Three-Year Experience in Outpatient Microwave Endometrial Ablation

Abstract

The authors present their experience with 117 women with therapy-resistant menorrhagia who underwent microwave endometrial ablation between April 2000 and March 2003. The procedures were performed on an outpatient basis under local anesthesia. Study criteria included at least 1 vaginal delivery, no previous vaginal surgery, no confounding medical problems, and normal weight. In addition, women with an anxious disposition, a history of mental illness, previous unwelcome sexual contact, or previous unpleasant obstetrical or gynecologic experience were not enrolled. The presence of a vaginal infection, intolerance of nonsteroidal antiinflammatory drugs, restricted hip or knee mobility, or a history of GnRH agonist therapy also prevented inclusion in the study. Anesthesia was delivered with the patient in the semirecumbent Lloyd-Davis position. First, the cervix was numbed with a small amount of local anesthetic placed in the anterior lip. Then, while grasping the cervix with a tenaculum, the operator injected a full 4 × 2.2-mL cartridge of citanest and octapressin (prilocaine 3% with felypressin) into the center of each 4 quadrants of the cervix, creating a ring block at the internal os. To provide postoperative analgesia, a second series of injections was administered using 20 mL of 0.25% bupivacaine or Chirocaine with a standard 20-mL syringe and 21-g needle. After completion of the ring block, the first of 2 initial soundings of the uterus was taken and checked against a sterile steel ruler. The cervix was then dilated with a no. 9 Hegar dilator and a second sounding made to confirm the length of the uterine cavity. The microwave applicator was introduced into the cavity through the cervix and inserted to the tip of the fundus. A series of graduations on the applicator shaft enabled confirmation of the depth of insertion. This depth was matched against the first 2 measurements. At this point, the patient was offered inhaled nitrous oxide/oxygen to lessen the pain associated with ablation. If this proved to be inadequate, 4 mg midazolam (Hypnoval-Roche) intravenously in conjunction with 0.4 mg alfentanil (Rapifen-Janssen) was administered using intravenous access established preoperatively. Ablation was performed by energizing the microwave applicator. After the temperature reached 60° C (approximately 6 seconds), the uterine fundus and corneal areas were evenly heated with a gentle side-to-side motion. When a yellow mark appeared at the external os, the applicator was slowly withdrawn until the mark was totally visible, at which time the power was turned off. After microwave ablation, coagulated debris in the uterus was removed with suction aspiration using a 7-mm Cory curette. One patient was found to have a large fibroid polyp inside the uterine cavity and the procedure was abandoned. In the remaining 116 patients, the average time of treatment was 254 seconds (range, 103-573 seconds). The ring block was sufficient anesthesia for most patients (81%). Seven patients required inhalation analgesia, and 14 needed inhalation analgesia and intravenous sedation. Abdominal pain caused 3 patients to be admitted to the hospital overnight, and 3 additional patients were admitted for abdominal pain within 3 days of treatment. In 1 patient, a hysteroscopy was done to confirm cavity integrity. There were no intraoperative or postoperative complications. A follow-up questionnaire was sent to participants at 3 and 6 months. Almost 90% (88.6%) reported being satisfied with their treatment. Of the 12 patients who were dissatisfied, 5 women elected repeat treatment with microwave endometrial ablation. Repeat treatment was successful in only 1 woman. Eleven women underwent subsequent hysterectomy for continued pain and bleeding, including 4 women who underwent repeat treatment. A fifth patient had a hysterectomy within 3 days of initial treatment, and 6 were operated on within 2 years of treatment. There was a 90% satisfaction rate among these