Right middle lobe torsion: evaluation with CT angiography

Abstract

A case of right middle lobe torsion occurring after a right upper lobectomy is described. HR-CT angiography was successful in identifying the obstructed right middle lobe bronchus and the avascular nature of the infected and displaced right middle lobe. This detailed information, obtainable from present day multislice HR-CT scanners with the right CT protocols, seems to diminish the need for further confirmation by other methods.

Spontaneous middle lobe torsion in a patient with multicentric Castleman disease: A case report

“…Lung torsion is rare, with a reported incidence of 0.09–0.4% . It usually occurs in a post‐operative setting, typically after right upper lobectomy; however, spontaneous torsion can occur in the setting of pleural effusion, trauma or neoplasm .…”

“…A torted lobe rotates up to 360° around the vascular pedicle, potentially resulting in venous congestion and haemorrhagic infarction if left untreated . Early recognition is important as morbidity and mortality is high without urgent surgical intervention …”

“…Additional CT findings include focal bronchial tapering, hilar distortion, abnormal fissure orientation, poorly enhancing consolidation with hyperinflation, ground glass attenuation and smooth interlobular septal thickening . CT angiogram may help to identify abnormal course of pulmonary vessels and decreased vascular flow to the torted lobe . An ‘antler sign’ has been used to describe the abnormal curvature and one‐sided branching of pulmonary arteries seen in upper and lower lobe torsion …”

Spontaneous middle-lobe torsion

“…CTA has been reported to be particularly useful, due to its ability to follow the course of the affected pulmonary vessels. It may also indicate decreased or absent blood flow to the torsed lung ( 9 ). Contrast was not administered in our case, which limited evaluation of the vascular supply.…”

Postoperative complications after thoracic surgery for lung cancer

“…Torsion occurs when a lobe, or the complete lung, rotates 180 degrees around hilar structures, although instances of 90 degree and 360 degree torsion have been described [16]. Lobar torsion most commonly involves the right middle lobe after right upper lobectomy or the lingula following a lingular sparing left upper lobectomy [28,29]. The torsed lung compromises the airways, arterial blood supply and lymphatic and venous drainage, resulting in hemorrhagic infarction or necrosis in the affected lobe(s) [30].…”