Bronchopulmonary sequestration

• Is more common in males.
• Is more common on the left. Usually the posterior basal segment of the left lung lower lobe.
• May communicate with the oesophagus. It arises as an accessory tracheobronchial foregut bud, hence its systemic arterial supply.
• Intralobar is more common than extralobar sequestration. Intralobar is about 3 times more common and usually presents in adulthood. It is enclosed by the visceral pleura of the affected pulmonary lobe.
• Systemic feeding vessels originate from the descending thoracic aorta. Vascular drainage into the left atrium occurs through the normal pulmonary veins resulting in a left-to-left shunt. Associated congenital abnormalities are rare.
• Extralobar sequestration has its own pleural sheath which prevents collateral air drift and usually presents in neonates. 90% are contiguous with the left hemidiaphragm in the thorax.
• Systemic feeding vessels commonly originate from the thoracic or abdominal aorta (80%), or from the splenic, gastric, subclavian or intercostal arteries. Vessels drain into the systemic circulation through the IVC, azygos or hemiazygos veins. Associated congenital abnormalities are frequent.