title: Is Montgomery tracheal Safe-T-Tube clinical failure induced by biofilm?
abstract: OBJECTIVE
  Montgomery Safe-T-Tube deterioration and early biofilm colonization may explain the discomfort claimed by many patients and clinical failures. The aim of the study was to analyze the deterioration of Montgomery Safe-T-Tube morphological and mechanical properties in vivo in 16 patients by using microbiological methods, optical and electron microscopy, and engineering tests.
  
  
  METHODS
  Prospective controlled study at a single medical center.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  The study, conducted from April 2007 to February 2012 at the "Sapienza" University of Rome, was designed to collect 2 Montgomery Safe-T-Tubes from each patient. The first was removed 3 to 15 days after insertion (group A) and the second at least 90 days after (group B). Specimens underwent microbiologic assays, electron microscopic analysis, immunocytologic analysis, and mechanical tests.
  
  
  RESULTS
  Microorganisms were not isolated in 2 group A cases (12%), whereas they were in all group B cases. Biofilm was identified in 11 of 16 (69%) group A samples and in 16 of 16 (100%) group B samples (P = .0149) using scanning electron microscopy. Immunohistochemistry showed monocyte-granulocyte line cells producing interleukin-1β on the external surfaces of Montgomery Safe-T-Tubes. The tensile test showed that the wear related to the longer period of use makes Montgomery Safe-T-Tubes more rigid than newer ones.
  
  
  CONCLUSIONS
  Early biofilm colonization takes place in Montgomery Safe-T-Tubes in most cases. The mechanical decay could be justified in part by the destructive biofilm activity and by the release of inflammatory effectors and enzymes.
authors: Department of Sensory Organs, Sapienza University of Rome, Italy.
authors: Massimo
authors: M
authors: Fusconi
authors: Vincenza Rita
authors: VR
authors: Lo Vasco
authors: Andrea
authors: A
authors: Delfini
authors: Armando
authors: A
authors: De Virgilio
authors: Anna Rita
authors: AR
authors: Taddei
authors: Carlo
authors: C
authors: Vassalli
authors: Michela
authors: M
authors: Conte
authors: Fausto
authors: F
authors: Del Sette
authors: Anna Teresa
authors: AT
authors: Benincasa
authors: Marco
authors: M
authors: de Vincentiis
mesh_terms: D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification / Q000648:ultrastructure; D018441:Biofilms / Q000254:growth & development*; D015169:Colony Count, Microbial; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007442:Intubation, Intratracheal / Q000009:adverse effects / Q000295:instrumentation*; D007829:Laryngostenosis / Q000601:surgery*; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D011446:Prospective Studies; D016459:Prosthesis-Related Infections / Q000382:microbiology*; D020545:Respiratory Mucosa / Q000382:microbiology / Q000648:ultrastructure; D014132:Trachea / Q000382:microbiology / Q000601:surgery*
keywords: Montgomery Safe-T-tube; biofilm; laryngeal stenosis; tensile test