Coloanal anastomosis
Coloanal anastomosis is a surgical procedure that involves the removal of part or all of the rectum due to conditions such as colorectal cancer or severe dysplasia. The surgery connects the colon directly to the remaining rectal tissue or anal muscle, aiming to preserve anal function and maintain normal stool elimination over time. Typically performed in two stages, the first operation involves resection of the diseased rectum and the creation of a temporary ileostomy to allow healing. After a recovery period, a second surgery is conducted to reverse the ileostomy and restore normal bowel function.
Patient preparation is crucial and includes optimizing medical status, managing nutrition, and conducting various pre-surgical tests. Post-operative care involves pain management, monitoring for complications, and gradual dietary progression. While the procedure generally helps avoid the long-term need for a colostomy bag, it does carry risks, including pouchitis and infection. Overall, coloanal anastomosis aims to enhance quality of life by improving continence and anal sensation after surgery.
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Coloanal anastomosis
ALSO KNOWN AS: Low anterior resection of the rectum; Ileoanal anastomosis (J-pouch) surgery; coloanal pull-through; straight end-to-end anastomosis (EEA); Baker-style side-to-end anastomosis (SEA); colonic J-pouch to anal anastomosis (CJPAA)
DEFINITION: Coloanal anastomosis is the surgical removal of a portion of a diseased rectum or the entire rectum and the attachment of the colon to the remaining rectum or the anal muscle. This technique preserves anal function so that, in the long term, the process of eliminating stool remains nearly the same.
Cancers treated:Colorectal cancer
Why performed: Coloanal anastomosis is performed to treat cancer or severe dysplasia with inflammatory bowel diseases when other medical therapies have not been effective. It is also performed when a stricture or fistula is suspected.
Patient preparation: Before surgery, the patient’s medical status must be optimized by managing malnutrition, treating infection, and correcting anemia and dehydration. In some cases, (tube feeding) may be required before surgery to rest the bowel and reduce symptoms that may be occurring as a result of eating solid foods.
Tests before surgery may include biopsy, endoscopic evaluation, and radiography. Patients should receive thorough education regarding the risks, benefits, and expected outcomes of the proposed surgery. The healthcare team should discuss the patient’s expectations after surgery as well as the care of the temporary ostomy.
One week before the procedure, patients must stop taking anticoagulants, as directed by the physician, to reduce the risk of increased bleeding during surgery. In many cases, antibiotics are given to reduce the risk of infection. The day before surgery, the patient follows a clear liquid diet and should not eat or drink anything after midnight the evening before surgery.
Steps of the procedure: The procedure is usually performed in two stages. During the first surgery, the diseased portion of the rectum or the entire rectum is removed, and the bowel is reconnected to the remaining rectum or the anal muscle. The surgeon also creates a temporary loop ileostomy during the first surgery to divert stool into an external colostomy bag outside the body to allow the bowel to heal. In some cases, the side of the colon is attached to the anus (side-to-end coloanal anastomosis), and a small pouch is created from a section of the colon (about two inches long) to store stool until it is eliminated. With the procedure, a larger, J-shaped pouch is created. About six to eight weeks after the first surgery, a second surgery is performed to reverse the loop ileostomy and restore anal function. When discussing the surgical procedure, patients may wish to ask their surgeon about the need for a temporary diverting stoma.
After the procedure: Medications are given to manage pain, and an intravenous line delivers fluids and medications as needed. In some cases, nutrients are delivered intravenously until the patient is well enough to take food orally. A urinary catheter removes urine and is removed about two to three days after surgery. Tubes may be in place to remove fluids and bloody drainage from the wound. Anal leakage is common after surgery and occurs as a result of the stress on the anal muscles during surgery. It may occur for several weeks and can be managed by wearing a cotton pad.
The patient cannot eat or drink until bowel function is restored, as indicated by the passage of liquid waste. Bowel function usually returns a few days after surgery. The patient gradually progresses from a clear liquid diet to full liquids and soft, bland foods. The hospital stay lasts five to seven days depending on the patient’s recovery. The patient is encouraged to get out of bed and walk the day after surgery, and activity gradually progresses to several daily walks in the hall.
Before going home, the patient receives instructions from an enterostomal therapy (ostomy) nurse who teaches the patient about caring for the temporary ostomy, obtaining ostomy supplies, and managing potential complications such as stomal blockage. The patient receives specific activity and dietary guidelines. A follow-up schedule is provided, and home-care nursing services are scheduled as necessary. The patient can gradually return to regular activities, with a full return to normal activities within five to six weeks after being discharged from the hospital.
Risks: The most frequent complication is pouchitis, an inflammation of the pouch characterized by increased stool frequency, urgency, incontinence, abdominal cramps and pain, and flu-like symptoms. Other risks include wound infection, urinary tract infection, poor postoperative anorectal function, stricture of the anastomosis, anal fistula or abscess, and reduced fertility. Traditional primary coloanal anastomosis has a higher rate of pelvic sepsis than the two-stage Turnbull-Cutait procedure. The Turnbull-Cutait method also has a lower leak rate of 13 percent.
Results: Coloanal anastomosis surgery prevents the long-term need for a colostomy bag, maintains anal sensation, and improves continence after the rectum has been removed. Baker SEA and J-pouch procedure recipients usually require fewer antidiarrheal medications and have lower stool frequency. SEA and CJPAA procedures usually result in lower rates of anastomotic leak.
Bibliography
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