The uterosacral/lateral cervical ligament complex is the cornerstone of apical support of the uterus, cervix, and upper vagina and is an important element in the prevention of pelvic organ prolapse (POP). Loss of apical support will lead to uterovaginal and vaginal vault prolapse but is also a major etiologic factor in most cystoceles and enteroceles. Assessment and diagnosis of support defects causing POP is necessary prior to surgical treatment. In this chapter, we review the role of the uterosacral-cardinal ligament complex (UCC) in the maintenance of pelvic organ support and their place in the surgical treatment of both uterovaginal and vaginal vault prolapse post hysterectomy.

DeLancey¹ has categorized three levels of support. Level 1 support is the vaginal apex of the cervix and upper vagina by the parametrium and the paracolpium. Level 2 supports the anterior and posterior vaginal walls with the attachments of the endopelvic fascia and vagina to the arcus tendinous fascia pelvis, and level 3 provides the support of the distal vaginal and the perineal body. Denervation and injury to the levator muscles and pelvic ligaments during childbirth together with the secondary aggravating factors of aging and lifestyle factors (e.g., obesity, heavy lifting) frequently result in uterovaginal prolapse later in life.

The pelvic organs are supported to the sacrum and lateral pelvis sidewall of the bony pelvis by the pelvic floor muscles and endopelvic fascial and ligamentous connective tissues. Level 1 support is achieved by the intermingling of the uterosacral ligament (USL) and the cardinal ligament (CL) attaching the cervix and upper vagina to the sacrum and lateral pelvic sidewalls maintaining the vaginal length and the cervix at the level of the ischial spines or above. Vu et al.² described the surgical anatomy; the average total length of the USL is 12 to 13 cm and can be divided into three sections according to thickness and attachments: The distal section, which attaches to the cervix and upper vagina and forms posterior-lateral aspect of the UCC, is about 2 to 3 cm in length and 5 to 20 mm thick. The intermediate portion is thick, well-defined structure that lies medially to the ureter. It is approximately 5 cm in length and 1 to 2 cm wide. The proximal sacral section is approximately 5 to 6 cm in length and has a generally thin and diffuse attachment. Histologically, the USL is composed of fibrous tissue, vessels, nerves, and fatty tissue and vary in composition at the different sections of the ligament. The ligament complex originates from S2 to S4 sacral vertebrae in a fan-shaped area and runs lateral to the rectum and medially to the ureter; it has a superficial component covered by peritoneum and a deep retroperitoneal component. Finally, the USL attaches distally at the posterior-lateral aspect of the cervix and/or the upper vaginal wall where they form an integrated complex with the CL.³ Its relation to the ureter is of a clinical and surgical significance as the distance from the ureter to the USL is greatest at the level of the sacrum (4.1 ± 0.6 cm), 2.3 ± 0.9 cm at the level of the ischial spines, and 0.9 ± 0.4 cm at the level of the cervical internal os.

Anatomically, the ligaments act in unison to provide not only apical support but also the correct vertical orientation of the vagina and uterus and other pelvic viscera (Fig. 47.1). Chen et al.⁴ created 3D models of CL and deep USL from magnetic resonance images to establish ligaments line of action and load sharing to study the mechanisms of apical support. They found that the CL is relatively vertical in the standing position, whereas the deep USL is more dorsally directed. These ligaments and fascia load share with the levator
pelvic floor musculature to provide apical support. The direction and magnitude of pelvic loading to the apex are important factors in the maintenance of support; the tension in these ligaments should be parallel and complementary to the direction of the levator plate (Fig. 47.2). Deviation of the axis by surgery either posteriorly as with sacrospinous suspension or anteriorly as in Burch colposuspension will predispose to development of prolapse in the opposing compartment. This has been known since the time of Victor Bonney. A higher incidence of postoperative compartment after Burch colposuspension compared to midurethral slings has repeatedly been shown.⁵,⁶ The sacrospinous suspension has a high incidence of recurrent cystocele, although there was no difference in anterior wall recurrence between sacrospinous versus USL suspension at 5-year follow-up in the OPTIMAL trial.⁷ A major advantage of using the UCC for apical re-support is to provide the correct alignment is maintained which will protect both the anterior and posterior compartment from developing POP.

The ureters have a close anatomical relationship to the UCC and are at significant risk when surgery is performed in this area for either hysterectomy or uterovaginal suspension procedures. A good understanding of the anatomy together with appropriate intraoperative assessment for ureteric integrity is important for pelvic surgeons performing POP surgery if ureteric injury is to be avoided.

The ureter enters the pelvis as an extraperitoneal structure crossing anterior to the common or external iliac arteries. On the pelvic sidewall, the ureter is anterior to the internal iliac artery and immediately posterior to the ovary in the peritoneum forming the posterior boundary of the ovarian fossa. The fascia of the obturator internus is situated laterally, and the ureter crosses and is medial to the umbilical artery;
the obturator nerve, artery, and vein; and the inferior vesical and middle rectal arteries.

The ureter descends into the pelvis anteriorly and superiorly to the uterosacral/lateral cervical ligament complex (see Fig. 47.1) and continues anteromedially close to the uterine artery, cervix, and vaginal fornices. The uterine artery initially lies lateral to the ureter and runs a short parallel course along the pelvic sidewall. The ureter then travels inferior medially in the broad ligament of the uterus where the uterine artery is anterosuperior for approximately 2.5 cm. The uterine artery crosses the ureter to its medial side to ascend alongside the uterus. The ureter turns anteriorly approximately 2 cm above the vaginal fornix and lateral to the uterine cervix and moves medially before entering the bladder posteriorly. The ureter courses medially for 1.5 cm in the intramural and submucosal segments of the bladder wall before entering the bladder lumen via the ureteric orifices sited at the upper trigone.

The UCC is primarily important not only in uterovaginal support but also in the surgical management of hysterectomy and POP. Knowledge of the anatomy is essential to enable surgeons to perform these procedures safely and effectively. At hysterectomy, clamping and ligation of the UCC is an essential step in the mobilization of the uterus and cervix. Reattachment of the UCC to the vaginal vault is necessary to treat apical prolapse and prevent future vault prolapse whether the hysterectomy is performed vaginally or abdominally. Correcting apical descent during POP surgery for cystocele significantly reduces anterior compartment reoperation rates.⁸ Unfortunately, the UCC reattachment is frequently not performed at the time of hysterectomy and is a major factor in the subsequent development of vaginal vault prolapse.

When the hysterectomy is performed vaginally, an incision is made circumferentially around the cervix to reflect the vagina off the UCC ligaments laterally and the bladder and ureters anteriorly. The bladder and ureters can then be removed from the operative field using a Breisky-Navratil retractor (Fig. 47.3), so dissection of and identification of the UCC is important to prevent ureteric injury and to identify the ligaments for suture placement. By pushing the vaginal tissue laterally, the UCC ligament can be exposed up to its intermediate portion, enabling a higher suspension suture placement.

There is a worldwide trend away from vaginal hysterectomy (VH) to abdominal hysterectomy either by robotic or laparoscopic surgery particularly in the United States, United Kingdom, and other developed countries. The popularity of robotic and laparoscopic surgery among gynecologists is occurring despite the vaginal approach being shown to be a safer and less expensive alternative.⁹ The American College of Obstetricians and Gynecologists¹⁰ in a Committee Opinion stated in 2017 that

Gynecologists may feel more comfortable performing the surgery abdominally because of their training and experience and feel less familiar performing vaginal surgery particularly where the uterus is well supported with little prolapse. However, once the uterosacral cardinal ligament has been exposed and uterus mobilized as described earlier (see Fig. 47.3), VH can be performed without difficulty if there is adequate vaginal access, even in nulliparous women with previous cesarean sections or large uteri. Increasing the VH rate can be achieved by education and reemphasis on the vaginal route.¹¹ In Finland, VH rate was as low as 7% in the 1980s. Following annual meetings on gynecologic surgery where vaginal and laparoscopic surgery were encouraged, and individual training provided, the VH rate increased to 44% in 2006 and the rate of laparoscopic hysterectomy increased from 24% to 36%. Over this time, the complication rates including ureteric injuries decreased.¹²

The aim of surgical repair is to restore the anatomical support while maintaining or restoring normal bowel and bladder functions and maintaining normal sexual and reproductive function if desired. Surgery is an effective treatment for POP but has operative morbidity and a recurrence rate. The risks of surgery will vary with the type of operation performed and experience of the surgeon. Surgical selection should be based on what suits the needs of the patient best: what is the most effective and safest way to surgically correct her POP. The operation and its benefits and risks to the patient should be discussed and then a joint decision made on what operation is to be performed.

In the first instance, the decision whether to operate or not should be based on the patient’s symptoms, degree of bother, and her medical health. Symptoms should correlate with the examination findings of the site of prolapse and its severity. Women with marked apical loss of support with uterocervical or vaginal vault prolapse will frequently have associated cystocele and/or enterocele; the options are whether to repair this vaginally or abdominally, and if abdominally by an open, laparoscopic, or a robotic procedure. There are advantages and disadvantages of all techniques, and the decision should be based on the patient’s needs. Relevant clinical factors in making this decision are the patient age and general health, whether further pregnancies are desired, the need for sexual activity, presence of dyspareunia, and vaginal length. The abdominal approach will be preferable in the presence of other abdominal pathology requiring treatment such as an ovarian cyst or when vaginal capacity is already reduced from previous surgery in a sexually active woman. However, the vaginal approach may be preferable in the presence of severe pelvic adhesions, which increase the difficulty and risk of the abdominal approach. The risk of recurrence may influence the decision in favor of the abdominal approach and the use of synthetic mesh. Finally, the surgeon’s training and experience will have an influence on the surgical choice so that the procedure can be completed. Preoperative and postoperative assessment should identify the support defects and surgical repair to the defects to minimize the surgery and therefore morbidity. Solitary rectoceles, enteroceles or cystocele where the vaginal vault is well supported do not need apical support operations, either vaginally or abdominally. Placement of synthetic mesh placed abdominally over the anterior, apical and posterior walls is unnecessary where apical support is good and increases morbidity.