Endometriosis, a familiar companion of isthmocele. A systematic review and meta-analysis.

Objective: To evaluate the prevalence of endometriosis in patients with isthmocele and the outcome of isthmocele repair.

Design: Systematic literature review and meta-analysis of existing retro- and prospective studies.

Data sources: A systematic search was conducted to identify trials published through May 2024 using Embase, MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews.

Methods of study selection: A systematic literature review and meta-analysis was performed. Studies that investigated the co-existence of isthmocele and endometriosis or adenomyosis and the outcomes of surgical isthmocele repair were included. Data were extracted from 15 studies comprising 1149 women, and a meta-analysis was conducted using a random-effects model.

Tabulation: Key outcomes were the prevalence of endometriosis and adenomyosis in women with isthmocele and pre-and postoperative outcomes, including abnormal uterine bleeding (AUB), dysmenorrhea, chronic pelvic pain, and infertility.

Integration and results: Fifteen studies, of which 13 were suitable for quantitative synthesis, were included in this systematic review and meta-analysis. One was of good, one of fair, and the other 13 of poor quality. The prevalence of endometriosis in women with isthmocele was 33.6% (95% confidence interval [CI], 23.7 - 45.1%). Uterine scar endometriosis was found in 20.1% (95% CI, 12.8-30.3%). Surgery significantly improved AUB (76.7% before surgery, 22.8% after surgery), dysmenorrhea (31.4% to 7.4%), chronic pelvic pain (74.6% to 18.3%), and infertility (75.1% to 29.8%). Clinical pregnancy rates following combined laparoscopic and hysteroscopic repair were high (71%).

Conclusion: Endometriosis is a frequent finding in women with isthmocele. Surgical repair of isthmocele significantly reduces symptoms and improves fertility outcomes. Nevertheless, the poor quality of most of the included studies must be taken into account. To establish causal relationships and refine surgical approaches, further research is needed.