1. Field of the Invention
This invention relates to urogenital and gastroenteric surgery.
2. Description of the Related Art
Rectal prolapse, in its most common form, is a condition in which the rectum, the most distal portion of the colon, protrudes from the anus. In fact, three different clinical entities are often called rectal prolapse. These include full-thickness rectal prolapse, mucosal prolapse, and internal prolapse (also known as internal intussusception). The treatment of each is different.
Full thickness prolapse is the most commonly recognized type of rectal prolapse, in which the full thickness of the rectal wall protrudes through the anus. In mucosal prolapse, only the rectal mucosa protrudes. Internal intussusception is a similar condition, but the prolapsed tissue does not extend beyond the anus.
Rectal prolapse is considered uncommon, but the true incidence is not known due to underreporting. Eighty to ninety percent of patients are women, and peaks in occurrence are seen in the fourth and seventh decades of life. Certain genetic or chromosomal abnormalities, such as cystic fibrosis, have been seen to result in increased incidence of rectal prolapse in children.
As a condition predominately affecting women, rectal prolapse is often concurrent with prolapse of other pelvic floor organs. The etiology is not clear. Chronic straining during defecation, hereditary factors, and stresses due to childbirth have been implicated, as have the normal changes in the strength of pelvic and anal sphincter muscles seen with aging, neurological disease, and previous gastrointestinal or urogenital surgery. Long-standing hemorrhoidal disease is also thought to lead to certain types of rectal prolapse.
Clinically, a rectal prolapse begins as a mass protruding from the anus only after a bowel movement which retracts when the patient stands. If the disease progresses, it eventually reaches a point where it protrudes in other situations, such as sneezing and walking, and reaches a point where it does not spontaneously retract. At this point, the patient may manually replace the mass. Eventually, the mass may continue prolapsing immediately after replacement. The rectum may become incarcerated, or ulcerated, and it may be painful. Incontinence is seen due to interruption of the normal function of the anal sphincter. In addition, the exposed mucosa of the rectum constantly secretes mucous. Bleeding is commonly seen. Trauma and strangulation of the protruded mass are possible.
Rectal prolapse is generally diagnosed by physical examination. Barium studies may be indicated, as may sigmoidoscopy, to assess the rectum for additional lesions, such as tumors or ulcers.
In young patients, conservative treatment with stool softeners and suppositories. However, in adults, these medical treatments are not generally effective, and surgery is indicated.
Full thickness prolapse is treated surgically. One common surgical technique is a sigmoid resection and rectopexy. In this procedure, a portion of the colon is removed, and the remaining portion of the rectum is anchored to the sacrum.
Various options are available for the rectopexy. The Ripstein procedure incorporates the use of a nonabsorbable material, such as a Marlex mesh, to augment the fixation to the presacral fascia. The mesh stimulates scarring that serves to hold the rectum in place. A similar process using suture instead of a mesh material is also known.
This procedure involves an abdominal surgical approach, and can be performed via laparatomy or laparoscopy. Compared to other surgical options, abdominal procedures have a lower recurrence rate, but higher morbidity. Further, abdominal approaches result in scarring from the healing of abdominal incisions.
Other surgical procedures are known, including perineal approaches. Several alternatives are available, including perineal protectomy. Also known as the Altemeier Procedure, the surgeon removes the prolapsed portion of the rectum via an incision in the protruding rectum. Other perineal methods include anal encirclement, which is essentially only palliative due to complications such as chronic constipation. The Delorme mucosal sleeve resection is a perineal approach often used for small prolapses. Compared to the abdominal approach, perineal approaches have higher recurrences, but lower morbidity.
Presently available methods of treatment are not without problems. The recurrence rate for anterior resection without sacral fixation is about 7-9%, with a morbidity rate of 15-29%.
For a rectopexy without resection, the recurrence rates range from 2-10%, with morbidity rates of 3-29%. Unfortunately, continence is only improved in 50-70% of patients, and constipation may actually worsen.
When a resection is combined with a rectopexy, the recurrence rate is reduced to about 3-4%. Morbidity ranges from 4-23%. Constipation improves in 60-80% of patients, and continence improves in 35-60% of patients.
Perineal approaches have recurrence rates up to 50%, with low morbidity. Incontinence and constipation improve in about 50% of patients.
U.S. Pat. No. 6,706,057 discloses an applicator and method for a perineal approach for treating hemorrhoids and concurrent mucosal membrane rectal prolapses. The method comprises applying compression sutures or staples to trap the tissue to be excised distal to the anus, with subsequent excision of the prolapsed tissue or hemorrhoid. Such treatment is less likely to be effective for larger prolapses.
U.S. Pat. No. 6,332,888 discloses a method and apparatus for treating rectal prolapse, the method comprising the step of constricting the opening of the anus by applying sutures around the opening. The sutures are applied using a finger-guided surgical instrument with an ejectable substantially semi-circular needle. Unfortunately, this type of treatment would appear to suffer all the problems of using anal encirclement, including chronic constipation problems.
There remains a need for safe and effective methods of treating rectal prolapse.