Introduction

Rectal prolapse most commonly occurs in young children and women in the sixth to seventh decade of life. The annual incidence is estimated to be 2.5 per 100,000 of the population. The prolapse may be full thickness (procidentia) involving all layers of the rectal wall that pass beyond the anal canal, or it may be a mucosal prolapse in which the rectal mucosa only passes externally. A third type of rectal prolapse is an internal prolapse also referred to as occult intussusception . This represents a rectal prolapse that does not extend beyond the anal canal and is usually only detected by defecating proctography.

There is still much debate about etiology with chronic straining secondary to constipation credited as the most significant factor. Other risk factors include female gender, postmenopausal status, and previous anorectal surgery. In adults anatomically, these patients commonly have a deep cul-de-sac, diastasis of the levator ani muscles, poor-quality tissues supporting the structures of the pelvic floor, and redundancy of the sigmoid colon. In children, immaturity of supporting rectal structures as well as absence of the sacral curvature have been implicated as possible causes. Rectal prolapse has been described in weight lifters, attributed to the extremes of raised intra-abdominal pressure. A percentage of patients may have psychiatric illness, neurologic illness including tumors, and congenital abnormalities. In children, rectal prolapse may occur against a background of cystic fibrosis, constipation, or diarrheal illness. Most children will initially be managed conservatively as the condition is usually self-limited or will resolve with non-operative therapy.

The majority of patients with external prolapse present with demonstrable protruding bowel. They complain of this protruding rectum leading to discharge of mucus, giving the patient difficulty with maintaining personal hygiene. If the prolapse is not seen readily, a provocative maneuver such as sitting on a commode with or without administrating an enema may be required to bring the prolapse into view. Another symptom may be rectal bleeding that results from trauma to the exposed mucosa. The prolapse often follows a progressive pattern from occurring intermittently to protrusion with minimal straining. Sometimes patients are referred with a provisional diagnosis of hemorrhoids or fecal incontinence. True procidentia is identified by concentric rings. In contrast, hemorrhoids have characteristic radial sulci. Incontinence may coexist because in elderly women there is already deterioration in sphincter function, which is further exacerbated by chronic stretching of the anal sphincter complex. Chronic stimulation of the rectoanal inhibitory reflex (RAIR), resulting in reflex relaxation of the internal anal sphincter, may also be a contributing factor. Prolonged stretching of the pudendal nerve may result in neuropathy.

Diagnosis of a solitary rectal ulcer or mucosal prolapse syndrome should raise an index of suspicion for an occult internal prolapse. These ulcers may be single or multiple, and typically involve the anterior rectal wall. It is believed by many that an internal rectal prolapse is a precursor for the development of a full thickness prolapse. However, others think that it is an anatomic variant of normal and that the majority of patients will never progress to procidentia. Patients with internal intussusception may complain of atypical symptoms suggestive of obstructive defecation such as fullness in the rectum exacerbated by prolonged standing or sitting. This may be accompanied by perineal pain and the inability to pass flatus.

In most cases, patients are seen in the elective setting. The rare occasions where the prolapse is irreducible or strangulated is an emergency. If there is no necrosis of the protruding rectum, placing table sugar on the mucosa can create an osmotic gradient, allowing reduction of the prolapse.

Because of the association of rectal prolapse with coexisting genitourinary organ prolapse, several groups recommend a multidisciplinary approach to the management of patients with rectal prolapse. All surgeons embarking on rectal prolapse surgery must have adequate training, which will help in deciding the appropriate intervention, and allow a comprehensive understanding of the technical steps critical to achieving a successful surgical outcome.

Patient Assessment

Assessment consists of history, physical examination, and appropriate tests. The history should elicit the presence of any medical co-morbidity; prior surgery, especially operations for rectal prolapse; and constipation or incontinence that may influence the treatment modality. If surgery is contemplated, the majority of patients will require an anesthetic assessment. This will help to determine if an abdominal approach is feasible or if the patient may be more suitable for a perineal approach under local or regional anesthesia. Patients on anticoagulants need to have them discontinued at an appropriate time interval before surgery.

When a functional problem is detected, it may be advantageous to determine the degree to which the patient’s quality of life is affected. Several studies suggest that colonic resection may benefit patients with constipation. Patients often experience fecal incontinence. The degree of incontinence may correlate with the extent of rectal protrusion. Correction of the prolapse will improve continence in a significant proportion of patients. Thus, even in patients with a sphincter defect, continence may improve following prolapse repair. Pudendal nerve studies may identify injury to the nerves supplying the sphincter muscles and the pelvic floor. This information may be useful when counseling patients of the potential for persistence of incontinence despite successful repair of the prolapse.

Many patients may have coexisting gynecologic or urologic problems with the prolapse, representing a generalized dysfunction rather than an isolated rectal problem. Thus, when evaluating these patients, other pelvic floor abnormalities such as pelvic organ prolapse and urinary incontinence should be looked for.

At the initial examination the perineum is assessed, looking for any defect or scars. The anus is often patulous. In many cases the prolapse is easily replicated with the patient straining or performing a Valsalva maneuver. If this does not work then an enema is administered and the patient examined while straining on the commode. More extreme measures include the administration of local anesthesia into the sphincter complex with resulting relaxation of the anal sphincters, allowing the prolapse to be confirmed. If the patient is unable to demonstrate the prolapse in the office setting, a picture may be taken when the prolapse occurs at home. Surgical intervention for rectal prolapse should only be considered when the surgeon personally visualizes the prolapse.

In the majority of patients, history and examination will provide sufficient information to make the diagnosis and direct the surgical approach. In patients in whom the clinical picture is complex or one suspects other functional problems, further studies such as colonic transit, anal manometry, defecating proctography, or dynamic magnetic resonance imaging (MRI) may be required. All patients should have a complete colonic evaluation to rule out the presence of other colorectal pathology.

Management Options

Operations for rectal prolapse may be stratified according to whether they are performed using an abdominal or perineal approach. In patients with full thickness prolapse, the abdominal approach has been reported to have a lower recurrence rate but a higher morbidity. It may be performed using an open or laparoscopic technique. The mobilized rectum may be fixed to the sacrum using sutures, tacks, or synthetic material. In general, mesh is used cautiously in patients undergoing concomitant resection because of the potential for infection of a foreign body. The decision to combine a rectopexy with a resection is determined by the degree of redundancy and constipation. Whether to divide or preserve the lateral ligaments is also controversial. Some surgeons divide the right lateral ligament only while leaving the left side in situ. Advocates for preservation of the ligaments believe that there is less constipation but at the expense of a higher recurrence rate.

The perineal approach is generally preferred for patients with significant co-morbidities and may be performed using local or spinal anesthesia. However, in comparison to the abdominal approach, it has a higher recurrence rate. Options for repair of a mucosal prolapse include Delorme’s procedure or circumferential stapled anoplasty using a procedure for prolapsed hemorrhoids (PPH). Indications for operative repair of rectal intussusception are controversial. If the patient is symptomatic then medical management with bulking agents and enemas is the initial treatment. In patients with obstructed defecation, biofeedback may be beneficial. Rubber band–ligation may provide relief for patients with redundant anterior rectal mucosa. If the patient has severe symptoms that do not respond to medical measures, repair is considered.

A management algorithm such as the one depicted in Figure 6-1 is helpful to decide the best treatment.

Algorithm of surgical management for rectal prolapse.

Following a successful repair, it is important that the patient institutes lifestyle changes to reduce the potential for recurrence. Patients are counseled on strategies to regularize bowel motions and to reduce the amount of straining required for defecation. Some of these therapies include increasing dietary fiber and fluid intake, avoiding drugs associated with constipation, and on occasion, the use of laxatives.

Perineal Approaches—Surgical Techniques