Rectocele

Etiology

The posterior vaginal wall is supported by uterosacral ligament complex superiorly, levator ani muscles in the middle, and by the endopelvic fascia in the lower segments. The rectovaginal septum is attached to the endopelvic fascia at the level of the perineal body and runs between the vagina and rectum. The loss of integrity in this septum would result in a herniation of the rectal tissue into the vaginal lumen resulting in a vaginal bulge on examination. Many factors play a role in the loss of integrity of the rectovaginal septum, including non-modifiable and modifiable factors.[7]

Non-modifiable risk factors: e.g., advanced age and genetics.

Modifiable risk factors: These include greater parity, history of vaginal delivery, history of pelvic surgery, obesity, level of education, constipation, and conditions that increase intra-abdominal pressure chronically such as COPD or a chronic cough.

Age, BMI, parity, and vaginal delivery are the most well-documented risk factors.[8][9]

Epidemiology

The incidence and prevalence of all pelvic organ prolapse are unknown because many patients are asymptomatic and do not seek out medical care for their prolapse. Another reason for unknown prevalence is the lack of a comprehensive classification system for rectoceles. For pelvic organ prolapse in general, the incidence is around 67% of parous women.[2] About 11.1% of women by the age of 80 years have undergone surgical intervention for pelvic organ prolapse.[10]

Pathophysiology

A rectocele occurs when healthy rectovaginal septal tissue loses integrity, and the rectum herniates through into the vaginal lumen. Loss of integrity can happen in a variety of ways, including childbirth, age-related connective tissue changes, and increased stress on the tissue through straining or obesity. A patient may have one or many of these issues, as they can be additive.[11] The most common findings of rectocele when symptomatic are a vaginal bulge from the herniation of tissue, pelvic pressure, and changes in defecation.

History and Physical

History:

Rectoceles have a broad range of symptoms. Some patients may present as asymptomatic while others may demonstrate a significant impact on the quality of life, including the following symptoms[3]:

• Pelvic pain/pressure
• Posterior vaginal bulge
• Obstructive defecation
• Incomplete defecation
• Constipation
• Dyspareunia
• Erosions and bleeding of mucosa if there is tissue exposure to the outside environment

Physical Exam:

A thorough examination will include a vaginal exam, rectal exam, abdominal exam, and focused neurological exam. 

The focused neurological exam consists of levator ani muscle tone and contraction strength.

The vaginal exam can be evaluated using the Baden-Walker or POP-Q exam. The Baden-Walker system utilizes one measurement. The distance of the most distal portion of the prolapse from the hymen while the patient is completing the Valsalva maneuver.[12] The grades are:

•  Grade 0 - normal position
•  Grade 1 - Descent halfway to the hymen
•  Grade 2 - Descent to the hymen
•  Grade 3 - Descent halfway past the hymen
•  Grade 4 - Descent is as far as possible past the hymen

The POP-Q system involves taking several measurements and is more complex, but it is highly reliable. The posterior points Ap and Bp are the measurements needed to determine the severity of the rectocele.[13]

• TVL: total vaginal length after reducing the prolapse
• Gh: Genital hiatus length
• Pb: perineal body length
• Ap: A Point on the posterior vaginal wall that is 3 cm proximal to the hymen
• Bp: A point that is the most distal position of the remaining upper posterior vaginal wall
• C: Cervical depth
• D: Posterior fornix depth (only in patients with a uterus)
• Aa: anterior point analogous to Ap
• Ba: anterior point analogous to Bp

These points are measured while the patient is performing the Valsalva maneuver. The range of values for the Ap and Bp points, which are important for rectocele measurement, is -3 cm to +3 cm for the Ap point and -3cm to +tvl length in the Bp point. The POP-Q staging criteria are[13]:

• Stage 0: Ap, Bp at the leading edge (X) = -3 cm
• Stage I: X less than -1 cm
• Stage II: -1 cm less than X less than +1 cm
• Stage III: +1 cm less than X less than +(TVL-2) cm
• Stage IV: X greater than +(TVL-2) cm

Evaluation

Evaluation of a rectocele is determined mainly by the clinical exam. Other laboratory tests and radiographic tests are generally not necessary.

A special test that can be done to confirm a rectocele is defecography. The patient will have contrast medium instilled in the vagina, bladder, and rectum. Using a special commode, the patient will be instructed to defecate while the X-ray is taken. This test can be useful to determine the size of the rectocele, larger than 2 cm is considered abnormal.[14]

Urodynamic studies can be helpful in patients with rectocele and complex voiding issues. If a patient is receiving surgery, it may be useful to determine if the patient has urinary incontinence with the prolapse reduced. If there is incontinence with reduction with prolapse, it may be helpful to include a procedure to prevent urinary incontinence in the plan.[15]

Another useful diagnostic tool for surgical planning is dynamic MRI (DMRI) which provides visualization of the rectocele and movements of the pelvic floor.[11] DMRI is a valuable adjunct test when a patient's symptoms are more significant than the physical examination findings suggest. Its use for preoperative planning has made it more widespread.[16]

Treatment / Management

The severity of the patient's symptomatology dictates the management approach to rectocele.

Conservative medical management of rectoceles begins with behavioral modifications. A high fiber diet and increased water intake to reduce constipation/defecatory symptoms may be enough to improve the patient’s quality of life. The patient should be drinking at least 2 to 3 liters of nonalcoholic, noncaffeinated fluids daily. The patient can also begin performing Kegel exercises and may benefit from the supervision of a pelvic floor physiotherapist.[4][6]

When the conservative treatment is unsuccessful, the next step is the use of a vaginal pessary. The vaginal pessaries come in different shapes and sizes. Therefore, fitting the patient with a pessary will come with a little trial and error. The function of this device is to stabilize the defects in the pelvic floor while also managing any other issues, such as cystoceles and prolapse of other organs.[5] Pessaries have been used to manage pelvic organ prolapse since Hippocrates when he used a halved pomegranate to treat prolapse.[17] Currently, there are a variety of devices used which differ in shape and size, made of medical-grade silicone. One of the most common shapes is the ring support pessary. Risk factors for pessary failure include large genital hiatus, short vaginal length, and prior pelvic organ prolapse surgery.[17] If the pessary cannot be manually inserted, then it may be inserted under anesthesia, or it may not be a treatment option for the patient. The most common complications from pessary use include vaginal discharge, vaginal bleeding, and odor.[17] There is little evidence on how often a pessary cleaning and changing should be performed.[18] However, teaching the patient how to remove and clean the pessary will increase the patient's bodily autonomy.[17](B2)

Surgical management is reserved for those with obstructive defecatory symptoms and bothersome symptoms who have failed other forms of treatment.[19] The principle of the surgical treatment is posterior vaginal wall or fibromuscular tissue repair or plication to strengthen the tissue and reduce the prolapsing rectum through the posterior vaginal wall. There are different surgical approaches to rectocele repair. These approaches include the vaginal approach, the abdominal approach, and the rectal approach. There is no consensus on the best approach or the best surgical repair for treating rectoceles.[20] Many factors contribute to determining which procedure would work best for the patient. These include age, vaginal length, desire for coitus, stage of prolapse, and symptoms of bowel dysfunction.[20][21] Urogynecologists generally perform vaginal and abdominal procedures, and colorectal surgeons generally perform transrectal procedures.[20] Traditionally, the posterior colporrhaphy with transvaginal access is the preferred approach to rectocele repair. In this procedure, the surgeon cuts the vaginal mucosa from the perineal body toward vaginal apex along the posterior wall. The vaginal lumen is then bluntly dissected from the rectovaginal septum. Then the fibromuscular tissue is plicated along the midline with sutures to increase the integrity of the rectovaginal fistula. Any areas of weakness are often plicated as well. After plication, the incision through the vaginal mucosa gets closed, with excision of redundant tissue. Several studies suggest a perineoplasty to avoid perineal rectocele.[22] There are proposals to use mesh as a method to strengthen the plication of fibromuscular tissue; however, recent studies have found no difference in failure rates in procedures that used mesh and those who did not.[23][24] For posterior colporrhaphy, rate of anatomic failure is 8.6% without mesh and 11.9% with graft.[24](A1)

Differential Diagnosis

While the condition will be very apparent on physical exam, some conditions may have similar symptoms. The differential diagnosis for these symptoms includes rectocele, rectal prolapse, enterocele, and sigmoidocele.[25] 

Prognosis

Rectoceles and other types of pelvic organ prolapse have a good prognosis as they are not life-threatening conditions. They affect the patient’s quality of life. Baden-Walker type I prolapse has an annual regression rate of 22% per 100-woman years. Baden-Walker types II and III, a lower regression rate. Increased parity correlates with increased progression rates for rectoceles.[26]

Complications

Lifestyle changes and pelvic floor physical therapy have a minimal risk for complications. Pessaries have a slightly increased risk of ulceration as a complication if not cared for properly.[5]

Surgery bears the highest potential for complications. Outside of the regular risk for surgery (bleeding, infection, etc.), complications vary depending on the type of surgery and whether the surgeon used a mesh. Mesh can erode the tissue. The most significant complication that can occur post-surgically is the risk of recurrent prolapse.

When using transvaginal mesh repair, there has been found to be a higher reoperation rate (11%) in comparison to native tissue repair (3.7%). Posterior vaginal repairs have less recurrent prolapse symptoms and lower recurrence on a physical exam than transanal repairs.[27]