Chapter 3 Uterine Artery Embolization as an Alternative to Hysterectomy , in Patients with Uterine Myomas

Uterine artery embolization (UAE) is a minimal invasive technique that uses transcutaneous common femoral artery approach to block uterine blood supply. The aim of the procedure is to occlude or markedly reduce blood flow in both uterine arteries at the arteriolar level. This causes irreversible ischemia and leads to necrosis and subsequent shrinkage of uterine myomas. In current clinical practice, uterine artery embolization represents an acceptable alternative to hysterectomy and myomectomy.


Introduction
Uterine artery embolization (UAE) is a minimal invasive technique that uses transcutaneous common femoral artery approach to block uterine blood supply.[1] It is based on established techniques for treating pelvic bleeding.[2] It was first described in 1976, for the treatment of abnormal uterine bleeding in patients with gynecological malignancies.[3] 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] In recent years, UAE represents an acceptable alternative to hysterectomy and myomectomy.[2,[6][7][8]

Technique
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.[4] An angiography is then performed, in order to manipulate a visceral angiography catheter into the left internal iliac artery [Figure 1].[4] Figure 1.After insertion of the sheath, an angiography is performed to manipulate a visceral angiography catheter into the contralateral internal iliac artery.
Thereafter, a new angiography is performed in the contralateral oblique projection in order to identify the origin of the left uterine artery.[4] Then, the angiography catheter, or a microcatheter, 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]

Approaches to Hysterectomy
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][10][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.[2] This causes irreversible ischemia and leads to necrosis and the subsequent shrinkage of uterine myomas.[1,2,12]

Indications
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] A point of special interest is that UAE can be performed in patients with relevant co-morbidities (obesity, coronary artery disease) and increased perioperative risk for hysterectomy.[2,7,8] Moreover, it can be performed on patients who refuse blood transfusion (for health concerns or religious reasons).[13]

Absolute contraindications
Relative contraindications The size and location of uterine myomas should also be considered in the patient selection process.[2]

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 Approaches to Hysterectomy 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.[24] Follicle stimulating hormone (FSH) levels have no significant differences between patients treated with UAE and hysterectomy patients.[24] A forthcoming pregnancy is feasible in patients treated with UAE.[25,26] However, close monitoring of the placental status is recommended.[25]

Postoperative complaints
Postoperative symptoms (bleeding, pain, and pressure complaints) during the first 6 weeks among patients treated with UAE are slightly more common than among hysterectomy patients.[17,18,20,21] 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.[18] 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.[18] Unscheduled hospital visits during the first 6 weeks are more common among patients treated with UAE than in patients treated with hysterectomy (32.5%-37% vs. 20%-25.3%).[17][18][19]

Treatment failure
The secondary intervention rate at 2 years of follow up is significantly higher among patients treated with UAE than among hysterectomy patients (23.5% vs. 8.0%).[17,21,23] The secondary intervention rate at 5 years of follow up is significantly higher among patients treated with UAE than among hysterectomy patients (28.4% vs. 10.7%).[17,21,22] Most of the secondary interventions on patients treated with UAE (77.2%) occur during the first 2 years of follow up.[14,17,22,23] 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.[13] 8. Complications The intraprocedural minor complication rate is significantly lower among patients treated with UAE than among hysterectomy patients (22.2% vs. 30.7%).[18] The most common intraprocedural minor complications in patients treated with UAE are: arterial spasm, postpuncture Approaches to Hysterectomy 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%).[18] Pulmonary embolism represents the most common intraprocedural major complication for patients treated with UAE [Table 2]. [18]

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.[2] It probably results from the release of cytokines related to ischemia and necrosis of uterine myomas.[2] The postembolization syndrome is not considered as a complication of the UAE procedure.[2] However, in many cases it can result in prolonged hospitalization (beyond 48 hours), readmissions, and unexpected increase in the required level of care.[11]

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] In particular, close monitoring of placental status is recommended for pregnant patients following UAE.[25,26]

Conclusion
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.[7] However, it is not the treatment of choice for infertile women and for women wanting to preserve future childbearing capability.[7, 8 30]

Figure 2 .
Figure 2. The angiography catheter or micro-catheter is illustrated, placed in the transverse segment of the uterine artery distal to the origin of cervicovaginal arteries.

Figure 3 .
Figure 3.Following the correct positioning of the catheter or micro-catheter and under angiographic control, an embolic agent is then injected and UAE is performed.

Figure 4 .
Figure 4. Subsequently the angiography catheter is manipulated into the ipsilateral internal iliac artery.

Figure 5 .
Figure 5. Finally the angiography catheter is placed in the lumen of the ipsilateral uterine artery.