INTRODUCTION:Pulmonary torsion is a rare cause of pulmonary infarction. There are approximately sixty cases described in the literature that were associated with pleural effusions, lobar atelectasis, tumor, or as a complication of pulmonary resection. It can also occur as result of lung transplantation.
CASE PRESENTATION:We present a case of lobar torsion of right upper lobe and right middle lobe complicating re-do bilateral lung transplantation. The patient is a 40 year old male with past medical history of double lung transplant for idiopathic pulmonary fibrosis in 2003 who underwent re-do lung transplantation secondary to progressive graft loss from bronchiolitis obliterans. His case was done off cardiopulmonary bypass. The ischemic times were 1 hour 52 minutes for right and 3 hours 11 minutes for the left lung. His post operative course was complicated by right hemothorax which required re-exploration of his chest. Removal of the blood clot resolved the right lower lobe collapse on post-operative day two. He was subsequently extubated the following day. On post-operative day number five, he developed acute hypoxemic respiratory failure and acute pulmonary hypertension. His immediate post-op pulmonary artery pressure right heart catheter readings were 24/15 (mean 18). By post operative day five, his pulmonary artery pressure readings jumped to 75/20 (mean 38) with a wedge of 10. The evaluation for the hypoxia included a chest x-ray and CT scan of the chest which showed a right sided apical pneumothorax and right upper lobe collapse. Bronchoscopy showed the orifices of the right upper lobe to have fish-mouth like narrowing. There was also total occlusion of the right middle lobe. He was emergently taken to the operating room with a suspicion for torsion. After intra-operative de-torsion of the right upper and middle lobes with bronchoscope guidance, his hypoxemia and acute pulmonary hypertension were corrected and the graft was saved.
DISCUSSIONS:Pulmonary torsion results from the rotation of a lobe of lung occurring along a bronchovascular pedicle. Compromising the pulmonary arterial, pulmonary venous, and bronchial artery vascular supplies, pulmonary torsion can quickly cause infarction. In lung transplantation, the risk of lung torsion is theoretically higher because of the division of the pulmonary ligament of the donor lung. It can also potentially occur with size difference. Ischemia-reperfusion injury may lead to an increase in lung water weight causing rotation around a pedicle. Diagnosis can be made with chest x-ray and CT findings. As in our case, bronchoscopic findings are also useful. Once diagnosis has been made, treatment should be promptly carried out to prevent the development of pulmonary gangrene. Treatment includes surgical detorsion or pulmonary resection of the involved segment.
CONCLUSION:From our survey of the literature, this is the third case of pulmonary torsion complicating lung transplantation. Pulmonary torsion should be promptly identified as an etiology of acute respiratory failure and acute development of pulmonary hypertension. In lung transplantation, restoration of circulation to the graft will preserve the graft and prevent the development of infarction.
DISCLOSURE:Rabih Loutfi, No Financial Disclosure Information; No Product/Research Disclosure Information