TBEA destroys the inner layers of the uterus by transferring heat from heated liquid within a balloon inserted into the uterine cavity.
The two devices available in Australia, Cavaterm and Thermachoice, both involve an electronic controller, a single-use silicone or latex balloon catheter housing a heating element and two thermocouples, and an umbilical cable.
TBEA cannot be used on women with large or irregular uterine cavities because the balloon must be in direct contact with the uterine wall to cause ablation.
Cavaterm is contraindicated for women whose uterine cavity is more than 10 cm long (from the internal os to the fundus)
Thermachoice is contraindicated for women whose uterine cavity is more than 12 cm long, and for those who have a latex allergy.
TBEA is also contraindicated if classical caesarean section (vertical midline incision in the upper segment of the uterus) has been performed, or if other uterine surgery has left a scar where the uterine wall is less than 8 mm thick.
The use of endometrial thinning agents before TBEA is not recommended.