Pulmonary sequestration

Introduction: Congenital bronchopulmonary malformations are rare lesions that may become apparent at any age. Pulmonary sequestration is defined as a cystic nonfunctioning lung tissue that usually has no communication with the normal bronchial tree and receives its blood supply from an anomalous systemic artery. Lobar emphysema is an "idiopathic" hyperinflation of one lobe that may cause severe respiratory distress in infancy.

Hereby a case of an unusual combination of upper lobe intralobar sequestration and congenital lobar emphysema is presented.

Case Presentation: A seven-year-old boy was admitted to our hospital for surreal treatment of congenital lobar emphysema of the left upper lobe. He had been treated for pneumonia and abscess in the same lobe one month before. His past medical history was remarkable for frequent respiratory infections. According to radiographic findings lobar emphysema had been suspected already during the first year of life. On admission plain chest radiograph demonstrated a hyperinflated left upper lobe with mediastinal shift toward the right and a consolidation with air-fluid level in the left hilum. Chest CT scan confirmed the diagnosis of congenital lobar emphysema in the left upper lobe and in addition a pulmonary sequestration was suspected. Subsequent aortogram demonstrated two systemic vessels arising from the abdominal aorta and supplying the pulmonary sequestration in the left upper lobe. Pulmonary arteriography demonstrated normal pulmonary artery branching except in the left upper lobe that was supplied by two branches only. The venous return from the left upper lobe was in addition to normal vein also to the left subclavian vein. Fiberoptic bronchoscopy revealed a normal bronchial anatomy. Barium swallow showed no communication of the pulmonary sequestration and the gastrointestinal tract.

During the operation the aberrant arteries and vein were ligated. Subsequently the emphysematous left upper lobe together with intralobar sequestration was resected. The postoperative course was uneventful and the patient has remained asymptomatic after 6 months.

Discussion: Pulmonary sequestrations involve the lower lobe in 97, 75% of cases. In this case it appeared in the upper lobe, having caused recurrent respiratory infections as common to intralobar sequestration. Congenital lung anomalies, including sequestration, although rare, are one of the main causes of recurrent pneumonia in infants. When pulmonary sequestration is suspected, a chest CT scan, aortography and pulmonary angiography are recommended to confirm the diagnosis. Defining the arterial and venous supply allows to prevent accidental intraoperative bleeding from aberrant vessels. A great variety of arterial and venous anomalies can exist.

Although intralobar sequestration is less often associated with other congenital anomalies, in this case it appeared in combination with congenital lobar emphysema. The diagnosis of congenital lobar emphysema is usually made before 6 months of age and it was also suspected in this patient. As overdistension of the affected lobe was only moderate, the patient was not referred to a thoracic surgeon. Therefore the correct diagnosis and surgical therapy were delayed, but fortunately that (lid not affect the outcome.

Conclusion: pulmonary sequestration can rarely occur in the upper lobe and in combination with congenital lobar emphysema. Preoperative studies for defining the arterial and venous supply are recommended as various concurrent anomalies can exist.

Tanel Laisaar, MD--Tartu University Lung Hospital, Tartu, ESTONIA

COPYRIGHT 1999 American College of Chest Physicians
COPYRIGHT 2000 Gale Group