Pulmonary Sequestration - Intralobar Sequestration

Intralobar Sequestration

·The intralobar variety accounts for 75 percent of all sequestrations.

·Usually presents in adolescence or adulthood as recurrent pneumonias.

·The lung tissue lies within the same visceral pleura as the lobe in which it occurs.

·Males and females are equally affected with ILS.

·In ILS, the arterial supply usually is derived from the lower thoracic or upper abdominal aorta.

·Venous drainage is usually to the left atrium via pulmonary veins establishing a left to right shunt.

·Abnormal connections to the vena cava, azygous vein, or right atrium may occur.

·Two thirds of the time, the sequestration is located in the paravertebral gutter in the posterior segment of the left lower lobe.

·Unlike extralobar sequestration, it is rarely associated with other developmental abnormalities.

·Patients present with signs and symptoms of pulmonary infection of a lower lobe mass.

·It is believed that sequestrations become infected when bacteria migrate through the Pores of Kohn or if the sequestration is incomplete.