Perineology
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Basic anatomic features in perineology


by THOMAS MOUCHEL - FRANÇOIS MOUCHEL

Clinique du tertre Rouge, Le Mans, France


Perineology is based on the diagnosis and treatment of "specific defects" so it is important to define these "defects"1-3 and for this purpose a good knowledge of anatomy is necessary.4-5 Although the anatomy of this area may seem well described in textbooks, some key features are usually underestimated or even forgotten. In order to improve the understanding of this complicated anatomy, we present a simplified three-dimensional model that describes the most important features of the functional anatomy together with some demonstrative figures.

THE PERINEAL BODY (Fig. 1)image

The Perineal Body is a medial fibro-muscular structure made by the bulbocavernosus, the transverse perineal muscles and the external anal sphincter.4-5 Apart from the transverse muscles it is the only superficial pelvic structure that is not lying in a sagittal or oblique axis. The Perineal Body makes a kind of structural beam positioned in the medial part of the perineum and able to support the sagittal overlying structures. As a result it can be regarded as the "center of gravity" of the perineum. The Perineal Body is involved in creating the angle of the vagina and is the key structure that defines the first part of the vagina.6 The angle of the vagina, divides it into two parts and facilitates perineal balance allowing the posterior movement of the viscera (bladder, second vaginal part and rectum) and their support on the levator plate. The perineal body is one of the key elements of vaginal support and its defects (usually post delivery) are causative for most of the perineal dysfunctions (Fig. 2)image.
Anatomical reconstitution of the perineal body is thus critical in perineal surgery.

THE LEVATOR ANI MUSCLES

Instead of the usual description in three components (pubo-coccygeus, ilio-coccygeus and coccygeus) which is open to anatomical and functional misinterpretation, we consider like Shafik there are only two anatomical and functional entities:

Because there is no levator ani muscle between the vagina and the rectum, levator myorrhaphy at this level would not be anatomical.11

THE PELVIC FASCIA (Fig. 5 )image

Mixed connective structure directly related with the different local connective tissues, it forms in places different ligaments described under specific names which are also open to misinterpretation. In our point of view,4, 5 the fascia must be seen as a thin layer stretching all over the pelvis with lateral insertions on the white lines and, from back to front, on the sacral wall to surrounding the cervix (utero-sacral ligament) and after, with a division in two sheets:

According to this concept, the 2nd part of the vagina is de facto included in the fascia which is involved in the angular layout of the vagina. Therefore, the anatomy of the vagina is dependent on the quality of the connective tissue even if we think that the fascia is totally passive, its defects being usually the repercussions of the underlying perineal neuro-muscular diseases rather than direct connective tissue lesions.

THE ANAL SPHINCTER(Fig. 1 , 3)image

We totally agree with the concept of the three loops described by Shafik: 8

These antagonistic forces contribute to anal continence but also to the balance of all the perineum. To-day, this anococcygeal ligament remains the "unknown" of the pelvic floor. Its size and its structure are surely linked with an important function.

THE PUDENDAL AND LEVATOR NERVES(Fig. 1 , 4)image


Their importance deserves a later updating.13, 14 It is this anatomical approach that led us to the concept of Perineology. It is a global vision of all the perineal structures, but also of the different perineal diseases. This global approach is also essential in planning and performing surgery.
All the perineal diseases can be summarized in seven defects more or less associated. The job of the perineologist is to assess and diagnose these different defects and then to cure each of them. A later contribution in this journal will explain the different surgical procedures available to cure these defects. The figures presented in this manuscript are samples of a DVD explaining the 3 D static and dynamic normal anatomy and perineal defects. This DVD will be available on www.perineology.com

REFERENCES

  1. Beco J, Mouchel J. Understanding the concept of perineology. Int Urogynecol J Pelvic Floor Dysfunct 2002; 13: 275-277.
  2. Beco J, Mouchel J. Perineology or pelviperineology: the same goal but different approaches. Pelviperineology 2007; 26: 139.
  3. Beco J, Mouchel J. Perineology: a new area. Urogynaecologia International Journal 2003; 17: 79-86.
  4. Mouchel F. Connaître et comprendre la nouvelle anatomie fonctionnelle. In: La Périnéologie, comprendre un équilibre et le préserver. Edited by Beco JMJ, Nélissen G. Verviers, Belgium: Odyssée 1372; 1998.
  5. Mouchel J, Beco J, Bonnet P, Isambert J, Mouchel F, Wurst C. L'acte sexuel féminin: son intégration dans la conception anatomo-physiologique du plancher pelvien. In: Mise à jour en Gynécologie-Obstétrique. Paris, Vigot, 1996; 193-231.
  6. Nichols DH, Randall CL. Vaginal surgery, 4 edn. Baltimore: William and Wilkins; 1996.
  7. Shafik A. New concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. II. Anatomy of the levator ani muscle with special reference to puborectalis. Invest Urol 1975; 13: 175-182.
  8. Shafik A. A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. The external anal sphincter: a triple-loop system. Invest Urol 1975; 12: 412-419.
  9. Shafik A. A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. VIII. Levator hiatus and tunnel: anatomy and function. Dis Colon Rectum 1979; 22: 539-549.
  10. Beco JL. Interest of retro-anal levator plate myorrhaphy in selected cases of descending perineum syndrome with positive anti-sagging test. BMC Surg 2008; 8:13.
  11. Mouchel T, Wurst C, Mouchel J: Faut-il encore faire des myorraphies des releveurs ? In: La Périnéologie, comprendre un équilibre et le préserver. Edited by Beco J MJ, Nélissen G. Verviers, Belgium: Odyssée 1372; 1998.
  12. DeLancey JO. The anatomy of the pelvic floor. Curr Opin Obstet Gynecol 1994; 6: 313-316.
  13. Barber MD, Bremer RE, Thor KB, Dolber PC, Kuehl TJ, Coates KW. Innervation of the female levator ani muscles. Am J Obstet Gynecol 2002; 187: 64-71.
  14. Juenemann KP, Lue TF, Schmidt RA, Tanagho EA. Clinical significance of sacral and pudendal nerve anatomy. J Urol 1988; 139: 74-80.
  15. Singh K, Jakab M, Reid WM, Berger LA, Hoyte L. Threedimensional magnetic resonance imaging assessment of levator ani morphologic features in different grades of prolapse. Am J Obstet Gynecol 2003; 188: 910-915.

Contact Details: MOUCHEL THOMAS, MOUCHEL JACK
Centre de Perineology Cabinet de Gynæcologie 4,
Avenue d'Haouza 72100 Le Mans (France)
E-mail: tmouchel@cegetel.net

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