Tracheobronchial Stenoses

Inhalation of mustard vapor primarily affects the laryngeal and tracheobronchial mucosa. Evidence exists to suggest that mustard inhalation causes sustained respiratory difficulties even after the acute lesions have healed. Clinical follow-ups on 200 Iranian soldiers who were severely injured by mustard during the Iran-lraq War indicate that about one third had experienced persistent respiratory effects 2 years or more after initial exposure. Reported problems included chronic bronchitis, asthma, rhinopharyngitis, tracheobronchitis, laryngitis, recurrent pneumonia, bronchiectasis, and, in some cases, severe, unrelenting tracheobronchial stenosis. ... 

Tanigawa N, Sawada S, Okuda Y, Kobayashi M, Mishima K (2000) Symptomatic improvement in dyspnea following tracheobronchial metallic stenting for malignant airway obstruction. Acta Radiol 41 425-428 Tojo T, lioka S, Kitamura S, Maeda M, Otsuji H, Uchida H, Mori T, Furuse K (1996) Management of malignant tracheobronchial stenosis with metal stents and Dumon stents. Ann Thorac Surg 61 1074-1078... 

Ghanei, M., Akhlaghpoor, A., Mohammad, M.M., 2004c. Tracheobronchial stenosis following mustard gas inhalation. Inhal. Toxicol. 16, 845-849. 

A follow-up study of 200 Iranian soldiers who had received severe injuries from mustard gas during the Iran-Iraq War showed that about one-third had persistent respiratory effects two years following exposure notably chronic bronchitis, asthma, tracheobronchitis, laryngitis, recurrent pneumonia and bronchiectasis. Those who had suffered a high concentration exposure to the large airways developed tracheobronchial stenosis. 

Acute, heavy exposure to SM causes loss of the columnar cells of the upper respiratory tract, peribronchial edema, hyperemia of the blood vessels, cellular infiltrations in the submucosa, and intense vacuolization and disorganization of the cytoplasmic and nuclear structures (Emad and Rezaian, 1997, 1999). Pulmonary hemorrhage, pulmonary edema, and respiratory failure similar to ARDS may also occur. These cytotoxic effects are associated with acute thermal injury sustained by the airway mucosa and lead to scarring and development of stenosis of the tracheobronchial tree as was observed in 9.64% of the SM-exposed patients. 

An especially devastating pulmonary complication, severe and progressive stenosis of the tracheobronchial tree (Figure 7-12), was found in about... 

Fig. 2.13. Congenital esophageal stenosis. Barium swallow reveals a discrete annular narrowing in the distal esophagus. Tracheobronchial rests were found at pathology...

The first report on the oldest metal stent used in the tracheobronchial system was pubUshed by Wallace et al. in 1986 (Wallace et al. 1986). Since then, several studies on the use of this stent type have been pub-hshed and the stent became one of the most frequently applied metal stents in tracheobronchial mahgnancy. Wallace and colleagues initially reported on two cancer patients. Gianturco stents were placed in one to dilate a postoperative bronchial stenosis that caused pneumonia, and in the second to support a tracheal graft that collapsed with respiration. Stents were successfully placed and the patients symptoms improved (Wallace et al. 1986). 

Bolliger CT, Heitz M, Hauser R, Probst R, Perruchoud AP (1996) An airway Wallstent for the treatment of tracheobronchial malignancies. Thorax 51 1127-1129 Bolliger CT, Wyser C, Wu X et al. (1999) Evaluation of a new self-expandable silicone stent in an experimental tracheal stenosis. Chest 115 496-501... 

Nomori H, Horio H, Imazu Y, Suemasu K (2000) Double stenting for esophageal and tracheobronchial stenoses. Ann Thorac Surg 70 1803 1807 Noppen M, Dhase J, Meysman M et al. (1996) A new screw-thread tracheal endoprosthesis. J Bronchol 3 22-26 Noppen M, Meysman M, Claes I et al. (1999) Screw-thread vs Dumon endoprosthesis in the management of tracheal stenosis. Chest 115 532-535... 

Regarding Y-shaped tubular scaffolds, a limited experimentation has been conducted. Sekine et al. [ 130] implanted a Y-shaped Marlex mesh tube in dogs. The tubes were reinforced with polypropylene spiral and coated with collagen from porcine skin. Six of the 20 dogs have survived after experimentation. The main causes of death were obstmction of the main bronchus, omental necrosis, and air leakage. The same prosthesis was grafted as tracheobronchial bifiircalion replacement after 5 years, the scaffold was completely incorporated. Neitho- stenosis nor dehiscence was observed, and a functional airway was revealed [131]. 

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