The success of NDVH surgery with confidence much depends on perfect knowledge of pelvic anatomy.
The pelvic visceras are connected to the lateral pelvic wall by their adventitial layers and thickening of the connective tissue that lie over the pelvic wall muscles.
The term ligament is most familiar when it describes a dense connective tissue band ridges in the peritoneum or thickening of endopelvic fascia.
Those attachments separate the different surgical cleavage planes from one another.
UTERINE LIGAMENTS
Broad Ligaments
Broad ligaments are peritoneal fold that extend laterally from the uterus and adnexal structures. Broad ligaments have got four parts.
- Mesovarium also known as ovarian mesentery. It is a fold of peritoneum which attaches the ovary with posterior layer of the broad ligament. Through this fold, ovarian vessels, nerves and lymphatics enter and leave the helum.
- Mesosalpinx is the part of broad ligament between fallopian tube and the level of attachment of the ovary. It contains utero-ovarian anastomotic vessels and vestigial remnants duct of Gartner, epoophoron and paroophoron.
- Mesomentrium is the part of broad ligaments lying below the Mesosalpinx. It is the longest portion which is related with the lateral border of uterus.
Mackenrodt's (MK) Ligament
It is also known as cardinal or transverse cervical ligaments. They are paired, bulkly, ill defined mass of fibrous tissue containing smooth muscles located on either side of cervix.
It is situated inferior to uterosacral ligament with which it is blended to the ring of endopelvic fascia surrounding the cervix. Near the cervix, it is related to uterine vessels and nerves.
Uterosacral (US) Ligaments
It is often called suspensory ligaments of the uterus. They lie on the either side of pouch of Douglas. These ligaments hold cervix posteriorly in the pelvis over the levator plate of the pelvic diaphragm.
Round Ligaments
These are paired 10–12 cm long ligaments on each side of uterus. It is attached at the cornu of the uterus, below and in front of fallopian tubes. It contains plain muscle and connective tissue. While it is not related to maintain the uterus in to anteverted position in full length. But shortning of this ligament to less than 6 cm makes the uterus anteverted.
Ovarian Ligaments
These are paired, one on each side. They are fibro muscular cord like structure which attaches to the inner pole of the ovary and to the cornu of the uterus posteriorly below the level of the attachment of the fallopian tube. Morphologically it is continues with the round ligament.
VAGINAL FASCIAE AND ATTACHMENT
The upper one-third of vagina is suspended within the pelvis by the downward extension of the cardinal ligaments.
Anterior to the vagina in this area is the vesico vaginal space. Posterior to it is cul-de-sac.
The middle third of the vagina develops significant lateral and posterior attachment to the pelvic wall at the arcus tendicus fasciae pelvis, separate from the cardinal ligaments. This forms the lateral attachments and suspends the anterior vaginal wall across the pelvis.
These lateral attachments together with connective tissue of the anterior walls adventitial form a sheet of 6tissue in the area called the Pubocervical fascia which is surgically a useful structure.
Posterolaterally, the vagina is attached to the parietal fascia of Denonvilliers. Its distal attachments to the perineal body plays a vital role in supporting the introitus. It is attached to posterior vaginal wall and lies anterior to the rectovaginal space.
The lower one third of vagina is firmly attached anteriorly to the pubic bones by perineal membranes. Posteriorly it fuses with the perineal body. Lateraly it adheres to medical border of levator ani musicles.
CLEAVAGE PLANES AND SPACES
Each of the pelvic viscera can expand, independently of its neighboring organs. This is due to their relatively loose attachments to one another.
This allows viscera to be easily separated from adjacent organs. These surgical cleavages are known as “spaces” and are filled with fatty or areolar connective tissue.
Vesicovaginal and Vesicocervical Spaces
The space between the lower urinary tract and the genital tract is separated into vesicovaginal and vesicocervical spaces by a thin septum known as supravaginal septum. The lower extent of the space is the junction of the proximal one third and lateral two thirds of the urethra, where it fuses with the vagina and extends under the peritoneum at the vesicocervical peritoneal reflection. There is a dense connective tissue at the point from the vesicle fascia near bladder base to cervical fascia transferring to vaginal fascia where loose anterior vaginal wall becomes adherent to anterior lip of cervix. This vesicocervical band is also called vesicocervical ligament.
This needs sharp dissection to enter vesicovaginal space leading to peritoneal reflection.
Rectovaginal Space
On the dorsal surface of the vagina lies the rectovaginal space. It begins at the apex of the perineal body and extends upward to the cul-de-sac and laterally around the sides of rectum and attaching to rectovaginal septum and parietal endopelvic fascia. It is easily opened by sharp or finger dissection as it contains loose areolar tissue.