BBI Contributing Editor
SAN FRANCISCO, California — Attendees and presenters at 30th annual meeting of the American Association of Gynecologic Laparoscopists' (AAGL; Santa Fe Springs, California) held here last November examined new minimally invasive procedures and the evidence to support their use, effectively bridging the gap from current knowledge to future advances. This relatively small organization (about 6,000 members) represents only 15% of the total population of gynecologists but performs about 35% of all gynecologic procedures. This group is the leading edge in terms of advancing technology into the daily practice of gynecologists.
It is estimated that about 25,000 uterine artery embolizations (UAE) are performed annually in the U.S. by interventional radiologists. The UAE procedure has exceptional success rates in patients who have a large uterus, multiple fibroids, abnormal bleeding and/or bulk symptoms. Tiny microspheres are injected through a catheter that is placed via the femoral artery into the uterine artery, which then egress into the pre-capillary beds of the fibroids and uterus itself. The microspheres eventually work their way through the vasculature and are eliminated by the body, but the temporary ischemia they caused kill off the fibroids leaving the uterus undamaged. A handful of laparoscopic gynecologists are trying to achieve these same results by ligating the uterine artery.
In a presentation on "Uterine Artery Occlusion for Leiomyoma Associated Uterine Bleeding," Malcolm Munro, MD, of the UCLA School of Medicine (Los Angeles, California), discussed the various treatment options for symptomatic fibroid patients. Current treatment often consists of hysterectomy, of which there are 200,000 a year performed for symptomatic fibroids. Medical management usually is the first line of defense, but if the patient doesn't tolerate the side effects well, or if the symptoms don't resolve, then surgical options are considered. This could be a hysterectomy, myomectomy or myolysis, all of which require an operating room and general anesthesia and a recovery period. Uterine artery embolization has been performed for various other bleeding problems such as postpartum or post-surgical hemorrhage since 1972, with a success rate of 86% to 100%. In 1995, a French physician started to perform UAE prior to myomectomy in order to reduce the intra-operative blood loss but found that the embolization itself often relieved the symptoms. Since then, interventional radiologists in the U.S. have been performing UAE with relative success, driven by the demand of many women who do not want, or do not have time for, a surgical procedure (see Table 7). The success of UAE left gynecologists with the option of referring their fibroid patients to a radiologist or learning how to perform a surgical uterine artery occlusion.
Several approaches have been tried, including electrocautery to dessicate the artery, clips to clamp the artery or sutures. The procedure is often performed laparoscopically. Studies have demonstrated similar outcomes for either myomectomy, embolization of the uterine artery or surgical ligation of the uterine artery. At this time, uterine artery occlusion appears to provide a similar outcome in treating fibroids with a risk equal to, or less than, that of a hysterectomy. The longevity of the results is not yet known, nor are pregnancy outcomes. It is currently reserved for those patients not desiring to have any more children.
Update on endometrial ablation
Endometrial ablation for abnormal uterine bleeding has been well accepted as an alternative to hysterectomy, as evidenced by one company's two-year results. BEI Medical Systems (Teterboro, New Jersey) reported that "Overall, 95.5% of the women continued to be satisfied with their results two years after treatment, and 92.5% reported alleviation of menstrual discomfort." Five Kaiser Permanente medical centers in California have purchased the BEI systems and are regularly using endometrial ablation as an alternative to hysterectomy. Besides practicing better medicine and a quick recuperation for the patient, the expected savings are almost $2,000 per procedure.
The most recent entry into endometrial ablation, Novacept (Palo Alto, California), recently received FDA clearance to begin marketing its device. Several doctors interviewed at the AAGL meeting said they felt, as one noted, that "these two companies [BEI and Novacept] seem to be taking the lead in terms of market share over Cryogen and Gynecare." Ease of use and safety were sited as being key reasons. A novel idea is being examined in a Philadelphia-area hospital, where patients undergoing tubal ligations are being offered an endometrial ablation at the same time — provided that dysfunctional bleeding also is present. The concept is to provide total patient care all at once and save the patient time and money to perform two procedures concomitantly.
Big market for adhesion prevention
Adhesions occur when one tissue adheres to another, often forming after surgery. More than 93% of all patients who have had a surgical procedure may have tissue adhesions. It is especially a critical matter in women, where it is believed that pelvic pain and/or infertility may be caused by adhesions. Adhesions have been reported to be the second-largest reason for laparoscopic surgery in the U.S. More than 5 million American women have impaired fertility, with an estimated 15% to 20% of these possibly caused by adhesion formation. Adhesions also have been associated with endometriosis, pelvic inflammatory disease and a host of gynecology-related syndromes. For these reasons, adhesion prevention has been the center of attention in gynecologic surgery.
The market for adhesion prevention products is large and can be segmented into surgical groups: open general surgery, laparoscopic gynecology, laparoscopic general surgery and open gynecology. The laparoscopic and open gynecology market segment alone represents 3 million procedures worldwide; 65% of those performed in the U.S. being laparoscopic gynecology procedures (see Table 8). Gynecologic surgical procedures are considered such a high risk for adhesions that analysts have predicted that 50% of all gynecologic surgeries will use some form of adhesion prevention over the next five years.
Three companies are addressing the adhesion prevention market: Genzyme Biosurgery (Cambridge, Massachusetts) with Seprafilm, Lifecore Biomedical (Chaska, Minnesota) with Intercede and newly approved Intergel, and Confluent Surgical (Waltham, Massachusetts), in development with its first product, SprayGel. Although the market demand exists, the first products developed for adhesion prevention met with limited success, primarily due to difficulty of use. Genzyme Biosurgery's Seprafilm is primarily used for incision line protection. The product is similar to Intergel in that it also is a gel-based hylauronic acid derivative. It has been reported to be difficult for surgeons to use in laparscopic procedures and too complicated for organ wrapping (such as the ovaries). Intergel has been in R&D since 1989, in worldwide human clinical trials since 1996, and has been marketed outside the U.S. since 1998 by Lifecore's global marketing partner, Gynecare (Cincinnati, Ohio), the women's health care division of Ethicon Endo-Surgery. Intergel is a gel that can be dropped onto the organ, such as an ovary, and is touted to be easy to use during surgery. Gynecare is launching Intergel with an 80-person direct sales force, initially targeting open gynecology surgery. A clinical trial for laparoscopic use is scheduled to begin shortly.
Lifecore received its final FDA approval for Intergel last Nov. 19, the day after the close of the AAGL meeting. This came after Lifecore entered an appeal to the FDA dispute resolution panel, which found in September that the FDA had wrongly rejected the medical device maker's gel designed to prevent adhesions. The decision was the first of its kind under the new dispute resolution system.
The newest entry into the sector is Confluent Surgical, with SprayGel, an aerosol polyurethane glycol designed for all surgical procedures, including laparoscopic procedures. Unlike hylauronic acid, which is a biological material, Spraygel is a synthetic that uses mechanical action to create a local barrier. Theoretically, infection control should be present because bacteria cannot thrive on a synthetic like they can on a biologic substance. Confluent is a venture-backed company formed in late 1998, with its first product expected to be released in 2003. The company also is developing a second line of products designed to provide sealing as well as adhesion prevention.
Although some analysts who follow the sector predict an adhesion prevention market of up to $500 million, that goal may not be achieved until all the newer products are on the market.