Role of Interventional Catheterization in Post-Operative TOF Patients

1. Role of Interventional Catheterization in Post-Operative TOF Patients Jennifer Rutledge, MD October 25, 2013

2. What is our role? • To keep patients with TOF away from the surgeons as long as possible

3. What is our role? • Treat / palliate the residual lesions patients may be left with and delay the need for future cardiac surgery • Hopefully to improve outcome and quality of life

4. Outline • When, Why and How? • Timing of intervention • Immediate post-operative versus later • Palliative procedures versus complete repair • Shunts • Pulmonary arteries • Conduits and Valves

5. Timing of Intervention: Early Post-Op • Patients who have difficulty recovering after surgery have a higher incidence of residual lesions • Diagnostic cath can be performed safely in the early post-op period and often results in the discovery of lesions that require further intervention

6. Timing of Intervention: Early Post-Op • Interventional cath has historically been avoided in the immediate post-op period • Concerns: • Transport of critically ill patients • Worsening clinical status as a result of the procedure • Fear of disruption (rupture) of fresh suture line

7. Timing of Intervention: Early Post-Op • Commonly thought a minimum of 6 weeks of adequate scar tissue formation is required for safe intervention • Recent data suggests intervention can be performed safely < 6 weeks • Performance of successful catheter intervention can improve survival to discharge

8. Timing of Intervention: Early Post-Op • Intervention only considered if the lesion is severe enough to compromise clinical status and repeat surgery is considered to be high risk • Requires multidisciplinary team • Interventional cath doc • Surgeon • Intensivist • Anesthesiologist • Nurses, RT, anesthesia and radiology technicians • ECMO team • Operating room team including nursing and perfusion

9. Timing of Intervention • Timing of catheterization outside of the immediate post-op period is largely based on non-invasive imaging and standard criteria • Significant right ventricular outflow tract obstruction • Branch pulmonary artery stenosis • Severe pulmonary valve regurgitation

10. Types of Intervention: Neonatal Shunts • Rarely performed in this population • Anomalous coronary artery • Multiple large VSD’s or TOF/AVSD • Contraindication to bypass • Central versus modified Blalock-Taussig shunt

11. Shunts • Shunt obstruction can occur 3-20% of cases • Thrombosis, suture line stenosis, intimal proliferation, vascular distortion, ductal tissue constriction • Results in cyanosis of the patient – can be life-threatening • Most often occurs acutely after surgery but can occur late • Risk factors: small shunt and pulmonary artery size, polycythemia, competitive blood flow

12. Shunts • Interventional cath options: • Mechanical or pharmacological disruption of clot • Goal is to break up the clot and dislodge it distally, improving flow across the shunt • Can be achieved manually by using catheters/wires/balloons but only useful for fresh clot • May be achieved by local thrombolysis or thrombectomy • Local injection of TPA – often requires prolonged infusions • Not practical for shunts or fresh post-op patients

13. Shunts • Shunt thrombosis most often develops in association with a stenosis of the shunt and/or adjacent blood vessel • Balloon dilation or stenting performed to disrupt the clot and treat the stenotic lesion • In the immediate post-op period stenting likely safer • More predictable and durable result, less recoil of vessel, smaller balloon/stenosis ratio for effective expansion

14. Shunts

15. Shunts

16. Shunts

17. Pulmonary Arteries • Branch pulmonary artery stenosis is a well-known association in TOF population • Post-surgical: at suture line (shunts, proximal branches), ductal constriction • Native: proximal or distal branches • Balloon dilation or stenting • What type of intervention is determined by patient/vessel size and anatomy, timing of surgical intervention (past, present and future)

18. Pulmonary Arteries • Lots of toys • Regular balloons • High pressure balloons • Ultra-high pressure balloons • Cutting balloons

19. Pulmonary Arteries • Intravascular Stents: • Ideally we like to implant stents that can be further dilated to adult size • Depending on the patient size, this is not always possible • Place smaller stents that will then need to be cut across at the time of subsequent surgery

20. Pulmonary Arteries Bergersen L et al. Cardiol Young 2005;15:597-604

21. Pulmonary Arteries Bergersen L et al. Cardiol Young 2005;15:597-604

22. Pulmonary Arteries

23. Pulmonary Arteries

24. Pulmonary Arteries Angtuaco, M. et al. Cathet Cardiovasc Int. 2011;77:395-399.

25. Pulmonary Artery Growth

26. Conduits • Frequently used in patients with TOF at various stages of life • Conduits fail due to stenosis and/or regurgitation • Freedom from conduit replacement 68-95% at 5 years and 0-59% at 10 years • Surgical conduit revision may be delayed in some patients by cath intervention

27. Conduits • Balloon dilation alone rarely achieves good result • Contraindication to conduit stenting • Anomalous coronary artery positioned behind the conduit • Risk of coronary compression

28. Conduits Freedom from conduit surgery Peng LF et al. Circulation 2006;113:2598-2605.

29. Conduits • Risk factors for need for earlier re-intervention • Younger age, higher pre-stent RV pressure, diagnosis OTHER than TOF, homograft conduits, conduits ≤ 10 mm • Stent fracture seen in 43% • 89% immediately behind the sternum • 82% had compromise of the integrity of the stent Peng LF et al. Circulation 2006;113:2598-2605.

30. Conduits

31. Chronic Pulmonary Regurgitation • Any patient with transannular patch repair • Majority of patients following conduit or bioprosthetic valve implantation • Ultimately all patients with TOF will require therapy (repeated) for chronic PR

32. Transcatheter Valves • Developed to treat dysfunctional bioprosthetic valves or conduits and reduce number of and prolong time to next surgical intervention • Two current options • Medtronic Melody valve • Edwards Sapien valve

33. Melody Valve • Bovine jugular vein; platinum/iridium stent • Available in Canada since late 2005; as of May 2013 there have been over 5000 implants in 180 centers in 35 countries • ~50% have underlying diagnosis of TOF

34. Melody Valve • Can be considered in patients: • > 30 kg, vessels large enough to accommodate the 22F sheath • Implant site 16-22 (24) mm in diameter • Evidence of conduit/valve dysfunction

35. Melody Valve www.medtronic.com

36. Melody Valve US IDE UK German Italian Canadian Patients, % Courtesy Medtronic

37. Baseline Patient CharacteristicsConduit Type Melody Valve US IDE UK German Italian Canadian Patients, % Courtesy Medtronic

38. Long-term Outcomes Pulmonary Valve Competence by Echocardiography Long Term Pulmonary Valve Competence 6 months Patients, % None None None Trace Trace Trace Mild Mild Mild Moderate Moderate Moderate 1 year Severe Severe Severe Patients, % 3 years Patients, % Courtesy Medtronic Courtesy Medtronic

39. Melody Valve • Freedom from re-operation: • Canada: 91%, 83% and 83% at 12, 24 and 36 months, respectively • Freedom from transcatheter intervention • Canada: 91% 1 year, 80% 2 year Courtesy Medtronic

40. Complications Stent Fractures (%) Melody Valve: Complications • Stent fracture in 5-25% • Increased use of pre-stenting of conduits reduces this risk • Conduit rupture - ~4% requiring treatment (covered stent/surgery) • <1% “uncontained” rupture but can be fatal • Coronary artery compression • Can be seen in ~5% of patients during test evaluation • Can be catastrophic Patients, % 24 28 12 30 7.5 Follow up (months) Morray BH et al. Circ Cardio Int;2013:6:535-542

43. Transcatheter Valve • Melody valve was expanded the role of interventional cath in post-operative patients • Limited size range • There are many patients with conduits and valves that are not candidates for a Melody valve

44. Sapien Valve • Bovine pericardial valve leaflets hand-sewn into a slotted stainless steel stent • Fabric sealing cuff on lower portion of stent • Designed for aortic position • Can be considered for pulmonary valves/conduits ~21 - 30 mm in diameter, patients > 30-35 kg • Shorter stent requires that conduits are fully stented prior to Sapien valve insertion Edwards Lifesciences

45. Sapien Valve

47. Sapien vs. Melody Faza et al. CathetCardiovascInt 2013;82(4):E535-41.

48. Sapien vs. Melody Faza et al. CathetCardiovascInt 2013;82(4):E535-41.

49. Transannular Patch • What about the really large RVOT’s? • Medtronic Native Outflow Tract Pulmonary Valve Courtesy Medtronic

50. Medtronic’s Early Feasibility Study: Non-randomized, Prospective • Primary Objective: • Obtain in vivo data to confirm assumptions on loading conditions for future in vitro frame evaluations • Secondary Objectives: • Characterize procedural feasibility, safety & TPV performance • Up to 20 subjects - Consented for 5 year follow-up at 3 North American Centers (Implants spring 2014 – F/U to 2019) • The Hospital for Sick Children ,Toronto Canada – Dr. Lee Benson • Nationwide Children’s Hospital, Columbus Ohio – Dr. John Cheatham • Children’s Hospital, Boston MA – Dr. Jim Lock Courtesy Medtronic Courtesy Medtronic