50. Histologic Effects of a Novel Vaginal Expansion Device on Vaginal Tissue in a Rat Model

• Published in: Journal of pediatric & adolescent gynecology Vol. 36; no. 2; pp. 193 - 194
• Main Authors: Meyer, Hannah, Shah-Bruce, Mila D., Welch, Valerie L., O'Quin, Collyn C., Trosclair, Lexus, Dao, Nhi, White, Luke A., Alexander, Jonathan S., Solitro, Giovanni, Sorrells, Donald
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.04.2023
• DOI: 10.1016/j.jpag.2023.01.138
• ISSN: 1083-3188

Vaginal agenesis is the congenital absence of the vaginal canal frequently associated with Mullerian Agenesis. Treatments include options such as mechanical dilation and surgical vaginoplasty. Our vaginal expansion sleeve (VES) is a transiently-implanted device less invasive than surgery and less reliant on patient compliance, acting to lengthen vaginal tissue over time. This study aims to evaluate the histologic effects of VES on rat vaginal tissue using tissue stains. The VESs were made using a proprietary woven cylindrical material with helicoid trusses and flat resin caps (Figure 1). The VESs were constructed to 25-30mm in length depending on initial vaginal canal lengths, pre-contracted, inserted, and secured into the vaginas of 6 Sprague Dawley rats, and allowed to re-expand post-deployment. After one week, the VESs were removed, and post-expansion vaginas were harvested and measured in length. Test (n=6) and control (n=4) formalin-fixed paraffin-embedded tissues were stained with hematoxylin and eosin (H&E), Masson's trichrome, and anti-Desmin antibodies. Mean vaginal canal length increased from 20.0 ± 2.4 mm to 23.8 ± 1.2 mm post-removal of the VESs (n=6, p < .001), a 19% increase. H&E stains reveal an increase in submucosal eosinophilic inflammation in five out of six test tissues (Figure 2A) compared to one out of four control tissues. The number of eosinophils per HPF in the five test tissues had an average of 30.2, (range 16 to 38 with a median of 35). The test tissues show increased scattered neutrophils and lymphocytes in the mucosa and submucosa, with one showing significant lymphocytic and neutrophilic inflammation (Figure 2B). Desmin immunostain and Masson's trichrome stain show a thinner muscularis with more infiltrative fibrous tissue between muscle fibers in the test tissue (Figure 2C) compared to control tissue (Figure 2D) The VESs achieved significant vaginal lengthening. The vaginal canal with the longest VES (30mm) experienced significantly increased neutrophilic and lymphocytic inflammation with mild eosinophilia. A positive correlation was suggested between the size of expander/tension generated in the vagina and the amount of acute and chronic inflammation. The eosinophilia in the test tissue may indicate a localized, specific immune reaction. The muscularis and adjacent fibrous tissue changes indicate muscularis remodeling. Future studies with increased duration of in-vivo VESs are needed to assess long-term changes in the test tissue, optimize the length-tension relationship, and further characterize the immune response. Supporting Figures or Tables  ▪ ▪