COMMENT
Bronchiectasis, regardless of etiology, can result in a significant decrease in quality of life. While surgical treatments are not the first line of treatment, it is therefore important to relegate these treatment options for those that would benefit in quality of life due to relief from symptoms such as chronic cough, excessive sputum production and hemoptysis, when medical therapies fail. Among all surgical forms for bronchiectasis treatment, lung resection (sublobar and lobar) of focal compromised areas is the most frequent and acceptable possibility. Resection of the compromised segments may reduce the bouts of infection. This results in a significant improvement in the patient quality of life and low morbidity and mortality after surgery (4). Improvements in surgical technique and use of effective antibiotics led to this dramatic change in surgical results.
Lung transplantation is another viable surgical option for selected patients with advanced bronchiectasis of any origin (CF’s and non-CF’s), who have poor quality of life and are at risk of death once the decrease on their lung capacity compromises their daily activities or leads to recurrent hospital admissions. Cystic fibrosis encompasses approximately 26% of all total bilateral lung transplantations while non-CF bronchiectasis patients accounts for 4.5% of all bilateral lung transplantations (5). Despite the challenges that CF patients present, the overall survival after lung transplantation is more favorable than that seen in patients with chronic obstructive pulmonary disease or pulmonary fibrosis.
In rare, advanced cases patients may present with a completely collapsed ipsilateral lung with concurrent retracted asymmetric hemithorax. This often poses significant surgical challenges in lung transplantation and several surgical techniques have been presented in several small case reports with good results. Jougon et al. reported long term outcomes in a case report of a patient undergoing a left lung transplantation with a concurrent right pneumonectomy in a patient who developed right sided bronchiectasis. They expressed concern with regards to an extensively retracted right hemithorax that would have compromised respiratory mechanics and therefore allograft function if a normal sized right lung was implanted without any major volume reduction (6). Other groups would also describe the combination of an unilateral lung transplant after a staged pneumonectomy. Samano and colleagues presented a case series of two patients who underwent bilateral sequential lung transplantation in the setting of bronchiectasis and asymmetric thoraces after undergoing lower lobectomies. In their series, due to the difference in size of the retracted hemithoraces, the surgical group elected to perform lower lobectomies of the donor lungs at the time of transplantation. This allowed for chest closure without any cardiopulmonary compromise (7).
In the current report, because of the extensive mediastinal shift resulting from their disease process, three possible surgical approaches were discussed at our lung transplant multidisciplinary meeting. Unilateral lung transplantation with contralateral pneumonectomy, left lung transplant plus right lobar transplant or sequential double lung transplantation. Unilateral lung transplantation was not considered as an option because the risk of allograft contamination via the non-transplanted native lung is high (8). Unilateral lung transplantation with contralateral pneumonectomy was deemed a feasible technique and has been previously described as well. In this situation, the pneumonectomy could be done in a staged fashion or at the time of unilateral transplantation (9,10).
Ultimately, as described, we elected to perform bilateral sequential lung transplantation despite the reduced size of the right chest cavity. Although the mediastinal shift required significant dissection of the pericardium and the atelectatic lung in the operating room at the time of transplantation, we found that the accommodation of the donor lungs and the return of the mediastinum to a more anatomical situation happened early after the surgery without significant hemodynamic compromise. This response shows that the sequential double lung transplantation is thoroughly possible, even in non-optimal anatomical conditions. Furthermore, this procedure leads to an increased post-transplantation pulmonary capacity.
In order to accomplish these transplants, three surgical aspects are worth mentioning. First, we elected to leave the chest open after successful implantation due to size mismatch especially in the setting of a shifted mediastinum. This allowed for the allografts as well as the chest cavities to accommodate to one another, noting a return to normal anatomy on the first POD1 chest x-ray. The second aspect is the use of antibiotic solution during the chest washout and closure. These patients are frequently colonized by many different species of bacteria and it is common to develop an empyema after lung transplantation. Therefore, chest washouts with antibiotics may prevent this complication, and we have used this procedure in all of our patients with such characteristics. The third aspect is the use of antibiotics targeting those species of bacteria or fungus previously cultured in the sputum in the pre-operative evaluation. In our practice this is a sine qua non condition after lung transplantation.
In conclusion, double lung transplantation is a safe and feasible option in patients with bronchiectasis with concurrent mediastinal shift. Favorable outcomes seen after sequential double lung transplantation in these patients were achieved by the used of delayed chest closure with concurrent antibiotic driven thoracic cavity washout.