A review of Ouyang et al.’s (2022) paper: Efficacy of excision versus ablation for improving endometriosis-related pain: A systematic review and meta-analysis.

The question

Within the endometriosis community, excision surgery is often presented as the “gold standard” (Whittaker, 2026), while ablation remains controversial. But does the evidence actually demonstrate that one provides better pain relief? This is the question tackled by Ouyang et al’s (2022) paper.

Endometriosis is a chronic inflammatory condition characterised by endometrial-like tissue found outside the uterus, causing debilitating pain, fatigue and many other symptoms (World Health Organization, 2023). The two surgical techniques commonly used to manage endometriosis are excision surgery (endometriosis lesions are cut out) and ablation surgery (cauterising the lesions with heat or a laser) (Whittaker, 2026).

The paper states that excision surgery is preferred for endometriomas (“chocolate” cysts commonly associated with advanced endometriosis (Cleveland Clinic, 2021)), with evidence suggesting benefits for pain, recurrence and IVF outcomes. Unlike ablation, excision also provides tissue that can be examined to confirm endometriosis. The bigger question still lies in which technique proves more effective for long-term pain management.

What did the researchers do?

Ouyang et al. decided to tackle this question by compiling previous literature and determining the outcomes of each surgical group specifically for superficial peritoneal endometriosis.

The researchers chose to exclude endometriosis beyond the peritoneum (the membrane that lines the inside of your abdomen and pelvis (Cleveland Clinic, 2022)) and any patients presenting with endometriomas.

The researchers searched the existing evidence and identified four randomised controlled trials (studies in which participants are randomly assigned to different treatment groups (Braga et al., 2024)) comparing excision and ablation. Across the four studies, 408 participants were included: 204 underwent excision and 204 underwent ablation.

The participants reported changes in their pain using pain-rating scales (an example provided in the paper was a Visual Analog Scale) at baseline and were followed up at 6 months and after 12 months.

Ouyang et al. decided to focus on 4 types of endometriosis-related pain: dysmenorrhea (painful periods), dyspareunia (pain during sex), dyschezia (pain during bowel movements) and non-cyclical pelvic pain.

So what did they find?

Ultimately, the researchers found no significant differences between the two groups for the four pain outcomes analysed.

Although pain generally improved in both groups after surgery, the researchers found no clear evidence that the amount of improvement differed between excision and ablation for any of the four pain outcomes studied.

How good is the evidence?

Despite the findings reported, does this mean that excision and ablation are equally effective? Not exactly.

From the studies analysed, several important limitations were identified.

Firstly, one of the four studies included (Riley et al. 2019) was an open-label study, meaning participants knew which surgery they received (Tran, 2024), which the authors identified as a potential source of bias.

Ouyang et al. reported that the pain measurement was inconsistent between studies, with different scales and definitions used to assess symptoms.

Additionally, post-surgical hormonal treatments also differed between studies and, in some cases, were not reported.

Surgical techniques also varied between studies. Riley et al. (2019) used robotic-assisted laparoscopy, while the other studies used conventional laparoscopic surgery.

Finally, loss to follow-up was substantial in some of the studies, with response rates falling to around 60% of participants at the later time points.

Importantly, the authors rated the overall evidence as low-to-moderate quality, meaning that these findings should be interpreted cautiously.

The takeaway

This paper does not prove that excision and ablation are equivalent, nor does it show that ablation is preferable.

Instead, the limited evidence available did not demonstrate that one technique produced better pain outcomes for superficial peritoneal endometriosis within 12 months.

Rather than settling the excision-versus-ablation debate, this paper highlights how limited the evidence behind it still is.

Ouyang et al. concluded the paper by calling for higher-quality research into endometriosis surgery before definitive conclusions about treatment efficacy can be made.

References

  1. Ouyang, C., Fitch, A., Cho, K.S., Driscoll, J., Wang, A. and Lamvu, G. (2022). Efficacy of excision versus ablation for improving endometriosis related pain: A systematic review and meta-analysis. Journal of Endometriosis and Pelvic Pain Disorders, 14(1), pp.52–62. doi:10.1177/22840265221074850.

  2. RRM Academy. (2026). Endometriosis Explained: Diagnosis, Excision Surgery, and the RRM Approach. Available at: https://rrmacademy.org/endometriosis/ [Accessed 14 Sept. 2026].

  3. World Health Organization (2023). Endometriosis. World Health Organization. Available at: https://www.who.int/news-room/fact-sheets/detail/endometriosis [Accessed 14 Sept. 2026].

  4. Cleveland Clinic (2021). Ovarian Endometrioma (Chocolate Cyst): Causes & Treatment. Available at: https://my.clevelandclinic.org/health/diseases/22004-ovarian-endometrioma [Accessed 14 Sept. 2026].

  5. Cleveland Clinic (2022). Peritoneum: Anatomy, function, location & definition. Cleveland Clinic. Available at: https://my.clevelandclinic.org/health/body/22894-peritoneum [Accessed 14 Sept. 2026].

  6. Braga, L.H., Farrokhyar, F., Dönmez, M.İ., Nelson, C.P., Haid, B., Herbst, K., Garriboli, M., Cascio, S., Nieuwhof-Leppink, A., Kaefer, M., Bägli, D.J., Kalfa, N., Ching, C., Fossum, M. and Harper, L. (2024). Randomized controlled trials – the what, when, how and why. Journal of Pediatric Urology, 21(2). doi:10.1016/j.jpurol.2024.11.021.

  7. AllClinicalTrials (2024). Open Label Study: What Is An Open Label Clinical Trial? Available at: https://www.allclinicaltrials.com/blog/what-is-an-open-label-clinical-trial [Accessed 14 Sept. 2026].