truncus arteriosus seoul national university hospital department of thoracic & cardiovascular...
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Truncus Arteriosus
Seoul National University Hospital
Department of Thoracic & Cardiovascular Surgery
Truncus Arteriosus
1. Definition Congenital cardiac malformation in which one great artery, arising
from the base of heart by way of a single semilunar(truncal) valve,
gives origin of coronary, systemic , and one or two pulmonary
arteries proximal to the origin of the brachiocephalic branches.
Beneath the truncal valve, there is a VSD.
2. History Wilson : 1st description in 1798
Buchanan : Clinical & autopsy report in 1864
Collett & Edwards : Classification in 1949
Van Praagh : Alternative classification in 1965
McGoon : 1st repair with homograft in 1967
Truncus Arteriosus
Pathophysiology• A single common artery, or truncus , overlying the
ventricular septum and a nonrestrictive VSD gives rise to the coronary arteries, pulmonary arteries, and ascending aorta.
• Complete mixing of systemic and pulmonary venous return at the VSD and truncal valve level results in moderate cyanosis.
• As the pulmonary vascular resistance decreases after birth, significant left-to-right shunting at the truncal valve level leads to excessive pulmonary blood flow, pulmonary hypertension, and congestive heart failure.
Truncus Arteriosus
Morphogenesis• Truncus arteriosus is called also as persistent truncus
arteriosus, truncus arteriosus communis, common aorticopulmonary trunk
• Chromosomal 22q11 deletion is present in a substantial number of patients with conotruncal abnormalities ( about one third with truncus arteriosus)
• Many of these have additional characteristic features of DiGeorge syndrome, velocardiofacial syndrome, or conotruncal face syndrome
• As such, their natural history may be complicated by hypocalcemia, palatal abnormalities, learning disability, or other noncardiac problems.
Morphology of Truncus Arteriosus
1. Truncal artery 2. Pulmonary arteries Type I, II : 80~90% III, IV : 5~10% Hemitruncus : 2% Stenosis of origin : 10%
3. Aorta & ductus arteriosus Wide PDA : Arch hypoplasia, IAA or CoA(10~15%) No PDA : majority
4. Coronary arteries 5. Semilunar valve Tricuspid (1/2~2/3), quadricuspid, bicuspid (5%) Myxomatous thickening (1/3) Truncal stenosis (20%)
6. VSD (juxtatruncal) 7. RV (absent conal septum) 8. Left ventricle ; normal 9. Associated anomalies IAA or CoA with PDA : 10~15% RAA : 25~35% Anomalous branch : 10% LSVC : 10% ASD : 10% DiGeorge synd. AV discordance, situs inversus, heterotaxia, DILV, MS, AV-canal, tricuspid stenosis
Classification of Truncus Arteriosus
Type ICommon arterial trunk gives rise to a main pulmonaryartery and the aorta
Type IIRight and left pulmonary arteries arise directly and inclose proximity from the posterior wall of the truncus
Type IIIRight and left pulmonary arteries arise from morewidely separate orifices on the posterior truncal wall
Type IVAbsence of branch pulmonary arteries: pulmonaryblood flow is derived from aortopulmonary collaterals
(Collett & Edwards)
Types of Truncus Arteriosus
Pathology of Truncus Arteriosus
Types of Truncus Arteriosus
Truncus Arteriosus
VSD
Truncal valve
Clinical Features & Diagnosis 1. Symptoms tachypnea, tachycardia, irritability, mild cyanosis
2. Physical examination signs of CHF, overactive heart
truncal insufficiency (systolic & diastolic murmur)
stenosis of PA (continuous murmur)
3. Chest radiography marked cardiomegaly as well as plethora
4. EKG RAD, biventricular hypertrophy
5. Echocardiography
6. Cardiac catheterization & cineangiography
Truncus Arteriosus
Natural History 1. Incidence rare, unfavorable natural history 1.7% to 2.8% of CHD 2. Survival 50% survival in 1 month 18% survival in 6 months 12% survival in 1 year Others : Eisenmenger syndrome (death in 3rd decade) 3. Modes of death . Congestive heart failure in early life . SBE, cerebral abscess, pulmonary vascular disease . Survival is favorably affected by PS
Operative Techniques
1. Repair with allograft valved conduit
2. Repair truncus I,II with autologous tissue
Barbero-Marcial technique
3. Repair of hemitruncus
Unifocalization of pulmonary artery
4. Repair of truncus arteriosus with IAA
Operative Indications
1. Diagnosis of truncus is an indication for it’s repair;
because about 50% of surgically untreated patients
die in the 1st month of life.
2. Repair should be recommended as early in life
as possible rather than deferring to some
predetermined age
3. Importantly elevated PVR is a contraindication
in old infant (more than 6~12 months old).
Operative Technique (1)
Operative Technique (2)
Truncal Valve Remodeling Technique
• Diagrams shows truncal valve repair by leaflet excision and annular remodeling, usually there is one leaflet that is grossly prolapsed
Surgical Results of Truncus Arteriosus
1. Survival Early death
Time-related survival
2. Modes of death
3. Incremental risk factors for premature death 1) Age at repair 2) Functional class
3) Type 4) Size of VSD
5) Predominance of origin of truncal artery
6) Small size of pulmonary arteries
7) Truncal valve abnormalities
8) Hemitruncus
9) Major associated cardiac anomalies
10) Pulmonary vascular disease
4. Progressing truncal valve incompetence 5. Conduit reoperation