Uterine artery embolization (UAE) is a minimally-invasive interventional procedure that addresses vaginal bleeding caused by a number of conditions. While uterine fibroids (noncancerous tumors within the uterus) is a frequent indication for UAE, it is also used as a means of treating heavy bleeding in emergency situations provoked by malignant tumors, childbirth and resulting postpartum hemorrhage, and trauma. While the terms uterine artery embolization and uterine fibroid embolization (UFE) are used interchangeably, UFE is a specific type of UAE procedure that addresses uterine fibroids.
For women with uterine fibroids, the symptoms that may necessitate a UAE include constipation, heavy periods, intercourse that is painful, increased urinary frequency and urgency, bloating, and pelvic pressure. Feelings of pelvic pressure occur due to the build up of the compressive effects of the fibroids within the lower abdomen which often results in uncomfortable bowel movements and frequent urination. Given that miscarriages can result due to the constraining effect of the fibroids on the growing embryo, a UAE may also be warranted in such settings to both kill and in turn shrink the fibroids as a means of helping the patient to be able to have a healthy and viable pregnancy.
However, a UAE procedure is not routinely recommended in patients who are asymptomatic from their fibroids. It’s also not recommended when pelvic infections are present, or when the patient has a disease of the arteries or veins. Patients have been referred routinely for the procedure in cases where medications or hormonal treatments have proven either ineffective in addressing the condition or the patient prefers a definitive solution and not medications that simply mask their symptoms but do not fail to address the root cause of the patients symptoms, namely the growing fibroids. Patients with fibroids are also often recommended for UAE when they prefer a nonsurgical solution to their condition that also allows them to retain a functioning uterus, avoiding both hysterectomy (surgical removal of the uterus) or myomectomy (surgical removal of the fibroids).
Once a patient has been seen by an interventional radiologist and is deemed a candidate for UAE, it's important for them to know how to prepare for the procedure. As with any procedure involving sedation, patients are advised to refrain from eating or drinking anything after midnight on the night before their UAE. On the morning of, a small sip of water can be taken as a means of ingesting the usual prescribed medications, as long as they are not blood thinning medications such as aspirin, Plavix, ibuprofen, Motrin, Advil, and anticoagulants such as Coumadin, each of which should be avoided for five full days prior to the procedure.
When performed as an outpatient, a UAE typically requires roughly two hours, with an interventional radiologist performing it in a cath lab or interventional suite, as opposed to an operating room. Once the universal pause for safety is performed, allowing the team to become fully oriented to the procedure at hand, sedation is then initiated. A sedative is then injected through a vein by a nurse or anesthesiologist in order to achieve conscious sedation, a state where the patient is adequately sedated for the procedure, drowsy, but awake and responsive to commands. An IV drip may also be placed in the arm, which allows the patient to receive medications and fluids throughout the procedure.
Prior to the procedure, the site that the interventional radiologist has chosen to get access to the patient's artery is cleaned vigorously, which could be the wrist or the thigh. Next, a local anesthetic is injected into the skin at that site, resulting in transient numbness. This allows the patient to still feel touch but not sharp pain. A tiny incision which is often the size of a grain of rice is often made at the vascular access site. A catheter is then inserted over a very thin wire into the patient's vasculature, and is then navigated into the uterine arteries, which carry blood directly to the uterus.
Next, an intraarterial injection of an X-ray contrast dye is performed, making the vessels of interest visible to the treating physician. The interventionalist then takes a diagnostic arteriogram (or angiogram) which involves X-ray pictures of the arteries of interest, which supply the uterine fibroid with blood.
On identification of the source and exact distribution of blood flow to the parasitized fibroids from the uterus, uterine artery embolization is then performed. This involves the careful and directed injection of small particles, similar to grains of sand, into the blood vessels of the uterine fibroids. The embolized particles work to halt the blood flow to the fibroid, causes it to die, shrink, and become absorbed.
The injected gelatin or polyvinyl alcohol particles are mixed with a contrast dye and are directed via the catheter to the targeted and problematic blood supply of each of the fibroids. After several minutes, the particles effectively block the flow of the oxygen rich blood to the fibroids. Once the source of blood supply to the fibroids from the right and left uterine arteries are satisfactorily blocked, a final diagnostic arteriogram is taken and the therapeutic end point is recorded. Finally, the catheter is removed, with manual pressure placed over the incision site in order to seal the access site to the artery and the overlying skin and soft tissues.
Generally considered safe, UAE carries notably rare risks such as injury to the uterus or artery, premature menopause, lack of periods, and ovarian dysfunction. It’s worth noting that the rare cancer type leiomyosarcoma which may be seen in a small fraction of patients presenting with fibroids is unresponsive to UAE treatment.
Given the highly effective nature of UAE for treating fibroids, it's ability to cure symptoms of menorraghia and bulk symptoms, with little post procedural downtime (usually 1 week), little to no scarring, the preservation of the patient's uterus and the nonsurgical nature of the treatment, UAE has become known as the best kept secret for treating women with fibroids.
