title: Effect of lung volume reduction surgery on pulmonary diffusion capacity in a rabbit model of emphysema.
abstract: BACKGROUND
  While there is renewed interest in lung volume reduction surgery (LVRS) for treatment of emphysema, many aspects of the operation such as patient selection and surgical end points of excision are uncertain. We studied the effects of LVRS on measured lung volumes and diffusion capacity in an animal model to investigate optimal resection volumes.
  
  
  METHODS
  Emphysema was induced in 32 New Zealand white (NZW) rabbits using aerosolized elastase. Helium dilution lung volumes and single breath DLCO were measured concurrently at baseline, following induction of emphysema (preop), and 1 week postoperatively (postop) following LVRS. Bilateral upper and middle lobe stapled lung resections were performed through midline sternotomies with excision of variable amounts of lung tissue from 1.8 to 5.8 g.
  
  
  RESULTS
  FRC increased following induction of emphysema and decreased postoperatively. DLCO improved with increasing lung tissue resection up to 3 g of tissue and then decreased as even greater amounts were removed (r = 0.54).
  
  
  CONCLUSIONS
  Measured lung volumes increase with development of emphysema and appropriately decrease in response to LVRS in this rabbit model. DLCO improves with moderate resection but then decreases with excessive excision of lung quantities and may help define one physiologic operative end point. In this rabbit model, excision of approximately 30% of lung volume was optimal and prevented further decrease in diffusion capacity.
authors.affiliation: Irvine Medical Center, University of California, Orange, California, 92868-3298, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Chen
authors.forename: M
authors.initials: M
authors.lastname: Brenner
authors.forename: J
authors.initials: J
authors.lastname: Huh
authors.forename: B
authors.initials: B
authors.lastname: Yoong
authors.forename: A
authors.initials: A
authors.lastname: Gassel
authors.forename: F
authors.initials: F
authors.lastname: Kafie
authors.forename: R
authors.initials: R
authors.lastname: McKenna
authors.forename: A
authors.initials: A
authors.lastname: Gelb
authors.forename: E A
authors.initials: EA
authors.lastname: Stemmer
authors.forename: A F
authors.initials: AF
authors.lastname: Wilson
mesh_terms: D000818:Animals; D001944:Breath Tests; D004195:Disease Models, Animal; D004646:Emphysema / Q000139:chemically induced / Q000503:physiopathology* / Q000601:surgery*; D006371:Helium / Q000032:analysis; D008176:Lung Volume Measurements; D010196:Pancreatic Elastase; D011013:Pneumonectomy; D011650:Pulmonary Alveoli / Q000502:physiology; D011653:Pulmonary Diffusing Capacity; D011817:Rabbits
chemical_list: D006371:Helium; D010196:Pancreatic Elastase