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RECTAL PROLAPSE

Rectal prolapse is relatively uncommon. A review of almost 800 patients undergoing radiologic evaluation for bowel dysfunction found that less than 10% of this symptomatic population had rectal prolapse; however, the dramatic presentation of the prolapsed rectum makes this entity relatively easy to identify. The chronic impact on quality of life and frequent association with bowel dysfunction.

Rectal prolapse is, quite literally, presentation of the rectum down through the anal canal. Clarification of the precise cause of rectal prolapse has been elusive. Moschowitz theorized that rectal prolapse was the result of a sliding hernia.

Attention then focused on pelvic floor dysfunction as the cause of rectal prolapse: chronic straining with defecation and anal sphincter abnormality were both considered as possibly contributory. Rectal prolapse is likely an expression of aberrant physiological forces that cause the loss of natural anatomic relationships. In order for the rectum to present through the anal canal, several events need to occur. First, laxity of the upper rectum and distal sigmoid colon and its lateral attachments needs to be present so that the rectum is able to slide downwards. Second, the rectum needs to move away from its normal position.

Clinical Presentation

Rectal prolapse is far more common in women than men. The incidence rises sharply after age 50 and peaks in the seventh decade. Aside from these observations, physiologic correlates are not clear. Systemic illnesses are not convincingly associated with rectal prolapse. More than 3 decades ago, Goligher observed that many of his patients seemed "odd."

Evaluation

In early stages, rectal prolapse may be difficult to diagnose; it may occur only when the patient is seated on the toilet and straining, and it may be difficult to reproduce these conditions during an examination in the prone jackknife or left lateral examining positions. When fully prolapsed, the appearance of rectal prolapse is striking and distinctive.

It is important to evaluate the colon and rectum for other pathology prior to consideration of treatment. Anatomic causes of constipation, such as cancers, polyps, or strictures may result in gradual increase in the effort required for evacuation of stool, and may precipitate the development of rectal prolapse. Rashid and Basson reviewed 70 patients with rectal prolapse and found that 5.7% had rectosigmoid carcinoma versus 1.4% of controls.

Treatment

Once rectal prolapse develops, it is essentially a surgical problem. It is an anatomic abnormality that requires an anatomic correction and does not respond to pharmacologic measures. Each patient's treatment plan should be optimized by consideration of the specific anatomic defects to be corrected, and the patient's functional level, associated medical problems.

Surgical management of rectal prolapse can be divided into two primary approaches: transabdominal operations and transrectal or perineal operations. Historically, various operations were developed based on each surgeon's understanding of the fundamental anatomic derangements. In general, transabdominal operations for rectal prolapse have a lower rate of recurrence and a higher morbidity than transrectal or perineal approaches.

Transrectal surgical repair of rectal prolapse is the next simplest type of procedure. Although this approach has a higher rate of recurrence than abdominal approaches, morbidity is lower and general anesthesia can often be avoided.

There are two primary variations of transrectal surgical repair of rectal prolapse. The Delorme procedure removes only the redundant rectal mucosa, leaving the muscular wall of the rectum (muscularis propria) intact. The muscularis is plicated, or accordion-pleated, with sutures and then the remaining mucosa is anastomosed, over the plicated muscle. The Altemeier procedure removes the entire thickness of the redundant rectal wall (mucosa plus muscularis propria).

The Delorme operation avoids a full-thickness anastomosis and can be done under regional or local anesthesia in a debilitated patient. The anatomic determinants of rectal prolapse (laxity of the lateral ligaments, and the anterior position of the rectum.

The abdominal approach has the greatest chance of correction of the anatomic defects that have led to the prolapse, and the lowest chance of recurrence. It generally is the procedure of choice for the younger, more active patient.

Rectopexy, whether with sutures or with prosthetic material, has been a popular technique. Recurrence rates for prolapse for these techniques generally are less than 6%; however, there are several complications specific to the use of prosthetic material.

Rectopexy using sutures alone is felt to provide equally low recurrence rates without the risk of foreign body implantation. Sigmoid resection combined with rectopexy has a lower recurrence rate than rectopexy alone and has been associated with a minimal increase in morbidity. The success of operative repair of rectal prolapse also is judged by resolution of bowel.

The cause of recurrent rectal prolapse is not clear, but is presumed to be the same as the causative factors of the original prolapse. Only small series of patients with recurrent prolapse are available for consideration. Hool et al retrospectively reviewed 24 patients over 30 years. Two-thirds of these patients had a transabdominal procedure initially. The authors found that in one-half of the patients, a cause for recurrence of rectal prolapse could not be identified.