Introduction
Rectal prolapse occurs when the full thickness of the rectal wall protrudes through the anal canal. This condition can cause discomfort, bleeding, and incontinence. Rectal prolapse is most commonly seen in older women, but it may occur in both sexes and at any age. Although the condition has fascinated surgeons for many years, the optimal surgical approach to rectal prolapse has not been determined. More than 100 surgical operations have been described, which can be grouped into perineal and abdominal approaches. Laparoscopic approaches have become common, with excellent functional results. Choice of the optimal repair for a patient involves many factors, including general health and bowel function. Constipation is reported in 30% to 67% of patients with rectal prolapse, and 60% to 80% have a history of incontinence.
Pathophysiology
The mechanisms by which prolapse occurs remain poorly understood. Brodén and Snellman suggested that prolapse is initiated by a midrectal intussusception, with its origin 8 to 10 cm inside the rectum. Chronic straining may be a precipitating factor, which might explain the association of prolapse with colitis cystica profunda and a solitary rectal ulcer. Another hypothesis relates prolapse and abnormal intestinal motility, such as that seen in slow-transit constipation.
Low anal resting pressures, which are frequently observed in patients with prolapse, may be caused by continuous rectoanal inhibition or by the dilating effect of the prolapse itself, with or without pudendal neuropathy. However, other investigators believe that an initial increase in external sphincter tone may cause a cycle of outlet obstruction, constipation, and straining. An impaired tolerance to distention, with reduced compliance and tone, may contribute to incontinence. Other features of patients with rectal prolapse include a deep pouch of Douglas, redundant sigmoid colon, deficient rectosacral fixation, weakness of the pelvic floor, and a patulous anus. Obviously it is difficult to determine which physiologic alterations are causative factors and which are a result of the progressive prolapse of the rectum.
Internal rectal intussusception, also called internal or hidden prolapse, occurs when the prolapse does not protrude through the anal orifice. This is often shown on defecography. Mucosal prolapse is diagnosed when the mucosa slides on the submucosa and protrudes into or through the anal canal. It is treated similarly to prolapsing internal hemorrhoids but is thought to predispose to true rectal prolapse.
Clinical Features
Rectal prolapse initially occurs only with defecation and straining, and patients are usually aware that it is happening. As the anus dilates and the rectal attachments loosen, the rectum may prolapse with the mildest straining, or even when the patient stands. Tenesmus, bleeding, and mucus discharge are common, and incontinence may range from mucus leakage to complete fecal incontinence. Some patients also report bladder and gynecologic dysfunction and may have prolapse of these organs. These patients are suitable for multidisciplinary assessment and management.
Upon physical examination, the anus may be patulous. Visual observation of everted bowel with concentric folds allows definitive diagnosis. If prolapse is not obvious, the patient should be examined while straining on the commode. Examinations with the patient in the left lateral or prone jackknife position often fail to reproduce the prolapse, and prolapse cannot be ruled out in this manner. Occasionally a prolapse is incarcerated, which requires the application of hypertonic sugar or honey to reduce edema and allow shrinkage and reduction. A small prolapse can be distinguished from prolapsing hemorrhoids by observing the concentric folds of the rectal wall, in contrast to the radial folds of the hemorrhoids. Digital examination also permits evaluation of sphincter tone and diagnosis of a rectocele.
Anoscopy is a good way to diagnose internal rectal intussusception. As the anoscope is gradually removed, the patient is asked to bear down and the prolapsing rectal mucosa or rectal wall can be seen descending toward the anus. Proctosigmoidoscopy facilitates examination of the rectal mucosa and allows one to check for an ulcer, a lead point, or additional disease. Most patients have already had a colonoscopy because of their age and the rectal bleeding often associated with their presentation.
The diagnosis of rectal prolapse is usually straightforward; however, the differential diagnosis includes hemorrhoids, prolapsing polyps, and anorectal neoplasia. Conditions such as a solitary rectal ulcer and colitis cystica profunda are often associated with rectal prolapse and present with similar symptoms.
Some persons advocate measuring colonic transit time in patients with constipation. We do not measure colonic transit time routinely, but only in patients with a history of severe constipation and associated sphincter weakness. Patients with chronic straining should undergo evaluation for paradoxical contraction of the puborectalis with anorectal physiologic testing or defecography, so that biofeedback may be instituted prior to repair of the prolapse. The clinical and financial value of routine preoperative studies, including anorectal manometry, pudendal nerve terminal motor latency, colonic transit studies, and defecography, is unclear. In most patients, an adequate history and physical examination should provide appropriate information to determine the correct operative approach.
Preoperative Considerations
The general health of the patient is an important factor in the choice of treatment. Abdominal surgery in elderly patients who have significant comorbidities carries risks that can be avoided with a perineal approach. However, increasing experience with laparoscopy suggests that the benefits of abdominal prolapse repair may be achieved with greatly reduced morbidity. This suggestion is supported by a recent National Surgical Quality Improvement Program analysis of 1469 patients older than 80 years undergoing abdominal and perineal approaches to prolapse repair, which demonstrated that among the highest risk groups (American Society of Anesthesiologists [ASA] 3 and 4), the relative risk for mortality was four times greater in the group undergoing a perineal approach.
Incontinence associated with rectal prolapse often improves after surgery and is associated with an increase in both resting and squeeze pressures. This improvement is likely related to prevention of the dilating effect of the prolapse and cessation of the constant stimulation of the rectoanal inhibitory reflex. Incontinence is reported to be better after abdominal repair than after perineal repair; however, most large series report improvement in at least 40% of patients regardless of technique. Sphincter repair is rarely performed at the time of prolapse surgery, with the option being reserved for those with complete or near-complete incontinence. In practically all cases, time is provided for the expected improvement in continence to occur spontaneously.
Constipation is also a concern because prolapse repair may exacerbate this symptom. Some series suggest that a rectopexy alone can worsen constipation. This outcome may be related to a redundant sigmoid loop falling forward over the area of mesh or suture fixation of the rectum to the sacral promontory, causing partial obstruction at the rectosigmoid junction. Because of this concern, we favor performance of a sigmoid colectomy with a sutured rectopexy in constipated patients. We have observed improvement of preoperative constipation in 95% of patients who undergo laparoscopic rectal prolapse surgery when a resection rectopexy is reserved for those with constipation. Conversely, a laparoscopic Well’s procedure for persons with diarrhea or incontinence can improve continence in upward of 80% of these patients. We avoid lateral ligament division during rectal mobilization because it also may precipitate constipation.
Surgical Options
The goals of surgery are to prevent prolapse while optimizing continence and bowel function. Prolapse repair may be achieved using either a perineal or abdominal approach; the primary techniques and alternatives are discussed in the following sections. Colonic resection is reserved for persons with significant constipation because of the increased risks associated with resection.
Perineal Repairs
Perineal repairs can be performed with use of a light anesthetic without paralysis and intubation, and even at times with a local anesthetic and intravenous sedation. The three main types of procedure used are anal encirclement (Thiersch procedure), perineal rectosigmoidectomy (Altemeier procedure), and mucosal stripping/rectal plication (Delorme procedure).
Anal encircling procedures have generally fallen out of practice because of high failure and complication rates. They are usually reserved for persons with the most severe comorbidities who would not tolerate or should not undergo perineal resection. Such patients include those with ascites and hepatic failure who are not appropriate candidates for the transjugular internal portosystemic shunt procedure, followed by abdominal repair. Anal encirclement procedures are associated with prolapse recurrence rates of 20% to 60% and cause such complications as breakage and erosion of the wire or suture and infection.
Altemeier popularized the perineal rectosigmoidectomy in the 1960s. Recurrence rates between 0% and 50% have been reported. Altemeier initially combined the operation with a levatorplasty, which may improve continence to a greater degree than just the resection alone. This approach attempts to remove the prolapsing segment and use the subsequent fibrosis to fix the rectum in position in the pelvis. The Altemeier procedure remains the ideal option for patients presenting with an incarcerated, gangrenous prolapse.
Delorme suggested a less invasive alternative. The rectal mucosa is stripped from 1 cm above the dentate line, continuing right up to the top of the prolapsing segment, where it is excised. The bared rectal muscle is then plicated with concertina-type stitches, and the proximal mucosa is anastomosed to the distal margin of mucosal resection. Submucosal infiltration with dilute epinephrine may reduce perioperative bleeding. Variable recurrence rates have been reported, but they are generally in the order of 5% to 20%.
Abdominal Procedures
Abdominal procedures for rectal prolapse are generally associated with a recurrence rate in the order of 5%, although recurrence rates between 0% and 20% have been reported. Abdominal repairs involve mobilization of the rectum and fixation to the sacral promontory with suture or a prosthetic material or mesh. In an anterior repair, such as the Ripstein procedure, the mesh is wrapped around the anterior aspect of the rectum and fixed on both sides to the sacral promontory. Posterior repairs, such as the Wells technique, involve the mesh being placed behind the rectum and superior rectal artery and fixed to the sacrum before being wrapped around both sides and fixed to the lateral mesorectum. Although recurrence rates are generally less than 10%, anterior wraps may be complicated by stenosis and obstruction. Posterior fixation avoids stenosis and may reduce constipation. Although a variety of materials have been used to fix the rectum, we favor use of polypropylene mesh to reduce the risk of septic complications, which are reported in 3% to 4% of cases using the Ivalon sponge.
The rectum is usually mobilized by dissecting posteriorly in the presacral space down to the pelvic floor, although the extent of lateral dissection varies. Division of the lateral ligaments has been evaluated in two small prospective randomized trials. One study suggested no difference in postoperative functional outcome, but the other study showed significantly less constipation with lateral ligament preservation, at the cost of increased recurrence rates.
Abdominal repairs may be performed with or without a concomitant bowel resection. Thus, resection rectopexy incorporates resection of the sigmoid and upper rectum. Fixation of the rectum is likely achieved by the perianastomotic fibrosis, with sutures providing additional fixation of the lateral tails of the mesorectum to the sacral promontory. Recurrence rates are generally in the order of 2% to 8%, but potential morbidity of a colorectal anastomosis exists. Some authors have advocated a formal anterior resection, but this procedure provides an increased potential for morbidity without reducing recurrence rates. We perform anterior dissection only when necessary in patients with a very distal prolapse, which requires circumferential mobilization to fully reduce the intussusception. This reduction is confirmed by digital examination at the completion of rectal mobilization.
Laparoscopic colorectal procedures are increasingly being used to accelerate recovery after major abdominal surgery. Smaller incisions result in fewer wound hernias and admissions for bowel obstruction. Most studies also demonstrate fewer complications and a lower direct cost of care by virtue of reduced postoperative pain, earlier introduction and tolerance of diet, and shortened length of hospital stay. The surgeon can perform exactly the same operation laparoscopically as when using the open approach; the primary difference is that the largest wound is the 10-mm incision for the camera port. When a laparoscopic resection rectopexy is performed, a 3- to 4-cm left lower quadrant muscle-splitting incision is also used. The rectum is fixed to the sacral promontory using a suture or stapled technique. Mesh can be used as in open surgery. Many series describe no cases of recurrence. Excellent outcomes can be achieved with laparoscopic resection rectopexy with resultant improvements in constipation, incontinence, and outlet obstruction rates when compared to open surgery. Several investigators have found that use of the laparoscopic Wells procedure is associated with reduced constipation and no recurrences, with a reduction in length of stay and in costs compared with open repair. Performance of a laparoscopic suture rectopexy without mesh or resection has been associated with a 7% recurrence rate.
The surgical approach used is the same as that used for open surgery. The presacral space is entered and a posterior rectal mobilization is performed to the level of the pelvic floor. We do not divide the lateral ligaments. For a Wells rectopexy, a precut piece of mesh is passed down a port and tacked or sutured to the sacral promontory in the midline. The edges are then sutured to the lateral mesorectal tissue to maintain rectal support. In patients undergoing a resection, the upper rectum is transected with an endoscopic stapler and passed out through a small left lower quadrant muscle-splitting incision. The proctosigmoidectomy is completed and the anvil of a circular stapler is inserted in the proximal bowel before it is returned to the abdomen. The anastomosis to the rectal stump is completed before suturing the lateral mesorectal tissue to the sacral promontory for additional support. We performed a case control study of 111 patients to compare laparoscopic and open surgery for rectal prolapse, with 5-year follow-up. Compared with the open surgery cohort, the laparoscopic cohort had a shorter hospital stay (3.9 vs. 6.0 days) and improved constipation scores.
Laparoscopic ventral rectopexy has been advocated for patients with significant constipation in an effort to avoid resection. This approach avoids posterior dissection and its potential for nerve damage by using anterior dissection and mobilization of the anterior wall of the rectum with placement of mesh anteriorly and fixated to the sacrum. Avoidance of posterior dissection has been suggested to improve obstructive defecation. In a case series described by D’Hoore and colleagues, resolution of obstructed defecation was found in 16 of 19 patients with this technique. Additionally, a recent systematic review found that patients undergoing ventral rectopexy without posterior dissection were significantly less constipated postoperatively compared with preoperative rates.
Robotic-assisted laparoscopic surgery for rectal prolapse has also been described, providing the benefits of minimally invasive surgery, but with extended operative times and prohibitive costs. Thus, although robotic surgery may play a role in the management of rectal prolapse in the future, its benefits currently do not warrant exploration in our practice.
Recommendations
Many options exist for repair of rectal prolapse. In a major review, Kim et al studied 188 perineal rectosigmoidectomies and 160 abdominal resection rectopexies performed over a 19-year period. Although the morbidity was lower for perineal repairs, recurrence rates were increased from 5% to 16%. In our opinion, laparoscopy helps reduce postoperative morbidity, allowing for a safe abdominal repair in a larger number of patients. Consequently, the reduced recurrence rates of abdominal surgery can be offered to older patients who previously would have been offered a perineal repair.
Thus, we use a laparoscopic Wells rectopexy to treat patients who do not have constipation or who have diarrhea or incontinence, and we use a laparoscopic resection rectopexy to treat patients with constipation. Perineal approaches are reserved for patients who are very unfit medically; we use both the Delorme and Altemeier approaches, and prefer using the Delorme approach in patients with poor continence.
Problems
Persistence of residual rectal mucosal prolapse (which occurs in 5% to 10% of cases) is not considered to be a true recurrence and can be treated with elastic banding.
Patients whose difficulties with continence persist should be observed for improvement for up to 6 or 12 months, unless symptoms are extremely severe and warrant earlier sphincter repair or additional operative intervention for fecal incontinence.
A solitary rectal ulcer, which is present in approximately 12% of patients with a prolapse, is often considered to be a complicating issue. A solitary ulcer should be treated separately. If the ulcer is associated with prolapse, then repair of the prolapse should be sought. If the ulcer is not associated with prolapse, then initial treatment involves correction of straining and improved defecation practices.
Internal intussusception, which is diagnosed by barium studies or defecating proctography, is not automatically an indication for surgical repair. Many asymptomatic patients are shown to have an internal intussusception upon defecating proctography, and a surgical repair is generally not warranted. Patients should be fully evaluated for other possible causes of their symptoms. Surgical repair is generally reserved for those with concomitant obstructive defecation or additional pathology, such as solitary rectal ulcer, only after exhaustion of conservative measures (pelvic floor physical therapy).
When rectal prolapse occurs in conjunction with urogenital prolapse or other pelvic floor disorders, a combined approach by colorectal, gynecologic, and urologic surgeons may be indicated. For this patient cohort, Sullivan et al have reported total pelvic mesh repair in 236 patients, involving the placement of mesh from the sacrum to the perineal body and around the vagina. In this report there were no recurrences, and patients had a 70% satisfaction rate, but 10% required a repeat operation because of problems with the mesh. A perineal approach to the rectal prolapse also can be used, combined with a perineal colporrhaphy.
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