Overview of Uterine Fibroid Embolization
Since 1995, a medical procedure called embolization has been used to treat uterine fibroids, which are noncancerous growths in the uterus. This procedure is often called uterine artery embolization (UAE) because it is done primarily through the uterine artery. Some people might refer to it as uterine fibroid embolization, but UAE is a more accurate term since this procedure has more uses than just treating fibroids.
The success of the UAE procedure is measured by being able to deliver tiny pieces intended to block the blood flow, known as embolic particles, to the fibroids. Skilled doctors have about a 95% success rate in performing this procedure.
However, success isn’t just about performing the procedure correctly. The main aim is to lessen the symptoms caused by these fibroids. Interestingly, how much the fibroids shrink after the therapy can indicate its effectiveness. A review of 84 fibroids treated over a year showed that, on average, they decreased in size by about 60%. Fibroids located beneath the lining of the uterus showed the most significant shrinkage, while those located beneath the outer surface of the uterus showed the least shrinkage. It’s important to note, though, that not all women remain symptom-free even if their procedures are technically successful, and in 10% of cases, the fibroids even increased in size.
Anatomy and Physiology of Uterine Fibroid Embolization
The uterine artery is like a branch on a tree, stemming from the main trunk, which in this case, is the internal iliac artery (IIA). The IIA has two main branches, each with its own ‘twigs’, or further branches. For women, one of these branches is called the uterine artery (UA), the primary artery supplying blood to the uterus.
There could be some variations in this layout. For instance, the vaginal artery could sprout from the uterine artery directly. The uterine artery is usually the first branch of the front section of the IIA. Though the dominant or largest branch of the IIA’s front section is often the inferior gluteal artery, which supplies blood to the lower part of the buttock.
The uterine artery has three main segments. The first part travels down the side of the pelvis, the second part goes across the body towards the belly button, and once the artery reaches the uterus, it turns upwards, forming the third segment. It’s these three segments that give the uterine artery its shape, going down, across and then up again.
The branches of the uterine artery cover the surface of the uterus and produce small blood vessels that supply blood to the muscle of the uterus. If there are fibroids (non-cancerous growths in the uterus), they are also supplied by these small vessels. There’s also the cervicovaginal branch that comes from either the middle or end of the second, transverse segment and sometimes from the ascending segment.
In almost half of females, the uterine artery can connect with the ovarian artery, which provides blood to the ovaries. But, this can only be seen during a special kind of X-ray called angiography about 10% of the time. There are three common configurations of this connection.
The ovarian arteries usually start from a large central artery, called the aorta, a little below the renal arteries, which provide blood to the kidneys. These arterial courses can often be too twisted to insert a standard tube for more than a few centimeters. Understanding these different connections between arteries is important in managing patients who undergo embolization, a treatment procedure that blocks one or more blood vessels.
Why do People Need Uterine Fibroid Embolization
Uterine artery embolization (UAE), a procedure used to treat conditions like fibroids and heavy menstrual bleeding, is most successful when the patient is an ideal candidate. Ideal candidates for UAE are women who have heavy, regular menstrual bleeding or pain related to fibroids in the wall of their uterus, are still having their periods (premenopausal), and don’t plan to become pregnant in the future.
Fibroids often cause heavy menstrual bleeding, but not irregular periods. If you’re experiencing periods that are more frequent (less than 21 days apart) or last longer (more than 10 days), this could be due to an issue in the lining of your uterus, such as polyps or cancer, rather than fibroids.
In addition to causing heavy bleeding, fibroids can also cause “bulk-related” symptoms, such as feeling pressure in your lower abdomen, legs, and back, or problems with urination, like needing to go frequently, especially at night, or incontinence. Studies have shown that UAE can help improve these symptoms, although it’s more successful in treating bleeding than these bulk-related symptoms.
There are also other conditions that can be treated with UAE:
Adenomyosis: This is a condition where the inner lining of the uterus breaks through the muscle wall. Studies have shown some success with treating it by UAE, although the effectiveness isn’t entirely certain and some patients report worse pain after the procedure.
Postpartum Hemorrhage (PPH): UAE can be a helpful treatment for severe bleeding after giving birth. The decision to use UAE first, or after other treatments have failed, varies – it could depend on risks like abnormal placenta attachment and abnormal blood clotting.
Preventing bleeding during or after surgery: In some cases, UAE can be used before surgery to reduce bleeding, such as prior to removing a uterine tumor or before delivery in case of a placenta accreta (where the placenta grows too deeply into the uterine wall).
If medical treatments for fibroids haven’t worked or aren’t appropriate, UAE can be considered. Some medications could help with fibroid symptoms and reduce fibroid size, but they have limitations, such as side effects or a restriction on getting pregnant. So, UAE might be a good alternative for women who don’t want surgery, medication hasn’t worked, or they wish to get pregnant.
When a Person Should Avoid Uterine Fibroid Embolization
Different organizations have varied rules about when it may not be a good idea to proceed with a procedure called Uterine Artery Embolization (UAE). UAE is a treatment option for fibroids which are non-cancerous growths in the uterus. The following list summarizes the main factors, in no particular order, that might prevent you from getting UAE:
– If you are pregnant.
– If you have an active inflammation in the uterus, known as endometritis.
– If you have cancer in the uterus or cervix and you are not planning other surgery to treat it.
– If you are a woman who has gone through menopause and have unknown causes of bleeding.
– If you have a fibroid that is dead or showing a lack of blood supply, as seen on an MRI scan.
– If you have a fibroid that is smaller than 1 cm.
– If your fibroid is attached to the uterus by a narrow stalk.
– If your fibroid is in the cervix.
– If you are currently taking a GnRH agonist, a medication that affects hormones.
– If you had radiotherapy in the pelvic region before.
– If you have a health condition that weakens your body’s ability to fight illness or infection.
– If you have fibroids making your uterus as big as or bigger than it would be at 24 weeks of pregnancy.
– If you have a severe allergy to contrast material used in imaging tests.
– If you have severe kidney problems and are not on dialysis treatment.
– If you have a blood disorder that can’t be corrected and makes it hard for your blood to clot, which can result in severe bleeding.
When it comes to a desire for future pregnancy or if you have a condition called adenomyosis (abnormal presence of uterine lining in the muscular wall of the uterus), neither of these should be seen as a complete stop to UAE as per 2014 guidelines by the Society of Interventional Radiology (SIR). It’s just that these should be discussed and considered thoroughly.
Hormone medications that might have been prescribed should be stopped at least three months before UAE, because these drugs can affect the blood vessels of the uterus potentially making the procedure more difficult.
When it comes to certain kinds of fibroids, if the fibroid has a thin stalk and is attached loosely, performing a different type of surgery could potentially be better to avoid the chance of the fibroid breaking off and causing an infection. If the fibroid is very large with a lot of blood supply, or if it’s very small, then UAE might not work well. Fibroids located in the cervix can often be easily removed surgically.
Equipment used for Uterine Fibroid Embolization
In simpler terms, tumors are typically treated with small substances called particles. These particles are likely to reach the smaller blood vessels in the tumor, causing the diseased tissue to die off. There are different types of particles that doctors can use, including TAG spheres, non-rounded PVA, and round PVA. TAG and PVA are types of materials used to make the particles.
When it comes to the size of the particles used, it was found that there was not a significant difference between using particles that were 500 microns or smaller compared to particles that were 500 to 700 microns in size. This was proven through a scientific study known as a randomized controlled trial (RCT). However, it is generally believed that smaller particles can lead to better rates of tissue death in the tumor, which can be both a good and a bad thing. This is because smaller particles may flow back into other parts of the artery and inadvertently affect nearby tissues, like the ovary. So, the doctor may choose bigger particles if the ovary artery is connected, while smaller particles may be chosen if there’s no visualized connection between the uterine and ovary artery.
Further studies comparing different types of particles (TAG and PVA) did not find significant differences in patient outcomes in the short term. Although one of the studies found that a type of particles called TAG resulted in better rates of tumor tissue death compared to PVA, it is important to note that there could be a conflict of interest because the study was funded by manufacturers of TAG. Therefore, we can’t make a final conclusion until we have studies comparing the effects of the same sizes of TAG and PVA particles.
Preparing for Uterine Fibroid Embolization
Doctors need to thoroughly investigate the possible causes of a patient’s symptoms before performing UAE, or Uterine Artery Embolization (a procedure to treat fibroids in the uterus), to make sure that no other health factors might complicate the process.
Before going ahead, the patient should be up to date with regular screening for cervical cancer (checking for signs of the disease). Current guidelines suggest that women should get an HPV test every 3 years if the test is positive, and every 5 years if negative. These tests should continue until the age of 65, unless there are specific reasons to keep testing. If any unusual signs are found in the womb, particularly in women over 45, they should have a biopsy (a test that checks for cancer cells) before UAE, because this procedure is not a recognized treatment for womb cancer.
The doctors will check certain aspects of health, including electrolytes, kidney function (using an estimated Glomerular Filtration Rate), a complete blood count, the number of platelets (blood cells that help to form clots), their rate of blood clotting (using an International Normalized Ratio), and they’ll do a particular type of hormone test to make sure that the patient is not pregnant.
Doctors will also use an MRI scan to provide more information about the size and location of the fibroids and to check the condition of the muscle layer of the womb (adenomyosis). The MRI is a more detailed scan than an ultrasound and can offer key insights before undergoing UAE.
A key part of preparing for the procedure is making sure the patient fully understands what will happen, known as informed consent. This includes discussing all treatment options, possibly welcoming further advice from other medical professionals, explaining hospital procedures, recovery and time off work. The patient should be given written materials to support their understanding and contact details for medical support outside of office hours.
Doctors are also advised to explain that there could be a risk that the tests miss a diagnosis of cancer, resulting in delayed treatment. They are reminded that their role is to uphold the patient’s right to make decisions about their own health.
Before the procedure, to prevent any possible future infections from the procedure, certain antibiotics are recommended, for example, cefazolin or levofloxacin. If needed, pain medication might be given before the procedure too. If the patient has any risk factors, such as sleep apnea (breathing stops and starts during sleep), extra precautions will be taken to make sure they can breathe properly while under sedation. Certain states have specific laws regarding monitoring breathing during procedures.
After the procedure, there are a number of things that could need attention.
Pain – This can be managed using nonsteroidal anti-inflammatory drugs (NSAIDs) and/or strong painkillers. Pain at the site where the procedure was performed, or in the leg, can be common and is usually treated with NSAIDs. If there is severe pain, another drug like gabapentin can be given.
If the patient has long-lasting pain in the lower tummy, tests can be done to check if the procedure has affected other areas. Conditions that cause long-term pain, like Inflammatory Bowel Disease, might get worse after UAE.
Potential blood clots in the lung – Devices or medicines can be used to help prevent these. It’s important to be aware that there have been cases where patients developed lethal blood clots in the lungs after UAE.
Bleeding – Some bleeding in the first week after treatment could be a sign of infection in the womb, usually accompanied by flu-like symptoms and fever. Cramping and bleeding after the first week could be due to the body getting rid of the fibroids.
Nausea – This can be treated with ondansetron, a drug to prevent vomiting and nausea.
High blood pressure – This often goes up a bit after the procedure. High blood pressure can lead to complications like fluid in the lungs, heart attack, and stroke.
After being discharged, it is important to maintain communication between doctor and patient, with the possibility of scheduled follow-up appointments.
How is Uterine Fibroid Embolization performed
Here, we’re going to describe the way doctors do a uterine artery embolization (UAE), which is a minimally invasive procedure used to treat conditions like fibroids in the uterus. This is a step-by-step breakdown written in a way that you can understand.
To start, a doctor will enter the common femoral artery (an artery located in the groin) to put in a narrow flexible tube. This tube is quite small, only 5 or 6 ‘French’, which is a measurement less than 2mm wide.
Next, they’ll take an image, known as an arteriogram, to see the layout of the arteries and locate the origins of the uterine arteries (UA). This is like a roadmap for the doctor to follow.
Once they have this image, they’ll place a catheter (another flexible tube) into a part of the artery leading to your uterus.
From there, they’ll advance a smaller, more detailed tube through the larger one. This tube goes into the UA to the area past any branches leading to the cervix or vagina.
Again they’ll grab another arteriogram through the smaller tube to check for any connections to the ovaries, bladder, or vagina that might affect where they send the treatment.
Now it’s time for the embolization part. That’s when the doctor will stop the blood flow to a specific part of the uterus.
After all that, another set of images is taken to check the new path of blood flow to the uterus.
This entire procedure is then repeated on the opposite side for thorough treatment.
Finally, they’ll stop any bleeding at the puncture sites in your groin where they inserted the tubes.
There are many variables that can change based on your specific situation and doctor preference. Some examples include the use of one or two entry points, whether they take images from just the iliac arteries or from the whole aorta, what medications they use during the procedure, and exactly how they decide when the embolization is done.
Possible Complications of Uterine Fibroid Embolization
The number of complications following a certain procedure can vary. According to different studies, the rate can go up to 40% at times, and on other occasions it can be as low as 5%.
Severe Complications
Some of the major complications include:
1. Death (very rare, less than 1 in 1000)
2. Need for additional surgery to fix problems like cutting into an artery (2 to 3 in 100)
3. Developing an abscess or other severe infection inside the uterus (1 in 100)
4. Blood clot in the lungs
5. Future complications during pregnancy, like spontaneous rupturing of the uterus or abnormal placenta growth
6. Premature failure of the ovaries
7. Decreased blood supply causing pain in the buttocks or legs
Death
Deaths can occur due to a procedure known as uterine artery embolization (UAE) as a result of severe uterine infection/sepsis and blood clot in the lungs.
Infection-related Symptoms
The most common side effect is postembolization syndrome. Symptoms include pain, low-grade fever, feeling unwell, nausea, and losing appetite. Signs of a bacterial infection of the uterus lining include pain, fever, unusual vaginal discharge, and/or increased white blood cells. Initial treatment includes intravenous antibiotics and pain relief medication.
Missing Menstrual Cycle (Amenorrhea) Related Symptoms
Missing menstrual periods (amenorrhea) occurs in less than 10% of the cases. It is much more common in patients who are 45 to 50 years old or older. Usually, it lasts for a few cycles without increased levels of a hormone known as FSH or symptoms of menopause.
Detachment of Fibroids
There can be a detachment of fibroid tissue (abnormal growths in the uterus) from the wall of the uterus, which can then pass out through the vagina. This process is known as expulsion and typically occurs with submucosal fibroids. Symptoms include uterus contractions, abdominal pain, fever, nausea, vomiting, and vaginal bleeding or discharge. In some cases, surgery may be necessary to alleviate discomfort and remove the tissue.
Complications from Imaging the Blood Vessels (Angiography)
These can include the formation of a lump filled with clotted blood (hematoma), dissection, false outpouching of the blood vessel (pseudoaneurysm), and kidney damage due to the dye used in angiography.
Other Complications
Other potential complications include persistent pain, contrast-enhanced CT or MRI might be used to look for any abnormalities. Radiation exposure is significantly less than the amount required to produce burns. There have been reports of small, red/purple spots appearing on the torso and limbs (1% to 7%) after uterine artery embolization.
What Else Should I Know About Uterine Fibroid Embolization?
Women who are good candidates for a type of procedure related to handling womb_ailments, can expect a high success rate in terms of symptom management, satisfaction with the process, and overall quality of life for up to 10 years post-treatment.
According to the SIR standards, nearly 90% of all women should experience relief from related ailments, and more than 90% of women should expect the elimination of abnormal bleeding from the uterus.
However, certain factors may prevent successful treatment, these include but are not limited to: choosing the wrong patients for the procedure, presence of large fibroids, inability to perform the procedure on the uterine arteries, not fully completing the artery blocking process, arteries spasms leading to poor embolic material flow, and the presence of additional arteries supplying blood to the uterus among others.
Numerous trials have compared the success rates of surgery and the UAE (Uterine Artery Embolization – a less invasive alternative to surgery). Notably, no significant difference was found between satisfaction rates or major adverse events amongst the treatment methods. However, the need for further surgery was found to be more common in women who underwent UAE compared to those who underwent surgery.
In one extensive study, the treatment of fibroids through UAE, proved to be just as successful as surgical methods. Both methods showed equal success in relieving pain, complication rates, and overall satisfaction. However, it was noted that surgery showed a higher guarantee of stopping abnormal uterine bleeding.
The largest study till date comparing all surgical interventions to UAE, found no significant difference between UAE and surgery on parameters such as the quality of life or major complications. However, it did find that UAE led to a reduced length of hospital stay, less pain 24-hours post-procedure, and lesser costs.
In a study investigating the effectiveness of treatment options for fibroids larger than 4 cm, UAE did show less effectiveness compared to surgical removal for women hoping to conceive.
Despite these findings, different bodies around the world suggest different approaches. For example, gynecological societies in France and the United States recommend surgery over UAE, particularly for women who hope to conceive in the future. However, in the United Kingdom, health bodies don’t favour one method over the other, even for women considering future pregnancies.
Outside of treating fibroids, there is lack of evidence and guidelines comparing UAE to other potential treatments. However, UAE has proven to be effective in controlling Postpartum Hemorrhage (PPH) – heavy bleeding after childbirth, with an approximately 90% to 95% success rate.