Transcript tetralogy of fallot and right ventricular outflow tract obstruction

TETRALOGY OF FALLOT AND
RIGHT VENTRICULAR
OUTFLOW TRACT
OBSTRUCTION
KSC MALEFAHLO
• "Dr.Blalock,I stand in awe and admiration of your
surgical skill but the truly great day will be when you
build a ductus for the child dying of anoxemia and not
when you tie off a ductus for a child with a little too much
blood going this lungs. "Dr. Blalock gave a Sigh and
replied, "When that day comes, this will seem like child's
play."
Outline
Anatomical Features
Associated Anomalies and Fallot Variants
Physiology and Clinical Presentation
Natural History
Diagnosis
Surgical Treatment
• Modified Blalock-Taussig shunt
• Technique of complete repair
Post-operative Care and Results
Anatomical Subsets
• Absent pulmonary valve syndrome
• With atrioventricular septal defect
• With anomalous course of coronary artery
Anatomical features
• DEFINITION
– Due to antero-cephalad deviation of outlet septum
leading to:
» Unrestricted malaligned large subaortic
VSD;
» RVOTO at any level;
» Consequent RVH and
» An overriding aorta(<50%)
– Additional features include muscular VSD, anomalous
coronaries, PDA, MAPCAs(esp with pulm.atresia) and
RSAarch
Pentalogy of Fallot has an ASD or PFO
•D. Mayer and C. Mullins, Congenital Heart Disease, A Diagrammatic Atlas. New York: Alan R. Liss, Inc, 1988. p. 5.
ASSOCIATED ANOMALIES
• PERSISTENT PATENCY OF THE FORAMEN OVALE
AND ASD
• ADDITIONAL MUSCULAR VSD
• 11% HAVE PERSISTENT LEFT SVC
• ABERRANT ORIGIN OF THE LEFT CORONARY 5 TO
15%. LAD ARISES FROM RCA
• 20 TO 25% HAVE A RIGHT SIDED AORTIC ARCH
• <5% HAVE MAPCAs
ANATOMIC VARIANTS
•
TET PULMONARY ATRESIA WITH OR WITHOUT
MAPCAs
• TET WITH ABSENT PULMONARY VALVE
• TET WITH DOUBLE OUTLET RIGHT VENTRICLE
• TET WITH ATRIOVENTRICULAR SEPTAL DEFECT
PHYSIOLOGY AND CLINICAL
PRESENTATION
• PRESENTATION VARIES DEPENDING ON THE
SEVERITY OF RVOTO
• MILD OR NO CYANOSIS WILL PRESENT LATER
WHEN RVOTO WORSENS
• CLUBBING IS SEEN IN LONG STANDING CYANOSIS
• TET-SPELLS ARE EPISODES OF CYANOTIC
HYPOXAEMIC ATTACKS. TREATMENT CONSISTS OF
INCREASING LV AFTERLOAD.
Fyler DC (1992) Tetralogy of Fallot. In: Keane JF, Dyler DC, Lock JE, Nadas’
(eds) Pediatric cardiology. Hanley & Belfus, Philadelphia, pp 471-491
NATURAL HISTORY
• VARIABLE AND DEPENDS ON THE SEVERITY OF RVOTO
• 25% WITH SEVERE RVOTO DIE IN THE FIRST YEAR IF NOT
SURGICALLY TREATED
• IF NOT TREATED 40% DIE BY AGE 3 YEARS, 70% BY AGE 10
YEARS AND 95% BY AGE OF 40 YEARS.
• MAJOR CAUSES OF DEATH IF UNTREATED INCLUDES
HYPOXAEMIC SPELLS AT 62%, CVI AT 17% AND BRAIN
ABSCESSES AT 13%
• HIGHEST RISK OF DEATH IS IN THE FIRST YEAR AND THEN IT
REMAINS CONSTANT UNTIL AGE 25 YEARS AND THEN
INCREASES.
Loh TF, Ang YH, Wong YK et al (1973) Fallot’s tetralogy-natural history. Singap Med J 14:
169-171
DIAGNOSIS
• PHYSICAL EXAM
• CXR AND ECG
•http://www.google.co.za/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=&url=http%3A%2F%2Fwww.nairaland.com%2F1235070%2Fmedicalrecall&ei=84uRVdmtA4KL7Aap7oXwDQ&bvm=bv.96783405,d.ZGU&psig=AFQjCNFTp8JE2OYMktwuU8iQAjP_DT2A1w&ust=1435688307586797
DIAGNOSIS
• LAB STUDIES
– POLYCYTHEMIA WITH CYANOSIS
– STUDIES FOR DELETION ON LONG ARM OF CHROMOSOME 22.
ACRONYM CATCH-22
• ECHOCARDIOGRAPHY
–
–
–
–
–
DEFINITIVE DIAGNOSTIC MODALITY
NUMBER AND LOCATION OF VSD’s
ANATOMY AND PULMONARY ARTERIES
CORONARY ARTERY PATTERN
PRENATAL DIAGNOSIS ACCURATE
• CATHETERIZATION
– HIGHLY ACCURATE AND INVASIVE
– WHEN SUSPECTING MAPCAs
– INTERVENTION
SURGICAL TREATMENT
TET
ASYMPTOMATIC
SYMPTOMATIC
>4 MONTHS &
>4 KG
1 – 6 MONTHS
<1 MONTH
REPAIR
SHUNT
>6 MONTHS
>4 KG
REPAIR
REPAIR
<4 KG
SHUNT
Surgical repair
• Historical perspective
– augmenting blood flow to the lungs, Blalock
and Taussig shunt.
– Lillehei et al, using controlled crosscirculation, performed first Tet correction in
1954
– When to repair depends in part on the degee
of cyanosis.
Surgical repair
• Palliation
– Blalock-Taussig shunt or modification (subclavian
artery-to-pulmonary artery shunt).
– Waterston shunt (ascending aorta-to-right pulmonary
artery).
– Potts shunt (descending aorta-to-left pulmonary
artery).
– Central interposition tube graft.
– Infundibular resection (Brock procedure) or
pulmonary valvotomy.
– RV-to-PA conduit without VSD closure or with
fenestrated closure
Surgical repair
• Technique ( first series late 1960’s)
– VSD repair via right ventriculotomy
– Resection of the RVOT muscle bundles and
pulmonary valve
• Long term results
– Aortic and pulmonary valve insufficiency
– RV dilatation
– Reinterventions
Surgical repair
Recent era from 1970 to present
• Complete repair in younger age including
neonates
Barratt-Boyes BG, Neutze JM (1973) Primary repair of tetralogy of Fallot in infancy using profound
hypothermia with circulatory arrest and limited cardiopulmonary bypass: a comparison with
conventional two stage management. Ann Surg 178:406–411
Surgical repair
Neonatal surgery:
McMillan noted that primary VSD closure had high
incidence of heart block and death.
Bonchek and Starr concluded that early repair was
advantageous with less mortality and prevention
of worsening fibrosis with RVOT
Bonchek LI, Starr A, Sunderland CO et al (1973) Natural history of tetralogy of
Fallot in infancy. Circulation 48:392–397
Surgical repair
Neonatal surgery:
Shunt first then complete repair?
Two-stage repair has high mortality( 20%
early and 6% late with shunts).
Primary repair 8%
Barratt-Boyes BG, Neutze JM (1973) Primary repair of tetralogy of
Fallot in infancy using profound hypothermia with circulatory arrest
and limited cardiopulmonary bypass: a comparison with
conventional two stage management. Ann Surg 178:406–411
Surgical repair
Transannular patch technique:
• Small PV annulus patients have improved relief of RVOT
• Results in regurgitation of PV with RV volume load
• Long term RV myocardial dysfunction and ventricular arrhythmias
Blackstone EH, Kirklin JW, Pacifico AD. Decision-making in the repair of tetralogy of Fallot based on
intraoperative measurements of the pulmonary arterial outflow tract. J Thorac Cardiovasc
Surg.1979;77:526-532.
Surgical repair
Transatrial–transpulmonary repair:
• To deal with complications related to the use of the TA Patch
technique
• Pulmonary valve sparing technique
• Avoid resection of the RV muscle
Right ventricular to Pulmonary artery conduit
• Tiny pulmonary arteries
• Aberrant origin of coronay arteries
• Type of conduit used is surgeon dependent
Future
• Tissue engineered valves and valved
conduits
• Percutaneous valves
• Genetic manipulation as a therapeutic tool
Conclusion
Initially an incurable condition, then a
condition for palliation, now it is a curable
condition!
References
1.
2.
Morales DL, Zafar F, Fraser CD Jr. Tetralogy of Fallot repair: the right ventricle
infundibulum sparing (RVIS) strategy. Semin Thorac Cardiovasc Surg PediatrCard
Surg Annu. 2009:54-58.
Cebotari S, Lichtenberg A, Tudorache I et al (2006) Clinical application of tissue
engineered human heart valves using autologous progenitor cells. Circulation
114(Suppl 1):132–137