From Probe to Procedure: UBESS Enhances Preoperative Planning

An ultrasound-based tool shows near-perfect accuracy in predicting endometriosis surgical complexity

Key Points

Highlights:

• UBESS is a reliable ultrasound-based system that accurately predicts laparoscopic surgical complexity in endometriosis, supports surgical triage and referral by identifying patients needing advanced operative expertise.

Importance:

• UBESS enables preoperative, noninvasive staging of endometriosis severity using transvaginal ultrasound, and helps guide resource allocation, optimize referrals, and improve multidisciplinary planning before surgery.

What's done here:

• A prospective cohort study was conducted in a tertiary center in Tehran, Iran, involving 157 women with suspected endometriosis, all of whom underwent transvaginal sonographic evaluation and laparoscopic surgery between June 2019 and May 2023.
• UBESS staging was performed preoperatively by a single expert sonologist, using a standardized five-domain ultrasound protocol. 
• Laparoscopic procedures were carried out by experienced gynecologic surgeons, and intraoperative complexity was classified using the RANZCOG/AGES surgical skill level system (excluding level 5, which does not pertain to endometriosis surgery).
• The study aimed to correlate UBESS stages (I–III) with RANZCOG/AGES levels (1/2, 3/4, and 6) to evaluate how accurately UBESS can anticipate surgical complexity.

Key Results:

• Out of 157 women evaluated, 152 underwent endometriosis surgery and were included in the final analysis.
• UBESS I, II, and III stagings were 5.9%, 40.1%, and 53.9%, respectively.
• The study found a strong correlation between UBESS stage and RANZCOG/AGES skill level, with high predictive values for each category:
  • For UBESS I predicting levels 1–2: Accuracy 99.3%, Specificity 100%
  • For UBESS II predicting levels 3–4: Accuracy 96.7%, Sensitivity 95.1%
  • For UBESS III predicting level 6: Accuracy 97.3%, Sensitivity 98.7%. 
• The overall agreement between sonographic staging and surgical complexity was excellent, supporting UBESS as a reliable tool for preoperative planning.  

Lay Summary

A new ultrasound-based system called UBESS (Ultrasound-Based Endometriosis Staging System) is designed to help surgeons estimate how complex endometriosis surgery might be before it happens. This system is used during a routine transvaginal ultrasound and classifies patients into three stages from least complex UBESS I, to most complex UBESS III based on the extent of disease visible on imaging.

In the study by Dr. Ebrahimi and colleagues from Tehran University of Medical Sciences  that will be published in Fertility and Sterility. examined 157 women with suspected endometriosis using UBESS and compared the ultrasound findings to the complexity of their laparoscopic surgeries. Most of these women had advanced-stage disease, and 152 proceeded with surgery. The surgical difficulty was graded using the RANZCOG/AGES system, which categorizes how much surgical skill is needed—ranging from basic to expert levels.

The results showed a very high level of agreement between UBESS and the actual surgical difficulty: UBESS II accurately predicted intermediate surgical complexity (RANZCOG/AGES 3–4) with over 90% accuracy. UBESS III accurately predicted the most complex cases (RANZCOG/AGES 6) with 96.7% accuracy.

These findings support UBESS as a valuable and reliable tool to guide surgical planning and patient referral. It can help ensure that patients with more severe disease are sent to expert surgical teams.

An accompanying editorial by Dr. Motamedi and colleagues from the University of Toronto pointed out that UBESS is extremely valuable and functions as intended. However it may only be practical in centers with specialized endometriosis ultrasound expertise. They emphasized that while the system is promising, broader use could be limited by training requirements and access to experienced sonologists.

Research Source: https://pubmed.ncbi.nlm.nih.gov/39988128