Truncus arteriosus

1. Truncus arteriosus cyanotic

2. Definition A single trunk arising from the heart Supplying the coronary, pulmonary, and systemic circulations No remnants of an atretic aorta or pulmonary artery, attached to both ventricles Overriding the ventricular septum due to failure of the Truncus arteriosus to divide during in the embryonic period

3. History Wilson : 1st description in 1798 Buchannan : Clinical & autopsy report in 1864 Collett & Edwards : Classification in 1949 Van Praagh : Alternative classification in 1965 McGoon : 1st repair with homograft in 1967

4. QUICK ANATOMY Single artery arising from the two ventricles which gives rise to both the aortic and pulmonary vessels Abnormal truncal valve Right sided aortic arch in about 30% of cases (not shown) Large ventricular septal defect Pulmonary hypertension Complete mixing occurring at level of the great vessel Right-to-left shunting of blood

5. Blamed Baltimore-Washington Infant Study: maternal cigarette smoke(odds ratio [OR]: 1.9, 95% CI 1.04-3.45) Texas Birth Defects Registry (1999 to 2004): advancing maternal age 22q11.2 deletions: Deletions in three genes in this locus (TBX1, CRKL, and ERK2) cause neural crest cell and anterior heart anomalies seen in patients with DiGeorge syndrome Retinoic acid Bismuth

6. EMBRYOLOGY Defect in the development of the truncoconal[more conal than Truncus] septum result in Conotruncal abnormalities including Truncus arteriosus Neural crest hypothesis Bulbar septum is deficient just below the singular truncal=semilunar valve

7. INCIDENCE 40% trunk connects predominantly with the right ventricle 40% overriding is symmetrical 20% trunk connects mainly with the left ventricle Prevalence:0.3:10,000 births 12 times higher in women with pregestational diabetes mellitus Sibling recurrence is 1/100 6 to 10 per 100,000 live births 0.7 percent of all CHD 4 % of all critical CHD.

8. semilunar cusps 2-6 Tricuspid:69% Quadricuspid:22% Bicuspid valve:9%

9. VSD Large Maligned Conoventricular Occasionally muscular

10. How the pulmonary artery is connected to the truncus ? Type 1: a single pulmonary vessel originates from the arterial trunk and bifurcates in left and right pulmonary arteries. Type 2: the pulmonary arteries originate from the back of the Truncus Type 3: the pulmonary arteries originate on each side of the Truncus Type 4: absent pulmonary arteries; collaterals originate from the systemic circulation, most frequently from the descending aorta Collet RW, Edwards JE. Persistent truncus arteriosus: a classification according to anatomic types. Surg Clin North Am 1949;29:501-10

11. VSD OR NO VSD[Society of Thoracic Surgeons (STS) ] TYPE A[VSD+] TYPE B[VSD-] A1: As CE type 1, in which a main pulmonary artery is present, and arises from the left side of the truncal root. A2: h CE types II and III, as the two CE types do not differ embryologically and the surgical approach is the same. Type A2 consists of right and left branch pulmonary arteries with separate origins (regardless of the distance separating the two pulmonary arteries) from the truncal root. A3: Unilateral pulmonary atresia with collateral supply to the affected lung. A4:Interrupted aortic arch Van Praagh R, Van Praagh S. The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications: a study of 57 necropsy cases. Am J Cariol 1965;16:406-26

12. Major classification systems for truncus arteriosus reproduced from [25] with permission from Elsevier. Sojak V et al. MMCTS 2012;2012:mms011 © The Author 2012. Published by Oxford University Press on behalf of the European Association for Cardio-thoracic Surgery. All rights reserved

13. Hemodynamic Hemodynamic is not affected during intrauterine life Cardiac failure occurs after birth because of the fall in blood pressure in the pulmonary circulation leads to medical emergency Pulmonary vascular obstructive disease may develop in surgically uncorrected patients with large pulmonary blood flow, with changes noted as early as six months of age Coronary under perfusion due to AR and pulmonary run off

14. Natural history  a mean age of death at five weeks survival of only 15 percent at one year of age beyond the first year of life develop severe pulmonary vascular obstructive disease

15. symptoms Bluish skin (cyanosis) Delayed growth or growth failure Fatigue Lethargy Poor feeding Rapid breathing (tachypnea) Shortness of breath (dyspnoea) Widening of the finger tips (clubbing)

16. Signs Cyanosis presents at birth Heart failure may occur within weeks Systolic ejection murmur is heard at the left sternal border Widened pulse pressure Bounding arterial pulses Loud second heart sound Biventricular hypertrophy Cardiomegaly Increased pulmonary vascularity Hypocalcemia (if associated with DiGeorge syndrome)

17. Associated Up to 50% of the cases, including unilateral renal agenesis or hypoplasia, absent gallbladder, pulmonary hypoplasia and cleft palate DiGeorge, velocardiofacial (DFG/VCFS) and conotruncal anomaly face syndromes (CTAFS) are associated with conotruncal anomalies Aortic arch anomalies :Right aortic arch – 21 to 36%,Interrupted aortic arch – 11 to 19 percent,Hypoplastic aortic arch (with or without coarctation of the aorta) – 3 percent Secundum ASD:9 to 20%, mild tricuspid stenosis:6%, aberrant subclavian arteries: 4 to 10%, persistent LSVC :4 to 9% and PDA :50%

18. Differential diagnosis Pulmonary atresia/intact IVS Tetralogy of Fallot large ventricular septal defect (VSD) pulmonary atresia with VSD U niventricular heart

19. TREATMENT Initial medical management Surgery Treat heart failure due to large left to right shunt Connect pulmonary artery[ right ventricle to pulmonary artery (RV-PA) conduits ] to right ventricle Primary surgical repair during the neonatal period (less than 30 days of age) has led to an improved survival rate at one year of age of greater than 80 percent compared with the 15 percent rate observed in uncorrected patients

20. Thanks http://en.wikipedia.org/wiki/Persistent_truncus_arteriosus http://www.cincinnatichildrens.org/patients/child/encyclopedia/defects/graphicsummaries/truncusswf/ http://www.youtube.com/watch?feature=player_embedded&v=RBYCU_DH4qY