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Prolapse and Intussusception

Donald G. Kim, M.D., F.A.C.S
Clinical Assistant Professor
Department of Surgery
Michigan State University
Grand Rapids, MI

Introduction
Three types of rectal prolapse are recognized which should be differentiated by the treating surgeon. Internal (hidden or occult) prolapse or intussusception occurs when the rectum intussuscepts but does not pass beyond the anal canal. Mucosal prolapse results from loosening of the submucosal attachments to the muscularis propria of the distal rectum and presents as hemorrhoidal disease. Complete rectal prolapse or procidentia is a full thickness protrusion of the rectum through the anal sphincters. True rectal prolapse is often associated with a myriad of functional disturbances significantly altering the patient's quality of life. Progressive pelvic floor dysfunction may lead to fecal and/or urinary incontinence, pelvic pain, obstructed defecation, rectal bleeding and mucoid discharge.

Epidemiology
Rectal prolapse is uncommon and its true incidence is unknown. Rectal prolapse can occur at any age, but peak incidences are observed in the fourth and seventh decades. The great majority of patients are female and in Western adult populations, females represent 80 to 90% of patients. In children, rectal prolapse occurs most commonly before 3 years of age. Unlike the adult population, in children, the sex distribution is equal.

Pathogenesis
The cause of rectal prolapse is unknown, although a number of physiologic and anatomic abnormalities are well recognized. It is unclear, however, if these abnormalities are primary or secondary to the prolapse. Rectal prolapse is thought to begin as an intussusception beginning about 6-8 cm proximal to the anal verge. In 1968, Broden and Snellman(1) demonstrated through cinedefecography that prolapse begins as an intussusception. Commonly cited predisposing factors include constipation with chronic straining, pregnancy, previous surgery, and neurologic disease. Anatomic features common to rectal prolapse include: 1) a deep cul-de-sac, 2) poor posterior rectal fixation with resultant loss of the normal horizontal position of the rectum, 3) a long rectal mesentery, 4) a redundant rectosigmoid, 5) levator diastasis, and 6) a patulous weak anal sphincter.

Anorectal physiologic studies have demonstrated impairment of sphincter function in rectal prolapse patients. Resting anal pressure is almost invariably decreased. This may be due to direct sphincter injury caused by repeated stretching by the prolapsing rectum. A second possibility is that intussuscepting rectum leads to chronic stimulation of the rectoanal inhibitory reflex. This theory is supported by Spencer(2), who found that the rectoanal inhibitory reflex was absent or markedly obtunded in patients with prolapse. Maximum voluntary contraction pressures are variably affected depending on the continence of the patient. When diminished in prolapse patients, this most likely represents denervation injury of the external anal sphincter.

The predominance of prolapse in women would suggest that birth trauma to the pelvic floor and nerves may be responsible; however, the fact that 35% of women with prolapse are nulliparous suggests a more complex explanation. Between 30 and 50% of women with rectal prolapse have had previous gynecologic surgery. In addition, 10-25% have an associated uterine prolapse, and 35% have a cystocele. This suggests that an abnormality of the pelvic floor that affects all the pelvic viscera may be present.

Clinical Presentation

Symptoms
The majority of patients present with a history of protrusion. Full thickness rectal prolapse must be distinguished from prolapsing hemorrhoids or rectal mucosal prolapse. Full thickness prolapse initially occurs with defecation, but may occur with coughing, sneezing, straining, walking or even spontaneously. Other symptoms of a true prolapse include rectal bleeding, mucous discharge, a sensation of a rectal mass, tenesmus, a sense of incomplete evacuation or obstructed defecation. The reported incidence of associated fecal incontinence is between 35 and 80%. Constipation is also present in 50% of patients with rectal prolapse.

Physical Examination Physical examination when the prolapse is not protruding is often suggestive of the underlying pathology. The anal orifice is often quite patulous. If the patient bears down, the full thickness of the rectal wall will prolapse and the concentric mucosal folds easily identified. A sulcus between the anus and the protruding bowel is present. This is in contrast to the radial folds and no sulcus associated with prolapsing internal hemorrhoids. Occasionally, the prolapse is not readily apparent and it may be necessary to have the patient strain in the sitting position to make the prolapse protrude. This is best accomplished while the patient is sitting on the toilet. A phosphate enema can be used to induce straining if necessary. Digital examination usually demonstrates diminished sphincter tone associated with full thickness prolapse. Voluntary sphincter contraction can be assessed.

Sigmoidoscopy
At a minimum flexible sigmoidoscopy should be performed. The exam may demonstrate localized inflammation or ulceration which should be biopsied to diagnose colitis cystica profunda or the solitary rectal ulcer syndrome. A solitary rectal ulcer occurs in 10-25% of patients with either complete or internal prolapse. In adults, evaluation of the entire large bowel should be performed prior to any surgical intervention.

Investigations
Anorectal physiologic testing may be helpful in identification of abnormalities in the rectal prolapse patient, but the clinical significance is unclear. Anal manometry objectively documents anal sphincter function. As pointed out earlier, patients with full thickness rectal prolapse have specific abnormalities detectable through manometry. Unfortunately, preoperative manometry results have not been predictive of the functional outcome regarding continence.(3-5) EMG pudendal nerve latencies may demonstrate an associated neuropathy. Birnbaum et al.(6) reported an association between pudendal nerve latencies and persistent postoperative incontinence, but this association has not been found in other studies.(7,8)

Videodefecography can be particularly useful in identifying an internal prolapse. It may also demonstrate a prolapse in the patient suspected of having a procidentia, but not demonstrated on physical exam. However, if an overt prolapse has been documented on physical examination, a videodefecography is not indicated. If an enterocele is suspected, the use of small bowel contrast and barium paste within the vagina can be extremely helpful in establishing this diagnosis.

Colonic transit studies may be indicated in patients with severe constipation as an abnormal transit time might influence the choice of operation. If the prolapse patient should suffer from total colonic inertia, consideration for a proctopexy with a total abdominal colectomy and ileorectal anastomosis should be made in the continent patient.

Surgical Management
The goal of surgical management of rectal prolapse is to correct the anatomical defect and to restore normal bowel function with a procedure which has minimal morbidity and an acceptable recurrence rate. The existence of hundreds of operations for rectal prolapse attests to the difficulty faced by surgeons in achieving this goal. The comparative analysis of the effectiveness of operations for rectal prolapse is limited by both the length and completeness of follow-up. Although most recurrences are said to occur in the first 2 to 3 years, it has been well documented that recurrence can occur after many years. Schlinkert et al.(9) reported that recurrence at 10 years was four fold greater than at 2 years. Studies with long follow-up report the highest recurrence rates emphasizing the importance of this variable.(10) Despite the large numbers of patients reported, prospective studies are uncommon, and randomized trials of prolapse surgery are rare.

Generally, prolapse repairs are categorized into abdominal and perineal approaches. Abdominal repairs may be performed with an open or laparoscopic technique. These operations may be categorized as resection alone, rectopexy with resection, and rectopexy alone. Perineal repairs include perineal rectosigmoidectomy and Delorme repair.

Abdominal Procedures

Anterior Resection
Anterior resection has been advocated for rectal prolapse but has not gained wide acceptance. Cirocco and Brown(11) reported a 7% recurrence rate in 41 patients treated with anterior resection with and average follow-up of six years. An older Mayo Clinic series reported similar results with a 9% recurrence rate in 113 patients followed for an average of seven years.(9) Pelvic sepsis is a potential risk, and advocates of this procedure favor an anastomosis above the peritoneal reflection to minimize leak rates.(9) Postoperative deterioration in continence has been reported.(9)

Rectal Fixation with Foreign Material
The Ripstein procedure(12), the Well's operation(13), and the Loygue procedure(14) amongst many other modifications are popular examples of operations for rectal prolapse that use a foreign material to fix the prolapsed rectum to the sacrum. Reported recurrence rates range from 2-10%. Initial procedures used a circumferential wrap which resulted in a common complaint of constipation postoperatively. Subsequent modifications left the anterior surface of the rectum free from the wrap. Despite these modifications, sacral fixation with mesh does not usually improve constipation and in fact several series report a worsening of constipation following these procedures.(15) Division of the lateral ligaments has been shown to be associated with an increase in the incidence of constipation.(5) However, continence generally improves postoperatively regardless of the method of fixation, with preoperative rates of 60-80% decreasing to 20% in may series. Complications of sacral fixation with foreign material include pelvic sepsis (1% with mesh, 2% with Ivalon sponge), stricture (2%), and fecal impaction (7%).

Suture Rectopexy with Sigmoid Resection
This procedure is a safe, effective procedure for rectal prolapse.(16) Simple suture fixation obviates the need for any foreign material. Earlier reports described bilateral fixation of the lateral ligaments to the presacral fascia; however, more recently a unilateral suture fixation is used which has less of a tendency to kink the rectum at the level of fixation. Recurrence rates average 3-4% ranging from 0-10%. Continence improves in 35-60% of patients. Constipation improves in 60-80% possibly because of the sigmoid resection.17 A prospective randomized study comparing suture rectopexy with sigmoidectomy to mesh rectopexy without sigmoidectomy demonstrated that rectopexy with sigmoidectomy resulted in less postoperative constipation.(18)

Suture Rectopexy Alone
Simple suture rectopexy without sigmoidectomy has been shown to be equally as effective at repairing rectal prolapse as other abdominal approaches with recurrence rates averaging 3%.(19) Without resection, this operation carries almost no risk of sepsis. Continence is restored in a similar percentage of patients. However, constipation is not improved by this procedure.(19)

Laparoscopic procedures
Laparoscopic repair represents the latest development in the evolution of the surgical treatment of rectal prolapse. Laparoscopic approaches to sutured rectopexy with and without resection, mesh rectopexy, and anterior resection have been reported.(20-23) Reported recurrence rates are acceptable, but the long-term recurrence data are not yet available.. Potential advantages include decreased pain, shorter hospitalization, minimal wounds, earlier return of bowel function, and faster recovery, although convincing controlled data is not available.

Perineal Procedures

Perineal Rectosigmoidectomy
Perineal rectosigmoidectomy is an appealing procedure for the repair of rectal prolapse because it is simple, effective and well-tolerated even by the elderly high risk patient population. Recurrence rates are higher than for abdominal repair, averaging in the vicinity of 10%, ranging from 0 to 50%. Concomitant levatoroplasty is easy to perform and has been shown to significantly improve continence.(24) Complications include pelvic bleeding and anastomotic dehiscence.

DeLorme Procedure
Mucosal sleeve resection or Delorme procedure is enjoying a resurgence of interest as a low morbidity procedure that avoids an abdominal incision while effectively repairing a prolapse. Recurrence rates average 12%. Fecal incontinence is alleviated in 50 to 75% of afflicted patients. Constipation has been reported to improve in 50%. This procedure is particularly useful when only a small prolapse is present since perineal rectosigmoidectomy may be difficult in this situation. Postoperative bleeding occurs in 1.5%.

Selecting the Best Operation for Rectal Prolapse
There is no ideal surgical procedure that is appropriate for all patient with rectal prolapse. Elderly poor risk patients are best treated with a perineal procedure. A perineal rectosigmoidectomy with levatoroplasty is well tolerated by these patients. The higher recurrence rate is offset by the minimal morbidity and faster recovery. Smaller prolapses, particularly those that protrude only 1-2 cm beyond the anal verge, are best treated with a Delorme procedure.

The choice procedure for the young, fit individual is more controversial. There is a growing trend to offer these patients a perineal procedure because of ease and simplicity despite the higher recurrence rate. Moreover, several recent studies have documented substantial restoration of continence and improvement in constipation with the perineal procedures.(24-26) However, young, fit patients do tolerate an abdominal operation well and can be assured of lower recurrence and better functional results particularly with respect to restoration of continence. Since recurrence rates and restoration of continence rates for all of the transabdominal sacral fixation procedures are similar, choosing the simplest method of fixation seems reasonable. There are no data to suggest that the addition of a foreign material to effect fixation offers any advantage over simple suture fixation. Although anterior resection may be an effective method of treating a rectal prolapse, there is a higher risk of pelvic sepsis from anastomotic leakage, and the procedure offers no advantage over suspension-fixation procedures. For patients without constipation, suture rectopexy alone should be sufficient. For patients with significant constipation, rectopexy with sigmoid resection may result in better functional results postoperatively. For patients with severe constipation with documented slow colonic transit by marker studies, rectopexy with subtotal colectomy can be considered as long as the anal sphincter function is adequate.(27)

Special Situations

Internal Prolapse
Whether an internal prolapse is a distinct entity or an intermediate stage of overt prolapse remains controversial. Videodefecographic reports demonstrate a significant internal prolapse in 40% of asymptomatic subjects(28) raising questions if this represents a normal variant. Furthermore, the likelihood of internal intussusception progressing to overt prolapse appears to be very low.(29) Common symptoms include a sensation of obstructed defecation, pelvic pain, anal incontinence and rectal bleeding. Full anorectal physiologic testing should be done. Patients with internal prolapse should be medically managed with bulk agent, suppositories or enemas, and biofeedback if incontinence or paradoxical contraction of the pelvic floor exists. Surgical management has been advocated(30), but the utility of surgical correction of internal intussusception for functional disorders remains unproven.(31, 32)

Solitary Rectal Ulcer Syndrome (SRUS)
This disorder of rectal evacuation is associated with a demonstrable internal prolapse in 60-80% of patients on defecography. Symptoms include prolonged straining at stool, tenesmus, bleeding, deep seated pelvic-rectal ache, frequent desire to defecate and sensation of incomplete evacuation. Treatment should be conservative in the majority of instances. Bulk agents, avoidance of straining, laxatives and use of suppositories will help about 20-30% of patients. Biofeedback may have a role.(33) Local measures, both topical and surgical are generally are generally not helpful although sucralfate retention enemas have been reported to be beneficial.(34) Operative intervention should be highly selective as results are variable. Rectopexy has been reported to benefit over 50% of patients in some series while others have reported poor results with this approach. The Delorme procedure may have a role in the management of SRUS. Some patients may be best served by a diverting stoma or in some instances by proctectomy.

Recurrent Prolapse
Recurrence in high risk patients who had an initial perineal procedure are best managed by a repeat perineal operation. Recurrence in low risk patients are dependent on the previous procedure. Perineal proctectomies can be repeated safely. Repeat resectional procedures such as a rectopexy and sigmoidectomy following a perineal rectosimoidectomy or vice versa risk ischemia of the intervening segment between anastomoses with potential mucosal slough, stricture and anastomotic dehiscence. Unless the surgeon is able to remove the previous anastomosis during reoperation, this approach should be avoided.(35) For this reason, if a transabdominal sigmoid resection was previously performed, a Delorme procedure should be considered to avoid a potentially ischemic segment due to alteration of the vascular supply from the previous procedure. If no resection was performed, a perineal rectosigmoidectomy would be a good option.

Prolapse in Children
Childhood prolapse usually occurs prior to the age of three years. Mucosal prolapse is more common than complete prolapse, particularly in children younger than one year. Associated factors include chronic cough, constipation, acute diarrheal illness, malnutrition, and several congenital abnormalities notably bladder extrophy, cystic fibrosis, and developmental delay. The majority of childhood prolapses resolve spontaneously or with treatment of the underlying condition. Surgical treatment is reserved for medical failures and is universally by the perineal approach. Fixation of the rectum can be achieved by perirectal injection of a sclerosing solution such as 30% saline, by linear cauterization of the rectal mucous and submucosa or by three quadrant mucosal stripping. Each of these techniques is reportedly successful in over 90% of patients. Other methods include a Delorme procedure, anal encirclement with absorbable or nonabsorbable suture, or a transperineal posterior incisional approach with sacral fixation or packing of the retrorectal space to create fibrosis.

Prolapse in Men
The potential risk of damage to the autonomic nerves in young men during the pelvic dissection should be considered when selecting the appropriate operation. The choice of a perineal procedure eliminates this small but potential risk and should be strongly considered for young men.

Incarcerated Prolapse
An incarcerated prolapse can generally be reduced by gentle pressure. When extensive edema is present, the application of granulated sugar for 15-20 minutes will reduce the edema and may allow reduction.(36) If strangulation of an incarcerated prolapse has occurred, perineal rectosigmoidectomy is the procedure of choice.(37)

Enterocele with Vaginal Vault Prolapse
Enterocele and vaginal vault prolapse, often in association with internal rectal prolapse, can occur with symptoms of obstructed defecation, a sensation of prolapse or protrusion from the vagina, urgency and incontinence. Videodefecographic exam with the use of small bowel contrast, vaginal contrast, and rectal contrast can help demonstrate this entity. Most patients have had a prior hysterectomy. Mellgren et al.38 reported excellent results using the Ripstein procedure for this problem. Similar results can be achieved with simple suture rectopexy and vaginopexy or rectovaginopexy with prosthetic mesh.39

References

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