The Application of Probe-based Confocal Laser Endomicroscopy in the Diagnosis of Deep Endometriosis

Endometriosis is defined as the presence of endometrial glands and stroma outside of the uterus.Endometriosis affects 5%-15% of women in the reproductive age. Deep endometriosis is mostly defined as a single endometrial nodule, located in the vesico-uterine fold or close to the distal 20 cm of the large bowel. Current guidelines recommends that laparoscopy with histology should be done to diagnose endometriosis. Probe-based confocal laser endomicroscopy (pCLE) has been used as a GI tract endoscopy additive tool in recent years, providing in-vivo cellular-level imaging, a concept known as "optical biopsy". considering the rectal bleeding that occurs in patients suffering from bowel endometriosis, usually with a normal mucosa seen at standard endoscopy (personal data), we hypothesized that there might be histological architectural changes in the vessels or the mucosa/sub mucosa in bowel endometriosis.

Endometriosis is defined as the presence of endometrial glands and stroma outside of the uterus, most commonly over the ovaries, fallopian tubes, bladder, recto-sigmoid colon and the uterine myometrium.Endometriosis affects 5%-15% of women in the reproductive age causing pelvic or abdominal pain, infertility and occasionally rectal bleeding (if involving the bowel). Deep endometriosis is mostly defined as a single endometrial nodule, usually larger than 1 cm which is located in the vesico-uterine fold or close to the distal 20 cm of the large bowel. Those lesions usually infiltrate at least 5 mm into the tissue involved. The gold standard of diagnosis is histological proven endometriosis, usually obtained during explorative laparoscopy. Other imaging tests that aid in the diagnosis are trans-vaginal or trans-rectal sonography (TRUS), MRI & CT. Current guidelines recommends that laparoscopy with histology should be done to diagnose endometriosis. Negative (normal) laparoscopy is highly accurate in excluding endometriosis, but a positive laparoscopy (i.e. with macroscopic findings) without biopsy has a limited value. In practice, many clinicians refrain from taking biopsies due-to the risk of bowel surgery, particularly on an un-prepared bowel. Probe-based confocal laser endomicroscopy (pCLE) has been used as a GI tract endoscopy additive tool in recent years, providing in-vivo cellular-level imaging, a concept known as "optical biopsy". considering the rectal bleeding that occurs in patients suffering from bowel endometriosis, usually with a normal mucosa seen at standard endoscopy (personal data), we hypothesized that there might be histological architectural changes in the vessels or the mucosa/sub mucosa in bowel endometriosis.

a probe-based Confocal Laser Endomicroscopy examination will be done using a standard recto-sigmoidoscopy, in women suffering from endometriosis who are referred for a TRUS examination as part of a suspected deep endometriosis diagnostic workup. pCLE images will be compared to normal bowel mucosa.

Eligible women will be offered to undergo pCLE examination. Conscious sedation will be offered to all patients, who will choose to receive it or not. pCLE will be done using a standard gastroscope, reaching a distance of 25 cm from the anus, to the level of the rectosigmoid angle. At this point, 2.5 ml fluorescein 10% will be injected. The pCLE probe (GastroFlex-UHD probe, Mauna Kea tech, Paris, France) will be inserted through the endoscope working channel and images will be recorded from areas suspected of harboring an endometriotic tissue.

Inclusion Criteria: Endometriosis Exclusion Criteria: Unable or unwilling to give and sign an informed consent Allergy to fluorescein Colitis Critical illness Pregnancy Malignancy