Endometrial ablation entails the destruction of the endometrial lining by one of several energy forms that is delivered through a hysteroscope-like or similar instrument. Some of the available endometrial ablation technologies include The NovaSure™ system [Hologic (Cytyc) Corporation, Marlborough, MA, USA, which ablates the endometrial surface via radiofrequency energy], the ThermaChoice UBT (Gynecare Inc, Somerville, NJ, USA) and Cavaterm (Wallsten Medical, Morges, Switzerland) systems (which deliver thermal energy from heated fluid in a balloon), the HerOption system [American Medical Systems Inc, Minnetonka, MN, USA, which is based on freezing the endometrium surface], the HTA system [BEI Medical/Boston Scientific, Natick, MA, USA, which is based on the use of heated saline], and the Microsulis system [Microsulis Medical Ltd, Pampano Beach, FL, USA, which is based on microwave energy].
As noted previously, NovaSure™ is one of several second-generation endometrial ablation systems and has been used with increasing frequency over the past decade. The NovaSure™ system received approval from the United States Food and Drug Administration (FDA) in 2001 for the permanent ablation of the endometrial lining of women with menorrhagia that can be attributed to non-neoplastic causes [1, 2]. The endometrial ablative power is derived from radiofrequency energy. Briefly, a conformable bipolar electrode array that is mounted on an expandable frame is transcervically inserted into the endometrial cavity. The array expands to form a confluent lesion on the entire internal surface of the endometrium. Radiofrequency energy is then transmitted for a period of approximately 90 seconds, and the endometrium and the superficial myometrium are thereby ablated. Increasing tissue depth of ablation causes an automatic cessation of power-delivery at a threshold of 50 ohms or at 120 seconds, and the maximum power requirements are predetermined [1, 2] Recently, we encountered a distinctive uterus that was removed from a patient who had undergone the NovaSure™ endometrial ablation and received a gonadotropin-releasing hormone receptor agonist (Leuprolide acetate) within the 7 months that preceded her hysterectomy. The leiomyomata in the sample displayed extensive infarct-type degeneration, which we attributed to the Leuprolide acetate pretreatment. However, the case raised the possibility that the NovaSure™ endometrial ablation may have contributed to the observed changes. The present analysis was designed to decipher any histologic changes (if any) associated with the NovaSure™ endometrial ablation system relative to benign smooth muscle tumors of the uterine corpus, since degenerative changes such as necrosis are components of the diagnostic criteria by which pathologists assign malignant potential to these tumors.