Impact of hospital and surgeon case volume on morbidity in colorectal endometriosis management: a plea to define criteria for expert centers.

National and international guidelines recommend referring patients with severe forms of endometriosis to expert centers. However, there is a lack of clear criteria to define an expert center. We examined the roles of surgeon and hospital procedure volumes as determinants of morbidity in deep infiltrating endometriosis of the rectum and sigmoid colon (DIERS).

METHODS: We conducted a French retrospective multicenter study of hospital facilities performing colorectal surgery for DIERS in 2015. The primary end point was to analyze the relation between case volume and the incidence of complications. We estimated the optimal cut-off (OCO) determined by a minimal p-value approach.

RESULTS: The study included 56 hospital facilities and collected data of 1135 cases of surgical management of colorectal endometriosis. The mean and median number of procedures per year and per surgeon were 9.17 and 5.58, respectively. The overall rate of grade III-V complication was 7.6% (82/1135). One grade V complication occurred. The rates of rectovaginal fistula, anastomotic leakage, pelvic abscess, and ureteral fistula were: 2.7% (31/1135), 0.79% (9/1135), 3.4% (39/1135), and 0.70% (8/1135), respectively. An OCO of 20 procedures per center and per year (p < 0.001) was defined. The OCO per surgeon and per year varied between seven (p = 0.007) and 13 procedures (p = 0.03). In a multivariate analysis, we found that only the volume of activity was independently correlated to complication outcomes (p = 0.0013).

CONCLUSION: Our results contribute to providing objective morbidity data to determine criteria for defining expert centers for colorectal surgery for endometriosis.