title: Rationale for the development and the mechanism of action of endoscopic thermal vapor ablation (InterVapor) for the treatment of emphysema.
abstract: BACKGROUND
  Emphysema remains a disabling disease despite current treatment. Novel approaches to the underlying physiological abnormalities responsible for symptom generation are warranted.
  
  
  METHODS
  A review of current hypotheses and preclinical and clinical data on the utility of endoscopic thermal vapor ablation (InterVapor) in the treatment of emphysema.
  
  
  RESULTS
  In animal studies, thermal energy in the form of heated water vapor both in healthy and in papain-induced emphysema in dogs and sheep leads to an inflammatory response followed by healing with airway and parenchymal fibrosis. The fibrosis and associated distal atelectasis result in volume reduction. The amount of thermal energy delivered has been based on the amount of target tissue mass determined from a high-resolution computed tomogram. Early human studies indicated the feasibility of InterVapor with 5 cal/g tissue; however, the dose appeared insufficient to induce lobar volume reduction. A study using 10 cal/g to 1 upper lobe (n=44) induced a mean of 46% lobar volume reduction at 12 months along with significant improvements in the physiology and health outcomes.
  
  
  CONCLUSIONS
  InterVapor induces lung volume reduction in patients with emphysema. The mechanism of action is through a thermally induced inflammatory response followed by healing with subsequent remodeling of tissue (fibrosis and distal atelectasis).
authors.affiliation: Uptake Medical Corp., Tustin, CA 92656, USA. skesten@uptakemedical.com
authors.forename: Steven
authors.initials: S
authors.lastname: Kesten
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Anderson
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Tuck
mesh_terms: D055011:Ablation Techniques / Q000379:methods*; D000818:Animals; D002921:Cicatrix / Q000473:pathology; D004285:Dogs; D004724:Endoscopy / Q000379:methods*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D018579:Patient Selection; D001261:Pulmonary Atelectasis / Q000473:pathology; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000601:surgery*; D011656:Pulmonary Emphysema / Q000150:complications / Q000601:surgery*; D012756:Sheep; D013227:Steam; D016896:Treatment Outcome
chemical_list: D013227:Steam