title: Protective effect of immunosuppression on granulation tissue formation in metallic airway stents.
abstract: OBJECTIVE
  The use of self-expanding metallic airway stents has been extended in recent years in inoperable patients with malignant and benign airway diseases. The risk of granulation tissue formation in the stent is a major concern. The objective of the present study was to determine whether immunosuppression modulates granulation tissue formation in airway stents, as seen in coronary stents.
  
  
  METHODS
  The study included 19 patients with benign airway obstructions and 11 recipients of lung transplants with anastomotic obstructions who were receiving immunosuppression therapy.
  
  
  METHODS
  The degree of in-stent granulation tissue formation was evaluated (score range, 0-3) every 3 months for 2 years.
  
  
  RESULTS
  Granulation tissue formation was significantly lower in the transplant recipients than in the nontransplant patients at 3 months (score 0.7 vs. 1.6, P = .031), 15 months (score 0 vs. 1.1, P = .026), and 18 months (score 0 vs. 1.8, P = .020). During the 2 years of follow-up, the transplant recipients underwent significantly fewer laser resections and brachytherapy treatments for in-stent granulation.
  
  
  CONCLUSIONS
  The immunosuppression given to lung transplant recipients may have an inhibitory effect on granulation tissue formation in metallic airway stents. Further studies are needed to evaluate the effect of systemic therapy or coated stents with drugs such as sirolimus.
authors.affiliation: Pulmonary Institute, Rabin Medical Center, Beilinson Campus, and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. dekels1@zahav.net.il
authors.forename: Dekel
authors.initials: D
authors.lastname: Shlomi
authors.forename: Nir
authors.initials: N
authors.lastname: Peled
authors.forename: David
authors.initials: D
authors.lastname: Shitrit
authors.forename: Daniele
authors.initials: D
authors.lastname: Bendayan
authors.forename: Anat
authors.initials: A
authors.lastname: Amital
authors.forename: Mordechai R
authors.initials: MR
authors.lastname: Kramer
mesh_terms: D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000209:etiology / Q000628:therapy*; D001999:Bronchoscopy; D004417:Dyspnea / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006097:Granulation Tissue / Q000187:drug effects* / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007165:Immunosuppression Therapy; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D016040:Lung Transplantation / Q000009:adverse effects / Q000276:immunology; D008297:Male; D008775:Methylprednisolone / Q000494:pharmacology; D008875:Middle Aged; D015607:Stents / Q000009:adverse effects*; D013529:Surgical Wound Dehiscence / Q000150:complications; D016559:Tacrolimus / Q000494:pharmacology; D014135:Tracheal Stenosis / Q000150:complications / Q000628:therapy*
chemical_list: D007166:Immunosuppressive Agents; D016559:Tacrolimus; D008775:Methylprednisolone