Chapter 75 Anorectal Surgery
Surgery of the rectum and anus is associated with a high rate of complications. The high bacterial population of the rectum increases the risk of wound infection and dehiscence. Bowel preparation with multiple enemas can mechanically remove large numbers of bacteria; however, enemas should not be done within 8 hours of anorectal surgery to avoid leakage of rectal contents during surgery. Prophylactic antibiotics are indicated with surgery of this area due to high numbers of bacteria. Synthetic absorbable sutures or monofilament non-absorbable sutures are recommended for surgery of the rectum and anus.
RECTAL PROLAPSE
Preoperative Considerations
• Treat underlying diseases (e.g., parasitism) while attempting conservative management of rectal prolapse.
• Initial management consists of cleaning and lubricating the prolapse, determining viability of the tissue, and then manually reducing the prolapsed tissue followed by a loose pursestring suture. The pursestring suture should be loose enough to allow passage of loose feces, but tight enough to keep the prolapsed tissue reduced.
• The preferred surgical procedure is colopexy (see Chapter 70), unless there is non-viable tissue within the prolapsed segment of rectum that requires resection and anastomosis.
Surgical Procedure: Resection and Anastomosis
Technique
3. Place three or four stay sutures around the circumference of the prolapsed tissue through all the layers of tissue. The needle should be against the syringe case at its deepest penetration (Fig. 75-1A).
4. Resect the prolapse around 180 degrees of the circumference, caudal to the stay sutures (Fig. 75-1B).
5. Place synthetic absorbable sutures (3-0 or 4-0) through the full thickness of the incised bowel, being sure to incorporate the serosal layers. A simple interrupted appositional pattern is preferred (Fig. 75-1C).
6. Incise the remaining 180 degrees and suture as described in Step 5. Push the rectum cranially into the pelvic canal.
Postoperative Care and Complications
Short Term
• Give a stool softener (see Chapter 74) with food, which is offered the day after surgery. Continue giving the stool softener for 2 weeks.
• Closely monitor for leakage from the anastomotic site for at least 48 hours by observing the animal’s temperature, level of activity, eating habits, and signs of excessive pain around the anorectal region. Be careful when placing a rectal thermometer.
ANORECTAL STRICTURE
• Inflammatory causes include perianal fistulas, prior anorectal surgery (including cryosurgery), and accidental trauma.
• Adenocarcinoma of the rectum and anus is the most common cause of stricture, resulting in a scirrhous, annular ring-type lesion.
Surgical Procedure: Resection/Anastomosis with Rectal Pull-Through
Technique
3. When the lesion is cranial to the anorectal junction, make an incision circumferentially around the anal ring.
4. Continue the perirectal dissection to normal tissue just cranial to the stricture ring. Avoid trauma to the sphincter muscles.
5. Place four stay sutures circumferentially through the normal rectal wall just ahead of the stricture.
7. Pull the healthy tissue being held by the stay sutures caudally and appose to the anus. Avoid suturing under tension; mobilize more rectal tissue if necessary.
ANAL STRICTURE LIMITED
Surgical Procedure
