Non-Invasive Electroviscerography for the Diagnosis of Endometriosis: A Prospective Pilot Study

Study Objective

To evaluate the sensitivity and specificity of non-invasive electroviscerography (EVG) in predicting the presence of endometriosis, compared to findings from transvaginal ultrasound with bowel preparation (TVUS) and laparoscopic surgery.

Design

Prospective validation study.

Setting

Two tertiary hospitals in Brazil

Patients or Participants

A total of 43 women aged 18 to 45 years were enrolled. Thirteen patients underwent laparoscopic surgery (12 with endometriosis and 1 without). Thirty patients underwent TVUS only (11 with endometriosis and 19 without). All participants underwent EVG testing prior to surgery or imaging.

Interventions

Participants underwent EVG, a non-invasive technique that records abdominal myoelectric activity using surface electrodes. TVUS was performed by experienced radiologists using bowel preparation. Laparoscopy with histological confirmation served as the gold standard in surgical patients.

Measurements and Primary Results

Compared to laparoscopy (n=13), EVG showed a sensitivity of 100.0% (95% CI: 73.54% to 100.0%) and specificity of 0.0% (95% CI: 0.0% to 97.50%). The positive predictive value was 92.31%, and accuracy was 92.31% (95% CI: 63.97% to 99.81%). Compared to TVUS (n=30), EVG showed a sensitivity of 81.82% (95% CI: 48.22% to 97.72%) and specificity of 26.32% (95% CI: 9.15% to 51.20%). The positive predictive value was 39.13%, negative predictive value was 71.43%, and accuracy was 46.67% (95% CI: 28.34% to 65.67%).

Conclusion

EVG demonstrated high sensitivity but low specificity when compared to both laparoscopy and ultrasound. Its best performance was observed in high-prevalence settings. While EVG is a promising non-invasive diagnostic tool, further validation in larger and more balanced populations is needed to confirm its clinical utility.