Impact of vasopressin-assisted laparoscopic endometrioma excision on ovarian reserve: a randomized controlled trial

Laparoscopic cystectomy is the standard surgical treatment for ovarian endometrioma; however, inadvertent removal of healthy ovarian tissue and thermal injury during hemostasis may compromise ovarian reserve. Vasopressin injection has been proposed as a surgical adjunct to reduce bleeding and limit the need for electrocoagulation, thereby potentially minimizing ovarian damage. However, evidence regarding its effectiveness in preserving ovarian reserve remains limited.

This randomized controlled trial was conducted at a tertiary university-affiliated medical center between September 2018 and July 2021. Seventy-five women undergoing laparoscopic cystectomy for unilateral ovarian endometrioma were stratified according to baseline serum anti-Müllerian hormone (AMH) levels and randomly assigned to either a vasopressin-assisted surgery group or a control group. The primary outcome was the change in serum AMH level 12 months after surgery. Secondary outcomes included operative parameters, including cyst stripping time and time required for bleeding control. Outcomes were analyzed using intention-to-treat and per-protocol approaches. Longitudinal changes in AMH were evaluated using linear mixed-effects models.

In the intention-to-treat analysis, vasopressin injection significantly reduced the time required for cyst stripping (8.9 ± 7.9 vs. 14.4 ± 13.7 min, p = 0.054) and bleeding control (2.2 ± 2.5 vs. 6.5 ± 6.8 min, p = 0.002) compared with the control group. However, the decline in AMH levels at 12 months after surgery did not differ significantly between the vasopressin and control groups (-0.96 ± 1.11 vs. -1.14 ± 0.92 ng/mL, p = 0.488). Subgroup analyses according to baseline AMH levels (<3 ng/mL and 3.0-<7.0 ng/mL) yielded similar findings. Linear mixed-effects modeling demonstrated a significant decline in AMH at 3 months after surgery, followed by partial recovery at 6 and 12 months, with no significant group-by-time interaction (p = 0.816). Per-protocol analyses produced consistent results. Histopathological evaluation revealed no significant between-group differences in the thickness or proportion of excised ovarian tissue.

Although vasopressin reduced operative time and electrocoagulation exposure during endometrioma surgery, it did not prevent postoperative decline in ovarian reserve.