title: Lung volume reduction surgery in canine model of predominantly upper lobe emphysema: advantages of new surgical system.
abstract: OBJECTIVE
  Lung volume reduction surgery has been shown to be an effective treatment for selected patients with advanced emphysema. Nevertheless, prolonged air leaks are a significant complication that limits the utility of this procedure. This study evaluated the safety and effectiveness of a novel surgical system designed to minimize this complication.
  
  
  METHODS
  In 14 dogs, severe upper lobe emphysema was produced by repeated bronchial instillations of papain administered over an approximate 6-month interval. Pulmonary function testing that included lung volumes and flows was performed at baseline, after emphysema, and at 1 month and 6 months after resection in the surgical group, while at comparable intervals in the nonsurgical group. Seven animals were randomly assigned to a surgical group to test a vacuum-assisted surgical system (VALR Surgical System; Spiration; Redmond, WA) that deploys a compression silicone sleeve over portions of the diseased tissue. The other seven dogs comprised the nonsurgical group.
  
  
  RESULTS
  In both groups, emphysema increased total lung capacity (TLC) approximately 125% as compared to baseline. In the surgical group, no air leaks were observed after resection, and TLC significantly decreased at the 1-month and 6-month periods as compared with postemphysema measurements. At necropsy, histologic examination revealed fibrosis of the compressed lung contained within the sleeve and fibrotic encapsulation of the device. Two animals had evidence of localized infection.
  
  
  CONCLUSIONS
  We successfully created a model of predominantly upper lobe emphysema. The vacuum-assisted surgical system provided safe and effective lung reduction without air leak complications and with sustained improvement in pulmonary function over 6 months.
authors.affiliation: Section of Respiratory, Department of Internal Medicine, University of Manitoba Health Sciences Centre, 700 William Avenue, Winnipeg, Manitoba R3E-0Z3, Canada. minksn@cc.umanitoba.ca
authors.forename: Steven N
authors.initials: SN
authors.lastname: Mink
authors.forename: Xavier
authors.initials: X
authors.lastname: Gonzalez
authors.forename: Krika
authors.initials: K
authors.lastname: Duke
authors.forename: Edgar
authors.initials: E
authors.lastname: Bautista
authors.forename: Lawrence
authors.initials: L
authors.lastname: Tan
mesh_terms: D000818:Animals; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D004285:Dogs; D004618:Embolism, Air / Q000517:prevention & control*; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D011013:Pneumonectomy / Q000295:instrumentation* / Q000379:methods; D011653:Pulmonary Diffusing Capacity; D011656:Pulmonary Emphysema / Q000473:pathology* / Q000601:surgery*; D011897:Random Allocation; D012129:Respiratory Function Tests; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013523:Surgical Equipment; D014109:Total Lung Capacity