Second-generation endometrial ablation technologies: the hot liquid balloons

Hysteroscopic endometrial ablation (HEA) was introduced in the 1980s to treat menorrhagia. Its use required additional training, surgical expertise and specialized equipment to minimize emergent complications such as uterine perforations, thermal injuries and excessive fluid absorption. To overcome these difficulties and concerns, thermal balloon endometrial ablation (TBEA) was introduced in the 1990s.

Four hot liquid balloons have been introduced into clinical practice. All systems consist of a catheter (4-10mm diameter), a silicone balloon and a control unit. Liquids used to inflate the balloons include internally heated dextrose in water (ThermaChoice, 87°C), and externally heated glycine (Cavaterm, 78°C), saline (Menotreat, 85°) and glycerine (Thermablate, 173°C). All balloons require pressurization from 160 to 240mmHg for treatment cycles of 2 to 10 minutes.

Prior to TBEA, preoperative endometrial thinning, including suction curettage, is optional. Several RCTs and cohort studies indicate that the advantages of TBEA include portability, ease of use and short learning curve. In addition, small diameter catheters requiring minimal cervical dilatation (5-7mm) and short duration of treatment cycles (2-8min) allow treatment under minimal analgesia/anesthesia requirements in a clinic setting.

Following TBEA serious adverse events, including thermal injuries to viscera have been experienced. To minimize such injuries some surgeons advocate the use of routine post-dilatation hysteroscopy and/or ultrasonography to confirm correct intrauterine placement of the balloon prior to initiating the treatment cycle. After 10 years of clinical practice, TBEA is thought to be the preferred first-line surgical treatment of menorrhagia in appropriately selected candidates. Economic modeling also suggested that TBEA may be more cost-effective than HEA.

Key words: menorrhagia, abnormal uterine bleeding, thermal balloon endometrial ablation, ThermaChoice, Cavaterm, Menotreat, Thermablate, hot liquid balloons