Surgical planning of bowel endometriosis relies on imaging

Endometriosis, the presence of endometrial tissue outside the uterine cavity, affects approximately 10% of women. When surgery is planned for patients with deep infiltrating endometriosis (DIE) – one of three types of clinical presentation – it is essential to define aspects of the intestinal DIE lesions. A radiologist and two gynecological specialists from Brazil explain the importance and relevance of diagnostic imaging in Clinical Medicine Insights: Reproductive Health.

This gynecologic disease is complex due to multifocal patterns of lesion distribution, the presence of extra pelvic sites such as in the urinary and intestinal tracts, and multiple clinical presentations. One of these, deep infiltrating endometriosis (DIE) which manifests itself in the intestine, is defined as a lesion infiltrating at least the muscular layer of the bowel wall. It usually affects the rectum and sigmoid. Surgical intervention is recommended. Ultrasound and/or MRI enable a surgeon to do preoperative mapping, determining the location and the extent of the disease. The preoperative workup helps enable surgeons to determine if conservative (a nodulectomy) or radical surgery should be performed.

Transvaginal ultrasound, transrectal ultrasound, and/or abdominal/pelvic MRI are used to detect ovarian endometrioma, deep endometriosis lesions, and indirect signs of adhesions. In their article, lead author Carlos H. Trippia, MD, of the department of radiology at Roentgen Diagnóstico Institute in Cuntiba, Paraná, and co-authors describe the imaging protocols used.

Morphological characteristics in both MRI and ultrasound include:

• retractile or nonretractile nodular lesions with regular or irregular contours, with or without endometriosis glands;
• plaque-like lesions, with or without endometriosis glands, with ill-defined margins, that are retractile and infiltrative.

For patients with intestinal DIE, the authors recommend that radiology reports contain the following information:

• Longitudinal and transverse measurements of the size of the lesion - The risk of the intestinal lumen’s stenosis can be determined by the size of the nodule and the percentage of bowel circumference involved by the lesion. Patients are candidates for conservative surgery if their DIE lesions do not exceed 25-30 mm.
• Depth of infiltration in the intestinal wall - The authors recommend the use of transvaginal ultrasound, which better identifies the layers of the bowel wall, and can determine if the DIE lesions affect the serosa, the muscle layer and/or the submucosa and mucosa. This information also helps determine the most appropriate type of surgical procedure.
• Percentage of the intestinal circumference affected – Lesions with severe impairment of the intestinal circumference may cause stenosis of the intestinal lumen and make it impossible to perform discoid resection.
• Distance between the intestinal DIE and anal verge – This provides information regarding the possible need for protective stoma.
• Presence of multifocal or multicentric lesions – When these are identified, surgical options are restricted, usually to intestinal resection.

REFERENCE

1. Trippia CH, Zomer MT, Terazaki CRT, et al. Relevance of imaging examinations in the Surgical Planning of Patients with Bowel Endometriosis. Clin Med Insights: Reprod Health 2016 21;10: 1-8.