Congenital pulmonary venolobar syndrome

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

• anomalous pulmonary venous drainage

  • particularly scimitar syndrome with hypogenetic right lung

• pulmonary sequestration with systemic pulmonary vascular supply

• horseshoe lung

Clinical presentation

• can present with shortness of breath and exercise intolerance due to the degree of left-to-right cardiopulmonary shunt causing pulmonary hypertension with right heart failure

• recurrent 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 which contributes to left-to-right shunting, leading to pulmonary hypertension, right heart dilation, and right ventricular hypertrophy and failure

Radiographic features

Plain radiograph

Non-specific and may show:

• 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

• anomalous pulmonary veins, e.g. scimitar vein, left vertical vein

• sequestration with systemic arterial supply from the upper abdominal aorta, celiaccoeliac trunk or SMA

• small right lung with mediastinal shift to the right

• horseshoe lung - right lung extends posteriorly to the heart, contiguous with the left lung

Cardiac MRI

In addition to CT, MRI allows the radiologist to:

• confirm anomalous pulmonary venous drainage

• identify any additional congenital heart abnormalities, e.g. sinus venosus atrial septal defect (ASD)

• measure the degree of left-to-right shunt via phase contrast flow volumes

• perform 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 cine MRI (cMRI) to monitor right heart progress

History and etymology

The term was initially coined by Benjamin Felson.

Related articles

• Scimitar syndrome