Materials and Methods

This study was approved by the Mayo Clinic Institutional Review Board. We retrospectively searched our electronic medical record for the cases of women who underwent GEA at Mayo Clinic (Rochester, MN) from Jan. 1, 1998, through Dec. 31, 2005, by using the International Classification of Diseases, Ninth Revision , Clinical Modification (ICD-9-CM) code for endometrial ablation.

Patients were included only if they had given consent for research use of their medical records. There were no age limits or other exclusion criteria for included patients. Some of the patients included in this study were also included in our previous publications.

The study group was separated into 2 cohorts: patients who had had at least 1 cesarean delivery and patients who were either nulliparous or had only had vaginal deliveries in the past. Patients with a history of cesarean delivery were identified by using the relevant ICD-9-CM codes. All records were also reviewed individually to confirm a past surgical history of 1 or more cesarean deliveries.

The 2 methods for GEA used at the Mayo Clinic during the study period were thermal balloon ablation (Gynecare ThermaChoice; Ethicon, Somerville, NJ) and radiofrequency ablation (NovaSure; Hologic Inc, Bedford, MA). Before GEA, all included patients underwent an endometrial biopsy for sampling, a Papanicolaou test, pelvic ultrasonography, and in-office hysteroscopy if anatomical anomalies were suspected. GEA was offered only to patients with benign endometrial polyps or with submucous leiomyomas smaller than 2 cm in largest diameter or those that did not distort the endometrial cavity. Such polyps and leiomyomas were removed by dilation and curettage or ablation in situ.

No patients were pretreated with gonadotropin-releasing hormone agonists. Demographic data collected included age, body mass index, pattern of bleeding, parity, presence of dysmenorrhea, uterine length, and endometrial thickness.

Efficacy of the GEA procedure was assessed by rate of amenorrhea, which was defined as lack of bleeding from immediately after the procedure for a minimum of 12 months after the procedure. Rates of post-GEA treatment failure, defined as bleeding or pain after ablation that required hysterectomy or reablation, were also calculated and used as an outcome measure of efficacy. Patients with treatment failure were identified by using the relevant ICD-9-CM codes, and time to failure was measured; all records were also reviewed individually to confirm failure by documentation of repeat ablation or hysterectomy. For women without treatment failure, follow-up was censored at last contact or death before the end of the study period. The last date medical records were reviewed for patient follow-up was May 31, 2010.

To assess the safety of GEA in both cohorts, intraoperative complications and postoperative complications within 6 weeks of surgery were noted. Uterine perforation (the main intraoperative complication) was defined as any breach in uterine cavity integrity that precluded ablation or warranted additional surgical intervention. Anatomical sites of all uterine perforations were noted. Other potential intraoperative complications, including cervical lacerations, failure to complete the ablation cycle, bowel or bladder injury, allergies to local or general anesthetics, and complications from anesthesia, also were documented. Potential postoperative complications included urinary tract infections, endometritis, and allergic reactions to medications used during or after surgery.