Diagnostic Imaging
August 2003

OVERREAD

Uterine fibroid embolization takes on new challenges

With basic efficacy proven, researchers shift focus to fertility and short- and long-term implications

Several years' worth of research on uterine fibroid embolization in North America and Europe has led to a similar conclusion: The technique is a safe alternative to both hysterectomy and myomectomy. New issues face investigators in the next stage, however.

The Ontario UFE Trial, one of the largest safety and efficacy studies, included 555 women who underwent uterine artery embolization of symptomatic fibroids. The study not only found the procedure to be an effective and less invasive alternative to myomectomy and hysterectomy, it also reported a surprisingly high number of successful pregnancies. The latest report on the study's results, including data on pregnancy occurrence, was presented at the Society of Interventional Radiology meeting in Salt Lake City in April.

The Royal Surrey County Hospital Trial, a uterine artery embolization study conducted in the U.K., included 400 women with symptomatic fibroids. Preliminary results were published in the November 2002 issue

of the Journal of Obstetrics and Gynaecology. Paralleling the Ontario trial, the study showed high clinical success and low complication rates among patients.

Georgetown University investigators published their results from 200 consecutive patients in the July 2001 issue of Obstetrics & Gynecology. They are now entering the fourth year of follow-up on every patient on the study, said lead author Dr. James B. Spies, chief of radiology at Georgetown University Hospital.

Thomas Jefferson University researchers, on the other hand, had previously published results on their prospective trial with 305 women in the August 1999 Journal of the American Association of Gynecologic Laparoscopists. Similar to their counterparts at Georgetown, the group found UFE to be a highly effective treatment for symptomatic uterine leiomyomata.

The Cardiovascular and Interventional Radiology Research and Education Foundation Uterine Artery Embolization Fibroid registry, the largest study on fibroid treatment, has finished enrolling candidates. The registry's data should allow researchers to assess the procedure's impact on patients and to compare it with other therapies.

Although UFE has replaced neither hysterectomy nor myomectomy, there is no question it is a safe and effective treatment alternative to both, said Dr. Gaylene Pron, Ph.D., an epidemiologist at the University of Toronto and the Ontario UFE trial's principal investigator. The trials' results, however, have left specialists pondering a number of other issues, and UFE's role in preserving fertility is number one among them.

Although increasing numbers of younger women are undergoing this treatment to maintain fertility and to become pregnant, physicians still lack data to support that choice. While the Ontario UFE trial had 20 pregnancies, the worldwide literature on pregnancy outcomes after such procedures is less than 50, Pron said.

Following up on these patients is also key. While these studies provide clues regarding the procedure's safety and short- and midterm effectiveness, many questions remain.

"What is this procedure's long-term effectiveness? Is there recurrence? Anything works for three months, but three years down the road, how many people are going to recur? That's the question we are trying to answer with our study," Spies said.

The end point used to achieve a successful embolization is also evolving. Interventionalists used to embolize the uterine arteries until no visible vessel flow remained. Today, most leave some flow within the uterine artery, with the hope of preserving arterial supply to the portions of the uterus unaffected by fibroids, said Dr. Gary Siskin, an associate professor of radiology at Albany Medical College in Albany, NY.

"At this point, the efficacy of this technique has not been convincingly proven but has been virtually universally adapted by the interventional radiology community," he said.