title: Respiratory infections increase the risk of granulation tissue formation following airway stenting in patients with malignant airway obstruction.
abstract: BACKGROUND
  The most serious complications of airway stenting are long term, including infection and granulation tissue formation. However, to our knowledge, no studies have quantified the incidence rate of long-term complications for different stents.
  
  
  METHODS
  To compare the incidence of complications of different airway stents, we conducted a retrospective cohort study of all patients at our institution who had airway stenting for malignant airway obstruction from January 2005 to August 2010. Patients were excluded if more than one type of stent was in place at the same time. Complications recorded were lower respiratory tract infections, stent migration, granulation tissue, mucus plugging requiring intervention, tumor overgrowth, and stent fracture.
  
  
  RESULTS
  One hundred seventy-two patients with 195 stent procedures were included. Aero stents were associated with an increased risk of infection (hazard ratio [HR] = 1.98; 95% CI, 1.03-3.81; P = .041). Dumon silicone tube stents had an increased risk of migration (HR = 3.52; 95% CI, 1.41-8.82; P = .007). Silicone stents (HR = 3.32; 95% CI, 1.59-6.93; P = .001) and lower respiratory tract infections (HR = 5.69; 95% CI, 2.60-12.42; P < .001) increased the risk of granulation tissue. Lower respiratory tract infections were associated with decreased survival (HR = 1.57; 95% CI, 1.11-2.21; P = .011).
  
  
  CONCLUSIONS
  Significant differences exist among airway stents in terms of infection, migration, and granulation tissue formation. These complications, in turn, are associated with significant morbidity and mortality. Granulation tissue formation develops because of repetitive motion trauma and infection.
authors.affiliation: Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX. Electronic address: dost@mdanderson.org.
authors.forename: David E
authors.initials: DE
authors.lastname: Ost
authors.affiliation: Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Archan M
authors.initials: AM
authors.lastname: Shah
authors.affiliation: Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Xiudong
authors.initials: X
authors.lastname: Lei
authors.affiliation: Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Myrna C B
authors.initials: MCB
authors.lastname: Godoy
authors.affiliation: Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Jimenez
authors.affiliation: Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: George A
authors.initials: GA
authors.lastname: Eapen
authors.affiliation: Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Pushan
authors.initials: P
authors.lastname: Jani
authors.affiliation: Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Larson
authors.affiliation: Department of Anesthesia, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Mona G
authors.initials: MG
authors.lastname: Sarkiss
authors.affiliation: Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Rodolfo C
authors.initials: RC
authors.lastname: Morice
mesh_terms: D000293:Adolescent; D000328:Adult; D000402:Airway Obstruction / Q000473:pathology* / Q000628:therapy*; D001999:Bronchoscopy; D004868:Equipment Failure; D005260:Female; D005548:Foreign-Body Migration / Q000453:epidemiology; D006097:Granulation Tissue / Q000473:pathology*; D006469:Hemoptysis / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009093:Mucus; D016016:Proportional Hazards Models; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects*; D015996:Survival Rate; D013997:Time Factors