Balloon Ablation May Simplify Endometrial Ablation

OB/GYN News, Oct 15, 1999 by Erik L. Goldman

BIG SKY, MONT. - Physicians who can put a Foley catheter into the bladder also will be able to perform a balloon ablation of the uterus, according to Dr. Steven McCarus.

For the management of dysfunctional uterine bleeding, balloon ablation is clinically equivalent to or better than most other approaches but far easier to perform, he said at an ob.gyn. update sponsored by the University of Chicago.

He believes broader use of balloon techniques and other ablative methods could reduce the number of hysterectomies now being done for menorrhagia.

Excessive uterine bleeding is technically defined as 80 mL of blood loss per menstrual period, though he stressed that "your patient will tell you what is excessive for her. It has to do with how much the bleeding affects her quality of life," said Dr. McCarus, head of the division of gynecologic endoscopy at Florida Hospital Celebration Health in Celebration, Fla.

While hysterectomy is the only guaranteed "cure," this procedure has big drawbacks: It requires general anesthesia and long, costly hospitalizations, and it carries morbidity rates of between 24% and 43% and a 3% serious complication rate. Further, many women object to it, wanting to keep their reproductive organs as long as possible.

Hysteroscopic ablation provides an outpatient, minimally invasive approach to dysfunctional bleeding. But it has not exactly "caught on," said Dr. McCarus. Currently, U.S. gynecologists do 20,000 ablations per year, compared with 120,000 hysterectomies.

He speculated this is due largely to the fact that hysteroscopic ablation is difficult. Results are highly operator dependent, and the procedure often requires general anesthesia. When lasers or electrosurgical devices are used, there is significant risk of burning or perforation of the uterus, bowel, or other pelvic organs.

Also hysteroscopy requires uterine distention with hypotonic solutions, posing risk of extravasation leading to edema, electrolyte imbalances, and water intoxication.

Balloon-based techniques simplify office-based ablation and eliminate many of the risks associated with hysteroscopic methods.

A recent unpublished 14-center U.S.-Canadian study, funded by Gynecare Inc., which makes a balloon system, compared balloon ablation with hysteroscopic electrosurgical "rollerball" ablation in a total of 260 women, commented Dr. McCarus.

The company's ThermaChoice system uses heavy water that is heated to 87[degrees]C and pumped into the intrauterine balloon. Heat is transferred directly to the endometrium for 8 minutes, causing thermal denaturing and tissue destruction.

All patients in the study were premenopausal but 30 years of age or older, with at least a 3-month history of menorrhagia. All had completed childbearing.

The patients used a validated pictorial and diary-based scoring system to rate menorrhagia. They also saved their menstrual pads, and blood loss was determined by chemical elution techniques.

A diary score of 100 correlated with loss of at least 80 cc, the minimum definition of menorrhagia. The mean pretreatment score for these patients was over 550, indicating that they had severely excessive bleeding.

A total of 134 patients were randomized to balloon ablation, while 126 had rollerball electrosurgery. By postoperative month 12, 125 balloon patients and 114 rollerball patients were able to be evaluated.

There were no intraoperative complications in the balloon group, but there were four in the rollerball group-one uterine perforation, two fluid overloads, and one cervical laceration.

Postoperatively, there were five complications in the balloon group-three cases of endometritis, one urinary tract infection, and one case of inflammatory polypoid endometrium with postcoital bleeding--and three in the rollerball group-endometritis, hematometria, and postablation tubal sterilization.

Using a postop score of 75 or less as eumenorrhea, the investigators found 80.8% of the balloon patients and 85.1% of the rollerball patients were eumenorrheic or better; 15% of balloon patients and 27% of rollerball patients were amenorrheic.

Rollerball patients who had menstrual blood flow experienced a mean 4-day reduction in duration of periods, compared with a 3-day reduction in the balloon-treated group. While the rollerball seemed to have a slight edge in terms of efficacy, balloon ablation was the hands-down winner in terms of operative ease.

"The balloon introducer is only 1.5 mm in diameter. You don't need to dilate the cervix," said Dr. McCarus, who has used the device but has no financial interest in Gynecare.

Eighty-four percent of the rollerball operations required general anesthesia, compared with only 54% of balloon procedures. And the latter were more likely to be done in office settings; at one study site, 12 of 13 balloon ablations were done in the office.

Mean operating time also was reduced with balloon ablation: The mean interval from end of preoperative prep to removal of ablation device was 40 minutes for rollerball versus 27 minutes for balloon.