Experimental evaluation of self-expandable metallic tracheobronchial stents

The self-expandable metallic stents have been widely used in tracheobronchial obstruction or fistulation, including the J-shaped and Y-shaped stents, named after the shape of the branch-stem junction of the stent. However, there is scarce data on the mechanical performance of these tracheobronchial stents, which is essential for optimal stent implantation. In this work, eight self-expandable metallic tracheobronchial stents in three types (i.e., straight, J-shaped, and Y-shaped), with or without cover, were characterized. The compression resistance of the stems was investigated through both compression and indentation tests. The bending resistance of the branches in the J-shaped and Y-shaped stents was assessed through the bending test. Our results demonstrated that the covered stents exhibited a significantly higher compression resistance and bending resistance than the uncovered ones. The branches had a minimal impact on the compression resistance of the stem. The branch of the J-shaped stent showed a significantly lower bending resistance than the Y shaped one. This work provides a testing framework for the J-shaped and Y-shaped stents,which could shed some light on the optimal design of stent with branches.

Adenoid cystic carcinoma in trachea: A rare presentation

Primary tracheal tumors are rare. Adenoid cystic carcinoma of trachea is even rarer. It occurs as a polypoidal mass in trachea presenting with dyspnea and respiratory distress due to tracheobronchial obstruction. We report a case of young male presenting with dyspnea for some time. CT scan revealed mass in trachea obliterating its lumen. Histopathological examination conirmed the diagnosis.