A surgical and functional approach to the pelvic gross neuroanatomy of the female Yucatan minipig

The Yucatan minipig is gaining widespread use in studies focused on spinal cord injury. As a large animal model, it offers unique advantages for developing novel and more effective therapies. Successful neuromodulation experiments require precise access to central and peripheral neural structures, which depends on a thorough understanding of topographical anatomy and advanced surgical techniques. The current study describes the topography of the pelvic organs in the female Yucatan minipig, as well as a surgical approach to the principal nerves and branches controlling the pelvic viscera. Eight postmortem specimens, five fixed with 4 % paraformaldehyde and three non-fixed, were used to perform dissections under stereoscopy. Muscles that form the lateral and ventrolateral walls of the pelvis were identified. The pudendal nerve, formed by S2 and S3 contributions, includes an extrapelvic component formed by S1 and S2 contributions. The hypogastric nerve converged with the pelvic nerve (formed by the splanchnic branch of the S2 trunk and two anastomotic splanchnic branches from S1 and S3) at the pelvic plexus which supplies the autonomic innervation of the urinary bladder, urethra, vagina, rectum, and cavernous tissue of the clitoris. Together, the current anatomical and neuroanatomical descriptions provide a comprehensive understanding of the structural anatomy of the urogenital and colorectal regions in the female Yucatan minipig.