SURGICAL CARE IN PULMONARY REHABILITATION
SURGICAL CARE
Over the past 50-75 years, researchers have described a variety of surgical approaches for improving symptoms and restoring function in patients who suffer from emphysema. Only giant bullectomy and, possibly, lung volume reduction surgery are useful.
BULLECTOMY
Removal of giant bullae has been a standard approach in selected patients for many years. The bullae in patients with emphysema generally range in size from 1-4 cm in diameter; however, on occasion, giant bullae can occupy more than 33% of the hemithorax.
Giant bullae may compress adjacent lung tissue, thereby reducing the blood flow to and ventilation of the normal tissue. Removal of these bullae may result in the expansion of compressed lungs and improved function.
Patients who are symptomatic and have an FEV1 of less than 50% predicted have a better outcome after bullectomy, which is performed through either a midline sternotomy or a lateral incision with or without video-assisted thoracoscopy. Postoperative leaks are the major potential complications.
Giant bullectomy can produce subjective and objective improvement in selected patients who have bullae that compress the adjacent lung and that occupy at least 30% (but preferably, 50%) of the hemithorax, who have an FEV1 of less than 50% predicted, and who otherwise have relatively preserved lung function.
LUNG-VOLUME REDUCTION SURGERY
Brantigan and colleagues first reported resectioning surgery for diffuse emphysema in 33 patients. They resected the 20-30% of each lung that appeared the most diseased. Brantigan hypothesized that removal of a portion of the emphysematous lung increased the radial traction on the airways in the remaining part of the lung, thereby reducing symptoms by improving the respiratory system's expiratory airflow and mechanical function.
Lung volume reduction surgery (LVRS) subsequently gained considerable momentum, after researchers documented a marked improvement in the FEV1 (+82%), the forced vital capacity (FVC; +27%), the 6-minute walk distance, and QOL indices. Currently, large, prospective clinical trials are underway in the US and Canada to evaluate the effectiveness of LVRS.
The indications and patient selection criteria for LVRS have not been rigorously defined. Generally, candidates for LVRS have symptoms that are secondary to severe emphysema, as well as having marked hyperinflation (ie, elevated residual volume/total lung capacity [RV/TLC] ratio) and computed tomography (CT) scan evidence of heterogeneous emphysema. The study excluded patients who are hypercapnic or who have pulmonary hypertension or other cardiac risk factors.
The surgical approach uses a midline sternotomy, with stapling of the lung margins. Surgeons generally resect 20-30% of each lung from the upper zones. The LVRS procedure has a mortality rate of 0-18%. Several complications, including pneumonia and prolonged air leaks, have been observed.
LUNG TRANSPLANTATION
Lung transplantation continues to gain acceptance for the treatment of end-stage lung disease, particularly emphysema and idiopathic pulmonary fibrosis. Lung transplantation also is used in patients with sarcoidosis, eosinophilic granuloma, extrinsic allergic alveolitis, lymphangioleiomyomatosis, pulmonary hypertension, cystic fibrosis, and severe bronchiectasis.
Single lung transplantation is preferred, because bilateral lung transplantation does not significantly alter patient survival. The initial morbidity and mortality is slightly less following a single transplant, and the lungs from 1 donor can be used to benefit 2 patients. The double lung transplant is used for patients with cystic fibrosis, because a single transplanted lung would be susceptible to the spread of infection from the native lung.
Patients with severe pulmonary hypertension have received double lung transplantation in the past to minimize hemodynamic instability. Patients treated with a double lung transplant tolerate bronchiolitis obliterans syndrome better than do patients with a single transplant.
For donor selection, a 10-20% difference in size between the donor and the recipient lungs is acceptable. Only blood group typing is performed. The recipient must have no history of a recent malignancy and should be taking less than 20 mg of prednisone per day.
Patients aged 65 years or less are candidates for single transplant, and patients aged 55 years or less are candidates for a bilateral transplant. Patients with a multisystem disease are considered to be poor candidates for lung transplant.
Patients with cystic fibrosis and pulmonary infection with pan antibiotic–resistant organisms (especially Pseudomonas cepacia) have high rates of reinfection after transplant, as well as a greater mortality rate. All patients being evaluated for lung transplant undergo CT scanning of the chest, and all noncalcified nodules need to be evaluated to exclude malignancy.
Survival for patients undergoing single lung transplantation is approximately 70-90% at 1 year and 50% at 3 years. Prognosis for survival is best in patients who require transplant for obstructive pulmonary disease. The proper timing of the transplant is difficult to assess; the patients selected to receive a transplant should have a life expectancy of 2 years or less. With lung transplantation, the profound dyspnea and limited lifestyle is replaced with improved QOL at the risk of worsening survival.