An Objective Measure of Vaginal Lubrication in Women With and Without Sexual Arousal Concerns

Vaginal self-lubrication following peritoneal, penile inversion, and colonic gender-affirming vaginoplasty: a physiologic, anatomic, and histologic review

INTRODUCTION

Vaginal self-lubrication is central to the sexual satisfaction and healthy genitourinary function of patients who have undergone gender-affirming vaginoplasty (GAV). Secretory capacities of different neovaginal lining tissues have been variably described in the literature, with little evidence-based consensus on their success in providing a functionally self-lubricating neovagina. We review the existing neovaginal lubrication data and the anatomy, histology, and physiology of penile and scrotal skin, colon, and peritoneum to better characterize their capacity to be functionally self-lubricating when used as neovaginal lining.

OBJECTIVES

The study sought to review and compare the merits of penile and scrotal skin grafts, spatulated urethra, colon, and peritoneal flaps to produce functional lubrication analogous to that of the natal vagina in the setting of GAV.

METHODS

We conducted a systematic review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Medline, EMBASE, ClinicalTrials.gov, and the Cochrane Library databases were searched for peer-reviewed studies published prior to December 12, 2022, that (1) included data specific to transfeminine individuals; (2) were full-text randomized controlled studies, case reports, case series, retrospective cohort studies, prospective cohort studies, qualitative studies, and cross-sectional studies; and (3) included specific discussion of vaginal lubrication or fluid secretion following GAV utilizing penile skin, colonic tissue, or peritoneum.

RESULTS

We identified 580 studies, of which 28 met our inclusion criteria. Data on neovaginal lubrication were limited to qualitative clinician observations, patient-reported outcomes, and satisfaction measures. No studies quantifying neovaginal secretions were identified for any GAV graft or flap technique. Anatomically, penile and scrotal skin have no self-lubricating potential, though penile inversion vaginoplasty may produce some sexually responsive secretory fluid when urethral tissue is incorporated and lubricating genitourinary accessory glands are retained. Colonic and peritoneal tissues both have secretory capacity, but fluid production by these tissues is continuous, nonresponsive to sexual arousal, and likely inappropriate in volume, and so may not meet the needs or expectations of some patients. The impact of surgical tissue translocation on their innate secretory function has not been documented.

CONCLUSIONS

None of penile/scrotal skin, colon, or peritoneum provides functional neovaginal lubrication comparable to that of the adult natal vagina. Each tissue has limitations, particularly with respect to inappropriate volume and/or chronicity of secretions. The existing evidence does not support recommending one GAV technique over others based on lubrication outcomes. Finally, difficulty distinguishing between physiologic and pathologic neovaginal fluid secretion may confound the assessment of neovaginal self-lubrication, as many pathologies of the neovagina present with symptomatic discharge.

Establishment of Rat Model of Female Genital Sexual Arousal Disorder

Introduction

Female Genital Sexual Arousal Disorder (FGSAD) seriously affects women's quality of life and Sexual life, but it still lacks ideal FGSAD animal models for further study.

Aim

To establish a specific model of female genital sexual arousal disorder and explore the mechanisms resulting in FGSAD.

Methods

After delivery, female rats were guided by expansions of the vagina and ovariectomy (VD+OVX, n = 10); in VD group female rats were just extended by the vagina (VD, n = 10), in OVX group female rats were treated with ovariectomy (OVX, n = 10);the remaining had 1 longitudinal incision as sham group(n = 10).

Outcomes

Vaginal dilatation combined with ovariectomy in rats may reflect female genital sexual arousal disorder with high reproducibility and stability.

Results

Vaginal tissue of female rats in OVX group and VD+OVX group showed an increase in blood flow, decrease in muscle content compared to the sham group. The proportion of collagen fiber I/III decreased and the elastic fiber showed significant rupture and fragmentation; Structural reticular integrity was also significantly separated and broken from the muscle fibers. However, there was no significant difference in vaginal blood flow, fibers and vascular between VD group and Sham group. The damage of vaginal tissue in VD+OVX group was more significant than that in OVX and VD groups.

Clinical Translation

We have constructed a specific animal model that can provide clinical insights into the mechanism of FGSAD and serves as a good avenue for further research of its treatment.

Strengths and Limitations

Vaginal dilatation combined with ovariectomy in rats is a specific animal model with high reproducibility and stability, but we do acknowledge the shortcomings and limitation present in our study. Since genital arousal disorder has many different etiologies that impact the vagina, the clitoris and surrounding tissues, there is no “gold standard” model that different models attempt to investigate different etiologies.

Conclusion

The female genital sexual arousal disorder model established by vaginal dilatation combined with ovariectomy is a novel rat model with simple induction conditions, which pathogenic mechanism of female genital sexual arousal disorders maybe connected with the change of VEGF and MMP-9 in vaginal fibromuscular system and microvascular.

Li G, Yu P, Hu Y, et al. Establishment of Rat Model of Female Genital Sexual Arousal Disorder. Sex Med 2022;10:100530.