|
|
Rectal Prolapse
What is rectal prolapse?
Complete rectal prolapse (procidentia) is a full-thickness, circumferential intussusception (folding in on itself) of the entire rectal wall through the anal canal.
Occult rectal prolapse (internal intussusception) is an internal folding in on itself of the mid- or upper rectum that does not protrude through the anal canal.
Mucosal rectal prolapse (which is not considered to be a true form of rectal prolapse) occurs when the connective tissue between the lining of the rectum and the underlying muscle weakens and only the rectal lining slips through the anal canal.
What are the risk factors?
Rectal prolapse is often associated with other conditions, including constipation, malnutrition/malabsorption, trauma to the anus or pelvic area and cystic fibrosis.
What are the symptoms?
The degree of prolapse will dictate a patient’s symptoms. Some patients complain of incomplete evacuation, resulting in frequent and severe straining at defecation. Others experience bloody mucus discharge, perineal pain and incontinence. Patients with complete rectal prolapse will complain of a mass protruding from the anus, usually after bowel movements. If the prolapse is small, it is often mistaken for hemorrhoidal prolapse, both by patients and by physicians. If the prolapse reduces spontaneously, the patient may only complain of passing mucus or blood per the rectum, usually associated with some degree of anal incontinence. As the prolapsed segment lengthens, patients learn to manually reduce it after bowel movements. Occasionally, the prolapsed rectum becomes confined, causing severe, acute discomfort.
Another symptom of rectal prolapse is anal incontinence. In addition, 25 – 50 percent of patients experience constipation, although the cause of constipation and its relationship to rectal prolapse is controversial and poorly understood. In some patients, constipation may be due to a delay in colonic transit, which causes chronic straining to evacuate hard stool, which in turn results in rectal prolapse. However, constipation can be secondary to obstruction of the colon at the pelvic outlet. Therefore, the decision to perform a colectomy at the time of rectal prolapse repair often hinges on the degree of constipation present in an individual patient.
Rectal prolapse often appears alongside other pelvic floor abnormalities, such as rectocele, enterocele, cystocele and uterine prolapse. Enterocele and rectocele may cause pelvic obstruction and obstructed defecation, contributing to the chronic straining of stool.
How is rectal prolapse diagnosed?
Following a complete history and physical examination, rectal prolapse is often confirmed by defecography.
What treatments are available?
Although extremely high-risk patients with easily reducible rectal prolapse can be managed with laxatives and manual reduction of the prolapse, most patients will benefit from surgical repair. The primary goals of surgery are to restore normal anatomy and improve symptoms of constipation and incontinence.
There are many operations used to treat rectal prolapse, and surgeons should select the one that produces the best possible functional result and the lowest complication and recurrence rate for every patient. The choice of operation depends on many factors, including the age and sex of the patient, associated constipation, degree of incontinence, history or prior repairs, comorbid conditions and the expertise of the surgeon.
Corrective procedures for rectal prolapse can be divided by approach: transabdominal or perineal. Most transabdominal procedures have low recurrence rates and today’s surgical treatments allow surgeons to perform colectomy for patients with severe constipation. Another benefit of the transabdominal procedure is that associated pelvic floor disorders, such as enterocele and rectocele, may be corrected simultaneously. Most procedures can be completed using local or regional anesthesia, thereby minimizing pain and risk.
Although most procedures performed using a perineal approach have higher recurrence rates than transabdominal procedures, they are excellent alternatives for patients who are considered high-risk and those patients who wish to avoid pelvic dissection (particularly male patients who do not want to risk sexual dysfunction). Regardless of the approach, all patients should undergo preoperative cathartic bowel preparation and receive antibiotics.
Abdominal Procedures
Patients with rectal prolapse and constipation may consider a procedure called sigmoid resection and rectopexy. In this procedure, the colon is resected and the rectum straightened and fixed to the sacrum. The advantages of resection/rectopexy are preservation of the rectum, removal of redundant sigmoid colon, alleviation of constipation and low recurrence rate (less than 3 percent). In addition, continence is improved in 35-60 percent of patients. Disadvantages are mainly related to the magnitude of the procedure.
An alternative transabdominal procedure that avoids the complication of anastomotic leak is rectopexy (sacral fixation of the prolapsing rectum). Rectopexy is an effective procedure for rectal prolapse, with recurrence rates of less than 5 percent in most series. However, constipation is not relieved through this procedure.
Patients with rectal prolapse and enterocele or large rectocele may be considered for a combined pelvic floor repair. The majority of these patients are women who have undergone hysterectomy and have loose pelvic floor muscles. The combined pelvic floor repair is effective in correcting prolapse, but will not improve pre-existing constipation. As with rectopexy alone, patients should be counseled that constipation will not be corrected by this procedure.
Laparoscopic Correction of Rectal Prolapse
Since the first use of laparoscopic repair of rectal prolapse in 1992, numerous laparoscopic techniques have been reported, including sutureless rectopexy, suture rectopexy, proctosigmoidectomy, resection/rectopexy and mesh rectopexy. The potential benefits of laparoscopic repair include early return of gastrointestinal function, less post-operative pain, better appearance and a shorter hospital stay. Short-term recurrence rates are similar to open transabdominal techniques. Postoperative incontinence and constipation are also comparable to open procedures, suggesting that the laparoscopic approach is an effective option in the treatment of rectal prolapse.
Perineal Procedures
Perineal rectosigmoidectomy has become the first choice surgical option for the vast majority of patients with rectal prolapse. During this procedure, the redundant rectum is removed by operating through the anus so that no external incisions are necessary. Patients, who are under regional anesthesia, have minimal discomfort and bowel function usually returns within 3-5 days. Another benefit of this procedure is that the anal sphincter can be repaired concurrently.
Another perineal procedure is mucosal sleeve resection (Delorme’s procedure), which involves the removal of the redundant lining of the rectum and bunching together (plication) of the underlying muscle wall. The advantage of the Delorme procedure is its technical simplicity and its ability to avoid an abdominal procedure, full-thickness bowel resection and/or anastomosis. Incontinence improves in 60-80 percent of patients undergoing mucosal sleeve resection. However, recurrence rates are higher than for perineal rectosigmoidectomy, in general, varying between 5 and 40 percent.
Extremely high operative risk patients with rectal prolapse may be considered for an anal encirclement procedure. The encircling procedure is performed with a band of soft synthetic mesh, a silicone tube, permanent suture or a muscle and tendon from the leg (gracilis transposition). The patient is started on a regimen of stool softeners and bulk-forming laxatives to avoid fecal impaction. Some patients require regular enemas in order to defecate.
|
|
|