Catheter Treatment for Uterine Growths (Fibroid Embolization)
I. Overview
Fibroid embolization is a treatment for non-cancerous growths of the uterus. It is a less-invasive alternative to traditional treatments such as myomectomy (surgical removal of the fibroid) and hysterectomy (surgical removal of the uterus).
Fibroids are benign (non-cancerous) tumors composed of muscular and fibrous material. Twenty-five percent of all women over age 35 have fibroids in their uterus. (This rate is 50 percent for black women over 35.) Whether fibroids cause symptoms depends on their size and number. Common symptoms are pelvic pain, abdominal distension, and heavy bleeding during menstrual periods. Fibroids can put pressure on the urethra, bladder, and bowel, and can cause leg, back, or side pains. Sometimes fibroids cause bleeding after sex or even constant bleeding, which can induce anemia. They also cause complications during pregnancy. Because their growth depends partly on estrogen levels, fibroids tend to grow during pregnancy and shrink after menopause.
During uterine fibroid emoblization, the doctor inserts a skinny
tube (catheter) into an artery in the upper thigh. He or she moves the
catheter into the uterine artery and releases small plastic
beads—ranging from 1/3 to 9/10 of a millimeter in diameter—into the
branches of the artery that feed the fibroid. (Sometimes small flakes
or foam are used in place of beads.) These beads block the fibroid’s
blood supply (embolize it). Fibroids consume blood rapidly, so the
beads preferentially travel to the branch arteries feeding the fibroid.
Because blood flows in one direction, from the artery to the fibroid,
there is no way for a bead to travel elsewhere in the body. Over the
next six months, the blood-starved fibroid tissue will die and the
fibroid will lose about 50 percent of its volume. The dead tissue does
not rot; instead, the cells shrivel up, like grapes drying into
raisins.
The procedure uses a local anesthetic and
takes about an hour. Some patients are discharged the same day, but
three-quarters stay overnight for observation and pain management. The
most common side effect is mild to moderate crampy pain, which begins
about eight hours after the procedure and fades rapidly over one to
four days. Patients are usually discharged with pain medication and can
resume normal activities in seven to ten days.
II. Medications
Local anesthetics are used during the procedure. Afterward, pain medication (fentanyl or Dilaudid) is delivered through a patient-controlled pump. The patient is also given Vicodin and anti-cramping medications.
III. Considerations
In the United States, uterine fibroids are responsible for 200,000 hysterectomies every year. For women who no longer want children and who want to reduce their risk for gynecological cancers, a hysterectomy may be an appropriate choice. Women who still want children or who place great value on keeping their uterus should consider a myomectomy or fibroid embolization. Fibroid embolization is less invasive, requires less recovery time, and has a smaller rate of recurrence than myomectomy.
In certain circumstances, fibroid embolization is not indicated. If the fibroid is less than 3 centimeters in diameter, nearby arteries may not be large enough to fit a catheter through. If the fibroid is larger than 10 centimeters in diameter, the tissue remaining after embolization may still be enough to cause “bulk symptoms,” such as abdominal distension, urinary frequency, constipation, and feelings of fullness or heaviness. If the patient’s fallopian tubes are unusually dilated (a condition known as hydrosalpinx), embolization has an increased risk of infection.
IV. Effectiveness
In several large studies, patients who underwent fibroid embolization saw the size of their fibroids shrink by a third to a half. Over 90 percent reported control of their symptoms after one year, while 5 percent to 10 percent required further intervention (either another embolization or surgery). Fibroids grow back about 10 percent of the time after embolization, and usually not until at least five years after the procedure. By comparison, fibroids grow back about half the time after myomectomy, and half of those with re-growths need more surgery. A hysterectomy is 100 percent effective at removing fibroids, of course, but it requires general anesthesia and six weeks of recovery. It also prevents future pregnancies.
V. Risks of Treatment
About 7 percent of embolization patients experience complications. This rate of complication is comparable to that experienced after surgery; however, embolization complications are usually less severe. About 2 percent of patients will get an infection of the bladder or uterus, and 2 percent will have an allergic reaction to dyes used during the procedure. In about 3 percent of patients, some of the dead fibroid tissue will pass through the cervix. If the tissue becomes lodged there, it can cause infection; in such situations, a gynecologist can help the tissue pass through the cervix, generally without the need for sedation.
Although many women have had successful pregnancies after embolization, there is not yet enough evidence to say with certainty whether uterine fibroid embolization will improve a woman’s chances of getting pregnant. By comparison, there is some data that suggests improved fertility after myomectomy. Therefore, when a woman specifically desires pregnancy and is a candidate for myomectomy, that option is generally preferable to embolization. If myomectomy is not an option, then embolization can be done instead.
VI. Risks of No Treatment
Women who do not treat their fibroids will typically continue to experience symptoms. However, fibroid size and symptoms may diminish on their own as a woman nears menopause.
VII. Urgency
In the absence of uncontrolled bleeding, uterine fibroids rarely represent an emergency. Fibroid embolization can usually be scheduled at a patient’s convenience.
