The internal innervation and morphology of the human female levator ani muscle

Abstract

Objective: The purpose of this study was to describe the microinnervation of the human the female levator ani muscle complex.

Study design: Detailed microdissection of 10 fresh female levator ani muscles was performed. Specimens were processed by modified Sihler's staining technique. A composite drawing of the levator ani nerve (LAN) distribution was created.

Results: Six hemi-levator ani muscles were stained and digitally reconstructed. The LAN traveled perpendicular to major muscular bundles while progressively branching into finer nerves that eventually entered single muscle fascicles. The LAN continued its course through the iliococcygeous muscle to innervate the puborectalis, puboperinealis, and puboanalis muscles. There was no distinct separation between pubovisceralis and iliococcygeous fibers. There were muscle fibers that could be best described as coccygeoperinealis.

Conclusion: The utilized staining technique enabled us to visualize the LAN microinnervation of the levator ani muscle that extends to puboperinealis and puboanalis muscles. A blueprint for LAN and levator ani morphology was created.