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Early results of endoscopic lung volume reduction for emphysemaYim APC, Hwong TMT, Lee TW, et al. J Thorac Cardiovasc Surg 2004;127:1564-1573Reviewers: Feroze Mahmood, MD
Andrew Maslow, MD
Background: Lung Volume Reduction Surgery is a controversial treatment for end stage emphysema. More commonly, LVRS is been performed via thoracoscopy, thoracotomy, or median sternotomy, all of which are considered invasive and carry significant morbidity. Yim et al report their experience with a new, less invasive approach to LVRS: Endoscopic [endobronchial] Lung Volume Reduction Surgery (EBLVRS). Methods: The authors report on the safety and efficacy of endoscopic lung volume reduction surgery (LVRS). Twenty patients (mean age 68.6 years; one female) with incapacitating emphysema and heterogenous distribution were included. Exclusion criteria included an FEV1 or DLCO < 25% of predicted, or a resting PaCO2 > 55 mmHg. All patients completed the followup evaluation. Evaluations consisted of transthoracic echocardiography, pulmonary function tests, computed tomography (CT) scan, ventilation/perfusion (V/Q) scan, baseline six-minute walk distance (6MWD), and quality of life assessments using standardized questionnaires. Assessments were made at baseline, and 30 and 90 days after the EBLVRS. End points included any major complication or death attributable to the procedure and the degree of improvement in the pulmonary function, 6MWD, and health-related quality of life (HRQOL) after EBLVRS. The procedure was performed during total intravenous anesthesia, with spontaneous/assisted ventilation via a rigid bronchoscope. Flexible bronchoscopy was employed to position guide wires into segmental airways, identified by preoperative CT and V/Q scans. The Endobronchial Valve (EBV) (Fig.1) was deployed using the Seldinger technique. Multiple EBVs may have been required in the same lobe.
Results: Bilateral insertions of the valves were performed in 8/20 patients (40%). Twenty-eight lobes were targeted in 20 patients. Complete lobar occlusion was achieved in 16 lobes using 45 valves (2.81/lobe). Incomplete lobar occlusion was noted in the remaining 12 lobes for which 32 valves were used (2.67/lobe). Three patients were admitted in the ICU for one day; two due to hypercapnea and one for bilateral pneumothoraces (PTX). No patient required postoperative mechanical ventilation. Six patients experienced complications in the immediate postoperative period. A pneumothorax was the most common, occurring in 4/20 (20%) patients. One patient, with bilateral PTXs underwent video assisted thoracoscopy for excision of left sided emphysematous bullae. All PTXs resolved by the one month follow up. There were no procedure-related deaths. Since awake postoperative bronchoscopy was not well tolerated, EBV function was assessed in only 6/20 patients. EBV function for these six was good. Improvements in FEV1 (15% at 30 days; 0.73L to 0.84L; 26% at 90 days; 0.92L), FVC at 90 days (1.94L to 2.25L), and the 6MWD (22% at 30 days, 252m to 306m); 28% at 90 days (322m) were reported. Analysis of questionnaires demonstrated improvement in patient function, dyspnea scores, and quality of life at 30 and 90 days. Although improvement in pulmonary functions tests and patient function were reported, lung volumes and DLCO did not show any significant changes by 90 days. Only 10/23 (43%) lobes, evaluated by CT scan, showed radiological evidence of collapse (6 had < 25%; 4 had 25-75% collapse). By 90 days, two lobes had re-expanded and 13 lobes showed no collapse. Comments: The authors report an improvement of patient function after this relatively less invasive surgical procedure. However, it is not clear that patient benefits are the direct result of the surgical procedure, since the majority of targeted lobes had less than 25% collapse of lung tissue and 57% had no collapse. The authors did not report any association between changes in lung volumes and patient function. During open procedures, "more abnormal" lung fails to collapse during a brief apneic period. This 'more abnormal' tissue is then excised. This identification and excision of lung tissue is more definitive than during endocscopic LVRS. The etiology of the pneumothorax is puzzling (no explanation offered), however, etiologies may include damage to remaining blebs or injury of airway or lung tissue injury during bronchoscopy. Although bronchoscopic LVRS appears to be less invasive, the results from this cohort are not convincing regarding both the safety and the benefits. It is also not clear that the currently performed EBLVRS is better than pulmonary rehabilitation alone. Nevertheless, with improved technique and technology, EBLVRS may prove to be an important and less invasive treatment for end-stage emphysema. Such a conclusion is premature at this time. Table of Contents:
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