Research eyes new sterilization option
Investigators now are looking at a transcervical sterilization option that, if proven safe and effective, will give women another alternative for permanent contraception.
The treatment phase for the Adiana system, now under development by the Redwood City, CA-based Adiana, recently has been completed at 14 centers in the United States and two international centers. All treated patients are being monitored, and the trial’s primary clinical endpoint — pregnancy prevention at one year — will be established at the appropriate statistical confidence interval, reports Paul Goeld, Adiana’s president and chief executive officer. The company expects to file a pre-market approval application with the Food and Drug Administration (FDA) in mid-2006, he reports.
Tubal sterilization is one of the leading contraceptive options for American women. In 2002, 27% of all contracepting U.S. women relied on the method.1 Of the 700,000 annual bilateral procedures, about half are performed postpartum and half as ambulatory interval procedures.2
Until November, 2002, no hysteroscopic method of tubal interruption had ever been approved by the FDA. With the advent of the Essure transcervical sterilization method, expect to see advances in these types of procedures, says Amy Pollack, MD, MPH, senior lecturer in the Mailman School of Public Health at the New York City-based Columbia University.
Review the procedure
Adiana was founded in 1997. It took approximately two years to develop Adiana’s technology, followed by three years of pilot clinical studies to refine its product design, says Goeld. An application for a formal clinical trial was filed with the FDA in late 2002. That trial still is ongoing, he adds.
The Adiana procedure is performed in two steps; first, a catheter is delivered through a hysteroscope into the intramural portion of the fallopian tube. Using low-level bipolar radiofrequency energy, a superficial lesion is created to remove surface epithelium. The second step calls for placing a matrix (a porous, nonbiodegradable implant material) into the lesion. The matrix remains implanted within the fallopian tube, where surrounding tissue grows into it over a few weeks. The ingrowth results in permanent and total occlusion of the fallopian tube.3 Alternative contraception is used for three months followed by determination of tubal occlusion by hysterosalpingography.
In a poster presentation at the recent annual clinical meeting of the Washington, DC-based American College of Obstetricians and Gynecologists, investigators reported no serious adverse events within the first 500 women treated in the device’s multicenter trial.4 Mean procedure time ("scope in to scope out") was fewer than 15 minutes, investigators noted. Local anesthesia without sedation was used in most patients. Women were "highly satisfied" with the procedure and many returned to their usual activities the same day. Preliminary results indicate the procedure is safe and effective, but more follow-up is required.
More research needed
The compact size of Adiana’s implant material, described as "smaller than a grain of rice," results in its ability to reside entirely within the patient’s fallopian tube. Since the implant material does not protrude into the uterine cavity, it may be advantageous for those women who would seek to reverse their permanent birth control through in vitro fertilization, observes Pollack. More research will need to be conducted in the matter to see if that claim is valid, she says.
Transcervical sterilization is particularly of interest because it allows the user to avoid a transabdominal surgical procedure, notes Pollack.
However, the need for use of special equipment in the form of a hysteroscope presents a challenge in implementing transcervical sterilization into current practice, she states. More focus will need to be given in training medical residents and providing continuing education for practicing physicians in use of outpatient hysteroscopy, says Pollack.
"In the past, there just hasn’t been that much use of it," she notes. "It’s been used as a diagnostic procedure; much of the demand for it has been in the private sector, where residents don’t get as much experience."
References
- Mosher WD, Martinez GM, Chandra A, et al. Use of contraception and use of family planning services in the United States: 1982-2002. Adv Data 2004; 350:1-36.
- Westhoff C, Davis A. Tubal sterilization: Focus on the U.S. experience. Fertil Steril 2000; 73:913-922.
- Association of Reproductive Health Professionals. Transcervical methods in the U.S. pipeline. ARHP Clinical Proceedings; May 2002:14.
- Price T, Herbst S, Harris M, et al. Permanent transcervical sterilization: The first 500 women treated in a multi-center trial. Presented at the Annual Clinical Meeting of the American College of Obstetricians and Gynecologists. San Francisco; May 2005.
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