Uterine artery embolization (UAE) is a minimal invasive technique that uses transcutaneous common femoral artery approach to block uterine blood supply.
- Uterine artery embolization
- selection criteria
Uterine artery embolization (UAE) is a minimal invasive technique that uses transcutaneous common femoral artery approach to block uterine blood supply. It is based on established techniques for treating pelvic bleeding.
It was first described in 1976, for the treatment of abnormal uterine bleeding in patients with gynecological malignancies. Several years later, in 1994, UAE has been used preoperatively in patients with uterine myomas in order to reduce intraoperative blood loss and decrease transfusion requirements.[1, 4, 5] One year later, in 1995, UAE was introduced in patients with uterine myomas as an alternative approach to avoid surgical operation.[1, 4]
The procedure is usually performed under intravenous conscious sedation. Using the transcutaneous unilateral common femoral artery approach where both uterine arteries are selectively catheterized with a catheter or micro-catheter.[1, 4]
Following the sterile preparation of the right groin and local anesthesia, an arterial sheath (4–6 French) is introduced in the right common femoral artery using the Seldinger technique. An angiography is then performed, in order to manipulate a visceral angiography catheter into the left internal iliac artery [Figure 1].
Thereafter, a new angiography is performed in the contralateral oblique projection in order to identify the origin of the left uterine artery. Then, the angiography catheter, or a micro-catheter, is placed into the transverse segment of the left uterine artery [Figure 2].[4, 9] If it is technically feasible, the catheter tip should be placed beyond the origin of the cervicovaginal branch, excluding it from embolization.[4, 9]
Following the correct positioning of the catheter or micro-catheter and under angiographic control, an embolic agent (trisacryl gelatin microspheres, spherical polyvinyl alcohol) is injected and UAE is performed [Figure 3].[1, 2, 4, 9-11]
Subsequently, the angiography catheter is manipulated into the right internal iliac artery and placed in the right uterine artery [Figures 4, 5]. If this is not made possible, then the left common femoral artery is punctured and the procedure repeated.
Finally, when UAE has been completed, the catheter and sheath are removed. Hemostasis of the common femoral artery is achieved with manual compression.
The aim of UAE is to occlude or markedly reduce the blood flow in both uterine arteries at the arteriolar level. This causes irreversible ischemia and leads to necrosis and the subsequent shrinkage of uterine myomas.[1, 2, 12]
3. Selection criteria
UAE is an alternative to hysterectomy in patients with uterine myomas.[2, 13] It is performed on appropriately selected patients who wish to preserve their uterus and avoid a surgical operation.[4, 6, 7, 10, 11, 13, 14]
Moreover, it can be performed on patients who refuse blood transfusion (for health concerns or religious reasons).
Conditions that represent absolute contraindications for an UAE procedure are: pregnancy, active pelvic inflammatory disease, or other pelvic infection, genital cancer, history of pelvic radiation and impaired immune status [Table 1].[2, 4, 6, 10, 11, 14, 15]
|Absolute contraindications||Relative contraindications|
|pregnancy||severe vascular disease limiting access|
|active pelvic inflammatory disease||severe allergy in radiographic contrast media|
|other pelvic infection||coagulopathy|
|genital cancer||impaired renal function|
|history of pelvic radiation||desire for future fertility|
|impaired immune status|
Relative contraindications for UAE procedure are: severe vascular disease limiting access and catheter manipulations, severe allergy in radiographic contrast media, coagulopathy, impaired renal function, and desire for future fertility [Table 1].[2, 4, 6, 10, 11, 14-16]
The size and location of uterine myomas should also be considered in the patient selection process.
4. Treatment advantages
Intraprocedural blood loss is significantly less among patients treated with UAE, than among hysterectomy patients (30.9 ml vs 436.1 ml).[17, 18] As a result, blood transfusion requirements are significantly lower for patients treated with UAE than for hysterectomy patients (0% vs. 10–13.3%).[17-19]
Postoperative pain score during the first 24 hours is significantly less for patients treated with UAE than for hysterectomy patients.[17, 20, 21] However, postoperative pain during the entire hospital stay did not differ between the two groups (88.9% vs. 94.7%).[17, 18, 20, 21]
The length of hospital stay is significantly shorter for patients treated with UAE, than for hysterectomy patients (1–2 vs. 5–5.85 days).[13, 14, 17-19, 21] Recovery and return to normal activities are significantly swifter for patients treated with UAE than for hysterectomy patients (28.1 days vs. 63.4 days).[13, 14, 17-21]
5. Treatment effectiveness
For the majority of patients treated with UAE, there is a substantial improvement in terms of symptoms and in quality of life aspects.[2, 4, 6, 10, 21] More specifically, there is reduction in bulk symptoms (88%–92%), elimination of abnormal uterine bleeding (>90%) and successful control of symptoms (75%).[2, 19]
Postoperatively among patients treated with UAE, there is a significant reduction in leiomyoma (50%–60%) and uterine (40%–50%) volumes.[2, 13, 19, 23] In the majority of cases, the reduction in leiomyoma and uterine volumes becomes noticeable in several weeks and sustains for 3–12 months after UAE.[2, 13, 23]
The effect of UAE on ovarian reserve is not well-established. Follicle stimulating hormone (FSH) levels have no significant differences between patients treated with UAE and hysterectomy patients.
6. Postoperative complaints
The readmission rate during the first 6 weeks for patients treated with UAE, is 11.1%; significantly higher than what it is for hysterectomy patients.[17, 18] However, since most readmissions in patients treated with UAE occurred at a time when patients treated with hysterectomy had not been yet discharged from the hospital, that figure might actually represent an overestimation.
Readmissions for patients treated with UAE are mostly for: pain (22.2%), febrile morbidity (22.2%), or a combination of both (44.4%).[17, 18] Most of them occurred within the first week after discharge (77.8%), underlining the need for adequate postoperative follow-up during this period.
7. Treatment failure
There are many possible reasons for a UAE failure.[13, 27] Perhaps an incomplete uterine artery infarction results in regrowth of uterine myomas despite an initial reduction.[13, 27] Otherwise, UAE preserves apparently normal myometrium that may give rise to new uterine myomas.
8.1. Intraprocedural complications
|Intraprocedural complications||Early postprocedural complications||Late postprocedural complications|
|Major complications||pulmonary embolism||pneumonia|
|deep venous thrombosis|
|fibroid expulsion (requiring reintervention)|
|small bowel volvulus|
|acute renal failure|
|Minor complications||arterial spasm||vaginal discharge||permanent amenorrhea|
|postpuncture hematoma||pain/fever (requiring readmission)||transient amenorrhea|
|nerve injury at puncture site||fibroid expulsion (not requiring intervention)||prolonged vaginal discharge|
|allergy in radiographic contrast media||postpuncture hematoma|
|nephrotoxicity||urinary tract infection|
|uterine artery dissection during catheterization||urinary retention|
|gluteal artery perforation||renoureteral colic|
|formation of blood clot in the gluteal artery||urinary incontinence|
The intraprocedural minor complication rate is significantly lower among patients treated with UAE than among hysterectomy patients (22.2% vs. 30.7%). The most common intraprocedural minor complications in patients treated with UAE are: arterial spasm, postpuncture hematoma, nerve injury at the puncture site, allergy in the radiographic contrast media, nephrotoxicity, and uterine artery dissection during catheterization [Table 2].[2, 11, 13, 18, 19] Other rare intraprocedural minor complications are: gluteal artery perforation and formation of blood clot in the gluteal artery [Table 2].[2, 11, 13, 18, 19]
The intraprocedural major complication rate has no significant differences between patients treated with UAE and hysterectomy patients (1.2% vs 1.3%). Pulmonary embolism represents the most common intraprocedural major complication for patients treated with UAE [Table 2].
8.2. Early postprocedural complications (up to 6 weeks)
Overall, the early postprocedural complication rate is significantly higher among patients treated with UAE than among hysterectomy patients (72% vs. 45%).
The early postprocedural minor complication rate is significantly higher among patients treated with UAE, than among hysterectomy patients (58% vs. 40%). The most common early postprocedural minor complications among patients treated with UAE are: vaginal discharge, pain/fever (requiring readmission), fibroid expulsion (not requiring intervention), postpuncture hematoma, urinary tract infection, urinary retention, renoureteral colic, urinary incontinence, endometritis, hot flashes, and thigh paresthesia [Table 2].[2, 11, 13, 18, 19]
The early postprocedural major complication rate is also higher among patients treated with UAE than among hysterectomy patients (3.7% vs. 1,3%). The most common early postprocedural major complications among patients treated with UAE are: pneumonia, sepsis, deep venous thrombosis, and fibroid expulsion (requiring reintervention) [Table 2].[11, 18, 19] Other rare early postprocedural major complications are: death (secondary to septic shock, pulmonary embolism, non-target embolization), uterine necrosis, non-target inadvertent embolization (buttock necrosis, labial necrosis), vesicouterine fistula, small bowel volvulus, and acute renal failure [Table 2].[2, 13, 28]
8.3. Late postprocedural complications (up to 6 months)
Transient amenorrhea after UAE is usually limited to a few cycles and it is not considered as a genuine complication. Permanent amenorrhea after UAE occurs much more frequently in patients older than 45 years.[2, 13]
9. Postembolization syndrome
The syndrome is characterized by the occurrence of: pelvic pain, low-range pyrexia, nausea, vomiting, loss of appetite, and malaise.[2, 13] It primarily occurs the first few days after the procedure.[2, 13] It has a variable degree of intensity.
It probably results from the release of cytokines related to ischemia and necrosis of uterine myomas.
The postembolization syndrome is not considered as a complication of the UAE procedure. However, in many cases it can result in prolonged hospitalization (beyond 48 hours), readmissions, and unexpected increase in the required level of care.
10. Pregnancy after UAE
Full-term pregnancy is feasible for patients treated with UAE.[25, 26] However, there is increased risk of obstetric complications (miscarriage, abnormal placentation, preterm labor, malpresentation, and postpartum hemorrhage) for patients treated with UAE.[13, 25, 26, 29]
It is obvious that nonsurgical management of uterine myomas has shown promising results, simplifying or eliminating the need for surgical intervention in carefully selected patients. However, it is not the treatment of choice for infertile women and for women wanting to preserve future childbearing capability. [7, 8 30]