Postpneumonectomy Syndrome: Results of mediastinal repositioning vs. stent placement

摘要

Background: Postpneumonectomy syndrome (PPS) is a late complication of pneumonectomy characterized by mediastinal shift and bronchial compression. It is most common following right pneumonectomy but is also seen left pneumonectomy. It can be treated with mediastinal repositioning and tissue expander placement in the postpneumonectomy space, but there is some interest in less invasive modalities. Endobronchial stent placement may be an option. We looked at our experience treating PPS with these two modalities.Methods: All patients with PPS treated with mediastinal repositioning/tissue expander placement or bronchial stenting at our institution from 1991 to 2005 were reviewed. Results: Mean age at the time of pneumonectomy was 45 years. Mean follow-up was 33 months. Six patients underwent tissue expander placement. They had relief of symptoms with the following complications: wound infection, atrial fibrillation, expander leak and esophageal dysmotility. Two patients underwent silastic stent placement with immediate resolution of symptoms, however they suffered from frequent mucous plugging, stent migration, and granulation tissue formation requiring repeat bronchoscopic treatment and stent replacement. Conclusions: Mediastinal repositioning with tissue expander placement provides durable relief of symptoms. Endobronchial stenting is a less invasive treatment option for PPS, however patients require close follow-up due to a high complication rate. Need for frequent bronchoscopy often emergently present serious limitations in this small group. Introduction Postpneumonectomy syndrome (PPS) is a rare complication occurring months to years after pneumonectomy1. Lung and mediastinal contents herniate into the empty postpneumonectomy space causing displacement and rotation of mediastinal contents. The displaced distal trachea, primary bronchus or lower lobe bronchus is stretched and compressed between the pulmonary artery anteriorly and the aorta or spine posteriorly234. This results in severe and progressive dyspnea and may lead to secondary malacia of the airway cartilages. Postpneumonectomy syndrome was initially described exclusively after right sided pneumonectomy, but subsequently cases following left pneumonectomy have been reported with and without a right aortic arch567. The syndrome occurs in all age groups but is most common in children and young adults3. Numerous treatment modalities for PPS have been described over the years. Mediastinal repositioning with hopes that scar tissue formation would prevent relapse was associated with an unacceptably high recurrence rate3. Aortic division and bypass graft is has been used with varied results38. The lowest recurrence rates were achieved when mediastinal repositioning was augmented by placement of a prosthetic device in the post pneumonectomy space to prevent relapse349. Although this is generally successful, mediastinal repositioning is a major operation that may not be tolerated by some patients10. Further, obstructive symptoms may persist after mediastinal repositioning in cases of severe malacia of the airways37. Alternative treatment has consisted of bronchoscopically placed endobronchial stents, however the long term outcome and complication rates following stent placement remains unknown1112131415. In an effort to examine the long term outcomes and complications associated with each technique, we present our experience treating postpneumonectomy syndrome with standard mediastinal repositioning-implant placement and endobronchial stent placement. Material and Methods Approval for this study was obtained from the hospital’s internal review board. All patients with the diagnosis of post-pneumonectomy syndrome were identified from the hospital’s medical record database. A retrospective chart review was performed based on information from the patient’s clinical chart including records that were obtained from outside institutions at the time of patient evaluations. Outcomes dat