Several studies show a significant drop in pain scores, improved fertility outcomes and amelioration of impaired sexual functioning in women following surgical resection of colorectal endometriosis. However, intermediate and long-term bowel dysfunction may occur as a consequence of radical surgery with typical symptoms such as constipation, feeling of incomplete evacuation, clustering of stools and urgency. This is described as low anterior resection syndrome (LARS).

The primary aim of this study is the prospective comparison of two surgical approaches for full thickness excision, i.e. transanal disc excision (TADE) and nerve-vessel sparing limited segmental resection (NVSSR), regarding gastrointestinal functional outcomes using the LARS / Gastrointestinal Quality of Life Index (GIQLI) by Eypasch questionnaires.

Several studies show a significant drop in pain scores, improved fertility outcomes and amelioration of impaired sexual functioning in women following surgical resection of colorectal endometriosis. However, there is inceasing evidence that intermediate and long-term bowel dysfunction may occur as a consequence of radical surgery for rectal deep endometriosis (DE). Typical symptoms include constipation, feeling of incomplete evacuation, clustering of stools and urgency. This is described in the colorectal surgical literature as low anterior resection syndrome (LARS). The choice of operation is largely dependent on the extent of disease. Statistically significant differences in functional outcomes were found in favor of the conservative surgical approach, i.e. resection of endometriotic tissue with preservation of the luminal structure of the rectal wall thereby avoiding segmental bowel resection. In a recent retrospective multicentric cohort analysis, the incidence of LARS after either nerve and vessel sparing segmental resection (NVSSR) or transanal disc excision (TADE) performed for the surgical treatment of colorectal DE was assessed. All patients underwent a low rectum resection, with a resection line lower than 7cm from anal verge. In contrast to previoisly published data, no statistically significant difference between the incidence of the LARS among patients operated using TADE when compared to women treated by NVSSR were found. Interestingly, the occurence of LARS was positively associated with the use of protective ileo-or colostomy. A higher rate of severe complications was observed in the TADE group than among patients who underwent a NVSSR. Weaknesses of this study are the retrospective design and a possible bias in the TADE regarding larger DE nodules as well as the possibility of bowel dysfunction prior to surgery in women with DE.

The primary aim of the present study is the prospective comparison of two surgical approaches for full thickness excision of rectal DE resulting in an anastomotic height ≤7 cm distance from the anal verge. One technique involves the preservation of the residual luminal wall integrity (disc resection) known as Rouen technique/ TADE. The other technique involves limited resection of the bowel wall with preservation of all adjacent structures (autonomic pelvic plexus, rectal vascular supply) known as NVSSR. Gastrointestinal functional outcomes of the two procedures will be compared using the LARS / GIQLI by Eypasch questionnaires. Since digestive complaints may also be present presurgically, evaluation of digestive complaints will be recorded pre- and post surgery.

Inclusion Criteria:

• Premenopausal women undergoing full thickness excision of rectal deep endometriosis (DE) resulting in an anastomotic height ≤7 cm distance from the anal verge

Exclusion Criteria:

• Diagnosed or suspected malignancy
• Previous colorectal surgery
• Previous history of chronic inflammatory diseases of the gastrointestinal tract and/or chronic defecation dysfunction related to other factors such as birth trauma etc.

Premenopausal women undergoing full thickness excision of rectal deep endometriosis (DE) resulting in an anastomotic height ≤7 cm distance from the anal verge will be included in this study. These women will undergo either nerve and vessel sparing segmental resection (NVSSR) or transanal disc excision (TADE).