Vaginal Er:YAG laser application in the menopausal ewe model: a randomised estrogen and sham‐controlled trial

Abstract

Objective To describe effects of non‐ablative erbium‐doped:yttrium‐aluminium‐garnet (Er:YAG) laser on vaginal atrophy induced by iatrogenic menopause in the ewe. Design Animal experimental, randomised, sham and estrogen‐treatment controlled study with blinding for primary outcome. Setting KU Leuven, Belgium. Sample Twenty‐four ewes. Methods Menopause was surgically induced, after which the ewes were randomised to three groups receiving vaginal Er:YAG laser application three times, with a 1‐month interval; three sham manipulations with a 1‐month interval; or estrogen replacement and sham manipulations. At given intervals, ewes were clinically examined and vaginal wall biopsies were taken. Vaginal compliance was determined by passive biomechanical testing from explants taken at autopsy. Main outcome measures Vaginal epithelial thickness (primary), composition of the lamina propria (collagen, elastin, glycogen and vessel content), vaginal compliance, clinical signs. Results Animals exposed to Er:YAG laser application and sham manipulation, but not to estrogens, displayed a significant and comparable increase in vaginal epithelial thickness between baseline and 7 days after the third application (69% and 67%, respectively, both P < 0.0008). In laser‐treated ewes, temporary vaginal discharge and limited thermal injury were observed. Estrogen‐substituted ewes displayed a more prominent increase in epithelial thickness (202%; P < 0.0001) and higher vaginal compliance (P < 0.05). None of the interventions induced changes in the lamina propria. Conclusions Vaginal Er:YAG laser has comparable effect to sham manipulation in menopausal ewes. Tweetable abstract Vaginal Er:YAG laser has comparable effect to sham manipulation in menopausal ewes #LASER #GSM #RCT.

Authors' reply re: Vaginal Er:YAG laser application in the menopausal ewe model: a randomised estrogen and sham‐controlled trial

“…Further, we wholeheartedly agree with Tamer Erel and Ozcivit, who have ample clinical experience with clinical laser application, that animal models have their limitations, hence also the ewe. These animals are often used to study menopause‐associated disorders, including genito‐urinary atrophy as described in our manuscript 2 . More precisely, ewes have vaginal dimensions close to that of women, and when they undergo ovariectomy, their vaginal epithelium thins to 34–118 µm, which is perhaps not identical, but is close to the range observed in women (50–180 µm) 4,5 .…”

“…We thank colleagues Tamer Erel and Ozcivit 1 for their comments on our experimental assessment of the effects of vaginal Er:YAG laser application in menopausal ewes 2 and are happy to clarify some details.…”

Re: Vaginal Er:YAG LASER application in the menopausal ewe model: a randomised estrogen and sham‐controlled trial

“…We read the recent BJOG article by Mackova et al. with great interest 1 . In this elaborate study, in which laser application and sham manipulation led to a significant but comparable increase in vaginal epithelial thickness (VET) in ewes (69 and 67%, respectively), estrogen substitution led to a prominent increase in VET (202%).…”

Authors' reply re: Vaginal Er:YAG laser application in the menopausal ewe model: a randomised estrogen and sham‐controlled trial

“…We thank colleagues Gaspar and Gambacciani for their compliments and comments 1 on our experimental study assessing the effects of vaginal Er:YAG LASER application in menopausal ewes 2 . Though they accept the comprehensive methods used, they question the experiment's relevance.…”

“…This should, however, not preclude attempts to study the mechanisms of human diseases or their treatment in species that do simulate all other measurable findings one can observe in women. This limitation is extensively discussed in the manuscript 2 . Conversely, we took advantage of the possibilities in an animal experimental model to conduct a controlled trial and a comprehensive set of outcome measurements, which clinically would not be acceptable, though it should permit the determination of findings that have been clinically claimed, and the understanding thereof.…”