Tracheal wall thickening is associated with the granulation tissue formation around silicone stents in patients with post-tuberculosis tracheal stenosis

Abstract

Purpose: Tracheal restenosis due to excessive granulation tissue around a silicone stent requires repeated bronchoscopic interventions in patients with post-tuberculosis tracheal stenosis (PTTS). The current study was conducted to identify the risk factors for granulation tissue formation after silicone stenting in PTTS patients.

Materials and methods: A retrospective study was conducted between January 1998 and December 2010. Forty-two PTTS patients with silicone stenting were selected. Clinical and radiological variables were retrospectively collected and analyzed.

Results: Tracheal restenosis due to granulation tissue formation were found in 20 patients (47.6%), and repeated bronchoscopic interventions were conducted. In multivariate analysis, tracheal wall thickness, measured on axial computed tomography scan, was independently associated with granulation tissue formation after silicone stenting. Furthermore, the degree of tracheal wall thickness was well correlated with the degree of granulation tissue formation.

Conclusion: Tracheal wall thickening was associated with granulation tissue formation around silicone stents in patients with post-tuberculosis tracheal stenosis.

Keywords: Trachea; bronchoscopy; intervention; stenosis; stents; tuberculosis.

Fig. 1

A representative case of post-tuberculosis tracheal stenosis. (A) The chest radiograph shows narrowing of the lower third of the trachea (black arrow). (B and C) Computed tomography revealed tracheal stenosis (white arrow) at the level of the T3 vertebra. Tracheal wall thickening (5.1 mm) was found at the stenotic lesion. (D and E) A rigid bronchoscopy was performed to reverse airway patency. The lower trachea was 5×10 mm narrowed by a fibrous stricture. After bougienation, a silicone stent was inserted (outer diameter, 14 mm; inner diameter, 12 mm; length, 40 mm).

Fig. 2

The therapeutic diagram of patients with post-tuberculosis tracheal stenosis. ^*Repeated bronchoscopic interventions were performed in an as-needed base according to the physician's decision.

Fig. 3

Relationship between the number of granulation tissue formations and tracheal wall thickness. (A) Scatter diagram shows positive correlation between the number of granulation tissue formation and tracheal wall thickness (p=0.016, ρ=0.662). (B) Receiver operating characteristic curve for predicting the occurrence of granulation tissue formation (p=0.005, area under the curve=0.756).