Effects of intravenous tranexamic acid on ovarian reserve and intra-operative blood loss during laparoscopic cystectomy of endometriotic cyst: a pilot randomized controlled trial

BACKGROUND: Strategies to preserve ovarian function after ovarian endometriotic cyst removal have been reported in many studies; however, no study has evaluated tranexamic acid administration during surgery. OBJECTIVE: To evaluate feasibility of conducting a definitive trial and assessing the potential efficacy of tranexamic acid on ovarian reserve and intra-operative blood loss by comparing mean differences in anti-Müllerian hormone (AMH) levels following laparoscopic ovarian cystectomy between tranexamic acid and control groups. MATERIALS AND METHODS: A parallel two-arm pilot trial was conducted with 40 participants with endometriotic cysts who underwent laparoscopic ovarian cystectomy. They were randomized 1:1 to either 1 g tranexamic acid (TXA) or no TXA (n = 20 per group). TXA was administered to the participants immediately after induction of general anesthesia and intubation. The primary outcome was the feasibility of conducting a definitive trial in terms of design and procedures (such as recruitment rate, retention, safety of intravenous 1 gm of TXA, sample size verification) and assess the efficacy of TXA on the ovarian reserve and intra-operative blood loss by comparing mean difference of AMH levels between TXA and control groups at pre- and 3 months post-surgery. RESULTS: The recruitment and successful completion rates were 95% and 100%. Baseline characteristics were similar in the two groups. The mean difference of serum AMH levels (pre- and 3 months post-surgery) between the TXA and control groups was not significantly different. When performing a subgroup analysis, the mean difference of AMH levels (pre- and 3 months post-surgery) seemed to be higher in the bilateral than in the unilateral ovarian cyst group but not significantly different. Operating time was significantly longer in bilateral than in unilateral cysts. No post-operative complications or adverse effects were found. CONCLUSION: The full randomized controlled trial for evaluating effects of TXA administration during laparoscopic cystectomy for endometrioma on ovarian reserve was shown to be feasible. Several modifications should be added for improving feasibility, for example, increasing the TXA dose, modifying TXA administration, focusing on either patients with unilateral or bilateral ovarian cysts, and exploring other outcome measures, e.g., surgeons’ satisfaction. TRIAL REGISTRATION: Thai Clinical Trials Registry, TCTR20190424002, Registered 24 April 2019.