P-313 Additional tubal flushing with ethiodized oil during transvaginal hydrolaparoscopy; feasibility and live birth rate, a pilot study in subfertile women
Authors: Bus M , Roest I , Bongers M , Mijatovic V , Mol B 
Published: July 2024

Abstract

Study question
Is tubal flushing with ethiodized oil during transvaginal hydrolaparoscopy (THL) feasible and what is the live birth rate within 6 months after THL?

Summary answer
Additional flushing with ethiodized oil during THL is feasible and safe with a live birth rate of 32.0% compared to 23.4% using solely water-based-contrast (p = 0.25).

What is known already
The use of ethiodized oil during hysterosalpingography (HSG), an alternative method to test tubal patency, has shown to have a positive effect on the live birth rate, compared to the use of water-based contrast (methylene blue). The benefit of THL over HSG as a tubal testing method is the possibility to also explore tubo-ovarian structures and the pouch of Douglas. Currently, only water-based media are used for tubal flushing during THL.

Study design, size, duration
A single-center cohort study at Máxima MC, the Netherlands, including 50 subfertile women who underwent THL and in whom there was at least unilateral tubal patency for methylene blue. Outcomes of interest included feasibility, safety and 6- months live birth rate. Our data were compared with a historical cohort of 111 subfertile women who underwent THL using solely water-based contrast (van Kessel MA. et al., 2021). Univariate – and multivariate logistic regression analysis were performed.

Participants/materials, setting, methods
Women with an iodine allergy and/or manifest thyroid dysfunction were excluded. Participants received additional tubal flushing with ethiodized oil (Lipiodol® Ultra Fluid). Main outcomes were appearance of oil and cell/mucus debris at the tubal fimbriae, pain scores (Visual Analogue Scale, VAS) and acceptability scores (0-10, completely unacceptable-acceptable). Secondary outcomes included; amount of ethiodized oil used, thyroid function four weeks afterwards, adverse events and live birth rate within 6 months after THL.

Main results and the role of chance
In 48 of the 50 THL procedures there was bilateral patency to methylene blue, ethiodized oil appeared from the tubal fimbriae bilateral in 77% (37/48), unilateral in 17% (8/48), while it did not appear in 6% (3/48). In two procedures there was unilateral patency to methylene blue. Ethiodized oil appeared unilateral in one and did not appear during the other THL. The amount of ethiodized oil used was 5 mL [3.4–6.3).
The median reported pain scores on the VAS were 2.9 [IQR 1.0–5.0] after flushing with methylene blue and 3.0 [IQR 1.0–5.0] after ethiodized oil. The acceptability of the procedure was rated as 10 out of 10 [IQR 8–10].
Four weeks after the procedure 14% (6/42) had developed subclinical hypothyroidism, one woman had overt hypothyroidism (FT4 slightly decreased to 11.0 pmol/L, TSH 5.60 mU/L) and one woman had isolated hypothyroxinemia (FT4 11.0 pmol/L, TSH 3.40 mU/L). One adverse event, persistent bleeding at the trocar insertion site was reported, for which a diagnostic laparoscopy was performed.
The live birth rate within 6 months after a THL was 32% (16/50), compared to 23% (26/111) in our historical cohort using solely water-based contrast (OR = 1.54, 95% CI 0.74–3.22, P = 0.25).

Limitations, reasons for caution
As this is a pilot study without a power analysis, the study is presumably underpowered to show an effect on the live birth rate. Also, the control group was historical.

Wider implications of the findings
By proving feasibility of using ethiodized oil during THL we encourage further research on its effect on pregnancy rates. Furthermore, the direct observation of tubal flushing with ethiodized oil during THL enables further investigation of the contrast characteristics, which are presumably responsible for its positive effect on live birth rate.

Trial registration number
NL8696