What is the new classification and treatment approach for uterine fibroids (leiomyomas)?

Modern Classification and Treatment Approach for Uterine Fibroids

The modern classification of uterine fibroids is based on the FIGO (International Federation of Gynecology and Obstetrics) system, which categorizes fibroids by their location and relationship to the uterine layers, with treatment approaches tailored to this classification to optimize outcomes for mortality, morbidity, and quality of life. 1

FIGO Classification System

The FIGO classification provides a systematic approach to describing fibroid locations:

• Type 0: Completely intracavitary (submucosal)
• Type 1: <50% intramural component (primarily submucosal)
• Type 2: ≥50% intramural component (primarily submucosal)
• Type 3: 100% intramural, contacts endometrium
• Type 4: Intramural, entirely within myometrium
• Type 5: Subserosal, ≥50% intramural
• Type 6: Subserosal, <50% intramural
• Type 7: Subserosal pedunculated
• Type 8: Other locations (cervical, parasitic)

This classification has replaced the traditional categories of simply submucosal, intramural, or subserosal, providing more precise guidance for treatment selection.

Treatment Approach Based on Classification

Medical Management

1. First-line options for bleeding control:

   • Progestin-containing IUDs (Levonorgestrel/Mirena): Most effective hormonal option for bleeding control and pain relief 2
   • Tranexamic acid: First-line non-hormonal medication for heavy menstrual bleeding, taken only during menstruation 2
   • NSAIDs: Can reduce bleeding by 20-40% 2

2. For fibroid volume reduction:

   • GnRH agonists/antagonists: Reduce bleeding and lesion volume by 40-50% 2
   • Selective progesterone receptor modulators (SPRMs): Ulipristal acetate achieves amenorrhea in 70-83% of patients with median fibroid volume reduction of 65-67% 2, 3

Surgical Management Based on FIGO Classification

1. Type 0-2 (Submucosal fibroids):

   • Hysteroscopic myomectomy: First-line conservative surgical therapy for symptomatic intracavitary fibroids 2, 4
   • Benefits: Shorter hospitalization, faster recovery than other surgical approaches

2. Type 3-4 (Intramural fibroids):

   • Laparoscopic myomectomy: For women desiring fertility preservation 2
   • Uterine Artery Embolization (UAE): For women not desiring future fertility 5, 2
   • Note: Intramural fibroids significantly reduce pregnancy and implantation rates (16.4% vs 30.1% in controls) 5

3. Type 5-7 (Subserosal fibroids):

   • Laparoscopic myomectomy: Preferred for isolated fibroids 2
   • Observation: May be appropriate as subserosal fibroids don't significantly impact pregnancy rates (34.1% vs 30.1% in controls) 5

4. Multiple or large fibroids (any type):

   • Open myomectomy: Preferred for multiple fibroids or very large uteri 2
   • Hysterectomy: Definitive treatment with 90% satisfaction rate at 2 years 5, 2

Minimally Invasive Alternatives

1. Uterine Artery Embolization (UAE):

   • Improves quality of life and symptom scores with 94% short-term and 85% long-term symptom improvement 2
   • Less effective for cervical fibroids and in women <40 years 5
   • Not recommended as first-line for women desiring future fertility

2. MR-guided Focused Ultrasound (MRgFUS):

   • Results in 18% decrease in lesion diameter 2
   • Limited effectiveness compared to other options

Treatment Algorithm

1. Asymptomatic fibroids: Observation with regular monitoring

2. Symptomatic fibroids with desire for fertility:

   • Type 0-2: Hysteroscopic myomectomy
   • Type 3-7: Laparoscopic or open myomectomy depending on size and number
   • Consider pre-surgical GnRH agonists or SPRMs to reduce fibroid size and correct anemia

3. Symptomatic fibroids without fertility desire:

   • Type 0-2: Hysteroscopic myomectomy or endometrial ablation
   • Type 3-7: UAE or hysterectomy
   • Consider medical management for temporary symptom control

4. Failed conservative treatment or multiple/large fibroids:

   • Hysterectomy (preferably by least invasive approach)

Important Clinical Considerations

• Pre-treatment evaluation: Rule out uterine sarcoma and endometrial cancer in postmenopausal women with abnormal uterine bleeding 2

• Surgical planning: Map location, size, and number of fibroids with appropriate imaging (MRI preferred) 4, 1

• Anemia correction: Should be addressed prior to elective surgery using SPRMs or GnRH analogues 4

• Morcellation risks: Patients should be informed about potential risks including rare cases of unexpected malignancy that could be spread by power morcellation 4

• Long-term outcomes: Hysterectomy has the highest satisfaction rate (>90%) and eliminates recurrence risk, but may lead to earlier onset of menopause even with ovarian preservation 5

The FIGO classification system has revolutionized fibroid management by providing a standardized approach to communication between clinicians and guiding appropriate treatment selection based on precise fibroid location rather than general categories.