Essure compatible with two endometrial ablation techniques.
The Essure procedure may be performed immediately before or immediately after using the ThermaChoice uterine balloon ablation system. It also can be done immediately after--but not immediately before--using the NovaSure radiofrequency ablation system, investigators reported.
The Food and Drug Administration approved the use of the Essure system with ThermaChoice ablation in July 2004. The agency has not approved the use of Essure with NovaSure, and a spokesperson for Conceptus Inc., which distributes Essure, told this newspaper that the company has no plans to apply for such approval.
"The majority of women who undergo endometrial ablation are in their reproductive years, so many of them request Essure sterilization to control fertility after or during endometrial ablation," Rafael F. Valle, M.D., a consultant for Conceptus, reported. "Because these two methods utilize the same approach, the transvaginal approach, they can be performed concomitantly," said Dr. Valle of Northwestern University, Chicago.
In his study, 40 women (average age 43) about to undergo hysterectomy for benign uterine bleeding consented to Therma-Choice endometrial ablation before or after placement of the Essure microinserts.
The microinserts were placed before ablation in 24 of the women. In 16 of these women, the combined procedure was successful. In the other eight, gross uterine pathology prevented proper placement of the microinserts.
Sixteen women underwent ablation before placement of the Essure microinserts, and placement was successful in eight of those cases. The failures were caused by unsuspected pathology and debris remaining in the cornual regions after the ablation, which made it difficult to visualize the tubal ostia. The combined procedure took an average of 25.7 minutes, including a second-look hysteroscopy.
The FDA requested a study on the temperature increase in the serosa during the combined procedure. Dr. Valle recruited nine additional women for this study: Seven underwent Essure insertion before ablation, and two underwent Essure insertion alone as controls. Each woman had eight thermocouples inserted via laparotomy before the procedure began.
The average maximum temperature in this subserosal space was 37.1[degrees]C, ranging from 34.7[degrees]C to 38.9[degrees]C. Tissue damage occurs only at temperatures above 45[degrees]C. Furthermore, no tissue damage could be seen either on gross or histologic examination.
Although the FDA required the investigators to perform the Essure procedure both before and after ThermaChoice ablation, in practice, "It doesn't make sense to do the endometrial ablation first," Dr. Valle said. When ablation was performed first, "there was a lot of tissue that sometimes even occluded the tubal os, and we had to remove it with forceps before we found the opening."
Placing the Essure microinserts before ablation is not an option when NovaSure radiofrequency ablation is used, said Robert Sabbah, M.D., of Sacre-Couer Hospital in Montreal.
"We don't feel that using an electrical current with a metal tail in the cavity would be safe," he said. "Therefore, we think the only way to go about doing it if you want to combine both procedures is to start first with endometrial ablation and follow later by the installation of the Essure."
Dr. Sabbah conducted his studies in three phases. The goal of the first phase was to see if the tubal ostia could be visualized after NovaSure ablation. In 9 of 10 women visualization was not a problem. In the 10th woman Dr. Sabbah had trouble visualizing the ostia even before endometrial ablation. He injected methylene blue into the ostia, and this helped him find the ostia after the ablation.
The goal of the second phase was to see whether the fallopian tubes would be patent before and after the ablation. In three of four women the tubes were patent, and in the fourth woman the tubes were occluded even before ablation.
In the third phase the combined procedure was attempted in 27 women, and the clinicians achieved successful bilateral placement of the Essure microinserts in 26 of them. Dr. Sabbah has not yet followed the women long enough to determine whether the Essure microinserts resulted in tubal occlusion in the normal amount of time (3 months).
Based on his experience, Dr. Sabbah offered two pearls for surgeons attempting a combined procedure. First, it's important to become proficient with both procedures independently before attempting to perform them together. Second, if there's any debris blocking the tubal os, it's better to peel it away (with forceps through the working channel of the endoscope) than to push against it with the Essure catheter, because pushing against the debris might damage the catheter.
BY ROBERT FINN
San Francisco Bureau