4 global ablation devices: Efficacy, indications, and technique
Newer endometrial ablation technologies are easy to learn, and high efficacy rates match earlier techniques.
Pretreatment is not necessary. The procedure can be performed any time during the menstrual cycle.
Technique. After measuring the uterine cavity with a sound, insert and deploy the wand. Because it is flexible, it will make contact with and conform to the shape of the uterine cavity. Ablation depth is controlled by tissue impedance (electrical resistance).
As the wand makes contact with the endometrial surface, tissue is vaporized, and vapors are evacuated from the uterine cavity by continuous suction—which also brings additional endometrial tissue layers into contact with the bipolar electrode. As the device reaches myometrial tissue, resistance increases to a preset threshold and the device automatically shuts down.
The ablation electrode is configured so that the ablation zone in the lower uterine segment and corneal region will not exceed 2 mm; in the miduterine cavity, meanwhile, it reaches a depth of 5 to 7 mm.
Safety features. If inadvertent perforation occurs before the treatment cycle begins, the device will not activate.
What the data show. In a large multicenter clinical trial of 265 patients followed for 12 months, 41% reported amenorrhea and 88% eumenorrhea or hypomenorrhea.13
Other techniques
Microwave. Novel endometrial ablation techniques include use of microwave energies delivered to the uterine cavity via an 8-mm probe (Microsoulis, Waterloo, UK).14
Laser. A procedure known as endometrial laser intrauterine thermal therapy, or ELITT,15 delivers laser energy via a tri-fibershaped intrauterine device.
Progestin-releasing intrauterine system. Recently, the medical treatment of excessive uterine bleeding has been advanced by the levonorgestrel-releasing intrauterine device, approved by the FDA in 2000 for intrauterine contraception. The Mirena device (Berlex, Montville, NJ) has a Pearl index of 0.11 and is more reliable than tubal ligation. It can induce endometrial thinning and reduce menstrual blood loss by as much as 90%. When Mirena was compared with rollerball endometrial ablation, it was more effective in reducing menstrual blood loss and had similar satisfaction rates.16 No doubt future trials will compare Mirena with the newer ablation devices.
Complications and long-term considerations
Short-term complications, which are rare, include uterine perforation, low-grade endometritis, cervical stenosis, hematometra, and pelvic infection. These problems can be minimized by giving preoperative antibiotics and reducing tissue destruction in the lower uterine segment and cervix.
Long-term complications. Development of occult endometrial carcinoma in islands of endometrial tissue is a remote possibility. The likelihood of this rare occurrence remains low if the patient is ovulatory. Once a woman transitions into menopause and desires hormone therapy, a progestin should be included in treatment to reduce the risk of endometrial hyperplasia.
Pregnancy after endometrial ablation has been reported even in the absence of significant amounts of normal endometrial tissue.17 Thus, it is vital that the patient have a reliable and permanent form of contraception, such as tubal ligation or vasectomy.
Failure rates. Long-term failure rates in women undergoing ablation are not known, but clinical trials exploring the issue are under way.18
Dr. Brzozowski is a speaker for Novasure. Dr. Liu reports no financial relationships relevant to this article.
