Advertisement

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

  • S. Abbas Shobeiri
    Correspondence
    Reprints: S. Abbas Shobeiri, MD, University of Oklahoma Health Sciences Center, Department of Obstetrics and Gynecology, Section of Female Pelvic Medicine and Reconstructive Surgery, 920 Stanton L. Young Blvd., PO Box 26901, WP2410, Oklahoma City, OK 73190
    Affiliations
    Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
    Search for articles by this author
  • Ralph R. Chesson
    Affiliations
    Section of Female Pelvic Medicine and Reconstructive Surgery, Department of Obstetrics and Gynecology, Louisiana State University Health Sciences Center, New Orleans, LA
    Search for articles by this author
  • Raymond F. Gasser
    Affiliations
    Section of Female Pelvic Medicine and Reconstructive Surgery, Department of Obstetrics and Gynecology, Louisiana State University Health Sciences Center, New Orleans, LA
    Search for articles by this author
Published:October 10, 2008DOI:https://doi.org/10.1016/j.ajog.2008.07.057

      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.

      Key words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to American Journal of Obstetrics & Gynecology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

      1. Hyrtl J. Lehrbuch der anatomie des Menschen. Wilhelm Braumuller, Wien. 12. Aufl. 1873. pp. 848-53.

        • Bergas J.T.
        • Rubin I.C.
        Study of the supportive structures of the uterus by levator myography.
        Surg Gynecol Obstet. 1953; 97: 677
        • DeLancey J.O.
        The pubocervical ligament, a separate structure from the urethral support (“pubourethral ligaments”).
        Neurourol Urodyn. 1989; 8: 53-61
        • DeLancey J.O.
        Structural aspects of the extrinsic continence mechanism.
        Obstet Gynecol. 1988; 72: 296-301
        • Kearney R.
        • Sawhney R.
        • DeLancey J.O.
        Levator ani muscle anatomy evaluated by origin insertion pairs.
        Obstet Gynecol. 2004; 104: 168-173
        • Percy J.P.
        • Neill M.E.
        • Swash M.
        • Parks A.G.
        Electrophysiological study of motor nerve supply of pelvic floor.
        Lancet. 1980; 1: 16-17
        • Barber M.D.
        • Bremer R.E.
        • Thor K.B.
        • Dolber P.C.
        • Kuehl T.J.
        • Coates K.W.
        Innervation of the female levator ani muscles.
        Am J Obstet Gynecol. 2002; 187: 64-71
        • Sato K.
        A morphological analysis of the nerve supply of the sphincter ani externus, levator ani and coccygeous.
        Acta Anat Nippon. 1980; 55: 187-223
        • Sato K.
        • Sato T.
        An anatomical investigation on the muscles of the pelvic outlet in crab-eating monkey (Macaca irus) and Japanese monkey (Macaca fuscata) with special reference to their nerve supply.
        Anat Anz. 1987; 163: 425-438
        • Kiff E.S.
        • Swash M.
        Slowed conduction in pudendal nerves in idiopathic (neurogenic) fecal incontinence.
        Br J Surg. 1984; 71: 614-616
        • Snooks S.J.
        • Setchell M.
        • Swash M.
        • Henry M.M.
        Injury to innervation of pelvic floor sphincter musculature in childbirth.
        Lancet. 1984; 2: 546-550
        • Damaser M.S.
        • Broxton-King C.
        • Ferguson C.
        • Kim F.J.
        • Kerns J.M.
        Functional and neuroanatomical effects of vaginal distention and pudendal nerve crush in the female rat.
        J Urol. 2003; 170: 1027-1031
        • Snooks S.J.
        • Barnes P.R.
        • Swash M.
        Damage to the innervation of the voluntary anal and periurethral sphincter musculature in incontinence: an electrophysiological study.
        J Neurol Neurosurg Psych. 1984; 47: 1269-1273
        • Pierce L.M.
        • Reyes M.
        • Thor K.B.
        • et al.
        Immunohistochemical evidence for the interaction between levator ani and pudendal motor neurons in the coordination of pelvic floor and visceral activity in the squirrel monkey.
        Am J Obstet Gynecol. 2005; 192: 1506-1515
        • Sihler C.
        Ober Muskelspindeln und intramuskulare Nervenendigungen bei Schlangen und Froschen.
        Arch Mikros Anat Entwick Lungs. 1895; 46: 709-725
        • Warton L.R.
        A technique for studying the innervation of organs.
        Anat Rec. 1937; 67: 469-475
        • Williams T.W.
        A technique for the gross differential staining of peripheral nerves in cleared vertebrate tissue.
        Anat Rec. 1943; 86: 189-194
        • Freihofer W.C.
        The Sihler technique of staining nerves for systematic study especially of fishes.
        Copeia. 1966; 3: 470-475
        • Wu B.L.
        • Sanders I.
        A technique for demonstrating the nerve supply of whole larynges.
        Arch Otolaryngol Head Neck Surg. 1992; 118: 822-827
        • Mu L.
        • Sanders I.
        Sensory nerve supply of the human oro- and laryngopharynx: a preliminary study.
        Anat Rec. 2000; 258: 406-420
        • Margulies R.U.
        • Huebner M.
        • DeLancey J.O.
        Origin and insertion points involved in levator ani muscle defects.
        Am J Obstet Gynecol. 2007; 196: 251.e1-251.e5
        • Lien K.C.
        • Morgan D.M.
        • Delancey J.O.
        • Ashton-Miller J.A.
        Pudendal nerve stretch during vaginal birth: a 3D computer simulation.
        Am J Obstet Gynecol. 2005; 192: 1669-1676
        • Lien K.C.
        • Mooney B.
        • DeLancey J.O.
        • Ashton-Miller J.A.
        Levator ani muscle stretch induced by simulated vaginal birth.
        Obstet Gynecol. 2004; 103: 31-40