Medical instruments and techniques for thermally-mediated therapies

摘要

A surgical instrument for thermally-mediated therapies in targeted tissue volumes and for causing thermal effects in polymer tissue-contacting members. In one embodiment, the instrument has a working end with an interior chamber that is supplied with a biocompatible liquid. An energy source causes a liquid-to-vapor phase change within the interior of the instrument. The vapor phase media then is ejected from the working surface of the instrument, and a controlled vapor-to-liquid phase change in an interface with tissue applies thermal energy substantially equal to the heat of vaporization to ablate tissue. The vapor-to-liquid phase transitions, or internal energy releases, can be provided about thin-film flexible structures for engaging body lumens and cavities. An exemplary embodiment can be used for shrinking, sealing, welding or creating lesions in tissue—while causing limited collateral thermal damage and while totally eliminating electrical current flow in the engaged tissue.

主权项

1. A method for a thermally-mediated therapy for treating tissue, the method comprising
providing an instrument having a selected media in a liquid form; applying energy to the selected media such that the selected media increases in volume causing a liquid-to-vapor phase transition of the selected media to a vapor form; delivering a pressurized vapor stream of the selected media to flow from the instrument while controlling a pressure of the pressurized vapor stream; and directing the pressurized vapor stream of the selected media to a tissue site such that contact with the tissue site causes a vapor-to-liquid phase state change of the pressurized vapor stream to the liquid form and where the vapor-to-liquid phase state change releases a thermal energy substantially equal to a heat of vaporization of the selected media to the tissue site to cause ablation of the tissue site.