Departments: Interventional Pulmonology in Other Journals
Bronchoscopic Lung Volume Reduction
J Cardiovasc Surg. 2003;44:101–108. Sabanathan S, Richardson J, Pieri-Davis S. Department of Thoracic Surgery, Bradford Royal Infirmary, Bradford, England.
The authors describe a new method of bronchoscopic lung volume reduction. The study group consisted of 8 patients (mean age, 62.5 y; range, 50–77 y; 5 males and 3 females) with severe emphysema with end-stage lung disease with preoperative breathlessness at rest and muscle wasting. Target areas for collapse therapy were upper lobes or segments with severe emphysematous destruction, occupying a large volume, with surrounding lung compression and little perfusion. These were delineated radiologically and with ventilation–perfusion lung scanning. Data collected preoperatively included SaO2, a visual analog score of symptom intensity before and after 6-minute shuttle walking, and a dyspnea score. Endobronchial blockade was initially with detachable silicone balloons originally designed for vascular occlusion. Later, specially designed and hospital-manufactured stainless steel wire stents containing biocompatible sponge were used. The wire mesh of the stents formed a circular cage with 6 V-shaped legs, each having internal and external barbs. The minimum outer diameter (OD) was 10 mm with the stent folded (length 25 mm) and 25 mm (length 14 mm) when fully expanded. The sponge plug was compressible to an OD of 4 mm and returned to its original size within 4 to 6 minutes immediately before deployment; the stent with its blocker was loaded into a capsule of high-density plastic with an internal diameter (ID) of 4 mm and a length of 60 mm. An internal introducer Teflon tube completed the equipment required for its ejection. All procedures were performed under general anesthesia or deep sedation. A rigid bronchoscope was introduced through which a flexible bronchoscope was inserted to identify subsegmental bronchi leading to target zones. Fluoroscopic guidance facilitated the identification of target zones. A fine-bore catheter inserted through the channel of the flexible bronchoscope was used to aspirate the air from the bronchoscopically occluded bronchus. The bronchial blocker was then deployed under direct vision, aided by fluoroscopy. (The configuration of the stent used is shown in the publication, and to me, the stent resembles a Gianturco metal stent.) Only 3 of the 8 patients underwent metal stent blockade; the remaining 5 patients were treated with detachable vascular occlusion balloons. The segments blocked included both upper lobe segments, including lingula. Operative time was a mean of 67.5 minutes (range, 30–90 min). Rehabilitation began immediately and 7 patients left the hospital the following day. Five patients had immediate improvements in well being, dyspnea, exercise tolerance, lifestyle, and medication requirements. Objective improvements in maximal inspiratory pressures were noted in 4 patients. Imaging procedures showed minor volume reductions in 4 patients. In one patient, severe cough led to expectoration of the blocking balloon. Migration of the blocking balloon was a problem in 3 patients, but the metal stents did not migrate in 3 patients who had these placed. In one patient, the metal stent disintegrated after 12 months. Complications were related to intraoperative oxygenation problems in 2 patients and late infections in 4. One patient developed bilateral tension pneumothoraces in recovery and died 3 weeks later from bronchopneumonia. Another patient died from sustained hypoxemia while in the intensive-care unit. Another patient survived a postoperative myocardial infarction. Other postoperative complications included pleuritic chest pain from balloon dislodgement, chest infections, and pneumonia. One patient survived for at least 2 years and 2 were alive 4.5 years later. The authors conclude that bronchoscopic lung volume reduction for the treatment of end-stage emphysema subjectively improved the majority of their patients, and even though the metallic stents were promising, balloons were disappointing. (It should be noted that the data presented are incomplete as a result of the death of the first author.) Based on the information provided in this publication, it is difficult to assess the benefit of bronchial blockade in this small group of patients. Five of the 8 patients died within 9 months of the procedure, 1 patient was lost to follow up after 2 years, and only 2 patients were alive at the time of publication. Because metal stent was used in these patients, one could surmise that the usual complication of significant granulation tissue growth and fracture of stent would occur had these patients lived long (all 3 died within 6 mo). The need for rigid bronchoscopy, and deep sedation or general anesthesia makes this particular procedure somewhat daunting in patients with severe hypoxemia from chronic obstructive pulmonary disease.