2. Perineal membrane12: The anterosuperior leaf of the endopelvic fascia, below its insertion to the pubic bone described above, crosses into the anterior part of the perineal membrane (Fig. 4B, 5B).
3. Perineal body: The inferoposterior leaf of the endopelvic fascia (the “rectovaginal fascia”), in its most inferior part, crosses into the perineal body (Fig. 4D, 5D). The perineal body represents the posterior part of the perineal membrane.
4. Superior fascia of the levator ani muscle (Fig. 4C, 5C): These wedge-shaped insertions (left and right) are broadest in the region of the vaginal introitus and gradually elongate as they extend toward the ischial spine. The anterior margin of the insertion is thickened, running from the lower part of the body of the pubic bone (approximately 1 cm from the midline, 1 cm above the inferior margin of the pubic bone) linearly to the ischial spine. This thickening has been described as the “arcus tendineus fasciae pelvis,”13 “arcus tendineus telae endopelvinae,”3 or the “fascial white line.”14 In its posterior portion, the arcus tendineus fasciae pelvis blends with the arcus tendineus levatoris ani (“muscle white line”). This common part of the arcus tendineus fasciae pelvis and arcus tendineus levatoris ani inserts into the ischial spine and the adjacent anterior margin of the greater sciatic notch.14,15
The posterior margin of the insertion of the endopelvic fascia into the superior fascia of the levator ani muscle has been described by Leffler et al16 as arcus tendineus fasciae rectovaginalis. The tissue here is not thickened and, thus, not as prominent as in the case of the arcus tendineus fasciae pelvis, but the attachment of the endopelvic fascia to the levator muscle is clearly pronounced (Figs. 3, 4, 5, 6). In the cranial part, the arcus tendineus fasciae rectovaginalis approaches the arcus tendineus fasciae pelvis.
The paired dorsosuperior part of the endopelvic fascia has been traditionally called the uterosacral ligaments and has three different portions:
1. The "vascular" part of the uterosacral ligament: Visceral branches of the internal iliac vessels (hypogastric artery and vein), which run to the rectum, uterus, vagina, and urinary bladder, are surrounded by a sheet of perivascular tissue, which creates a compact mass that is connected to the rest of the endopelvic fascia. This “vascular stalk” lies in front of the sacroiliac joint and medially from the bony margin of the greater sciatic notch. It is not attached to the bone (Fig. 7c).
2. The "neural" part of the uterosacral ligament: The pelvic splanchnic nerves (the “erigent nerves”) proceed from the ventral aspect of the sacral plexus, and together with fibers of inferior hypogastric nerves and fibers from the sympathetic chain, create the neural pelvic plexus (plexus hypogastricus inferior). The perineural connective tissue that arises from the fascia of the piriformis muscle, together with the errigent nerves, creates the “neural portion” of the uterosacral ligament. This stalk lies inferomedially from the “vascular portion” and is also not attached to the bone (Fig. 7b).
3. Sacral bone (true uterosacral ligament): Some fibers insert into the periosteum of the sacral bone, in the vertical line that runs medially from the anterior sacral foramina from S1 to S4. (Fig. 7a). This insertion is shared with the presacral fascia.17
The anterosuperior leaf (pubocervical fascia) and inferoposterior leaf (rectovaginal fascia) of the endopelvic fascia are connected at both sides of the vagina and craniodorsally fade into the cardinal and further uterosacral ligaments (Fig. 3). The vagina is, therefore, circularly surrounded by the endopelvic fascia.
The adventitia of the base of the urinary bladder is connected to the “pubocervical fascia” by the left and right “bladder pillar.” These structures contain terminal branches of the middle and inferior vesical artery. The bladder pillars separate the vesicovaginal space from the left and right paravesical space (Fig. 6).18 The vesicovaginal space is closed from below by tight attachment of the middle urethra to the anterior vaginal wall and from above by the supracervical septum.19
The rectum is wrapped in its fascia (“perirectal fascia” per Jonnesco, 20 and “fascia propria recti” per Waldeyer21). This fascia contains branches of the middle rectal artery, veins, lymph vessels, and nerves, which are all embedded in a variable amount of fatty tissue. The anterior and posterior leaf of the perirectal fascia insert into the inferoposterior aspect of the endopelvic fascia, close to where the endopelvic fascia attaches to the superior fascia of the levator ani muscle, together constituting the so-called “rectal pillars” or “lateral ligaments of rectum.”22 The rectal pillars separate the rectovaginal space from the retrorectal space (Figs. 6, 8). Figures 6 and 8 show the spatial relationship of the prevesical, paravesical, vesicovaginal, rectovaginal, and retrorectal spaces to the endopelvic fascia, bladder pillars, and rectal pillars.
The continuity of the various parts of the suspensory apparatus of the pelvic floor organs has been well known for more than 150 years. However, this reality is often not emphasized enough. For an explanation of this argument, we use the scheme shown in Figure 9. The middle field of the 3×3 grid represents a cross-section of the vagina, and the other eight fields represent the endopelvic fascia, which surrounds the vagina.
The aspect of the fascia facing the urinary bladder is usually called the pubocervical fascia. It inserts into the pubic bone, except for a few millimeters in the midline, and beneath this insertion it fades into the anterior part of the perineal membrane. Laterally, the endopelvic fascia inserts into the superior fascia of the levator ani muscle. The pubocervical fascia is represented by the fields ABC. It is obvious that field A is also part of the right paracolpium, and field C is part of the left paracolpium. The superior part of the pubocervical fascia fades into the cardinal ligaments, and these further fade into the uterosacral ligaments. This continuity from the pubic bone to the sacral bone was expressed by Holl, 23 who termed the endopelvic fascia the “pubosacral fascia.” The attachment of the pubocervical fascia to the pubic bone was described as the “pubovesical ligaments,”24,25 “pars pubica of the pubosacral fascia,”23 “female puboprostatic ligaments,”26 and “pubourethral ligaments.” Later, Zacharin27 concluded that all theses terms describe the same structure and subsequently referred to them as “posterior pubourethral ligaments.”
The aspect of the endopelvic fascia facing the rectum is typically called the rectovaginal fascia. It fades into the perineal body inferiorly and inserts into the superior fascia of the levator ani laterally. The superior part of the pubocervical fascia fades into the cardinal ligaments, and these further fade into the uterosacral ligaments. The rectovaginal fascia is represented by the fields “QPR.” It is clear that field Q is part of the right paracolpium and that field R is part of the left paracolpium. The rectovaginal fascia is thickest in the region of transition to the perineal body, but it thins cranially.
The paracolpia are located laterally to the vagina. In the scheme depicted in Figure 9, the right and left paracolpia are represented by the fields AXQ and CYR, respectively. The paracolpia in the region of distal vagina are very short (Luschka fibers). In microscopic specimens in the region of the anterior vaginal sulcus, the lamina muscularis vaginae nearly reaches the muscle fibers of the levator ani muscle (“vaginolevator attachment,” per DeLancey).28 Macroscopically, during dissection the tissue of the lower paracolpia is well pronounced (“hiatal ligament” per Shafik,29 “thick levator fascia” per Krantz26). The length of the paracolpia increases with increasing distance of the vagina from the superior surface of the levator muscle. The upper paracolpia fade into the cardinal ligaments (“ligamentum uteri laterale” per Kocks,30 “ligamentum cardinale” per Mackenrodt31), and these run into the uterosacral ligaments.32
The scheme shown in Figure 9 is not valid for the most distal part of the vagina. The vagina in this region is not surrounded by the endopelvic fascia but does run through the perineal membrane.1
It is important for surgeons working in the paravesical spaces to fully understand the relationship of the most prominent landmark of this region—the arcus tendineus fasciae pelvis—to the margin of the levator muscle—the arcus tendineus levatoris ani. The arcus tendineus levatoris ani represents the upper margin of the aponeurosis of the iliococcygeus muscle. This aponeurosis is composed of the degenerated upper part of the iliococcygeus muscle and its investing fasciae.33,34 During phylogeny of this muscle, there is descent of its origin on the lateral wall of the pelvic cavity from the ilio-pectineal line to the fascia obturatoria. In the dorsal portion, the aponeurosis inserts into the ischial spine and into the neighboring anterior margin of the greater sciatic notch (Figs. 3 and 4).35 The line of attachment of the aponeurosis of the levator ani may assume any position between the pelvic brim and a horizontal line drawn through the ischial spine to the back of the body of the pubis.14 This observation, together with many unrecognized obstetric tears, accounts for great variability in the level of insertion seen in dissection and during surgical repair.
There is an anatomical concept supported by the Federative Committee on Anatomic Terminology that the pelvic floor is covered by parietal fascia and that the visceral fascia is reflected from this parietal fascia upward upon the viscera.2,14,36 However, the manner of reflection of the fascia on the vagina and cervix is very different from that of the rectum and urinary bladder. Endopelvic fascia surrounds the vagina and cervix and is connected to the adventitia of the base of the urinary bladder by bladder pillars (Fig. 6). The urinary bladder itself is not wrapped by fibrous tissue of the same quality that surrounds the vagina. This would significantly interfere with its storage function. Even more pronounced is this arrangement of the rectum. The rectum is connected to the endopelvic fascia by distal parts of the rectal pillars, which are composed of the lateral anterior and posterior leaf of the perirectal fascia. In contrast to the bladder pillars, they contain fatty tissue except for the most distal and lateral parts (Figs. 6 and 8).
The embryonic origin of the endopelvic fascia remains an interesting question. The endopelvic fascia divides the lesser pelvis in much the same fashion as the urorectal septum divides the embryonic cloaca. It is possible that the vagina stems from break-up of the vaginal bud, which grows within the urorectal septum. This would explain why the vagina is surrounded by the endopelvic fascia, while the urinary bladder and rectum are not. Thus far, the remnants of the urorectal septum have been considered to comprise only the perineal body.37 It seems more probable that the perineal body originates from the complex of the cloacal membrane and the cloacal sphincter, together with the perineal membrane, external urethral sphincter, external anal sphincter, and anococcygeal ligament.
The endopelvic fascia does not contain any fatty tissue.38 Only in the region of the uterosacral ligament do the strands of fibrous tissue run in a fan-like shape in a large area through the subperitoneal adipose tissue. There is a variable amount of fatty tissue outside the adventitia of the urinary bladder and rectum.
The density and stronghold of the endopelvic fascia is not uniform in all regions. The tissue density increases in the craniocaudal direction. The tissue is strongest and most dense, and its surface is best defined in the region of the distal pubocervical and distal rectovaginal fascia. In contrast, in the region of the uterosacral ligament, the strands of fibrous tissue are fine and scattered in the surrounding subperitoneal fat. Furthermore, there is a plexiform crossover of the vessels and nerves of individual organs in this region. In the distal part of the fascia, the vessels and nerves for the vagina, bladder base, and urethra run in a parallel fashion along the edge of the vagina.
The term “endopelvic fascia” is widely used by clinicians as described above but is not accepted by anatomists. According to current anatomical nomenclature, the described “endopelvic fascia” is part of the visceral pelvic fascia (fascia pelvis visceralis). The term “endopelvic fascia” is reserved for the parietal pelvic fascia (fascia pelvis parietalis).36 In this anatomical concept, the visceral pelvic fascia is further subdivided according to the organ that it covers. There is agreement that the composition of the fascia pelvis visceralis is much different from what “fascia” generally means, the cover of skeletal muscle. The differences in quality and function of the tissue are not addressed. This theoretical framework is too general and does not provide enough detail needed for clinical applications.39
Because of the similarity between the “endopelvic fascia” described above and the embryonic urorectal septum, this structure might be hereafter named “the pelvic septum” (Fig. 4). Its composition fulfills what is accepted as the “septum,” rather than what is accepted as the “fascia.” This would allow us to differentiate this tissue from the loose areolar tissue that surrounds the rectum and the vertex of the urinary bladder and is also complementary to the widely accepted description of the parietal pelvic fascia and its components: the obturator fascia, the piriformis fascia, and the superior fascia of the pelvic diaphragm.
This study has several limitations. First, the accuracy of the model is limited. Artifacts can occur in how the computer connects the outlines made in different cross-sections; the decision about where to trace the outlines requires judgment and some preconceived notions of anatomy. Second, the cadaver specimens are heterogeneous in terms of age and cause of death. The information regarding pelvic floor dysfunction prior to death is missing. Third, the three-dimensional illustration had to be prepared so that the posterior aspect of the pubic bone and the anterior aspect of the sacral bone are visible in a single image (Fig. 3). This is not possible in a real specimen, and some deformation, therefore, had to be applied.
As a result, this study avoids the description of artificially isolated parts of the fascia as separate structures due to the dissectability of the tissue. Instead, we emphasize the three-dimensional representation of the whole structure, allowing us to describe the entity as a system rather than describing components of the fascia as single ligaments. The majority of clinical terms can be recognized within this concept.
1. DeLancey JOL. Anatomic aspects of vaginal eversion after hysterectomy. Am J Obstet Gynecol 1992;166:1717–28.
2. Curtis AH, Anson BJ, McVay CB. The anatomy of the pelvic and urogenital diaphragms, in relation to urethrocele and cystocele. Surg Gynecol Obstet 1939;68:161–6.
3. Halban J, Tandler J. Anatomie und ätiologie der genitalprolapse beim weibe. Wien und Leipzig: Wilhelm Braunmüller; 1907.
4. Berglas B, Rubin IC. Histologic study of the pelvic connective tissue. Surg Gynecol Obstet 1953;97:277–89.
5. Smith WC. The levator ani muscle: its structure in man, and its comparative relationships. Anat Rec 1923;26:175–203.
6. Kearney R, Sawhney R, DeLancey JOL. Levator ani muscle anatomy evaluated by origin-insertion pairs. Obstet Gynecol 2004;104:168–73.
7. Abrams P, Cardozo L, Fall M, Griffiths D, Rosier P, Ulmsten U, et al. The standardisation of terminology of lower urinary tract function: report from the Standardisation Sub-committee of the International Continence Society. Standardization report. Am J Obstet Gynecol 2002;187:116–26.
8. Otcenasek M, Krofta L, Baca V, Grill R, Kucera E, Herman H, et al. Bilateral avulsion of the puborectal muscle: Magnetic resonance imaging-based three-dimensional reconstruction and comparison with a model of a healthy nulliparous woman. Ultrasound Obstet Gynecol 2007;29:692–6.
9. Thiel W. The preservation of the whole corpse with natural color [in German]. Ann Anat 1992;174:185–95.
10. Mengert WF. Mechanics of uterine support and position. Am J Obstet Gynecol 1936;31:775–82.
11. DeLancey JOL. Structural anatomy of the posterior pelvic compartment as it relates to rectocele. Am J Obstet Gynecol 1999;180:815–23.
12. Oelrich TM. The striated urogenital sphincter muscle in the female. Anat Rec 1983;205:223–32.
13. DeLancey JO, Starr RA. Histology of the connection between the vagina and levator ani muscles: implications for urinary tract function. J Reprod Med 1990;35:765–71.
14. Thompson P. On the arrangement of the fasciae of the pelvis and their relationship to the levator ani. J Anat Physiol 1901;35:127–50.
15. Cameron J. The fascia of the perineum and the pelvis of the female with special reference to. the mechanical supports of the pelvic viscera. J Anat Physiol 1908;42:438–55.
16. Leffler KS, Thompson JR, Cundiff GW, Buller JL, Burrows MD, Schon Ybarra MA. Attachment of the rectovaginal septum to the pelvic sidewall. Am J Obstet Gynecol 2001;185:41–3.
17. Buller JL, Thompson JR, Cundiff GW, Krueger Sullivan L, Schon Ybarra MA, Bent AE. Uterosacral ligament: description of anatomic relationships to optimize surgical safety. Obstet Gynecol 2001;97:873–8.
18. Uhlenhuth E, Nolley GW. Vaginal fascia, a myth? Obstet Gynecol 1957;10:349–58.
19. von Peham H, Amreich J. Gynäkologische Operationslehre. Berlin/Basel: Verlag S. Karger; 1930.
20. Jonnesco T. Appareil digestif. In: Poirier P, Charpy A, editors. Traité dánatomie humaine. Volume IV. 2nd ed. Paris, France: Masson et Cie; 1901. p. 372–3.
21. Waldeyer W. Das Becken. Bonn: Cohen; 1899.
22. Chapuis P, Bokey L, Fahrer M, Sinclair G, Bogduk N. Mobilization of the rectum: anatomic concepts and the bookshelf revisited. Dis Colon Rectum 2002;45:1–9.
23. Holl M. Die muskeln im beckenausgange des menschen. Ergeb Anat Entwickelungsgesch 1901;11:1115–73.
24. Todd R. The Cyclopaedia of anatomy and physiology. Vol IV. London: Longmans; 1852.
25. Poirier P, Charpy A. Traite dÁnatomie Humaine. 4th ed. Paris: Masson et Cie; 1931.
26. Krantz KE. The anatomy of the urethra and anterior vaginal wall. Am J Obstet Gynecol 1951;62:374–86.
27. Zacharin RF. The suspensory mechanism of the female urethra. J Anat 1963;97:423–27.
28. DeLancey JO. Correlative study of paraurethral anatomy. Obstet Gynecol 1986;68:91–7.
29. 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;13:175–82.
30. Kocks J. Normale und pathologische lage und gestalt des uterus sowie deren mechanik. Bonn: Cohen; 1880.
31. Mackenrodt A. Über die ursachen der normalen und pathologischen lage des uterus. Arch Gynecol Obstet 1895;48:393–421.
32. Campbell RM. The anatomy and histology of the sacrouterine ligaments. Am J Obstet Gynecol 1950;59:1–12.
33. Dickinson RL. Studies of the levator ani muscle. Am J Dis Women 1889;22:897–917.
34. Derry DE. Pelvic muscles and fasciae. J Anat Physiol 1907;10:107–11.
35. Smith GE. Studies in the anatomy of the pelvis, with special reference to the fasciae and visceral supports. J Anat Physiol 1908;42:198–218.
36. Federative Committee on Anatomical Terminology (FCAT). Terminologia anatomica. New York (NY): Thieme Stuttgart; 1998.
37. DeLancey JO. Anatomy and embryology of the lower urinary tract. Obstet Gynecol Clin North Am 1989;16:717–31.
38. Fothergill WE. The supports of the pelvic viscera: a review of some recent contributions to pelvic anatomy, with a clinical introduction. Int J Obstet Gynecol 1908;13:18–28.
39. Ercoli A, Delmas V, Fanfani F, Gadonneix P, Ceccaroni M, Fagotti A, et al. Terminologia Anatomica versus unofficial descriptions and nomenclature of the fasciae and ligaments of the female pelvis: a dissection-based comparative study. Am J Obstet Gynecol 2005;193:1565–73.
© 2008 The American College of Obstetricians and Gynecologists
Figure. No caption available.