Congenital pulmonary stenosis

A congenital pulmonary stenosis (CPS) broadly refers to a congenital narrowing along any segment of the pulmonary arterial system.

Epidemiology

The estimated incidence is at ~ 1 in 2000 births

Pathology

Can be morphologically categorised depending on the relationship to the pulmonary valve ³

1. supra valvular - distal to the valve : commonest  ~ 60% ⁴
2. valvular  
3. sub valvular - infundibular

Sub classification 

Supra-valvular stenoses have been traditionally classified in to four types.  

Associations

Generally occurs as an isolated feature and associations are rare ³. They include:

• Noonan syndrome
• Williams syndrome (supravalvular)
• tetralogy of Fallot
• in utero rubella exposure
• Down syndrome
• Ehlers Danlos syndrome
• 22q deletion syndrome

Radiographic features

Chest radiograph

Non specific. Can have a normal heart size or may show evidence of right ventricular hypertrophy. May also show evidence of a dilated pulmonary trunk or a main pulmonary artery.

CT / CTA

Direct visualisation of stenotic segment +/- post stenotic dilatation of distal arterial segments.

MRI / MRA

Direct visualisation of stenotic segment +/- associated features. Velocity encoded phase contrast (VEC) cine sequences can assist assessing the severity of the stenosis by allowing measurement of blood flow velocities and volumes ²

Ultrasound

Doppler ultrasound / echocardiography

May show a high flow jet with turbulent flow through the pulmonary valve or narrowed segment.

See also

• pulmonary atresia