Uterine Artery Embolisation​

Uterine Artery Embolisation

Dr. Yajush and Dr. Ashish

Here we explore the complexities and advancements in Uterine Artery Embolization (UAE), a groundbreaking approach in the treatment of uterine fibroids. This minimally invasive procedure, integral in the management of symptomatic fibroids, has evolved significantly, offering a vital alternative to traditional surgical methods. We delve into the technical aspects of UAE, focusing on its efficacy, procedural nuances, and the critical interplay between the ovarian and uterine arteries. A key aspect of our exploration is the subtype Ia anastomosis, where the balance of blood flow between the tubal and ovarian arteries critically influences the success of the embolisation process.

Through a detailed analysis, provides insights into the identification and implications of various anastomosis patterns observed during angiography, a pivotal step in the pre-embolisation phase. We discuss how these patterns impact the effectiveness of UAE and the potential for complications such as inadvertent ovarian embolisation and the risk of premature menopause.

Category	Subcategory	Details
General Information		1. 20%–30% in reproductive-age women 2. Depend on age and race (more in black women) 3. Red meat increase the risk of fibroid by > 70% 4. Dairy consumption (>4 servings per day) reduce risk for fibroids by 33%
Histopathology	Nature	1. Benign neoplasms with whorled fascicles of smooth muscle and fibrous connective tissue. 2. Disseminated peritoneal leiomyomatosis can spread in a miliary manner throughout the peritoneum but is benign is nature with no invasion of adjacent structures
	Role of Harmones	1. Estrogen and Progesterone influence the growth of uterine fibroid. 2. Uterine remodelling post pregnancy can help shrink fibroid 3. Regress after menopause
	Degeneration Types	1. Hyaline or myxoid 2. Calcification 3. Cystic 4. Red (hemorrhagic) most commonly seen during pregnancy 5. Fatty degeneration.
Biomarkers	Identify women at higher risk of developing rapidly growing fibroids	1. Prolactin 2. HLA-G antigen 3. VEGF 4. Appetite-regulating hormone (also known as ghrelin) 5. Lactate dehydrogenase 6. Mucin 16 (also known as cancer antigen 125 (CA125)
Classification	Types	1. Submucosal (least common) - just below the mucosal lining, can also protrude into uterine cavity 2. Intramural - within uterine wall 3. Subserosal - below the uterine serosa causing distortion of uterine shape 4. Pedunculated (intra-cavitary or exophytic) - connected to uterus by a stalk
	Submucosal (Least common)	1. Associated with menorrhagia, dysmenorrhea and infertility 2. Act as irritant to endometrium and therefore has the maximum effect on irregular menses and also interfere with embryo implantation. 3. If pedunculated then protrude into cervical or vaginal canal. 4. Potential to become intracavitary after UFE; MR imaging predicts likelihood.
	Intramural	1. Most common type 2. Usually asymptomatic 3. Menorrhagia is considered secondary to loss of symmetric uterine contractions 4. Infertility is secondary to extrinsic compression of fallopian tubes
	Subserosal	1. Usually asymptomatic 2. Pedunculated subserosal fibroid can undergo torsion and present with pain and accompanied infarction.
	Pedunculated Leiomyomas	1. Importance of diagnosing pedunculated leiomyomas with narrow stalk before UFE (< 2 cm), as stalk necrosis can lead to detachment of leiomyoma and further complications like peritonitis (subserosal pedunculated), transcervical expulsion (submucosal pedunculated), pain and infection can occur.
	Cervical Leiomyomas	Alternate blood supply; may not become devascularized after UFE.
	Nonviable Leiomyomas	UFE not recommended as they are already devascularized.
Symptoms	Menstrual History: preferred choice of treatment for - FIGO 0-1 - Hysteroscopic myomectomy - FIGO 2 - Hysteroscopic myomectomy (high risk of recurrence) - FIGO 3-8 - Medical management should be considered for women who don't want to get pregnant. Surgery is 2nd line management for such patients.	1. Heavy (menorrhagia) and prolonged (menometrorrhagia) menstrual bleeding > 7 days , can lead to Iron deficiency anemia 2. Clots 3. Frequency of pad/tampon change > 7 pads.
	Pelvic Symptoms (pressure on adjacent organs)	1. Pelvic pain/pressure 2. Bloating 3. Urinary symptoms (like urgency, frequency, nocturia, or retention of urine) - Anterior wall leiomyoma 4. Constipation and diarrhea - Posterior wall leiomyoma 5. Hydroureter / Hydroureteronephrosis - Broad ligament compressing along pelvic wall. UFE effective as it shrinks fibroid and uterine size
	Reproductive Dysfunction (FEMME 2020 trial results show similar results for patients getting pregnant post UFE, however myomectomy was still considered superior because of lesser number of reinterventions required and more number of complications like increased risk of miscarriage, premature menopause associated with UFE)	1. Infertility 2. Miscarriage risks 3. Impact on embryo implantation 4. Risk of placental abruption - Leiomyoma is under the placental site
Diagnostic Imaging	Ultrasound	Initial diagnostic test.
Diagnostic Imaging	Magnetic Resonance Imaging (MRI)	Most accurate for detection, localization; essential for UFE planning.
MR Imaging Appearance	Non-degenerated Leiomyomas	1. Well circumscribed mass with homogeneously decreased T2-weighted signal intensity (compared to outer myometrium), increased T2 signal intensity can been seen in cellular leiomyoma. 2. Homogenous enhancement on contrast imaging
MR Imaging Appearance	Degenerated Leiomyomas (More detail below)	Variable appearances on T1/T2-weighted and contrast enhanced images depending on degeneration type.
Differential Diagnosis		1. Adenomyosis 2. Solid adnexal masses 3. Focal myometrial contractions 4. Leiomyosarcomas.
Treatment Options	Only Follow-Up	No therapeutic intervention, but recommend follow-up evaluations
	Nonsurgical	1. Progesterone receptor modulators (PRMs) - Most commonly used for fibroid with bulk symptoms - Rapid onset of action and are - Effective at reducing both fibroid and uterine volume - Sustained long-term effect of 3–12 months 2. Tranexamic acid - First line management for reducing menstrual blood loss with good safety profile 3. Gonadotropin-releasing hormone (GnRH) analogs x 3–6 months duration - Down regulation of estrogen receptor which decreases growth of leiomyoma - Can be used in patients with fibroid size > 10 cm prior to UFE or surgery - A single dose of GnRHa produces an initial stimulation of pituitary gonadotrophins, resulting in increased secretion of follicle-stimulating hormone (FSH) and LH and the expected gonadal response. - Side effects include hot flashes, sleep disturbance, vaginal dryness, mood changes, and loss of bone mineral density. 4. Symptomatic relief (mainly oral contraceptives and the levonorgestrel intrauterine device) 5. NSAIDs
	Surgical	1. Hysterectomy (main stay for women who don't want to get pregnant) 2. Myomectomy 3. Hysteroscopic myomectomy (For FIGO 0-2) 4. Laparoscopic myomectomy 5. Laparoscopic myoma coagulation
	Interventional Radiology (more acceptable with women going for repeat interventions)	1. Uterine Fibroid Embolization 2. Other Imaging-guided procedures: High Intensity Focused Ultrasound (HIFU), Magnetic resonance-guided focused ultrasound (MRgFUS) 3. Thermoablative procedures
Uterine Artery Embolization (UAE)	Indications	Symptomatic fibroids, particularly with heavy menstrual bleeding, bulk related symptoms and pelvic pain.
	Contraindications	1. Absolute: - Pregnancy - Gynecologic malignancy - Infection (Uterine / Adenexal) 2. Relative: - Allergy to contrast - Coagulopathy - Renal failure
	Lab investigations	1. Complete Blood Count 2. Renal Function Test 3. PT/INR 4. AMH (Anti-Mullerian Hormone) - ovarian reserves 5. Follicle stimulating hormone [FSH] 6. Estradiol
	Pre-UFE MR Imaging	1. Analyse and report location, size, number, stalk size (if pedunculated), and enhancement characteristics of leiomyomas. 2. Nonviable leiomyomas 3. Pedunculated leiomyomas 4. Cervical Leiomyoma 5. Submucosal Leiomyoma with potential to become intracavitary 6. Associated Adenomyosis, endometrial polyps or other endometrial disease - can cause late reoccurrence of symptoms needing additional treatment (like hysterectomy) leading to failure of UFE.
	Vascular anatomy for consideration	1. Ovarian artery–to– uterine artery anastomoses type should be considered.
	Embolic Materials (most commonly used particle size 350-500 µm)	1. PVA particles 2. Trisacryl gelatin microsphere (Embospheres) 3. Polyethylene glycol 4.Hydrogel microspheres
	Anaesthesia	1. Superior Hypogastric nerve block can be applied for pain management. 2. Spinal Anaesthesia 3. General Anaesthesia (rarely used)
	Technique	1. Contralateral anterior-oblique angle of 25-40 degree s best to identify uterine artery and embolisation to near stasis in main artery (after crossing the cervical branch). 2. Unilateral / Bilateral approach (save time and radiation dose to uterus) 3. Avoid cervical and vaginal branches by selective catheterisation of the uterine artery distal to the origin of these branches. 4. Uterine artery can quickly go into vasospasm and ~ 200 mg of nitroglycerin can help prevent vasospasm. 5. End point is occlusion of perileiomyoma plexus with stasis or near stasis of blood flow in main uterine artery
	Post-UFE Imaging Surveillance	1. Follow up is performed at 1 weeks, 1, 3 and 6 months. 2. Assesses for residual enhancement, infarction success and complications.
	Post procedure lab investigations	1. AMH (Anti-Mullerian Hormone) - ovarian reserves 2. Follicle stimulating hormone [FSH] - raised in case of permanent amenorrhea with menopausal symptoms 3. Estradiol
Complications and Post-Treatment Monitoring	Post-UFE Complications	1. Transient pain 2. Post-embolisation syndrome 3. Hematoma 4. Leiomyoma expulsion 5. Infection - extends from low grade infection to uterine necrosis needing to emergency hysterectomy 6. Early menopause - occurs due to embolisation of ovarian vessels. - Presence of amenorrhea, increased FSH (follicle-stimulating hormone levels), and menopausal symptoms (night sweats, mood swings, irritability, and/or vaginal dryness) after undergoing UAE. - Transient amenorrhea lacks increased FSH and menopausal symptoms. 7. Non-Target embolisation involving bowel and bladder necrosis

MRI changes in degenerative type:

Degeneration Type	T1-Weighted Signal Intensity	T2-Weighted Signal Intensity	Contrast Enhancement	Additional Notes
Hyaline or Calcific Degeneration	Variable	Low	Similar to non-degenerated leiomyomas	Resembles non-degenerated leiomyomas; no distinct enhancement patterns.
Cystic Degeneration	-	High	No enhancement in cystic area	Cystic areas appear bright on T2 but do not enhance with contrast.
Myxoid Degeneration	-	Extremely high	Minimal	Very bright on T2 images; minimal contrast enhancement.
Necrotic (Non-Liquefied)	Variable	Low	-	Seen in leiomyomas with hyaline or coagulative necrosis; variable signal on T1.
Red Degeneration (Hemorrhagic Necrosis)	High (peripheral/diffuse)	Variable, can be low	-	1. Increased signal intensity on T1 due to methemoglobin or proteinaceous content of blood. 2. High-intensity rim may indicate blood products in thrombosed vessels.

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