Introduction
Dickinson pioneered wax cylinders for vaginal wall impression, and later, Morgan introduced the material that dentists use.1, 2 These three-dimensional vaginal impression molds demonstrate gross-topographical anatomy and its potential aberrations. Pendergrass verified these techniques and findings.3 When analyzing these vaginal molds, one can conclude there is a separate anatomical structure in vertical orientation that fused with the vaginal wall being in the horizontal orientation.1, 2 The vaginal casting method findings were confirmed by magnetic resonance imaging (MRI) with gel contrast filling the vaginal canal.4 MRI technology provides more detailed information about the shape and strata of the vaginal walls with three identifiable zones a) the “distal vaginal sphincteric zone” (the vaginal outlet wall); b) the “transition zone”; c) the “forniceal zone.” 4 Also, the dynamic ultrasonographic investigation showed the sphincteric zone within the distal vaginal wall.5 Furthermore, Hart documented that the hymen wall was always present in the female newborn at term without demonstrating the hymeneal anatomical wall layers.6
The current variable terminology used for the vaginal entrance wall did not reflect the vaginal outlet wall. Often terms are used such as vaginal introitus (introitus vaginae), the vaginal vestibule (vestibulum vaginalis), the vaginal opening, and the vaginal orifice.2-5 These terminologies do not reflect a specific anatomical architecture of the vaginal outlet. The analysis of the current nomenclatures reveals that a) the “vaginal introitus” is a vaginal atrium located in front of the hymen; b) “the vaginal vestibule” is located between the posterior surface of the hymen and the anterior border of the posterior perineum; anteriorly, it runs from the posterior surface hymen to the inferior edge of the clitoral frenulum; laterally, it extends from the inferior hymen to base of the labia minora, and there is a small crease between them6, 7; c) The “vaginal orifice “or vaginal opening” is a space and isn’t an anatomical structure. These terminologies do not represent the entry to the vaginal canal. The electronic and manual medical literature searches failed to identify any scientific-clinical article describing the vaginal outlet wall. The new terminology suggested by the author adequately encompasses this part of the vaginal ingress or egress, and the author suggests the term “the vaginal outlet wall.” Therefore, the present study is the first anatomical and H/E histological description of the vaginal outlet wall.
There is no description of the vaginal outlet wall in anatomy educational textbooks or atlases of human anatomy.8-13To the best of this author’s knowledge, there is no anatomical description of the vaginal outlet in the scientific-clinical articles.
The present study question is, “does the vaginal outlet wall have different anatomical and histological architectures than the vaginal wall?” The study’s objectives are to describe the vaginal outlet wall gross, topographic, and microscopic anatomy and document findings by digital photograms. The primary outcome measures gross, topographic anatomy and characteristic histologic features of the vavinal outlet wall.