Appendectomy in Chronic Pelvic Pain - The True Prevalence of Appendiceal Endometriosis: A Systematic Review and Meta-Analysis

Study Objective

Through systematic review and meta-analysis, to determine the prevalence of histologically-proven endometriosis of the appendix in patients undergoing gynecologic surgery for chronic pelvic pain or suspected endometriosis.

Design

Systematic review and meta-analysis.

Setting

N/A.

Patients or Participants

Systematic review of MEDLINE, EMBASE, and Scopus from inception to April 2024, including cross-sectional or cohort studies and excluding case reports or case series. Studies must report the proportion of histologically-proven appendiceal endometriosis (AppE) among all appendectomies performed during gynecologic surgery for pelvic pain or suspected endometriosis.

Interventions

Comparison of findings between incidental appendectomy (removal of appendix without evidence of appendicitis or appendiceal pathology) vs visible appendectomy (removal of abnormal appearing appendix with suspected pathology). Random-effects meta-analysis was performed to determine the pooled prevalence.

Measurements and Main Results

29 studies were identified with 6,111 appendectomies performed during gynecologic surgery for pelvic pain or suspected endometriosis. Results appear in Figure 1. The pooled prevalence of histologically-proven endometriosis in the appendix (AppE) differed significantly between incidental appendectomy and appendectomy for an appendix with suspected pathology. Incidental appendectomy resulted in histologically-proven endometriosis in 8% of patients (95% confidence interval 6-11%). When only the abnormal appearing appendix was removed, the pooled prevalence of appendiceal endometriosis was 66% (95% confidence interval 34-88%).

Conclusion

Among those with “visible abnormalities”, the rate of histologically-proven endometriosis of the appendix was quite variable between studies – reinforcing the inconsistency between visual and histologic diagnosis of endometriosis. When appendectomy is performed routinely at the time of surgery for chronic pelvic pain or suspected endometriosis, the pooled prevalence of appendiceal endometriosis is 8%; as such, routine appendectomy should be considered for inclusion as a standard component of endometriosis excision surgery.