Single Ventricle Fontan Pathway UCSF Congenital Cardiac Anesthesia

Single Ventricle & Fontan Pathway UCSF Congenital Cardiac Anesthesia Tutorials William C. K. Ng Division of Congenital Cardiac Anesthesia 2017

Normal Cardiopulmonary Anatomy Paediatric to Adult circulation § PFO § PDA § RV (Pulmonary Vascular System) in series with LV (Systemic Vascular System) • RV is the auxiliary pump, synchrony, interdependence • Preload to LV and reduced afterload to LV (RAP < LAP) ‒ Contribution to CO • Pulmonary vascular volume reserve: recruitment ‒ Further contribution to CO in exercise 2 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Neonatal Circulation Transition from Foetal to Neonatal circulation: 2 shunts Bruce Blaus - Own work, CC BY-SA 4. 0, https: //commons. wikimedia. or g/w/index. php? curid=449681 62 3 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

The classic TA and the early Fontan and Baudet, French. (First reported in Thorax. 1971, 26: 240 -248) Diagram_of_the_human_hea rt_(cropped). svg: Yaddah cropped image by Wapcaplet derivative work: Rupert Millard (talk) Diagram_of_the_human_hea rt_(cropped). svg, CC BY-SA 3. 0, https: //commons. wikimedia. or g/w/index. php? curid=610370 0 4 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Congenital Cardiac Lesions Various lesions may benefit from Single Ventricular Surgical Palliation Pathway: § DORV, DILV § HRHS • PA/IVS • TA § HLHS • MA • Schone’s, Williams’ § Unbalanced CAVC, Truncus Arteriosus 5 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Staged Palliation for HLHS management Using HLHS as the context for understanding Single Ventricles: § Stage I – Norwood + Sano/AP shunt/BTS § Stage II – Glenn (bidirectional Glenn shunt, superior cavopulmonary connection) § Stage III – Fontan (superior & inferior cavopulmonary connections) • N. B. Damus-Kaye-Stansel Shunt for conversion to Univentricular conversion, such as DORV. 6 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Stage I: The “Norwood” Norwood, Lang, Hansen. Physiologic Repair of Aortic Atresia–Hypoplastic Left Heart Syndrome. NEJM. 1981; 308: 23 -26 Sano et al. Right ventricle-pulmonary artery shunt in first-stage palliation of hypoplastic left heart syndrome. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2004; 7: 22 -31 7 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Goals of the “Norwood” Goals and effects § Relieve LVOTO, increased organ perfusion and growth • Increased oxygenation by decreased mixing § Maintained but limited pulmonary blood flow, growth, maturity • Non-distorted pulmonary arteries • Unrestricted pulmonary venous return • Preparation for cavopulmonary connections § Performed in neonatal period, within first-week of life § Adjunct include PA band 8 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

The classic -> bidirectional Glenn shunt W. Glenn. Circulatory Bypass of the Right Side of the Heart. NEJM 1958; 259: 117 -120. Khairy P, et al. Univentricular heart. Circ 2007; 115: 800 -812 9 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Goals of the Glenn in Staged Palliation Ventricular volume unloading in the transitional period is key. § Decreased end-diastolic ventricular volume • Decreased ventricular wall-thickness ‒ Favourable geometry (prevent eccentric hypertrophy, dilation, dysfunction) ‒ Diuretics ‒ Age-dependent • Ventricular load change ‒ Stage I 300% normal/BSA, stage II 90%, stage III 70%. § Volume load paradox: adequate PV load vs. SV off-load § 3 -6 Months § Sats 75 -85% (IVC/hepatic blood is deoxygenated) 10 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

F. Fontan and M. Baudet. Thorax. 1971, 26: 240 -248 Surgical repair of tricuspid atresia has been carried out in three patients; two of these operations have been successful. 11 Presentation Title and/or Sub Brand Name Here 6/17/2021

Gross Anatomy of Fontan Cavopulmonary anastomosis: lateral tunnel or extra-cardiac Jolley M, Colan S, Rhodes J, Dinardo J. Fontan Physiology Revisited. Anes Analg 2015; 121: 172 -82. 12 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Goals of Fontan And some major circulatory side-effects, § Near normal saturation: implications for survival, growth § Performed 18 -24 months: improved outcomes after staged BDG § But… increased afterload, increased hydraulic power (Wt/CI), reduced preload, reduced contractile reserve. • Smaller venous capacitance (smaller baseline unstressed volume) § Inefficient pulmonary vascular bed • SVC/IVC collision, shear stress, • APC (80%) -> turbulence, increased Fontan pathway pressures § Lack of pulmonary vascular growth • Non-pulsatile flow (physical and molecular mechanisms) • Lack of hepatic factor -> AV malformations § Increased hepatic, splanchnic pressures 13 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Schematic diagram of Series SVR, PVR and the CPVR Circulation Jolley M, Colan S, Rhodes J, Dinardo J. Fontan Physiology Revisited. Anes Analg 2015; 121: 172 -82. 14 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Scheme of SV CVP, RAP, PAP/LAP, Ao. P pressures Jolley M, Colan S, Rhodes J, Dinardo J. Fontan Physiology Revisited. Anes Analg 2015; 121: 172 -82. Gewillig M, Brown SC. The Fontan circulation after 45 years. Heart 2016; 102: 1081 -6. 15 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Fontan: Cavopulmonary Bottleneck Absence of RV, normal PV vasculature, pulsatility PBF is bad § Gewillig: the critical “bottleneck” to flow is the neoportal impedance, causing upstream congestion and downstream limitation. Gewillig M, Brown SC. The Fontan circulation after 45 years. Heart 2016; 102: 1081 -6. 16 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Fontan: associated conditions § PLE (3. 7 – 24%) • Hepatic and Portal venous congestion: Fontan liver-associated disease § Plastic bronchitis § SVT and other Arrhythmias (7 -50%; major cause of death outside perioperation; 23% pacemaker) • Atrio-pulmonary connection > lateral tunnel > extra-cardiac Fontan § Heterotaxy • Spleen, GI, SVC/IVC/azygous § Cavopulmonary failure but rarely ventricular dysfunction – • Failed Fontan: low CO, increased systemic venous pressure, • Diastolic (overgrown, stiff); Systolic § Pulmonary vascular system already discussed 17 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Anesthesia Strategem Despite the spectrum of badness, there’re common elements: § Pre- & Post-Stage I • PGE 1 infusion. • Balancing PVR : SVR, CO; systemic venous saturation; coronary (diastolic) steal in BTS § Post-Stage II • Cerebral venous return, SVC, positioning • CO incompletely dependent on PBF. Qp: Qs 0. 5 -0. 7 & inhalation induction • Ventilation, PAW, p. CO 2 § Post-Stage III • CO is dependent on PBF: PVR or PV impedance is the single most important factor • AW pressures: 30% respiratory dependent c. c. 15% in biventricular system), ‒ MAW inversely related to CO. • Preload deprivation • Fenestration (pop-off), saturation • Ventricular diastolic and systolic function 18 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

CHD for non-cardiac surgery scenario 5 y. o. for laparoscopic appendicectomy § HLHS, post completion of FONTAN § What are your anaesthetic • Preoperative concerns & optimisations? • Intraoperative concerns & optimisations? • Post-operative concerns & optimisations? 19 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Anaesthetic Consideration continued § Pre-op • Function and ET. PE: SPO 2, associated conditions. • Meds: ASA, PDE-I/ACE-I/ETA/PGI 2 • Labs: HCT, plt. Echo. CXR. • Access: previous procedures, BTS, difficult IV, § Intra-op: TIME-OUT (intraop. pitfalls, disposition) • Premed: benzo +/- ketamine. Induction: opioid; tolerance. • Preload sensitive. Systemic-Pulmonary venous return and ventilation (CO 2, PEEP, venous tone). Low-threshold for OPEN procedure. • Inotropy: Dopamine PIV/EJV temporarily. CPR strategy: PADS, drugs, help. • Monitoring: NIRS, standard +/- 5 -lead ECG § Post-op: • PACU or PICU. Spontaneous ventilation. • Other: Dexmedetomidine. 20 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

Outcomes of Fontan Good, Bad, and Failing § HLHS pre 1980 s • <30% survival into adulthood § HLHS post- 1990 s • Up to 70% survival into adulthood • 90% of hospital survivors remain in NYHA I & II for two or more decades 21 Single Ventricle and Fontan Pathway - William C. K. Ng 2017

References Selected reviews § Gewillig M, Brown C. The Fontan circulation after 45 years: update in physiology. Heart 2016; 102: 1081– 1086 § Jolley M, Colan S, Rhodes J, Dinardo J. Fontan Physiology Revisited. Anesth Analg 2015; 121: 172– 82 § Feinstein et al. Hypoplastic Left Heart Syndrome - Current Considerations and Expectations. J Am Coll Card. Vol. 59, No. 1, Suppl S, 2012 § Freedom R, Nykanen D, Benson LN. The physiology of the bidirectional cavopulmonary connection. Ann Thorac Surg. 1998; 66: 664 -7. 22 Single Ventricle and Fontan Pathway - William C. K. Ng 2017