Comparison
The vaginal wall anatomical and histological descriptions are well-studied, and the findings are noncontroversial.8-17 Therefore, this type of study on the vaginal wall was not performed in the current experimental investigation. However, the medical literature does not describe the vaginal outlet wall anatomy and histology. The vaginal introitus, vaginal vestibule, and vaginal orifice are often used for the vaginal outlet. The present cadaveric gross-topographic anatomy investigation shows that the vaginal outlet wall is a different structure than the vaginal wall, vaginal introitus, vaginal vestibule, or vaginal orifice because the hymeneal ring layer (intermedial stratum) of the vaginal outlet wall consists of a white cartilage structure Fig. 1B. The gross vaginal anatomy consists of four walls that create a canal (the anterior, posterior, and two lateral walls). The vaginal outlet comprises only one circular wall surrounding the vaginal wall’s distal edges. The anterior vaginal wall fuses with the posterior urethral wall and the based of the urinary bladder, the vaginal outlet anterior-superior part fuses with the inferior border of the membraneous urethral sphincter, and the free margin of the vaginal outlet wall hangs over the vaginal lumen. The topographical position of the vaginal wall is in a horizontal orientation, and the vaginal outlet is in a vertical position. The vaginal sagittal dissection reveals three vaginal layers: the mucosa, muscular, and adventitia (surgical fascia). The sagittal dissections of the vaginal outlet present different layers: the membraneous soft tissue — the thin mucosa (hymeneal membrane), flexible but rigid tissue — hymeneal ring (hymeneal cartilage), soft, muscular, and elastic tissue — hymeneal plate.
The educational textbooks of histology and atlas also provide an uncontroversial description of the vaginal wall mucosal epithelium, histologically described as a stratified squamous epithelium with a small degree of keratinization. The vaginal outlet wall membrane layer consists of a stratified non-keratinized squamous epithelium. In the vaginal wall below the epithelium is a thick and loosely organized layer of dense connective tissue containing blood vessels and nerves ending. The vaginal mucosa is thicker (up to 10-roses of the epithelium squamous cells) than the vaginal outlet wall (3-rose). There is no corresponding vaginal histology to the cartilage of the hymeneal ring. Documentation
The digital photographic documentation of the anatomy and histology of the vaginal outlet wall proves that this structure is fused with the vaginal walls; however, it is not an identical anatomical extension of the vaginal walls. Moreover, the present study’s findings can assist obstetricians, general practitioners, midwives, and surgeons in better understanding this vital anatomical structure. Finally, this study confirmed the accuracy of the existing clinical classification of vaginal introitus.9 Future Research
The present study laid the foundation for basic and clinical research. Determining the cartilage, type of collagens, and elastin distribution within the vaginal outlet wall was beyond the scope of the present investigation; therefore, it creates an additional essential medical study option.
The current study findings showed that the vaginal outlet wall could play a significant role in developing a new episiotomy procedure (vaginal outlectomy) and, by doing so, eliminating the incisions of the posterior perineal musculature postpartum posterior perineal pain. Clinical-scientific research will answer that traditional episiotomy techniques should be changed to a new episiotomy (vaginal outlectomy). Future studies on a new episiotomy can revolutionize our current obstetrical practice.
The present study suggests that superficial dyspareunia can be caused by vaginal outlet wall stenosis or other aberrations. Additionally, vulvar vestibulitis syndrome (vulvodynia) can be associated with the abnormality of the vaginal outlet wall because the vaginal entry severe pain is dominant in vulvodynia. This characteristic-induced pain suggests that the vaginal outlet can play a significant role in vulvodynia and superficial dyspareunia, and vaginal wall prolapse, Fig. 3A and Fig. 3C. Conclusion
The vaginal outlet wall is an anatomical structure that consists of the hymeneal membrane, hymeneal ring (cartilage), and hymeneal plate. This structure is in vertical topographic orientation. Anatomically and histologically, it differs from the vaginal wall, which fuses with the deep layer-hymeneal plate.