The effect of CO 2 laser therapy on vaginal microcirculatory parameters in an animal model for genitourinary syndrome of menopause

• Published in: Neurourology and urodynamics Vol. 42; no. 6; pp. 1381 - 1389
• Main Authors: Latul, Yani P, Vodegel, Eva V, Kastelein, Arnoud W, Alkemade, Lily, Ras, Lamees, Hilty, Matthias P, Favaron, Emanuele, Ince, Yasin, Ince, Can, Jeffery, Stephen, Guler, Zeliha, Roovers, Jan-Paul W R
• Format: Journal Article
• Language: English
• Published: United States 01-08-2023
• Subjects: Animals; Carbon Dioxide; Female; Female Urogenital Diseases - therapy; Humans; Laser Therapy - methods; Menopause; Microcirculation; Models, Animal; Sheep; Syndrome; Vagina; epithelial thickness; estrogen; angioarchitecture; vaginal atrophy; microcirculation; genitourinary syndrome of menopause; laser therapy
• ISSN: 0733-2467; 1520-6777
• DOI: 10.1002/nau.25227

Vaginal laser therapy for the treatment of genitourinary syndrome of menopause (GSM) has been introduced to the market with limited (pre)clinical and experimental evidence supporting its efficacy. It is suggested that vaginal laser therapy increases epithelial thickness and improves vascularization, but the underlying biological working mechanism has not been substantiated yet.
To evaluate the effects of CO
laser therapy on vaginal atrophy using noninvasive incident dark field (IDF) imaging in a large animal model for GSM.
An animal study was conducted between 2018 and 2019 and included 25 Dohne Merino ewes, of which 20 underwent bilateral ovariectomy (OVX) to induce iatrogenic menopause, and 5 did not. The total study duration was 10 months.
Five months after OVX, ovariectomized ewes received monthly applications of CO
laser (n = 7), vaginal estrogen (n = 7), or no treatment (n = 6) for 3 months. IDF imaging was performed monthly in all animals.
The primary outcome was the proportion of image sequences containing capillary loops (angioarchitecture). Secondary outcomes included focal depth (epithelial thickness), and quantitative measures of vessel density and perfusion. Treatment effects were evaluated using ANCOVA and binary logistic regression.
Compared to OVX-only, ewes treated with estrogen demonstrated a higher capillary loops proportion (4% vs. 75%, p < 0.01), and higher focal depth (60 (IQR 60-80) vs. 80 (IQR 80-80) p < 0.05). CO
laser therapy did not change microcirculatory parameters. As the ewes' vaginal epithelium is thinner than that of humans, it may demand different laser settings.
In a large animal model for GSM, CO
laser therapy does not affect microcirculatory outcomes related to GSM, whereas vaginal estrogen treatment does. Until more homogeneous and objective evidence about its efficacy is available, CO
laser therapy should not be adopted into widespread practice for treating GSM.