title: Comparison of short-term functional outcomes following unilateral and bilateral lung volume reduction surgery.
abstract: OBJECTIVE
  To compare short-term functional outcomes following unilateral and bilateral lung volume reduction surgery (LVRS) performed in patients with advanced emphysema.
  
  
  METHODS
  LVRS was performed unilaterally in 32 patients and bilaterally in 119 patients. Pulmonary function testing and 6-min walk test (6MWT) were performed preoperatively and repeated at 3 to 6 months postoperatively.
  
  
  RESULTS
  Bilateral LVRS was associated with increased in-hospital mortality (10% vs 0%, p<0.05) and a higher incidence of postoperative respiratory failure (12.6% vs 0%; p<0.05) compared with unilateral LVRS. There was no significant difference in duration of air leaks between unilateral and bilateral groups, but the mean hospital stay was significantly longer following bilateral LVRS (21.1+/-32.0 days vs 14.2+/-14.0 days; p<0.05). Preoperatively, there was no significant difference between the unilateral and bilateral groups with respect to FEV1, FVC, residual volume, or 6MWT distance. However, for all of these parameters, the magnitude of improvement was significantly greater following bilateral LVRS. Notably, the magnitude of improvement in each parameter following unilateral LVRS exceeded half that following bilateral LVRS, suggesting that functional outcomes after the unilateral procedure were disproportionate to the amount of tissue resected. Serial functional assessment of seven patients undergoing staged unilateral procedures (two unilateral procedures separated in time by at least 3 months) demonstrated somewhat unpredictable responses; failure to achieve a favorable response to the initial procedure did not necessarily portend a similar outcome with the contralateral side, and vise versa.
  
  
  CONCLUSIONS
  Bilateral LVRS produces a greater magnitude of short-term functional improvement than does the unilateral procedure and should be considered the procedure of choice for most patients. Unilateral LVRS should be reserved for patients in whom factors contraindicating entrance into one hemithorax exist.
authors.affiliation: Department of Medicine, University of Pennsylvania Medical Center, Philadelphia 19104, USA. kotloff@mail.med.upenn.edu
authors.forename: R M
authors.initials: RM
authors.lastname: Kotloff
authors.forename: G
authors.initials: G
authors.lastname: Tino
authors.forename: H I
authors.initials: HI
authors.lastname: Palevsky
authors.forename: J
authors.initials: J
authors.lastname: Hansen-Flaschen
authors.forename: P M
authors.initials: PM
authors.lastname: Wahl
authors.forename: L R
authors.initials: LR
authors.lastname: Kaiser
authors.forename: J E
authors.initials: JE
authors.lastname: Bavaria
mesh_terms: D004724:Endoscopy; D006801:Humans; D011013:Pneumonectomy / Q000379:methods*; D011656:Pulmonary Emphysema / Q000503:physiopathology / Q000601:surgery*; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics; D016896:Treatment Outcome; D014741:Video Recording