1. Tetralogy of Fallot for Cardiac Anaesthesia
UCSF Congenital Cardiac Anesthesia Tutorials
Tetralogy of Fallot for Cardiac Anaesthesia
William C K Ng

2. acknowledgements
2016 Jun, Paris and Boston.

3. ToF: Intro 10% of CHD Tetrad Over-riding Aorta RVOTO (sub-PS)
Unrestrictive VSD
RVHT
TOF/PA, TOF/Absent PV
MAPCA
Other lesions and syndromes
Associated lesions: bicuspid PV, LPA stenosis, P/TAPVR, LSVC, AV septal defect, PDA, ASD PFO (Pentalogy), interrupted IVC.
Syndromes: VACTERL, CHARGE, Alagille, 22q11 deletion (TOF: 11% had 22q),
Down’s Syndrome:

4. History, Examination, Investigations
Prenatal diagnosis vs. Postnatal diagnosis - more obvious when PDA is closed.
Cyanosis
Syndromes
Chest
ECG: RAD
CXR: “clog-shaped” heart Cœur en sabot.
APCs can be seen on this CXR diagram.

5. Consequences and associations of ToF
Biventricular origin of Aorta
HT RVOT
PA hypoplasia or PV absence, and consequences of each
Other
PV dysplasia
RAA with mirror branching
Coronary pathways: LAD from RCA
Syndromes: VACTERL, CHARGE, Alagille, 22q11 deletion, Trisomy- 21
5-12% have abnormal coronary origins, most commonly LAD from RCA.
Even tracheobronchial stenoses! Int J Pediatr Otorhinolaryngol Apr;83:1-6. doi: /j.ijporl
Down’s: Eur J Med Genet Dec;58(12): doi: /j.ejmg Epub 2015 Nov 11.
Associated congenital anomalies among cases with Down syndrome.
Stoll C1, Dott B2, Alembik Y2, Roth MP2.
Author information
Abstract
Down syndrome (DS) is the most common congenital anomaly widely studied for at least 150 years. However, the type and the frequency of congenital anomalies associated with DS are still controversial. Despite prenatal diagnosis and elective termination of pregnancy for fetal anomalies, in Europe, from 2008 to 2012 the live birth prevalence of DS per 10,000 was The objectives of this study were to examine the major congenital anomalies occurring in infants and fetuses with Down syndrome. The material for this study came from 402,532 consecutive pregnancies of known outcome registered by our registry of congenital anomalies between 1979 and Four hundred sixty seven (64%) out of the 728 cases with DS registered had at least one major associated congenital anomaly. The most common associated anomalies were cardiac anomalies, 323 cases (44%), followed by digestive system anomalies, 42 cases (6%), musculoskeletal system anomalies, 35 cases (5%), urinary system anomalies, 28 cases (4%), respiratory system anomalies, 13 cases (2%), and other system anomalies, 26 cases (3.6%). Among the cases with DS with congenital heart defects, the most common cardiac anomaly was atrioventricular septal defect (30%) followed by atrial septum defect (25%), ventricular septal defect (22%), patent ductus arteriosus (5%), coarctation of aorta (5%), and tetralogy of Fallot (3%). Among the cases with DS with a digestive system anomaly recorded, duodenal atresia (67%), Hirschsprung disease (14%), and tracheo-esophageal atresia (10%) were the most common. Fourteen (2%) of the cases with DS had an obstructive anomaly of the renal pelvis, including hydronephrosis. The other most common anomalies associated with cases with DS were syndactyly, club foot, polydactyly, limb reduction, cataract, hydrocephaly, cleft palate, hypospadias and diaphragmatic hernia. Many studies to assess the anomalies associated with DS have reported various results. There is no agreement in the literature as to which associated anomalies are most common in cases with DS with associated anomalies. In this study we observed a higher percentage of associated anomalies than in the other reported series as well as an increase in the incidence of duodenal atresia, urinary system anomalies, musculoskeletal system anomalies, and respiratory system anomalies, and a decrease in the incidence of anal atresia, annular pancreas, and limb reduction defects. In conclusion, we observed a high prevalence of total congenital anomalies and specific patterns of malformations associated with Down syndrome which emphasizes the need to evaluate carefully all cases with Down syndrome for possible associated major congenital anomalies.

6. APCs in pulmonary atresia:
“No Flow, No Grow.” said a wise man from Alabama.
Absent PV -> PR -> RV volume overload - > dilated PAs.

7. Echocardiograp hy RVOTO and dynamic changes
Echocardiograp hy
RVOTO and dynamic changes
VSD: number, location, size (unrestricted)
Coronaries
Other abnormalities
Function and dynamic changes

8. Pathophysiology
R-L shunt, cyanotic “Tet” spells, dynamic RVOTO (infundibular spasms).
“Pink Tets”
CHF, pulmonary volume overload
RV HT -> diastolic dysfunction, risk for ischaemia, poor protection on CPB, post-operative problems.
SVR and PVR balance
Avoid increased contractility, tachycardia and decreased preload
Because of the detrimental effects of RV HT, surgical repair should be done during infancy.

9. Repair: Pre-operative Considerations
Surgical Planning
Symptoms?
Palliative Shunt prior to Repair?
<1 month
<6 months, <4kg
Alternative: balloon dilation
Definite Repair
>6 months
>4 months, >4kg
Premedication
IV access
Hemodynamic goals
contractility
preload
afterload
rate
PDA, APC, Interventions?
Medications
Induction
We’ll focus one Repair…
BTS has a different approach: R thoractomy, lung retraction, low-dose heparin, PDA and shunt-opening problems, post-op problems such as unilateral haemorrhage, RLN/Horner’s, chylothorax.

10. Repair: Intraoperative Considerations
PVR
O2, CO2, pH
Perfusion Pressure
RV, LV
Surgical Goals:
Relief of RVOTO
VSD repair
Preservation of RV function
Morales et al. on Right Infundibular sparing
Induction dangers, access and plan B
IM/IV: Ketamine, Fentanyl, Rocuronium, low-dose Sevoflurane
Monitoring
NIRS
Invasive monitoring and CVC
Rescue drugs, fluid, maneouvres
alpha, IVF, beta-blocker, sevoflurane, abdominal pressure, position
Maintenance
Fentanyl
Fast-track
Lillehei in 1954 performed first complete repair of TOF and stated the classic surgical goals.
Morales et al. Tetralogy of Fallot repair: the right ventricle infundibulum sparing strategy. Semi Thorac Cardiovasc Surg Pediatr Card Surg Ann 2009;12:54-58.

11. Repair of ToF RVOT TAP Ventricular incision vs. infundibular sparing
Valve sparing, repair
RV-PA conduit in coronaries over RVOT
Homograft
VSD
ASD

12. Post-operative and Late considerations
RV function
Inotropes, filling & RAp, PVR
RVp:LVp (<0.75)
Disposition
Conduction system (VSD); JET (10%)
Shunt: physiological, post-op ventilation; thrombosis, stenosis
Ventricular incision, TA patch and complications
Residual VSDs (>3mm)
PBF: too much/little
Cardiac Catherization
Pulmonary rehabilitation
BDs, Stents, APCs
Redo: RV-PA conduit, PVR
Mortality
Predictors on CMR (LV CS, RV LS)
Morbidity
Ventricular function, ET
Atrial Tachyarrhythmias (atrial dilation), VT
QRS >180s and PVR
Aortic Dilation
Aortic Dilation: Pediatr Int May;58(5): doi: /ped
Mechanism of aortic root dilation and cardiovascular function in tetralogy of Fallot.
Seki M
Orwat S, et al. Myocardial deformation parameters predict outcome in patients with repaired tetralogy of Fallot. Heart Feb;102(3): doi: /heartjnl Epub 2015 Dec 29.
JET is associated with AV dissociation and HD instability (risk factors: long CPB, inotropes, AV node interruption). Treatment with cooling, amiodarone, procainamide, sedation.

13. ToF and non-Cardiac Surgery
Pre-repair? Hemodynamic goals: C.R.A.P.
Un-repaired with cyanosis?
Earlier repairs with Transannuloplasty: PR and RV dilation
Post-repair:
Function on history
Echo assessment, RVOT, PV, RV
PA: anatomy and haemodynamics
EPS: atrial tachy-arrhythmias (AF)
Role of CMR (see. Ezzat et al.)
Ezzat VA, et al. Radiofrequency ablation of atrial tachyarrhythmias in adults with tetralogy of Fallot - predictors of success and outcome. Cardiol Young May 26:1-10. DOI: /S

14. ToF: Key Points Most common form of cyanotic heart disease
Hemodynamic Management Goals
Unrepaired: PVR vs. SVR
Repaired:
Induction
Post-op. complications
Cath-lab pulmonary rehabilitation
Late outcomes
BTS: another time