The current generation of women is maintaining a more active lifestyle into an older age, resulting in an increase in the number of women who seek treatment for prolapse conditions. Consequently, an increased need for expertise in the diagnosis and treatment of these conditions is likely. An active lifestyle and improved quality of life can usually be preserved; however, this requires a thorough understanding of pelvic anatomy and pathophysiology and experience in selecting appropriate surgical procedures.

Problem:
A relaxed vaginal outlet can be defined as the relaxation of the tissues of the distal rectovaginal septum and perineal body. Common symptoms include difficulty with defecation and, possibly, sexual dysfunction.

Etiology:
The main support for the pelvic viscera is provided by a group of muscles collectively called the levator ani. An intact pelvic floor allows the pelvic and abdominal viscera to "rest" on the levator ani, significantly reducing the tension on the supporting fascia and ligaments. These pelvic ligaments are not true ligaments and are simply condensations of endopelvic fascia covering the pelvic structures.

The pelvic floor musculature and the pelvic ligaments work together to provide support to the pelvic floor structures. Most of the weight of the pelvic viscera is supported by the levator ani, whereas the pelvic ligaments stabilize these structures in position, much as a ship's weight is supported by the water and the moorings simply keep the ship from straying from the dock. When the levator ani is damaged, excessive force is placed on the ligaments, creating a predisposition for pelvic prolapse.

Pathophysiology:
Conditions of vaginal prolapse, including urethral hypermobility, cystocele, rectocele, enterocele, perineal relaxation, and uterine prolapse, all result from weakness or damage to the normal pelvic support systems. Collectively, these conditions are called pelvic floor relaxation.

The pathophysiology of this relaxation can often be linked to multiparity, advanced age, hormonal insufficiency, obesity, neurogenic dysfunction of the pelvic floor, connective tissue abnormalities, or strenuous physical activity. However, pelvic relaxation can occur in young, inactive, nulliparous patients; therefore, a single etiology can rarely be implicated.

More recently, an association between collagen and connective tissue disorders and pelvic floor relaxation has been established. Some vaginal prolapse conditions may even be caused by prior pelvic surgery. For example, a hysterectomy may cause an enterocele or vault prolapse to form if the vault is not adequately resuspended and the cul-de-sac is not prophylactically obliterated. A bladder neck suspension can alter the vaginal axis, predisposing the patient to enterocele formation.

A rectocele is a prolapse of the rectum into the vagina through a damaged rectovaginal septum. The most likely etiology for rectocele formation and perineal relaxation presumably is childbirth because these conditions are essentially confined to parous women. In some cases, a relaxed outlet may be caused by an inadequately or incompletely healed episiotomy performed at the time of childbirth.

The most important fascia within the rectovaginal septum is Denonvilliers fascia, which is fused to the inner layer of the posterior vaginal wall and is believed to be disrupted at the caudal and lateral attachments at the perineal body during childbirth. In some cases, enterocele and rectocele formation occur simultaneously, especially if the patient had a hysterectomy. Although a high rectocele may be distinguished from an enterocele only at the time of surgery, a rectocele often forms a pocket just proximal to the anal sphincter. This pocket can trap stool and cause the typical symptoms of straining or the need for digital manipulation to facilitate bowel movements.

Perineal body relaxation, a separate and distinct entity from a rectocele, usually manifests as a wide vaginal opening and is usually repaired at the same time as a rectocele. Because the levator ani is attached at the perineal body, strengthening of the perineal body by perineorrhaphy tightens the levator plate, improving the overall degree of pelvic relaxation.

Clinical Presentation:
The most common symptoms of a rectocele and relaxed outlet are constipation, which is nonspecific, and "splinting," which is the need to place fingers on the posterior wall of the vagina to effectively empty the bowels.  Although uncommon, other presenting symptoms may include perineal pain or sexual dysfunction. Conversely, dyspareunia has been reported after surgical repair in as many as 30% of cases; however, the incidence today is less than 10% because the older method of repair is seldom used.

The repair of a relaxed outlet or rectocele is rarely required unless it is large or symptomatic because justifying postoperative dyspareunia to fix a small asymptomatic rectocele or perineal body is difficult. Conversely, some investigators believe that not performing these repairs at the time of an incontinence procedure or hysterectomy may cause undue pressure on other areas of the pelvic floor, possibly necessitating additional surgery at a later date.

Relevant Anatomy:
The vagina can be anatomically divided into the proximal, middle, and distal regions. The proximal segment, called the vault or cuff, is stabilized by the parametrium, which includes the cardinal and uterosacral ligaments. Uterine and vault prolapse are both associated with damage to these supportive structures.

The mid portion of the vagina is attached laterally to the pelvic sidewalls by the lower portion of the paracolpium to the arcus tendineus fascia pelvis (ATFP), which creates the superior lateral vaginal sulcus observed during a physical examination. The pubocervical fascia stretches between the ATFP to support the anterior vaginal wall and bladder. A cystocele can occur when damage to the pubocervical fascia in the central or lateral areas (or both) allows the bladder to prolapse into the vagina.

In a similar fashion, the posterior vaginal wall in the mid vagina is supported centrally and laterally by the rectovaginal fascia, which is attached to the fascia of the levator ani musculature. These attachments prevent the rectum from prolapsing into the vagina and causing a rectocele. The distal vagina is firmly attached to the surrounding structures, including the urethra and symphysis pubis anteriorly, levator ani laterally, and perineal musculature posteriorly. Damage to the perineal musculature by childbirth or surgery are common causes of a relaxed outlet.

Contraindications:
Although no absolute contraindications to performing these procedures exist, they are usually not performed unless the patient is symptomatic. In most cases, these procedures are performed in conjunction with other pelvic prolapse repairs.

Imaging Studies:

• Imaging studies are rarely indicated for pelvic prolapse of any type because the physical examination almost always yields a clear diagnosis, and therapy is seldom altered by additional study findings.
• In the rare instances when multiple prior procedures have been performed and the patient remains symptomatic, a dynamic MRI or defecographic examination may be helpful in diagnosing an occult prolapse defect.
• Unfortunately, radiographic studies (eg, defecography) and measurements of anal and rectal pressures have not been shown to correlate well with the diagnosis of a symptomatic rectocele.

Diagnostic Procedures:

• Physical examination

• A systematic pelvic examination is the best method of diagnosing pelvic prolapse conditions.

• Each section of the vagina (ie, anterior, posterior, lateral, apex) must be separately evaluated to define the character and degree of prolapse.

• The examination should be performed with a moderate amount of urine in the bladder, and the patient must strain forcefully during the procedure. The patient may need to assume the upright position, or straining may need to be maintained for a sufficient period to allow all areas of prolapse to occur. In some cases, a cystocele or rectocele may be easily observed when the patient quickly bears down; however, if this pressure is maintained for only a very short period of time, an enterocele or moderate degrees of vault prolapse may not be appreciated. These provocative maneuvers should reliably reproduce the prolapse and stress incontinence experienced by the patient under normal circumstances.

• The examination should identify all areas with inadequate support, the degree of prolapse present, and possible etiologies for the lack of support.

• A surgical plan should be prepared before going to the operating room; this evaluation cannot be adequately performed under anesthesia because the patient is unable to strain and the pelvic muscles are relaxed.

• The posterior vaginal wall is examined by placing the lower blade of the Graves speculum against the anterior vaginal wall. A bulging of the posterior vaginal wall with straining may indicate an enterocele or a rectocele. Descent of the vaginal wall at the level of the hymen or below is usually a rectocele, whereas prolapse near the apex may be an enterocele. In patients who have had a hysterectomy, descent of the vaginal apex with the patient straining indicates a lack of vault support.

• In most patients, an enterocele coexists with vault prolapse, and each defect requires a separate procedure.

• Lastly, the perineal body, which lies between the vagina and anus, should be evaluated for structural integrity. A lax perineal body is demonstrated during the physical examination as an enlarged introitus.

Surgical therapy: Surgical therapy, including rectocele and perineal body repair, are the mainstays of treatment.

Preoperative details: Typically, the patient is administered enemas the night before the procedure to cleanse the rectum, and preoperative intravenous antibiotics are also given. Generally, if other procedures are to be performed, the rectocele and perineal body repair are performed last because these repairs decrease vaginal exposure.

Intraoperative details: Some investigators place Betadine-soaked rectal packing to assist in the identification of the rectum and to avoid injury. The ultimate size of the vaginal orifice is determined by placing Allis clamps on the inner aspect of the posterior labia and bringing the clamps together. Two fingers should be admitted easily. The skin between the Allis clamps is incised, followed by a triangular skin incision (with the apex pointing toward the anus) on the perineal body. The overlying skin is removed and a midline vaginal incision is made in the rectovaginal space, extending at least 1 cm proximal to the beginning of the rectocele.

The underlying rectum is dissected off the posterior vaginal wall until the medial margins of the pubococcygeus muscle are observed. Starting near the vaginal apex, the pararectal fascia is closed over the rectal wall using absorbable or nonabsorbable 2-0 or 0 sutures in an interrupted fashion, all the way to the perineal body .       

An evaluation after the first few sutures are placed should allow 2 fingers to be admitted easily. If an inadequate vaginal caliber is created, dyspareunia or an inability to engage in sexual intercourse may occur. The sutures are placed sequentially all the way to the perineal body. The perineal body is repaired by placing multiple 0 absorbable sutures deeply into the bulbocavernosus and superficial transverse perineal muscles. Again, 2 fingers should be admitted easily into the vaginal opening. The vaginal mucosa is closed with absorbable suture in a running locking fashion, and the perineal skin is closed subcuticularly. A vaginal pack is placed.

Postoperative details: Patients should maintain a diet that keeps their stools soft, avoid any straining or heavy lifting, and refrain from sexual intercourse for approximately 4-6 weeks to allow complete tissue healing.

Complications are uncommon, with one study reporting a 12.5% incidence of transient urinary retention but no rectal injuries, fecal incontinence, or hemorrhage.

Dyspareunia can also occur after a surgical repair, although this problem appears to be uncommon if a sufficient vaginal caliber is maintained.

The exact incidence of rectal injury is unknown and probably underreported because most can be easily repaired during surgery, without long-term sequelae. A rectovaginal fistula is a rare complication, but one study reported a 5% incidence after posterior pelvic floor repairs.

The long-term results of rectocele and perineal body repairs are unclear because long-term prospective studies have not been performed. Current thinking is that rectoceles and perineal body relaxation rarely recur after a surgical repair.