Evaluation of the Efficacy of HIFU Treatment on Rectal Endometriosis Symptoms.

Doubled Blind Evaluation of the Efficacy of High Intensity Focused Ultrasound (HIFU) Treatment on Symptoms in Patients Treated for Rectal Endometriosis Compared to Sham.

Rectal endometriosis (RE) induces lesions associated with painful symptoms that can alter quality of life. High Intensity Focused Ultrasound (HIFU) is a non-invasive ablative procedure using a high-intensity ultrasound probe to induce tissue devitalization using acoustic cavitation and thermal ablation.

Focal One® is a transrectal HIFU device, which is validated to treat prostatic cancer.

In this comparative, randomized, double blind study , the primary objective is to evaluate the efficacy of the HIFU treatment of rectal endometriosis with Focal One® HIFU device on the Acute Pelvic Pain 3 months after HIFU treatment, in comparison to a Sham group.

Inclusion Criteria:

• Patient 18 years of age or older,
• Rectal endometriosis on preoperative imaging with no other digestive location,
• Symptomatic patient (Acute pelvic pain > 3), in failure of drug treatment,
• Endometriotic lesion visible on ultrasound and confirmed on MRI,
• Centralized MRI, reviewed and validated by the MRI review committee,
• No current pregnancy and no pregnancy plan during the study period,
• Patient agreeing not to change her hormonal treatment throughout the study period,
• Patient accepting the constraints of follow-up defined in the framework of the study,
• Patient affiliated to French health insurance.

Exclusion Criteria:

• Ongoing urogenital infection,
• Anorectal anatomy incompatible with HIFU treatment,
• Overall pain level considered intolerable by the patient and making a potential 3-months delay management impossible,
• History of segmental rectal resection or discoid resection,
• Patient with an implant located less than 1 cm from the treatment area,
• Inflammatory disease of the colon,
• Allergy to latex,
• No scheduled endometriosis procedures during study follow-up,
• Treatment of endometriosis in the context of pregnancy desire for which a 3-month delay is not appropriate
• Patient with contraindications to MRI,
• Patient who has already received HIFU treatment for a rectal endometriotic lesion,
• Patient who does not speak or read French,
• Patient deprived of liberty following a judicial or administrative decision,
• Patient in labor or nursing,
• Patient under guardianship or curatorship