What does the Enzian classification (TIE or POABCF) in endometriosis mean?

Understanding the Enzian Classification System for Endometriosis

The Enzian classification system is a specialized tool designed to describe deep infiltrating endometriosis that complements the revised American Society for Reproductive Medicine (r-ASRM) classification by providing detailed mapping of deep endometriotic lesions based on anatomical location and size. 1

Core Components of the Enzian Classification

Original Enzian Classification (Compartment System)

The Enzian classification divides the pelvis into three main compartments for deep endometriosis:

• Compartment A: Rectovaginal septum and vagina (vertical)
• Compartment B: Uterosacral and cardinal ligaments, parametrium, and pelvic sidewalls (horizontal)
• Compartment C: Rectum (dorsal)

Each compartment is further graded by lesion size:

• Grade 1: < 1 cm
• Grade 2: 1-3 cm
• Grade 3: > 3 cm

Additional Locations (F Compartments)

The Enzian system also classifies involvement of other organs with the "F" designation:

• FA: Adenomyosis
• FB: Bladder involvement
• FU: Ureter involvement (with signs of obstruction)
• FI: Other intestinal locations (beyond rectum)
• FO: Other extragenital locations 1, 2

Evolution to #Enzian Classification

The newer #Enzian classification (with hashtag) represents an updated and more comprehensive system that includes:

• O: Ovarian endometriosis
• T: Adhesions at the tubo-ovarian unit
• A, B, C: The original compartments for deep endometriosis
• F: Additional locations as described above 2, 3

This updated system aims to provide a complete mapping of all endometriosis manifestations, including peritoneal disease, ovarian disease, deep infiltrating disease, and adhesions 2.

Clinical Utility of Enzian Classification

1. Complementary to r-ASRM: The Enzian classification should be used alongside r-ASRM when deep endometriosis is present to give a complete description of operative findings 1

2. Surgical Planning: Enzian may be used preoperatively based on clinical examination, transvaginal ultrasound, and MRI to predict the extent of deep endometriosis and plan surgical approach 1

3. Non-invasive Diagnosis: The #Enzian classification can be accurately applied using transvaginal and transabdominal sonography, with concordance rates between ultrasound and surgical findings ranging from 86% to 99% 4

Limitations of the Enzian Classification

• Correlation with symptoms and infertility is poor 1
• Limited prognostic value for symptom progression, quality of life, and infertility 1
• Uncertain predictive capacity for treatment response 1
• Requires further external validation 1

Practical Application

When documenting endometriosis findings, the World Endometriosis Society recommends:

• All women undergoing surgery should have r-ASRM classification completed
• Women with deep endometriosis should additionally have Enzian classification completed
• Women concerned about future fertility should have Endometriosis Fertility Index (EFI) completed 1

Example of Enzian Documentation

A patient with a 2.5 cm nodule in the rectovaginal septum, a 1.5 cm lesion on the left uterosacral ligament, and adenomyosis would be classified as:

• A2 (rectovaginal septum, 1-3 cm)
• B2 (left uterosacral ligament, 1-3 cm)
• FA (adenomyosis)

This standardized approach allows for better communication between healthcare providers and improved surgical planning for patients with deep infiltrating endometriosis.