The Female Periurethral Tissue and the Vulvar Vestibule: Translational Anatomy of Female Sexual Function and Dysfunction

Abstract

This thesis presents a series of investigations which aimed to expand anatomical knowledge of two understudied regions of the female pelvis—the female periurethral tissue (FPT) and the vulvar vestibule—and explore related knowledge translation (KT) questions. While these tissues may be important contributors to sexual responses, insufficient anatomical characterization has led to deficiencies in understanding potential underlying structure-function relationships. Negative impacts to sexual functioning following mid-urethral sling (MUS) surgery, and the identification of difficult to treat chronic pain syndromes localized to the vulvar vestibule have underscored the clinical significance of these regions respectively, highlighting the need for further investigation. This research addressed key aspects of the gross and/or microscopic anatomy of these regions and applied this information to clinically relevant contexts to improve understanding of iatrogenic injury and pathologic conditions, respectively. Tissues were characterized using histology, immunohistochemistry, cadaveric dissection, and/or surgical simulation. To address relevant aspects of KT, the quality and content of patient education materials (PEMs) for related surgical procedures was assessed, and an appraisal of Canadian clinical practice guidelines (CPGs) for female sexual dysfunction (FSD) was conducted. The major findings are: (i) the FPT contains microscopic nerves and prostate-like glands that could be negatively impacted by MUS surgery, possibly contributing to post-operative FSD; (ii) the vulvar vestibule contains sensory and autonomic innervation originating from pudendal nerve branches and potentially the inferior hypogastric plexus. Further, neuroproliferative vestibulodynia is characterized by the proliferation of sensory and autonomic nerve fibers and neuroimmune interactions; (iii) online PEMs for MUS and radical prostatectomy show inconsistent disclosure of risk information, and do not meet thresholds for adequate health literacy, limiting their effectiveness in KT; and (iv) appraisal of the existing Canadian CPG for FSD identifies areas of methodological weakness that should be addressed to improve guideline quality. This body of work elucidated key aspects of the anatomy of clinically significant tissues and lays the foundation for advancing knowledge of important genito-pelvic structures involved in female sexual function and dysfunction. Our exploration of related KT questions identified where there may be deficiencies in translating evidence to practice, guiding directions for future research.