CRYOGENIC BALLOON ABLATION INSTRUMENTS AND SYSTEMS

摘要

Cryogenic tissue ablation instruments for treating body tissue include an elongate flexible body with a proximal supply port for coupling with a pressurized coolant (e.g., liquid N2O), a supply lumen in fluid communication with the proximal supply port, and an expandable cryogenic balloon carried on a distal portion of the elongate body, the balloon having a wall defining an interior of the balloon. A dispersion member coupled to or otherwise formed out of a distal end portion of the elongate body has an interior lumen in fluid communication with or otherwise comprising a portion of the supply lumen, the dispersion member having one or more coolant dispersion apertures in fluid communication with the balloon interior and sized and located with respect to the balloon wall such that a pressurized flowable coolant in the supply lumen will enter the balloon interior through the one or more apertures in the form of a liquid spray that contacts and provides (through rapid evaporation) substantially uniform cooling of an interior wall surface of a treatment region of the balloon.