title: Short-term and long-term outcomes after bilateral lung volume reduction surgery : prediction by quantitative CT.
abstract: OBJECTIVE
  To evaluate selection criteria and duration of benefit for patients undergoing lung volume reduction surgery (LVRS).
  
  
  METHODS
  Eighty-nine consecutive patients with severe emphysema who underwent bilateral LVRS were prospectively followed up for up to 3 years. Patients underwent preoperative pulmonary function testing, 6-min walk, chest CT, and answered a baseline dyspnea questionnaire. CT scans in 65 patients were analyzed for emphysema extent and distribution using the percentage of emphysema in the lung, percentage of normal lower lung, and the CT emphysema ratio (CTR, an index of the craniocaudal distribution of emphysema). All patients underwent at least 6 weeks of pulmonary rehabilitation prior to surgery. Outcome measures were FEV(1), 6-min walk distance, and transitional dyspnea index (TDI).
  
  
  RESULTS
  Compared to baseline, FEV(1) was significantly increased at 3, 6, 12, 18, 24, and 36 months after surgery (p < or = 0.008). The 6-min walk distance increased from 871 feet (baseline) to 1,110 feet (3 months), 1,214 feet (6 months), 1,326 feet (12 months), 1,342 feet (18 months), 1,371 feet (24 months), and 1,390 feet (36 months) after surgery. Despite a decline in FEV(1) over time, 6-min walk distance was preserved. Dyspnea as measured by TDI improved at 3, 6, 12, 18, 24, and 36 months after surgery. A high CTR was the best predictor of a 12% increase over baseline and an absolute increase of 200 mL in FEV(1), although with a low area under the receiver operating characteristic curve. In addition, the sensitivity and negative predictive value of the CTR were limited. No radiographic or physiologic predictor was able to consistently predict a successful increase in walk distance or TDI.
  
  
  CONCLUSIONS
  LVRS improves pulmonary function, decreases dyspnea, and enhances exercise capacity in many patients with severe emphysema, although improvement wanes 36 months after surgery.
authors.affiliation: Department of Internal Medicine , Division of Pulmonary and Critical Care Medicine, University of Michigan Health System, Ann Arbor, USA.
authors.forename: K R
authors.initials: KR
authors.lastname: Flaherty
authors.forename: E A
authors.initials: EA
authors.lastname: Kazerooni
authors.forename: J L
authors.initials: JL
authors.lastname: Curtis
authors.forename: M
authors.initials: M
authors.lastname: Iannettoni
authors.forename: L
authors.initials: L
authors.lastname: Lange
authors.forename: M A
authors.initials: MA
authors.lastname: Schork
authors.forename: F J
authors.initials: FJ
authors.lastname: Martinez
mesh_terms: D000328:Adult; D000368:Aged; D004646:Emphysema / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011013:Pneumonectomy / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011446:Prospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome