRV Volume > LV Volume In “Balanced” AV Canal Degree Of Unbalance Of AV Valves May Not Correlate With Ventricular VolumesDegree Of Unbalance Of AV Valves May Not Correlate With Ventricular Volumes Position Of Ventricular Septum May Be DisplacedPosition Of Ventricular Septum May Be Displaced Patch Closure Of VSD May Increase LV VolumePatch Closure Of VSD May Increase LV Volume Abnormal Geometry Of LV Outflow Tract And Ventricle Alters Accuracy Of MeasurementsAbnormal Geometry Of LV Outflow Tract And Ventricle Alters Accuracy Of Measurements UNBALANCED AV CANAL ERRORS IN MEASUREMENT OF VENTRICULAR VOLUME IN AVC

17. UNBALANCED AV CANAL Considered To Be Higher Risk Lesion Than HLHS In Staged Reconstruction Atrioventricular Valve Regurgitation Is Common More Likely To Require Atrioventricular Valvuloplasty Or Replacement Than HLHS SINGLE VENTRICLE REPAIR

18. UNBALANCED AV CANAL Antegrade Flow In Ascending AortaAntegrade Flow In Ascending Aorta No PDA Or Only Left-To-Right Ductal FlowNo PDA Or Only Left-To-Right Ductal Flow Restrictive Or No VSDRestrictive Or No VSD AVVI > 0.27, Inflow Into Both Ventricles SymmetricAVVI > 0.27, Inflow Into Both Ventricles Symmetric “Potential” LV Volume > 15 ml/m 2“Potential” LV Volume > 15 ml/m 2 Unbalance To The Left VentricleUnbalance To The Left Ventricle FACTORS FAVORING TWO VENTRICLE REPAIR

19. LV GROWTH IN UNBALANCED AVSD LV Inflow Primary Issue, Not LV Size Small MV, Especially With Small/Restrictive VSD or Restricted LV Inflow May Preclude Successful Repair Despite Reasonable LV Size (MR Through Cleft)

20. UNBALANCED AV CANAL IMPORTANT ANATOMIC/PHYSIOLOGIC VARIABLES IMPORTANT ANATOMIC/PHYSIOLOGIC VARIABLES Direction Of Ascending Aortic Flow Ductal Shunt Direction Relative Atrioventricular Valve Size Atrioventricular Valve Anatomy/Fxn Subaortic Stenosis Arch Hypoplasia/Coarctation Size Of VSD And Direction Of Shunt Size Of LV/RVSize Of LV/RV

21. UNBALANCED AV CANAL

22. STAGED LV RECRUITMENT From: Emani, SM, et al. JACC 2012;60:1966-74

23. ADVANTAGES OF LV “Rehabilitation” BVR eventually accomplished in 33% or more LV size, function improves Growth of left heart structures DISADVANTAGES OF LV “Rehabilitation” AV still abnormal – AVR likely if previous intervention MV still abnormal – MS/MR common, may eventually require MVR LV diastolic function improved – long-term outcome unknown Late exercise performance not known PA pressures may not normalize All risks of Norwood still present

24. LV POST “Rehabilitation” From: Emani, SM et al. JACC 2012;60:1966-74

25. CHOP Selection Criteria For BVR (Survival 96%) MV Z-score >-3.7, Smallest MV dimension >5 mm No significant MS whether or not MV abnormal Small PFO/ASD, modest gradient (<8 mm Hg.) Mild LV hypoplasia (RV/LV 0.7-1.9) Small or no VSD No significant EFE Mild-moderate arch gradient Antegrade flow in arch

26. Endocardial Fibroelastosis (EFE) Major risk factor for poor outcome Hard to diagnose 3 Types: Grade 1 – Pap M involvement only Grade 2 – Pap M and some endocardial involvement Grade 3 – Extensive endocardial involvement Should all grades be addressed? ? Effect of residual EFE ? Results of scarring after resection

27. WHEN IS SVR BETTER THAN BVR? After 1 Yr., SVR functional survival good for >20 yr. Functional results after BVR not well studied long-term Late decrease in compliance, elevated PVR and valve lesions may limit late options (Tx) Survival @ 20 yr. may be better with SVR, but ? @ 40 yr.

28. “GOOD” BVR CANDIDATES Anatomically normal but hypoplastic left- sided intracardiac structures with antegrade arch flow AV stenosis with normally-functioning MV No or Grade 1 EFE MV Z-score >-3 AAVI >.27 with inflow into LV (CAVC)

29. “POOR” BVR CANDIDATES LV hypoplasia plus unrestrictive VSD Stenotic AV plus abnormal/stenotic/hypoplastic MV ? Grade 3 EFE with abnormal MV ? Left-sided structures with Z-value <-4 AVVI >0.27 but with inflow directed into RV (CAVC)

30. SUMMARY Decisions About Ventricular Suitability For BV Repair Remain Difficult Despite Improved Measurement Techniques, Absolute Limits of LV/RV Hypoplasia Preventing BVR Remain Unclear Primary Issue Is Asessment Of Adequacy Of Ventricular Inflow and EFE Much Early LV/RV “Growth” After BVR Is Septal Repostioning From VSD Closure Or Decrease In RV Volume Load And Increase In LV Preload

31. SUMMARY Adjusting Preload To Stimulate Ventricular Growth May Be Useful After Relief Of Obstruction Distally, but presumes adequate MV Overall Results With BVR In Patients With Borderline LV Not Much Different Than SV Reconstruction, Possibly With More Morbidity and Late Mortality Even When BVR Successful, Ventricles Can Have Abnormal Compliance AVSD Group Especially Difficult- MR May Limit Ability To Tolerate LV Loading Molecular Mechanisms Of LV Growth Remain To Be Clarified

34. From: Emani, SM et al. JACC 2012;60:1966-74

40. From: Emani, SM, et al. JTCVS 2009;138:1276-82

43. From: Cavigelli-Brunner, A., et al. Pediatr Cardiol 2012;33:506-12

47. From: Hickey, EJ, et al. JTCVS 2007;134:1429-37

55. From: Avitabile, CM, et al. Ann Thorac Surg 2015;99:877-83