Intraoperative Sono-assessment In Deep Endometriosis (INSIDE)

Intraoperative Ultrasound in Rectal Shaving for Deep Infiltrating Endometriosis: Evaluation of Residual Disease, Bowel Wall Thickness, and Clinical Outcomes

Deep infiltrating endometriosis (DIE) involving the bowel, particularly the rectosigmoid region, is associated with significant gastrointestinal symptoms and impaired quality of life. Rectal shaving is a conservative surgical technique aimed at removing endometriotic lesions while preserving bowel integrity; however, it may result in residual disease or excessive thinning of the bowel wall, potentially leading to recurrence or complications.

Intraoperative ultrasound (IOUS) allows real-time assessment of residual nodule thickness and bowel wall thickness after shaving. This prospective observational study aims to evaluate the relationship between intraoperative ultrasound measurements and postoperative clinical outcomes, including gastrointestinal symptoms and quality of life.

The study also seeks to identify ultrasound cut-off values that may guide intraoperative surgical decision-making and optimize the balance between radicality and safety.

Study Overview

• Status: Not yet recruiting
• Conditions: Endometriosis; Endometriosis-related Pain; Pelvic Pain Syndrome; Endometriosis, Rectum; Endometriosis of Colon

Detailed Description

Endometriosis affects approximately 7-10% of women of reproductive age and is frequently associated with delayed diagnosis. Deep infiltrating endometriosis involving the posterior compartment often causes gastrointestinal symptoms such as dyschezia, constipation, diarrhea, and rectal bleeding.

Surgical management of bowel DIE includes conservative approaches (rectal shaving) and radical procedures (disc excision or segmental resection). Current guidelines emphasize individualized treatment decisions.

Rectal shaving avoids bowel resection and is associated with lower morbidity but carries risks of residual disease and bowel wall thinning. Intraoperative ultrasound enables precise measurement of residual lesions and bowel wall thickness, potentially improving surgical outcomes.

This study evaluates whether:

• Greater residual nodule thickness is associated with persistent or recurrent symptoms;
• Reduced bowel wall thickness is associated with increased postoperative complications.

• Study Type: Observational
• Enrollment (Estimated): 57

Contacts and Locations

• Study Contact: Name: Giorgia Gaia; Phone Number: +393384406299; Email: giorgia.gaia@policlinicogemelli.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of women of reproductive age diagnosed with deep infiltrating endometriosis involving the rectum or sigmoid colon, with muscularis propria infiltration between 1 and 20 mm as assessed by expert preoperative transvaginal ultrasound. Eligible patients are those scheduled to undergo laparoscopic rectal shaving as part of standard clinical care at a tertiary referral center for endometriosis. All participants provide written informed consent prior to enrollment.

Description

Inclusion Criteria:

• Female patients aged 20-60 years
• Rectal or sigmoid nodule with muscularis propria infiltration ≥1 mm and <20 mm (assessed by expert transvaginal ultrasound)
• Indication for surgery agreed upon with the patient
• Written informed consent

Exclusion Criteria:

• Previous major bowel surgery or primary indication for bowel resection
• Inflammatory bowel disease, malignancy, or severe pelvic pathology
• Inability to complete study questionnaires

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Gastrointestinal Symptoms and Quality of Life Scores	Change in gastrointestinal symptom severity and quality of life (PAC-SYM and PAC-QOL scores) from baseline to 12 months, stratified by depth of muscular infiltration (1-6 mm, 7-12 mm, 13-20 mm)	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Association Between Residual Bowel Wall Thickness and Surgical Complications	Evaluation of the relationship between intraoperatively measured minimum residual bowel wall thickness at the site of rectal shaving and the occurrence of postoperative complications, including bowel perforation, rectovaginal fistula, anastomotic stenosis, and other complications.	12 months
Identification of Predictive Ultrasound Cut-off Values	Identification of predictive cut-off values for intraoperative ultrasound parameters (e.g., residual nodule thickness, depth of infiltration, and bowel wall thickness) associated with postoperative outcomes and surgical complexity.	12 months

Collaborators and Investigators

• Sponsor: Fondazione Policlinico Universitario Agostino Gemelli IRCCS
• Investigators: Principal Investigator: Giorgia Gaia, Fondazione Policlinico Universitario Agostino Gemelli IRCCS

Study record dates

Study Major Dates

• Study Start (Estimated): April 7, 2026
• Primary Completion (Estimated): April 7, 2027
• Study Completion (Estimated): July 7, 2028

Study Registration Dates

• First Submitted: April 1, 2026
• First Submitted That Met QC Criteria: April 1, 2026
• First Posted (Actual): April 8, 2026

Study Record Updates

• Last Update Posted (Actual): April 8, 2026
• Last Update Submitted That Met QC Criteria: April 1, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Genital Diseases, Female; Endometriosis
• Other Study ID Numbers: 27052

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No