c l i n i c a l f o l i o s : d i s c u s s i o n



Pulmonary Sequestration

 

 

Related narrative: Pulmonary Sequestration, Thoracoscopic Sequestrectomy

Pulmonary sequestration is a non-functional lobe or part of a lobe supplied by a large systemic artery and lacking a normal connection to the tracheobronchial tree (20% have some connection with a normal bronchus, explaining trapped air, and a path of entry for bacteria). The sequestered segment may be intralobar, within the visceral pleura, or extralobar. The intralobar form usually drains into a pulmonary vein (and rarely into the right atrium), while the extralobar form drains into the azygous/hemiazygous system. Intralobar is more common (75%) than extralobar (25%).

The origin of the condition is uncertain, but is most likely from an accessory lung bud arising from the foregut where the normal lung buds develop. This origin explains the occasional fistula between the sequestered lung and the esophagus. Sequestration is most commonly found in the lower lobes, and more often on the left than the right. Extralobar sequestration more commonly presents in the neonatal period with respiratory distress and is occasionally associated with diaphragmatic hernia. Minimally invasive technique has recently been used for extralobar resection. Intralobar lesions often present later and are manifested by chronic or recurrent infection in the dilated, cystic, mucous filled bronchi. Magnetic resonance gadolinium enhanced angiography has been beneficial for operative planning. Bronchogenic cysts, which may be mistaken for sequestration, occur more proximally in the tracheobronchial tree, and lack a systemic arterial supply. The treatment of sequestration is ligation of the systemic vessel and resection of the involved lung segment or lobe.

References:

Skandalakis, JE, Gray, SW, Embryology for Surgeons, 2nd ed, Williams and Wilkins, Phila, 1994, pp 463-470.

Greenfield, LJ, Surgery, Scientific Principles & Practice (3rd ed), JB Lippincott, Phila., 2001, pp 1941-2.

Shields, TW, LoCicero III, J, Ponn, RB, General Thoracic Surgery, 5th ed, Williams & Wilkins, Phila., 1999, p 184.


This page was last modified on 17-Jan-2001.