UTERINE FIBROID EMBOLIZATION

Embolizasyon Tedavisi Uterine fibroid embolization (UFE) is an angiographic intervention performed with a special angiography device called “digital subtraction angiography” (DSA). For this, the patient is put on the angiography table, some relaxating medications are given and local anesthetic is injected into the groin. Then, the artery at the groin is punctured and a tiny tube called catheter is placed into the uterine artery. Next, angiographic films are taken to see the fibroids and their feeding vessels. After it is made sure that the catheter is in the right location, small particles are injected into the uterine arteries until all the fibroid-feeding arteries are occluded. Then, the other uterine artery is catheterized and embolization is done in the same manner.


Video: How do we perform pain free UFE?

The UFE procedure lasts about one hour. After UFE is completed, control angiograms are taken and the catheter is taken out. The puncture site at the groin is compressed by hand for about 15 minutes, and after the bleeding stops, an elastic bandage is applied.

During UFE, occluding particles are injected into the main uterine arteries and these particles go into the feeding arteries of fibroids as well as into the arteries of the normal uterine tissue. Despite that, after UFE, all the fibroids become dead while all the normal uterine tissue continues to be alive. There are a number of explanations for this interesting occurrence:

  1. Fibroids have much more feeding vessels than the normal uterine tissue. These vessels produce a “flush” effect and suck most of the particles into the fibroids. As a result, most of the particles go into the feeding arteries of fibroids instead of those of the normal uterine tissue.
  2. Fibroids are used to a high blood supply. When their feeding arteries are blocked, they die in a short time because they can not tolerate such a low blood supply. By contrast, normal uterine tissue is not so sensitive to changes in blood circulation and can easily resist to a temporary low blood supply.
  3. Fibroids get their blood supply only from the uterine arteries and once these are occluded the fibroids will die. By contrast, normal uterine tissue has also alternative blood supply from the other pelvic organs. Thus, even if the uterine arteries are occluded the blood circulation of the normal uterine tissue is decreased but maintained.
  4. After UFE, the main uterine arteries are generally reopened in a short time. The time to reopening mainly depends on the types of particles. Thus, after a temporary occlusion, normal uterine tissue may regain its normal blood supply. But even this temporary “bloodless” state is sufficient to kill the fibroids because they heavily depend on a high volume blood supply to survive.

Click to see the animation of UFE

Because of these reasons, UFE kills the fibroids but leave the surrounding normal uterine tissue intact. This can be best appreciated by comparing the MRI images taken before and after UFE.

After UFE, patients generally stay at the hospital for 1-3 days. During that time, the patient may have some pain, fatigue, nausea and lack of appetite but these can be easily overcome with simple medications. After the patient is discharged, she can do normal physical activities but return to normal life completely only after 5-7 days.

After UFE, the fibroids symptoms such as pain, bleeding and frequency will substantially decrease or completely disappear in more than 90% of the patients. This rate is comparable to hysterectomy and better than myomectomy. Since UFE is effective to all of the fibroids in the uterus, regrowth or recurrence of fibroids are unlikely after a successful embolization. In one study, patients were followed up for 6 years after UFE, and it was seen that none of the embolized fibroids have grown again. Since UFE is a minimally invasive procedure, it can be repeated when necessary or if it fails, surgical operation can still be performed any time. Because of these advantages, UFE is considered the first line treatment for many patients with fibroids.

Therapeutic goals

Histerectomy

Myomectomy

Embolization

Improvement of vaginal bleeding

%100

%64

%86

Improvement of compression symptoms

%80-94

%91

%80-83

Improvement of abdominal pain

%98

%54

%74-84

Hospitalization time

2-7 day

3-4 day

0-2 day

Return to normal life

33-36 day

36 day

5-7 day

Probability of recurrence-free survival

%100

%75

%87-99

History

Embolizasyonun TarihçesiEmbolization of the uterine arteries has been successfully used for the treatment of vaginal bleeding due to reasons other than fibroids for more than 25 years. It has been understood just by coincidence that the same method can also be used for the treatment of uterine fibroids. In 1989, Dr Jacques-Henry Ravina, a gynecologist who lived in Paris, noticed that embolization can stop bleeding due to uterine tumors and thought for the first time that if performed before the operation, it may also reduce the bleeding during myomectomy. Then, he started to operate his patients some days after the uterine artery embolization was done. Surprisingly however, he saw that some patients refused myomectomy after the embolization because they had no more complaints and in those who were operated, he noticed that the fibroids became smaller and dead. Based on these observations, Dr Ravina realized and then reported that embolization alone can successfully treat uterine fibroids.

In the following years, UFE was mainly used in France, but then in Europe and finally in USA. Today, it is extensively used in western countries but also increasingly used in the rest of the world. In France, owing to the increased use of UFE, the number of hysterectomies have dropped significantly. Today, it is estimated that each year, more than 25.000 UFE are performed in USA and more than 100.000 UFE in the rest of the world.

Risks of UFE

UFE is a very safe treatment and has much lower complication rates compared with hysterectomy and myomectomy. Despite that, as in any other intervention in medicine, UFE may have some adverse effects:

  • After UFE, mensturation may stop in a small number of patients (amenorrhea). This is temporary in most cases and the patients may have normal menses in a couple of months. In about 1-2 percent of patients however, mensturation may stop permenantly. In the vast majority of such cases, this is not a real menapause, as ovarian hormon levels are frequently found normal. Instead, it is probably because the endometrium has become unresponsive to hormonal stimulation for some reasons. Permanent amenorrhea is very rare in young patients but may be more common in premenapausal women.
  • In less than 1% of the patients, an infection may develop in the uterus and may require antibiotic treatment and hospitalization.
  • In less than 1% of the patients, a noninfectious vaginal discharge may develop and last for a couple of weeks or months.
  • In about 2-3% of the patients, the embolized fibroids may break down and fall through the vagina. Although this will help fibroids to disappear quickly and is desired by most patients, large fibroids may cause pain and discomfort.

Complications

(%)

Hysterectomy

%

Myomectomy

%

Embolization

%

Bleeding during the procedure

1-30

8-13

0

Deep vein thrombosis, pulmonary embolism

5

2

0.5

Infection

10-24

5-31

0-2

Secondary interventions

5-12

3

5

Advantages of UFE

UFE has a number of advantages over myomectomy and hysterectomy in the treatment of uterine fibroids:

  • Instead of general or spinal anesthesia, UFE is performed under local anesthesia.
  • Since there is no blood loss, transfusion is not necessary.
  • There is no skin incision, wound or stitches. All the procedure is done through a 2mm angiography hole at the groin.
  • The duration of hospital stay and time to return to normal life are shorter compared with myomectomy and hysterectomy.
  • Unlike hysterectomy, the uterus and ovaries are left intact. In this way, fertility may be preserved and the problems of hysterectomy can be avoided.
  • In myomectomy, only the fibroids that can be surgically removed are treated, and those that can not be removed stay inside the uterus and may grow later. By contrast, in UFE, all the fibroids inside the uterus are treated regardless of their size, number and location. And this is achieved without a single incision in the uterus.

The Effect of UFE on Fertility

embolizasyon hamilelik In the early years of UFE, it was thought that UFE may harm uterus and ovaries and thus, should not be used in women who desire pregnancy. Later however, it was proved in many studies that pregnancy is possible after UFE. It was even seen that in women who can not become pregnant due to fibroids, UFE can treat fibroids and help such women become pregnant.

However, it is known that any treatment option may have risks for pregnancy. In myomectomy, incisions and stitches may cause infection, bridging and deformation in the uterus. Besides, if there is an uncontrolable bleeding during myomectomy, emergency hysterectomy may become necessary. In HIFU and percutaneous ablation, there is always the risk of unintentional thermal damage to the normal tissue around the fibroid and to endometrium, which may endanger fertility.

In UFE, especially if too small particles are used, the particles may go into the ovarian arteries and, although rarely, may cause some degree of ovarian failure. It has been reported that this is unlikely if larger than 500 micron particles are used during UFE since these particles can not pass through the channels between the uterine and ovarian arteries. After UFE, it is also possible that the particles may go into the normal uterine tissue vessels. In the vast majority of the cases, this will not cause any problem, but rarely, it may make the endometrium unresponsive to hormonal stimulation and cause amenorrhea. Theoretically again, large particles are less likely to cause this problem, because during UFE, the smaller the particle size is, the more aggressive the embolization will be.

During UFE, this effect of the particle size can be used to obtain maximum benefit in different patient groups; if the patient has severe fibroid symptoms such as heavy bleeding, anemia or urinary frequency, and does not want pregnancy in the future, then it may be best to perform an aggressive embolization using smaller particles. If the patient has mild symptoms and desires pregnancy, then a less agressive embolization using larger particles is more appropriate. In this way, the fibroids can still be treated, and the ovarian and endometrial function will be more likely to be spared.

Embolization + myomectomy:

Both UFE and myomectomy can treat the fibroids individually. In certain situations however, it may be beneficial for the patient to use both treatments. For instance, in patients who have multiple fibroids, which can be best treated with embolization, there may also be pedinculated subserosal or submucosal fibroids, which can be easily treated with myomectomy. In such patients, UFE can be performed first to treat multiple fibroids and also to reduce the blood supply of pedinculated fibroids. Then these fibroids can be easily removed with laparoscopic or histeroscopic myomectomy with minimal blood loss. In this way, all the fibroids can be treated and hysterectomy can be avoided. In patients who underwent myomectomy after UFE, it has been demonstrated that there is very little blood loss, the operation is much easier and more fibroids can be removed with less risk.