Stent-induced tracheal stenosis can be predicted by IL-8 expression in rabbits.
BACKGROUND
Bare metal stents may cause complications like fibrous encapsulation, granulation and tracheal stenosis. We investigated the behaviour of three commercially available stents in vivo (rabbits) and in vitro (coculture of those stents with epithelial and fibroblast cell lines). Also, we investigated whether development of tracheal stenosis could be predicted by any biological marker.


MATERIALS AND METHODS
The tracheae of 30 rabbits were implanted with either nitinol stents, with or without paclitaxel elution, or a cobalt-based stent. An additional ten rabbits underwent mock implantation (controls). Serial peripheral venous blood samples were taken throughout the study, and several cytokines measured. Animals were euthanized on day 90, with immediate tracheal endoscopy and lavage performed, then necropsy.


RESULTS
Rabbits with cobalt-based stent exhibited more inflammation and the highest stenosis incidence, with reduced survival. Both in vivo and in vitro, this stent induced higher IL-8 levels than nitinol stents. Most important, the presence of stent-induced tracheal stenosis was closely associated to increase in IL-8 expression in blood just 1 day after tracheal stent implantation: a 1·19-fold increase vs. baseline had 83% sensitivity, 83% specificity, 77% positive predictive value, 88% negative predictive value and 83% accuracy to predict development of stenosis.


CONCLUSIONS
The cobalt-based stent had the highest incidence of tracheal inflammation and stenosis. On the other hand, the paclitaxel-eluting nitinol stent did not prevent those complications and provoked a marked reaction compared with the bare nitinol stent. Early increase in IL-8 expression in blood after stent implantation could predict development of tracheal stenosis in rabbits.
['Arellano-Orden|Elena|E|', 'Serrano|Carolina|C|', 'Montes-Worboys|Ana|A|', 'Sánchez-López|Verónica|V|', 'Laborda|Alicia|A|', 'Lostalé|Fernando|F|', 'Lahuerta|Celia|C|', 'Rodríguez-Panadero|Francisco|F|', 'de Gregorio|Miguel Ángel|MÁ|']
D000497:Alloys D000818:Animals D000970:Antineoplastic Agents D002460:Cell Line D054855:Drug-Eluting Stents D004847:Epithelial Cells D005260:Female D005347:Fibroblasts D006801:Humans D066298:In Vitro Techniques D016209:Interleukin-8 D053208:Kaplan-Meier Estimate D017239:Paclitaxel D011474:Prosthesis Design D011817:Rabbits D012137:Respiratory System D015607:Stents D014135:Tracheal Stenosis D014805:Vitamin B 12
tracheal stenosis rabbits stents Cytokine fibrosis