Rectum: prolapse - surgical management (Anorectal prolapse, everted rectum, everted anus, anal prolapse)

Jump to... Requirements Preparation Procedure Aftercare Sequelae Sources

• Rectal prolapse  is protrusion of a portion of the rectum or rectal mucosa through the anus, usually caused by an underlying disorder. Just about any gastrointestinal (enteritis ) or urogenital condition (dystocia, urethral calculus ) that causes tenesmus can result in rectal prolapse. The problem is most commonly seen in young cats afflicted with endoparasitism. Laxity of the anal sphincter (Manx cats with sacral-caudaly dysgenesis-young cats ) or perianal connective tissue (perineal hernia with rectal sacculation - older cats) may also predispose cats to this condition. Constipated cats with megacolon can develop rectal prolapse from persistent straining. It is critical for the surgeon to be aware of predisposing cause(s) because the success of the surgery often correlates with proper treatment of the primary cause of tenesmus. For example, in the case of a cat with idiopathic megacolon and a rectal prolapse, after medical management fails, reduction of the prolapse until simple subtotal colectomy is often successful. Attempts at directly treating the rectal prolapse without successful management of the megacolon will routinely result in failure.
• There are three surgical techniques designed to treat/prevent rectal prolapse (perianal pursestring suture, colopexy, and rectal resection). The choice of technique depends on the underlying condition (whether it can be successfully treated and if it is recurrent or not) and on the viability of  the prolapsed tissue.
• A thorough physical and rectal examination should be performed. Additional diagnostics such as fecal analysis , complete blood count , chemistry panel, urinalysis and culture , abdominal and thoracic imaging may be required. Rectal examination under sedation should be performed in older cats to detect perineal herniation. It is critical that the primary cause of the prolapse be identified and treated.
• Rectal prolapse must be differentiated from intussusception , particularly in cats. The latter must be approached from the abdomen for treatment. Insert a finger or probe alongside the prolapse: if the probe can be inserted cranially more than a few centimeters, the condition is an intussusception.
• Treatment of the prolapse should be prompt to reduce further trauma. Extensive colorectal preoperative preparation is often not necessary. Partial rectal prolapse (mucosal eversion only)   is quite common in very young cats, and these should be protected from self-trauma by using a Elizabethan collar until the primary condition is properly treated. 

• Pursestring sutures are relatively quick and easy to perform with little risk of complications. Since this is the least expensive and least invasive technique, it is usually chosen first when the condition causing the tenesmus is expected to be eradicated with medical therapy.
• Colopexy requires an invasive midline laparotomy , but the technique is readily performed, with little additional risk to the patient.
• Rectal resection is performed outside the patient's body to excise diseased tissue, so contamination of sterile tissues during surgery is minimized. Rectal resection has the advantage of removing the diseased portion of the rectum and additionally it eliminates redundant rectum, thereby decreasing the risk of re-prolapse. There is more danger of serious complications with this technique so it is performed only when absolutely necessary and with owner's full understanding about the risks.

• Pursestring sutures are often unsuccessful unless the condition causing the problem is readily treatable, and tenesmus can be controlled.
• Colopexy is an invasive treatment, and recurrence may occur if the cause of the tenesmus is not controlled.
• Rectal resection has several serious postoperative complications, such as stricture formation , incontinence, and dehiscence which may be life-threatening.

• Pursestring sutures must be tightened just enough to prevent recurrence but not too tight to cause obstruction of fecal matter. The amount of suture tightening required is a judgment decision for each patient.
• Colopexy must form a strong fibrous adhesion between the terminal colon and the left abdominal wall and this is best achieved by removing the peritoneal lining between the two structures. Scarifying or removing the serosal layer of the colon should be performed with caution to avoid contamination from an inadvertent penetration of the wall. Excessive traction of the colon during the procedure can cause temporary or, more rarely, permanent fecal incontinence.
• Rectal resection: the inner "tube" of the prolapse is often under considerable tension, so complete excision of the affected prolapsed tissue should only commence after the prolapse is fixed in position with stay sutures or long pins. If the prolapse is excised circumferentially without some form of fixation, the inner "tube" will slip back into the pelvic or abdominal cavity and become lost. If excess tension is placed on the anastomosis, there will be increased risk of stricture formation or dehiscence. When excess rectal tissue is removed, partial or complete fecal incontinence may occur.

• Pursestring: reduction is usually completed within 10 minutes.  Skin preparation, 5 minutes.
• Colopexy: abdominal skin preparation, 10 minutes.
• Rectal resection: lavage and cleansing of prolapse, 10 minutes.

• Pursestring: 5-10 minutes.
• Colopexy: 30-60 minutes.
• Rectal resection: 30-45 minutes.

• If the prolapse is acute and viable, and the cause can be treated and resolved medically, the pursestring suture technique is usually successful.
• When the prolapse reoccurs despite appropriate therapy, colopexy is considered. Colopexy is reserved for conditions in which the rectum is not irreversibly affected, especially when other surgical treatments have been unsuccessful. This technique can be considered only when the prolapse appears reducible.
• Rectal resection is reserved for patients with necrotic prolapsed tissue, when the prolapse is irreducible (rare), or when primary rectal disease (such as neoplasia) needs to be removed to eliminate the cause of the persistent tenesmus.

• Choose the least invasive and risky technique to treat the prolapse.  See disadvantages section above for complication risk related to the three techniques.

• None of the techniques requires a board certified surgeon. The techniques can be readily performed by the general practitioner.
• Pursestring: entry level surgeon.
• Colopexy: some surgical experience suggested.
• Resection: experienced surgeon in practice.

• Provided the patient is otherwise in good health, no particular anesthetic expertise is required.

• None required.

• General surgery pack of instruments.

• Balfour retractors to help with exposure during colopexy.

• Suture material (see technique below for suggestions). 
• 4x4 sponges.
• Draping and laparotomy pads for the colopexy.

• Sedate the patient especially if you contemplate using epidural anesthesia (recommended). Epidural anesthesia  is an excellent method to safely provide analgesia for the procedure and reduce tenesmus during and immediately following surgery.

• Food is withheld for patients undergoing general anesthesia .

• To aid in reduction of the prolapse before pursestring suture or colopexy, lavage the prolapsed tissue with saline, and lubricate the area with a water soluble gel. Manually reduce the viable prolapse carefully with a lubricated gloved finger. Some surgeons have been successful in reducing severe rectal edema using hypertonic solutions of dextrose.
• Standard abdominal preparation for laparotomy when colopexy is chosen.

• No intestinal preparation is necessary.

• The patient is positioned in ventral recumbency with the rear limbs draped over a padded table edge for both the pursestring and rectal resection techniques; dorsal recumbency for colopexy.
• Anesthesia concerns: if the patient is in a Trendelenburg position (head down ventral recumbency), be aware that ventilation may have to be assisted throughout the procedure due to reduced tidal volume from abdominal viscera pressing on the diaphragm.

• After aseptic preparation and draping of the ventral abdomen, an incision is made through the linea alba extending 5-10 cm cranial to the umbilicus to 1-2 cm from the pubis.

Perineal exposure for pursestring suture or prolapse resection technique

• Clip and aseptically prepare perineal skin, extending well away from the anus.

• Reduce prolapse - see description above.

• 3-0 monofilament nonabsorbable material is used; an appropriate size cutting ½ circle needle should be chosen.

• Plan on taking 6 needle bites of tissue to complete the pursestring. Bites should penetrate full thickness skin, be equally spaced and between 4-6 mm in length (depending on the size of the cat). Avoid the 4-5 and 7-8 o'clock regions so the anal sac or neck is not damaged. Place suture bites at least 0.5 cm away from the mucocutaneous junction.  Leave the ends long such that hand-tying can be performed .

• For small cats, snug the suture around a 14 French red rubber catheter;  for larger cats, a standard pencil size or a probe is chosen. The goal is to tighten the pursestring suture just enough to prevent prolapse of rectal wall and allow fecal material and gas to escape.

• Tie at least 4-6 square throws to complete a secure knot. Alternately, some surgeons will create one square throw and use a lead fishing split-shot to secure the pursestring. The split shot can be removed/replaced and the suture tightness can be adjusted without resorting to placement of a new pursestring.

• Perform a standard midline laparotomy approach (described above)  .

• Identify the colon and retract the abdominal wall laterally to expose the left inner abdominal wall surface.
• If the prolapse could not be reduced before surgery, gently grasp the colon and pull while an assistant pushes the prolapse forward with a lubricated gloved finger.

• Create a 5-7 cm incision (depending on the size of the patient) through the transversus abdominis muscle only, parallel to the linea alba about 3-5 cm away from the incised linea alba edge. The caudal part of the incision is located 5 cm cranial to the pelvic inlet.

• In an area adjacent to the left abdominal wall incision, gently scrape or roughen the surface of the colon with a scalpel blade. 
   More than one traditional technique (incisional/nonincisional) exists - the author prefers to use a different modified technique.

• With the colon held under light tension, pass the needle from the edge of the denuded colon (starting at the caudal aspect), with 4-0 monofilament absorbable suture on a taper needle. Interrupted, horizontal mattress, or continuous sutures are placed through the submucosa of the colon and into 0.5 cm of the incised edge of abdominal muscle. Avoid penetrating the colonic mucosa with the needle. Sutures are placed evenly, and separated 0.5-1 cm from each other. Preplacing the sutures may help the surgeon secure the colon to the abdominal wall with more even tension. The suture line is completed on the dorsal aspect first and finished on the ventral, or more exposed aspect, last.

Rectal resection/anastomosis

Step 1- Fix the rectal tube in preparation for resection

• Four full thickness stay sutures are placed at the 6,9,12, and 3 o'clock positions through both layers (tubes) of the prolapse with an inexpensive suture material . This fixes the inner rectal tube to the outer tube to prevent slippage during resection and suturing. A 18 French catheter can be used to help determine if the suture is catching the inner tube of rectal wall. Stuff a small gauze sponge well cranial into the rectum to reduce fecal contamination of the surgery field. Be sure to note that the gauze sponge is inserted - to ensure it will be removed following the surgery.

Step 2 - Resect the rectal prolapse

• Using a scalpel blade or Metzenbaum scissors resect the diseased prolapse, and attempt to leave at least 1cm of healthy rectum caudal to the anus . Alternately, some surgeons will incise just half the circumference first, suture these incised edges, and then complete the circumferential incision and repair.

Step 3 - Complete the full thickness, single layer anastomosis

• Using 4-0 monofilament absorbable suture .

• Routine anesthetic monitoring during recovery is recommended.
• The patient should be monitored for straining and signs of pain after surgery. (see analgesia section)
• Self-limiting rectal bleeding is expected for up to several days after resection of a prolapse.

• In most cases, if the anesthesia was uncomplicated and the patient is otherwise healthy and hydrated, maintenance isotonic fluids are administered until the patient is able to eat and drink.

• Preoperatively, a narcotic or local anesthetic epidural should be considered. Additional epidural administration of analgesics can be done after surgery if necessary.
• If there are no contraindications to do so, appropriate nonsteroidal anti-inflammatory drugs are given for 3-5 days after surgery.
• Breakthrough pain or continued straining can be managed with narcotics intermittently given as needed or as a constant rate infusion.
• Local anesthetic or steroid suppositories may help reduce local pain following surgery.

• In most uncomplicated cases, antibiotics are not warranted during or after surgery. If the prolapse is necrotic, or fecal contamination occurs during surgery, the contaminated area should be irrigated with warm sterile saline, and intravenous antibiotics (such as a potentiated penicillin agent (clavulanic acid-amoxicillin ) or a second generation cephalosporin antibiotic (cefoxitin ) are given. Continue oral antibiotic therapy afterwards for 7-10 days.

• Lactulose , a stool softener, works particularly well after surgery.
• Local anesthetic or corticosteroid suppositories are useful to reduce local irritation and pain after surgery.

• Place an Elizabethan collar on the patient if a pursestring suture technique is performed.
• Stool softeners should be considered if the fecal matter is firm to help reduce discomfort while voiding and decrease straining after surgery.
• If the wounds are primarily closed, no wound protection is necessary.
• Elizabethan collars are used after the pursestring technique.

• Remember to treat the primary cause of the rectal prolapse.
• Do not use a rectal thermometer or perform digital rectal examination after the prolapse resection technique for at least 7 days.
• Remove pursestring sutures generally 3-5 days after surgery.

Pursestring technique

• Obstruction of feces/remove pursestring suture and replace, loosen suture.
• Persistent straining/rule out obstruction, give appropriate analgesic and anti-inflammatory drugs, look for causes of the straining
• Recurrence/redo the pursestring and be sure primary cause has been treated successfully, or consider colopexy next.

Colopexy

• Persistent straining/rule out obstruction, give appropriate analgesic and anti-inflammatory drugs, look for causes of the straining.
• Mild incontinence/keep patient in confined area, wait of condition to improve.
• Recurrence/consider resection if the primary cause of the prolapse has been successfully managed, otherwise, treat the primary cause aggressively.

Rectal prolapse resection

• Stricture/careful dilation of the narrowed rectum is done under anesthesia. This may have to be performed weekly, and multiple times. If the stricture cannot be managed with dilation, consider resection of the stricture.
• Dehiscence/open and drain perirectal tissue adjacent to perforation.  Attempt to reduce swelling, inflammation and infection by frequent irrigation and cleansing of local tissues, and antibiotic therapy. When inflammation is contained, consider repairing the perforation and patching area with a vascularized internal obturator muscle flap. If all else fails, a diverting colostomy can be performed.
• Recurrence/be sure primary cause has been successfully managed, otherwise, aggressively treat primary cause. If colopexy has not been performed previously, consider this procedure.

• Remember to treat the primary cause of the straining that resulted in prolapse.

• If external skin sutures were used, remove the sutures at the 10 day to 2 week recheck appointment.
• Continue to treat primary cause of the prolapse and make follow-up visits to ensure the problem has been managed appropriately.
• Consider a rectal examination after rectal prolapse excision at 2-4 weeks after surgery. Determine if stricture formation is occurring.

• The prognosis after surgery with all techniques is generally good provided the primary cause of the prolapse has been managed successfully, straining is controlled, and the appropriate surgical procedure was performed correctly.
• For example, in a young patient with endoparasites, successful treatment of the parasite and temporary pursestring suture of a viable prolapse is usually curative.
• Manx cats with anal laxity due to sacral-caudal anomaly generally have a guarded to poor prognosis even when surgery is performed.

• Wrong choice of procedure for condition, failure to treat primary cause of the prolapse, failure to manage straining after surgery, poor technique.

• Recent references from PubMed.
• Popovich C A et al (1994) Colopexy as a treatment for rectal prolapse in dogs and cats. Vet Surg 23, 115-118 PubMed.

• Aronson L (2003) Rectum and Anus. In: Slatter D H editor, 3rd edition Textbook of Small Animal Surgery. W B Saunders, Philadelphia, pp 686-688.

• Dr Daniel Smeak DVM DipACVS
• Dr Rosa Ragni DVM DipSPCA MRCVS

Back to top
© Copyright Vetstream

FELIS TEQ60076

---