The Univentricular Repair: Indications, Procedures, Outcomes and Controversies

1. Karyn P. Luna, M.D. The Univentricular Repair: Indications, Procedures, Outcomes and Controversies

2. Topics • Updates on the indications, timing and outcome of univentricular repair. • Present surgical options. • Discuss the controversies regarding the modifications of the Fontan operation.

3. The Univentricular Heart • A heart that lacks two well-developed ventricles: Hypoplastic left heart syndrome Hypoplastic right heart

4. The Univentricular Heart • Tricuspid atresia+/- pulmonary atresia with intact ventricular septum, double inlet left ventricle, double outlet right ventricle, unbalanced atrioventricular septal defects and hypoplastic left heart syndrome.

5. The Univentricular Heart • Generally, the risk to siblings and offspring of affected individuals is 2% to 5% (19% -33% of siblings HLHS) . • Clinical manifestations and initial management hinge on the presence or absence of pulmonary and systemic outflow obstruction. • Natural history Left ventricle dominant= 70% died before age 16 Right ventricle dominant =50% died before 4 years • Fontan operation: 20-year survival rate and freedom from heart transplantation of 80%-82%. Paul Khairy, MD, PhD et al.Circulation. 2008 • Staged repair allows progressive adaptation of the heart and lungs and reduces the overall perioperative morbidity and mortality. SandeepNayak,PD Booker MBBS MD FRCA

6. Aims of Intervention • Create unobstructed systemic outflow, unobstructed systemic and pulmonary venous return • Provide balanced pulmonary and systemic circulations. • Totally separate the systemic and pulmonary venous return and provides pulmonary blood flow without a ventricular pumping chamber. • Effective strategies to preserve pulmonary, ventricular and valvular function. Paul Khairy, MD, PhD et al.Circulation.2007

7. Stages toward a Univentricular Pathway: Early Infancy • Balanced circulation: No early intervention • The aim of the initial palliation is to provide complete relief of any systemic obstruction, if it exists, and provide pulmonary blood flow just sufficient to allow adequate oxygen delivery to tissues and pulmonary arterial growth. • Procedures: Pulmonary Artery banding Modified Blalock-Taussig shunt Modified Norwood 1/Sano repair Hybrid procedure

8. Stages toward a Univentricular Pathway: Early Infancy Setting:Pulmonary overcirculation • Pulmonary artery banding : • Pulmonary blood flow must be minimized to ensure that PVR is kept low and the ventricle does not have an excessive volume load.

9. Stages toward a Univentricular Pathway: Early Infancy Setting: Hypoxemia • Modified Blalock-Taussig shunt • PDA stenting

10. Stages toward a Univentricular Pathway: Early Infancy Advantages of mBTS: • Improve oxygen saturation • Facilitate growth of pulmonary arteries Disadvantages of mBTS: • Ventricular volume overload • Increase in pulmonary arterial pressure • Distortion of pulmonary arteries

11. Stages toward a Univentricular Pathway: Early Infancy The long-term effects of marked single-ventricle preload and inefficient oxygenation via an arterial shunt rarely allowed survival beyond the second or third decade of life. WeltonM. Gersony, MD Circulation2008

12. Stages toward a Univentricular Pathway: Early Infancy Setting: HLHS • Modified Norwood 1 or Sano repair • Hybrid procedure • First 2 weeks of life • Permanent systemic outflow utilising the right ventricle • Temporary pulmonary blood supply to allow the pulmonary vasculature to develop and mature. • Up to 20-25% mortality rate

13. Stages toward a Univentricular Pathway: Early Infancy U Theilen, L Shekerdemian. Arch Dis Child Fetal Neonatal Ed 2005

14. Stages toward a Univentricular Pathway: Early Infancy • Modified Norwood 1 • The main pulmonary artery(MPA) is divided • Proximal MPA is anastomosed to the ascending aorta • Aortic arch is repaired • Augmented pulmonary blood flow is maintained via a mBTS

15. Stages toward a Univentricular Pathway: Early Infancy • Sano repair: • Similar to NW 1 but with RV-PA conduit instead of mBTS. • Theoretical advantage of avoidance of aorto-pulmonary runoff, resulting in higher coronary and systemic perfusion pressures and reducing the incidence of ventricular.

16. Mod. Norwood 1 vs Sano Repair • Risk factors for midterm mortality were cardiorespiratory failure requiring ventilation and ACS ≥20, but not shunt type. • Increased number of shunt-related interventions before the Glenn procedure were noted with Sano. • CONCLUSIONS: Preoperative risk factors, regardless of shunt type, influence midterm survival after the Norwood procedure with an excellent outcome in low-risk patients, while high-risk cases still incur a significant mortality. • Given the possible negative effects of ventriculotomy on right ventricle function, the widespread use of Sano shunt should be reconsidered. Does the shunt type determine mid-term outcome after Norwood operation? Joachim Photiadisa, et al November 15, 2011.

17. Stages toward a Univentricular Pathway: Early Infancy Setting: HLHS • The Hybrid Procedure • Interventional ductal stenting & surgical bilateral pulmonary artery banding • An alternative to the NW in HLHS for high-risk patients • This approach has been extended to borderline left heart structures. David Anderson, Conal Austin, Shakeel Qureshi et al. European Journal of Echocardiography (2010)

18. Stages toward a Univentricular Pathway: Early Infancy • Hybrid vs NW: • Hybrid has lower 1st stage mortality but higher interstage mortality. Possible causes are closing PFO, short stent, myocardial ischemia. = the 2nd stage is a more difficult operation. Pizarro et al. Eur J CTS. 2008 Overall, no difference in outcome at 6 months. Pizarro et al Thorac CVS 2010

19. Stages toward a Univentricular Pathway: Late Infancy • The advantage of the BDG/HemiFontan over the Blalock-Taussig shunt is to allow an increase of effective pulmonary blood flow without an increase in total pulmonary blood flow and cardiac work. Davide F. Calvaruso, et al Ann Thorac Surg 2008 • An interstage mortality of 10–15% • Most interstage deaths are sudden and apparently unpredictable. U Theilen, L Shekerdemian. Arch Dis Child Fetal Neonatal Ed 2005

20. Stages toward a Univentricular Pathway: Late Infancy Setting: Cyanosis or pulmonary overcirculation or balanced • CavoPulmonary Connection • Bidirectional Glenn Shunt or • Hemi-Fontan operation : Duration of 15 months because after surgery, the patient is at risk of developing intrapulmonary arteriovenous shunts SandeepNayak, PD Booker MBBS MD FRCA

21. Stages toward a Univentricular Pathway: Late Infancy Benefits of Cavopulmonary connection: • Decreased cyanosis • Decreased intracardiac volume overload O MonteinNgodngamthaweesuk et al Asian CardiovascThorac Ann 2007

22. Stages toward a Univentricular Pathway: Late Infancy

23. Stages toward a Univentricular Pathway: Late Infancy

24. Stages toward a Univentricular Pathway: Late Infancy

25. Stages toward a Univentricular Pathway: Late Infancy

26. Stages toward a Univentricular Pathway: Late Infancy

27. Stages toward a Univentricular Pathway: Late Infancy HemiFontan Operation

28. Stages toward a Univentricular Pathway: Late Infancy HemiFontan Operation

29. Pre-Fontan Procedures

30. Pre-Fontan Procedures

31. Operative mortality rate of BDG/HemiFontan is 5%-7% • Freedom from failure at 10 years was99.2% for the Fontan group and 67.4%for the BDG patients. Jenkins KJ.Eur J Cardiothorac Surg 2010

32. Stages toward a Univentricular Pathway: Childhood • Modified Fontan operation: • Total cavopulmonary connection (TCPC) • 18 months – 4 yrs. old (or 6-18 months post-Glenn or hemi-fontan)

33. Evolution of the Fontan Procedures Original Fontan Modified Fontan

34. Evolution of the Fontan Procedures Lateral tunnel Fontan ExtracardiacFontan

35. Modified Fontan Procedures Lateral tunnel Extracardiac A tube graft from the IVC to RPA outside the heart. • Intra- atrial baffle from IVC to SVC

36. Modified Fontan Procedures Lateral tunnel Extracardiac

37. Modified Fontan Procedures

38. Modified Fontan Procedures • STS Congenital Heart Surgery Database: 2,747 Fontan operations (2000 to 2009) in 68 centers A right-dominant ventricle 45%. Extracardiac conduit Fontanvs lateral tunnel)was performed in 63%; in all, 65% were fenestrated. In multivariable analysis the extracardiac conduit Fontan was associated with significantly higher Fontan takedown/revision and Fontan failure and longer postoperative hospital stay. • Conclusions: The lateral atrial tunnel Fontan may be associated with superior early outcomes. Constantine Mavroudis, Marshall L. Jacobs, et al January 3, 2012.

39. Suitability for Fontan Procedure: Choussat’s ‘Ten Commandments’ • Age above 4 years • Normalventricular function • Adequate pulmonary artery size • No distortionof pulmonary arteries from prior shunt surgery • Low pulmonaryartery pressure (below 15 mmHg) • Low pulmonary vascular resistance • Normal systemic venous drainage • No atrioventricular valve leak • Normal heart rhythm • No right atrial enlargement

40. Suitability for Fontan Procedure • Negative prognostic factors for both early and late outcome: Ventricular function Pulmonary artery pressure William J. Brawn.Circulation. 2001

41. Suitability for Fontan Procedure: Pulmonary Artery Size • Three groups of PA sizes using the PA index (PAI) • Hypoplastic PA (<180 mm2/m2)=impedance increase especially at 100mm2/m2 • Relatively small PA (180-250 mm2/m2) • Good PA (250mm2/m2) Jae Suk Baek et al. Ann ThoracSurg2011

42. Outcome of Univentricular Repair ACC/AHA 2008 Guidelines guch

43. Outcome of Univentricular Repair: Survival Rate • Recent 15-year survival reports post-Fontan: • 85% was recently reported by the Boston Children’s Hospital , USA • 82 ± 3% recently reported by Birmingham Children’s Hospital, UK • Preoperatively impaired ventricular function and elevated pulmonary artery pressures have an adverse influence on both early and late outcome. • Long-term viability after the creation of a Fontan circulatory arrangement is most dependent on maintenance of sinus rhythm, the behavior of the pulmonary vasculature, and the performance characteristics of the ventricle Alvin J. Chin et al. World Journal for Pediatric and Congenital Heart Surgery 2010 Riad B.M. Hoseina, William J. BrawnJ ThoracCardiovascSurg 2012

44. The PHC 10-Year Experience • Norwood 1 operation (n=9):100% early mortality rate • Glenn shunts (n=128): 5.4% mortality rate • HemiFontan (n=11): 100% early midterm survival rate • BTS to Fontan operation (n=6) : 17% • Glenn to Fontan operation (n=9): 25% • Modified Fontan operation (n=36): 5.5% mortality rate

45. Long-term Outcome of Univentricular Repair: Physical Development • A 15 year follow-up on somatic growth after Fontan operation: • Body weight and BMI have significantly improved by 1 year after the operation. • Height has significantly improved by 2 years postoperatively. • Patients with BDG shunts showed significantly better weight and BMI at the time of the Fontan operation compared with those without prior BDG shunts . • Fenestration is beneficial suggesting that mild arterial desaturation is well tolerated and permits catch-up growth. • The pace of catch-up growth after the Fontan operation is much slower than that after biventricular repair. Masamichi Ono et al. J Thorac Cardiovasc Surg 2007 • Oxygen delivery index, at least through their preadolescent years, was normal or near normal to reach a relatively normal height. Alvin J. Chin et al. World Journal for Pediatric and Congenital Heart Surgery 2010

46. Outcome of Univentricular Repair: Physical Development • Oxygen delivery index, at least through their preadolescent years, was normal or near normal to reach a relatively normal height. Alvin J. Chin et al. World Journal for Pediatric and Congenital Heart Surgery 2010

47. Long-term Outcome of Univentricular Repair: Functional Health Status • Physical and Psychosocial Summary scores of the Child Health Questionnaire Parent Form were within the normal range for over 80% of patients. Carl Lewis Backer.J. Am. Coll. Cardiol. 2008 • Greater differences between parent and child-completed scores for the domains of physical functioning and impact of physical limitations. • Children may “adapt” better to their situation and rate the impact of the illness to be better. • Recommendation: Clinicians should consider both parent and patient viewpoints when counseling patients. Parent- Versus Child-Reported Functional Health Status After the Fontan Procedure Linda M. Lambert et al. Pediatrics2009

48. Long-term Outcome of Univentricular Repair: RV vs LV dominance • Finding of apparently impaired systolic function in the RV subgroup relative to the LV and mixed subgroups is consistent with the general opinion that the structure of the RV is suboptimal for a systemic ventricle. • The tricuspid valve is more likely to fail as a systemic AV valve. Page A. W. Anderson, MD, et al. J Am CollCardiol 2008

49. Long-Term Outcome of Univentricular Repair: Arrhythmia • Arrhythmia occur in 10-40% of patients regardless of the type of Fontan. • Cardiac rhythm is important in this circulation: • Loss of atrio-ventricular synchronisation will cause an increase of the pulmonary venous atrial pressure and/or • a diminished ventricular preload, • Both of which are known to have negative effects on a Fontan circuit. Marc Gewilliga et al. European Association for Cardio-Thoracic Surgery 2010. • Ventriculartachycardia was detected 15 years post surgery, especially inolder patients with older age at Fontan operation. Yuki Nakamura, MD .J ThoracCardiovascSurg 2010

50. Long-Term Outcome of Univentricular Repair: Lymphatic Obstruction • Lymphatic circulation may be affected by high venous pressure and impaired thoracic duct drainage. • Increased pulmonary lymphatic pressure may result in interstitial pulmonary edema, lymphedema &/or protein losing enteropathy. • Protein losing enteropathy is characterized by excessive loss of proteins from serum into the intestinal lumen with mesenteric vascular inflammation. • Manifestations include oedema, immunodeficiency, ascites, malabsorption of fat, hypercoagulopathy, hypocalcaemia, and hypomagnesaemia. SandeepNayak , PD Booker MBBS MD FRCA