D R V I S H W A N A T H H E S A R U R

J N M C , B E L G A U M

TRUNCUS ARTERIOSUS

FORMATION OF CONOTRUNCAL SEPTUM

Single outflow tract from the heart• Improper formation of truncal ridges & aorticopulmonary

septum such that aorta & pulmonary trunk are not fully divided• 1-2% of all CHDs

DEFECT OF CONOTRUNCAL SEPTATION

TRUNCUS ARTERIOSUS

Truncus arteriosus is one of the least common cynotic

congenital heart disease.

1-2.5 % in all CHD.

Frequently syndromic as 22q 11 deletion syndrome.

DiGeorge’s syndrome.

DiGeorge’s syndrome

Definition

It is congenital cardiac malformation in which one great

artery arises from the base of the heart by a way of single

semilunar valve (truncal valve),it gives origin to systemic

arteries,coronary arteries and pulmonary arteries.

History – Wilson – 1st described in 1798.

Buchanan – clinical and autopsy reports in 1864.

Collett and Edwards –classification in 1949.

Van praagh- alternative classification in 1965.

McGoon – 1st repair with homograft in 1967.

Echocardiography

It starts with situs –visceral situs ,atrial situs

Atrioventricular concordance.

Two balanced ventricles are usually present & separated by large VSD.

Very rare form with discordant atrioventricular connection.

Truncal valve continuity with the anterior leaflet of mitral valve.

Truncal valve

It is best seen in parasternal short axis view.

It can be tricuspid – 60-67 %.

Quadricuspid – 25- 31%

Bicuspid – 8%

Pentacuspid -0.3%

Valve leaflet can be normal or may be stenotic or

regurgitant.

Truncal valve

Classification of truncus arteriosus

I) Edward & Collett classification-

Type I – main pulmonary trunk arises from truncus

arteriosus and gives rise to RPA & LPA.

Type II- RPA & LPA arteries arises directly and lying

close to one another.

Type III- RPA & LPA arises from separate ostium lying at

some distance from one another.

Type IV-absence of branch of PA ,pulmonary blood flow

is derived from aortopulmonary collaterals.

EDWARD AND COLLETT CLASSIFICATION-1949

Van praagh classification-1965

Type A1-corresponds to type I of collett & Edward.

Type A2- corresponds to Type II and Type III of collett &

Edward.

Type A3-Absence of truncus origin of one of the

pulmonary Artery.

Type A4- Hypoplasia of Aorta.

Differential diagnosis

A)Pulmonary atresia-pulmonary ateries are small with

continues flow being seen in branch PA either from PDA

or collateral flow.

B) very rarely this large great vessel may be PA in

patient’s of aortic atresia.(Imp – identify Aorta).

C) anomalous origin of RPA from posterior aspect of

aorta.

2D-Parastenal long axis view

Common arterial trunk arising predominantly from LV –

4-6%

Truncus arteriosus with biventricular origin – 69%

Right ventricular origin – 11 – 29 %

Truncal override –

It is discontinuity between IVS and anterior truncal wall.

Large ventricular septal defect

In truncus arteriosus large VSD is commonly seen.

It developes due to absence or deficiency of infundibular

septum.

Restrictive VSD or no VSD is very rare.

Short MPA with RPA & LPA arising frm left lateral aspect of TR

NO MPA –direct RPA & LPA arising from posterior aspect of TR

Parasternal short axis view

Apical view

Suprasternal long axis view

Regurgitant truncal valve

Causes-

1) Thickening , dysplastic cusps.

2) Prolapsed cusps.

3) unequal cusps.

4) truncal root dilation.

Stenotic truncal valve

By using colour and continues doppler gradient across

pulmonary arteries and stenotic truncal valve can be

recorded.

Stenosis and regurgitant gradient is frequently

overestimated across truncal valve bz both the ventricular

output has to pass across it.

Gradient up to 40 – 50 mmHg have been documented.

Significant stenosis of origin of branch of pulmonary

artery is the presence of diastolic spill on doppler.

Coronary artery anomalies

Associated anomalies

Right aortic arch- 25 to 35 %

Coarction of aorta.-10 to 15 %

Patent ductus arteriosus-10%

Interrupted aortic arch- 10 to 15 %

Ostium secundum ASD-10 %

Left SVC draining into coronary sinus- 10%

TAPVC / PAPVC

Surgical correction