The muscles of the pelvic floor and the connective tissue of pelvis, including pelvic fascia, provide stability to the pelvic floor and are essential for the support of pelvic viscera. The visceral layer of pelvic fascia and parametrium becomes condensed around the uterus to form primary support of uterus in the form of true ligaments. These are pubocervical ligament anteriorly, cardinal ligament laterally, uterosacral ligament posteriorly, and round ligament. Cardinal ligament and the uterosacral ligaments provide apical support for the uterus and upper vagina.[1] The cardinal ligament is a paired thickening of the parametrium and pelvic fascia at the base of the broad ligament, which extends between the cervix and vaginal fornix medially to the sidewall of pelvis laterally. It is composed of loose areolar connective tissue surrounded by blood vessels, nerves, and lymphatics.[2] As per Terminologia Anatomica, the cardinal ligament has the name parametrium or paracervix; however, Mackenrodt ligament, transverse cervical ligament, lateral cervical ligament, paracervical ligament, retinaculum uteri sustentaculum of Bonny or the web are the other terms also used for it.[3]
Peritoneal folds related to the uterus form less important secondary support of uterus in the form of peritoneal ligaments. These are uterovesical fold (anterior ligament) anteriorly, rectouterine fold (posterior ligament) posteriorly, and broad ligament laterally.
Macroscopic Structure
The cardinal ligament is the bilateral fan-shaped condensation of the parametrium and endopelvic fascia at the base of the broad ligament with following attachments
From its medial attachment, it runs posterolaterally, and near the pelvic wall, it spreads out in a fan-shaped manner in the transverse plane.
Sections
The total average length of the cardinal ligament is around 10 cm, which is divisible into the following three sections.
According to Tauchi, the cardinal ligament divides in a Y-shaped manner at about the middle of the proximal and distal attachments into two parts (branches).[7] One branch which is composed of nerve fibers and the veins returning from the post-lateral wall of the bladder is the vesical branch of the cardinal ligament, and the other branch which is composed of nerve fibers and the veins returning from the uterine cervix is the cervical branch of the cardinal ligament).
Subdivisions and Contents
The cardinal ligament is divisible into two parts: (a) the cranial or superficial vascular part which chiefly contains vessels, and the (b) the caudal or deep neural part which contains inferior hypogastric plexus nerves.[8][9][10]
The passage of the ureter in the intermediate section divides cardinal ligament into two parts. Tissues that are situated and cross cranially over the ureter are categorized with the parametrium, and the tissues that are situated and cross underneath to the ureter categorize along with the paracervix. The former was considered to be corresponding to the cranial portion of the cardinal ligament, whereas the latter was considered to be corresponding to the caudal portion of the cardinal ligament.[4]
(a) Vascular part (the cranial portion of cardinal ligament, parametrium): It is an extension of the perivascular sheath of internal iliac vessel branches going to the genital tract which contains - internal iliac artery, uterine artery and vein, vaginal artery, vesical artery, smooth muscle, connective tissue, lymph nodes, and adipose tissue.[4]
(b) Neural part (the caudal portion of cardinal ligament, paracervix): the neural section is an extension of the inferior hypogastric plexus. It contains autonomous nerve fibers, hypogastric nerve, extensions of inferior hypogastric plexus (pelvic plexus), and Vessels.[4]
Microscopic Structure
According to Range et al., microscopically, the cardinal ligament is chiefly made up of blood vessels (mainly veins), nerves originating from the inferior hypogastric plexus, lymphatic vessels, and the surrounding loose areolar connective tissue.[2] It contains a network of collagen fibers and few isolated elastic fibers with numerous cellular elements, particularly fibroblasts. They determined that it was not a ligament in the sense of a separate thickening of connective tissue. The cardinal ligaments of women with a prolapsed uterus showed a higher expression of collagen III and tenascin and lower quantities of elastin.[11] Altered connective tissue distribution in the cardinal ligaments with fewer and thinner collagen fibers have been reported in women with prolapse of the pelvic organ.[12]
Functions
In the standing position, the cardinal ligament has a vertical orientation while the uterosacral ligaments are dorsally oriented, and together they provide apical support for the uterus and vagina.[13] It gives hammock-like support to the uterus that holds the cervix in position and prevents its downward displacement through the vagina.
The lateral cervical ligament appears during the tenth week of intrauterine life.[14]
The cardinal ligament is one of the pedicles the surgeon must secure during a hysterectomy. Due to the absence of basic neurovascular structure, the first pedicle of transvaginal hysterectomy involves a distal section of cardinal ligament along with the uterosacral ligament (CUSC). The presence of ureter and other neural and vascular structures make the intermediate section unsuitable for surgical use.[6] During a vaginal hysterectomy, the traction and cutting of the cardinal ligaments will lead to the movement of ureter out of the operative field. This action guards the ureter against possible iatrogenic injury.[5] After a hysterectomy, suspension of the vaginal vault to the cardinal-uterosacral confluence (CUSC) will provide surgical support of the vaginal vault and may reduce the chances of pelvic prolapse.[15]
Lymphatic vessels and lymph nodes in cardinal ligaments may be involved in cervical cancer even up to the most lateral region near the pelvic sidewall. So in this condition, extensive resection of the cardinal ligament is a must to ensure a disease-free state.[16]
[1] | DeLancey JO, Anatomic aspects of vaginal eversion after hysterectomy. American journal of obstetrics and gynecology. 1992 Jun; [PubMed PMID: 1615980] |
[2] | RANGE RL,WOODBURNE RT, THE GROSS AND MICROSCOPIC ANATOMY OF THE TRANSVERSE CERVICAL LIGAMENT. American journal of obstetrics and gynecology. 1964 Oct 15; [PubMed PMID: 14217646] |
[3] | Ercoli A,Delmas V,Fanfani F,Gadonneix P,Ceccaroni M,Fagotti A,Mancuso S,Scambia G, Terminologia Anatomica versus unofficial descriptions and nomenclature of the fasciae and ligaments of the female pelvis: a dissection-based comparative study. American journal of obstetrics and gynecology. 2005 Oct; [PubMed PMID: 16202758] |
[4] | Ramanah R,Berger MB,Parratte BM,DeLancey JO, Anatomy and histology of apical support: a literature review concerning cardinal and uterosacral ligaments. International urogynecology journal. 2012 Nov; [PubMed PMID: 22618209] |
[5] | Cruikshank SH,Kovac SR, Role of the uterosacral-cardinal ligament complex in protecting the ureter during vaginal hysterectomy. International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics. 1993 Feb; [PubMed PMID: 8094684] |
[6] | Samaan A,Vu D,Haylen BT,Tse K, Cardinal ligament surgical anatomy: cardinal points at hysterectomy. International urogynecology journal. 2014 Feb; [PubMed PMID: 24170225] |
[7] | Tauchi K, [Studies on preservation of the vesical branch of the cardinal ligament in total hysterectomy for malignant uterine tumors]. Nihon Gan Chiryo Gakkai shi. 1989 Jul 20; [PubMed PMID: 2809376] |
[8] | Yabuki Y,Sasaki H,Hatakeyama N,Murakami G, Discrepancies between classic anatomy and modern gynecologic surgery on pelvic connective tissue structure: harmonization of those concepts by collaborative cadaver dissection. American journal of obstetrics and gynecology. 2005 Jul; [PubMed PMID: 16021052] |
[9] | Kato T,Murakami G,Yabuki Y, Does the cardinal ligament of the uterus contain a nerve that should be preserved in radical hysterectomy? Anatomical science international. 2002 Sep; [PubMed PMID: 12422408] |
[10] | Kato T,Murakami G,Yabuki Y, A new perspective on nerve-sparing radical hysterectomy: nerve topography and over-preservation of the cardinal ligament. Japanese journal of clinical oncology. 2003 Nov; [PubMed PMID: 14711985] |
[11] | Ewies AA,Al-Azzawi F,Thompson J, Changes in extracellular matrix proteins in the cardinal ligaments of post-menopausal women with or without prolapse: a computerized immunohistomorphometric analysis. Human reproduction (Oxford, England). 2003 Oct; [PubMed PMID: 14507843] |
[12] | Eid S,Iwanaga J,Oskouian RJ,Loukas M,Tubbs RS, Comprehensive Review of the Cardinal Ligament. Cureus. 2018 Jun 20; [PubMed PMID: 30140597] |
[13] | Chen L,Ramanah R,Hsu Y,Ashton-Miller JA,Delancey JO, Cardinal and deep uterosacral ligament lines of action: MRI based 3D technique development and preliminary findings in normal women. International urogynecology journal. 2013 Jan; [PubMed PMID: 22618207] |
[14] | Pietryga E,Woźniak W, The development of the uterine ligaments in human fetuses. Folia morphologica. 1992; [PubMed PMID: 1478574] |
[15] | Sloth SB,Schroll JB,Settnes A,Gimbel H,Rudnicki M,Topsoee MF,Joergensen A,Nortvig H,Moeller C, Systematic review of the limited evidence for different surgical techniques at benign hysterectomy: A clinical guideline initiated by the Danish Health Authority. European journal of obstetrics, gynecology, and reproductive biology. 2017 Sep; [PubMed PMID: 28779691] |
[16] | Girardi F,Lichtenegger W,Tamussino K,Haas J, The importance of parametrial lymph nodes in the treatment of cervical cancer. Gynecologic oncology. 1989 Aug; [PubMed PMID: 2753426] |