LAUSR

Tubular tissue, such as the bile duct and esophagus, often suffers from stenosis due to chronic inflammation or excessive contraction of smooth muscle. Laser treatment using a balloon catheter has been used to treat tubular tissue stenosis by mechanically expanding the tissue and irradiating laser light circumferentially on the tissue lumen. As the balloon is inflated with saline, the residual air in a delivery channel is often accumulated in the inflated balloon. Thus, the air trap may cause physical discontinuities at air‐saline interface, leading to unpredictable and nonuniform photothermal interactions. The aim of the current study was to evaluate the optical‐thermal effects of the air trap in the balloon on laser treatment of the tubular tissue by means of numerical simulations and experimental validations.