Endometriosis Excision Surgery – It Starts With Imaging

As noted in the present edition of NewsScope, Miller and Koh point out in the “The Endometriosis Excision Surgeon – It’s not how you start, but where you finish”, the importance of imaging to aid in preparing the surgical plan. Furthermore, it helps in providing proper informed consent.

Ultrasound has always been the primary imaging modality in patients with symptoms of endometriosis.^1-2 While The American Institute of Ultrasound in Medicine (AIUM) recommends ultrasound assessment including the uterus, ovaries and the cul-de-sac for fluid or mass, as MIGS surgeons, it must be realized that this represents only the “tip of the iceberg”.³ Clinically, relevant structures – rectum, vagina, uterosacral ligaments, ureter and bladder, can be, and must be properly imaged to provide a clear understanding as to the degree of disease that awaits. To make this imaging uniform (figure 1 & 2), The International Deep Endometriosis Analysis (IDEA) group published a consensus paper 2016 providing a systematic approach to the sonographic evaluation of the pelvis in women with suspected endometriosis, including terms, definitions and measurements.⁴

It is well documented by Abrão et al. that proper imaging is a critical factor that must be considered preoperatively to enable an evidence based approach to timing and degree of surgical intervention.⁵ Abrão noted that transvaginal ultrasound with bowel preparation has shown superior sensitivity (75% – 98%) for detecting deep infiltrative endometriosis. Moreover, transvaginal ultrasound with bowel preparation is able to define the size and number of lesions, the depth of penetration into the bowel wall and the distance from the anal verge.^6-8

To further enhance visualization, techniques have been described using both saline or ultrasound gel in the vagina (sonovaginography) or saline in the cul-de-sac (SonoPODography).^9-10  In situations when transvaginal ultrasound cannot provide clear imaging, especially in the case of rectal vaginal masses, when evaluation of organ involvement is above the pelvic brim (appendix, small bowel, diaphragm), or when deep or infiltrative endometriosis involves the pelvic wall or sacral plexus, use of MRI is appropriate. MRI for deep endometriosis has a sensitivity of 94% and specificity of 77%.¹¹ To isolate rectovaginal disease on MRI, we always designate that we are looking for deep infiltrative endometriosis of the rectum and vagina and will even order MRI with rectal cancer views to make sure proper evaluation is performed.

The take home message is quite simple. Successful endometriosis surgery should have smooth, fluent, carefully planned steps that are individualized. A mental image of previously mapped pelvic anatomy provides comfort during surgery. Preparedness is key to any surgery. We prepare our surgical skills through years of training. We prepare for individual cases with comprehensive preoperative information,  primarily imaging.