Congenital pulmonary venolobar syndrome

Congenital pulmonary venolobar syndrome is a condition comprised of a rare group of cardiac and pulmonary congenital abnormalities occurring variably in combination. The abnormalities include:

• anomalous pulmonary venous drainage
  • particularly scimitar syndrome with hypogenic right lung
• pulmonary sequestration with systemic pulmonary vascular supply
• horseshoe lung

Clinical presentation

• can present with shortness and breath and exercise intolerance due to the degree of left to right cardiopulmonary shunt causing pulmonary hypertension with right heart failure
• recurent pulmonary infection/ lower lobe pneumonia and / or haemoptysis due to sequestration
• frequently asymptomatic, picked up incidentally on plain chest radiograph or echocardiography 

Associations

• anomalous pulmonary venous drainage, including scimitar syndrome
• sinus venosus type atrial septal defect; which contributes to left to right shunting, leading to pulmonary hypertension, right heart dilation, right ventricular hypertrophy and failure.

Radiographic features

Plain radiograph

Nonspecific and may show:

• an enlarged right heart
• small right hemithorax with mediastinal shift to the right
• right sided scimitar vein
• recurrent lower lobe consolidation

CT

May show:

• right ventricular dilation and hypertrophy
• anomolous pulmonary veins, eg. Scimitar, left vertical vein
• sequestration with systemic arterial supply from upper abdominal aorta, coeliac trunk or SMA.
• small right lung with mediastinal shift to right.
• horseshoe lung - right lung extends posterior to the heart, contiguous with the left lung.

Cardiac MRI

• can confirm anomalous pulmonary venous drainage
• can identify any further congenital heart abnormalities eg. Sinus venosus ASD
• can measure the degree of left to right shunt via phase contrast flow volumes
• quantitation of right ventricular volumes and systolic function.
• identify systemic pulmonary arterial supply with differential pulmonary perfusion

Practical points

Identification of the systemic arterial supply to the lung in these patients is important in the context of planning for surgical repair of the anomalous venous drainage, in order to avoid injury and bleeding from this vessel.

Treatment and prognosis

• in patients with a large left to right shunt, at risk of developing pulmonary hypertension and right heart failure, corrective surgery is a consideration.
• surgical resection of the sequestration in cases of recurrent haemoptysis and/ or infection.
• conservative management with serial cMRI to monitor right heart progress.

History and etymology

The term was initially coined by Dr Benjamin Felson.

Related articles

• Scimitar syndrome