Clinical Results and Clinical Trials in Lung Volume Reduction Surgery

Abstract

Early recognition of the anatomic changes characteristic of chronic emphysema resulted in a number of operative interventions designed to restore normal thoracic anatomy, improve pulmonary mechanics, and treat perceived physiologic abnormalities (1).These included attempts at thoracoplasty to reduce chest volume, disruption of the phrenic nerve (2), or pneumoperitoneum (3) to elevate the diaphragm, mechanical pleurodesis to create ancillary systemic to pulmonary blood flow (4),denervation of the lung via pulmonary plexectomy (5),and excision of the carotid body (glomectomy) as originally reported by Nakayama (6).Despite anecdotal reports of clinical success and subjective improvement in patient symptoms, none of these historical procedures has been demonstrated by objective postoperative criteria to produce significant improvement in pulmonary function or patient survival (see Chapter 7 for a more detailed discussion of these and other historical operations for emphysema). In this chapter, we will review the available clinical data reported in the modern era of lung volume reduction surgery (LVRS), summarize the areas of agreement as to the method and efficacy of LVRS from nonrandomized studies, and critically analyze the utility and limitations of randomized controlled trials in LVRS in the context of the National Emphysema Treatment Trial (NETT).