by Krisha McCoy, MS
Anatomy and Physiology
The colon, or large intestine, is a long, muscular tube located at the end of the intestinal tract. After the stomach and small intestine digest food, the remaining material passes through the colon, where water and electrolytes are absorbed. The residual stool passes into the last six inches of the colon, known as the rectum, where it is stored until released.
Most of the conditions that are treated by colon resection, including colorectal cancer, occur in the layer of cells that cover the inside surface of the colon, known as the mucosal lining.
Reasons for Procedure
Colon resection is usually performed to treat colorectal cancer, one of the most common cancers. It may also be used, however, to treat other conditions, including: blockage of the intestine from any cause, ulcerative colitis and Crohn's disease, especially when medicines fail to control these conditions or if cancer develops, trauma to the intestine, colon polyps, especially when numerous and large or if they cannot be removed during colonoscopy, frequent recurrences or complications of diverticulitis, ischemic bowel.
Essentially all colorectal cancers are believed to begin as benignpolyps, which usually cause no symptoms. Although colorectal cancer may initially cause no symptoms, it can eventually produce: changes in bowel habits, blood in the stool, stools that are narrower than usual, abdominal discomfort, unexplained weight loss or fatigue.
A colonoscopy is used to diagnose colon polyps or cancer. It may be done as a routine screening examination in people over 50, or earlier if family members have had colon polyps or cancer. It may also be done to find the cause of signs or symptoms related to the colon.
To determine whether an abnormality in the colon is cancerous or not, doctors often remove tissue samples during the colonoscopy and send them to a lab for testing.
The three standard types of treatment for colon cancer are: colon resection, the most common and primary treatment; Chemotherapy Radiation therapy.
The type of treatment you receive will depend on a number of factors, including how far your cancer has progressed through the colon wall and your general state of health. Most colon polyps can be removed during colonoscopy in a technique called polypectomy. If cancer cells are discovered in the polyp, the polypectomy procedure may have successfully treated the cancer. However, since colon cancer can spread into the colon wall and beyond, additional treatment may be needed if cancer cells are seen near the polyp's edge.
Other less commonly used treatments for colon cancer include: biologic therapy, which is the use of medications to boost or direct your immune system to fight cancer; radiofrequency ablation, which uses a special probe with tiny electrodes that kill certain kinds of cancer cells; cryosurgery, which uses a special instrument to freeze and destroy abnormal tissue.
When colon resection is performed for colon cancer, your surgeon will remove the cancer, along with an adjacent margin of normal tissue to increase the chances that all of the cancer is gone.
As an alternative to traditional, open surgery, laparoscopic surgery for colon cancer is sometimes performed. In a laparoscopic procedure, a lighted instrument equipped with a camera and small surgical instruments are inserted through tiny incisions in the abdomen. Laparoscopic surgeries require smaller incisions and allow for quicker recovery times than open surgeries. However, not all colon cancers can be safely removed with this newer technique.
In the days leading up to your colorectal resection: Arrange for a ride to and from the hospital and for help at home as you recover. Your doctor may recommend taking antibiotics. Your doctor may ask you to temporarily discontinue any medications, herbs, or dietary supplements you normally take. Do not begin taking any new medications, herbs, or dietary supplements unless instructed by your doctor. Drink plenty of fluids: up to eight 8-ounce glasses of water daily.
Your doctor will have you clean out your colon, which may involve enemas, special laxatives, and a clear liquid diet. The night before your surgery, eat a light meal, and do not eat or drink anything after midnight. You may be asked to shower the morning of your procedure with a special antibacterial soap.
Most uncomplicated colon resections take 1-4 hours. Before the surgery, you will be given general anesthesia to put you to sleep for the duration of the operation. This will involve the insertion of a breathing tube through your mouth and into your windpipe to help you breathe.
Your surgeon will begin by making an incision in your abdomen over the part of the colon that needs to be removed.
Your surgeon will clamp your colon in two places, on each side of the section to be removed. He or she will cut through the colon at each clamp and remove the diseased portion in between, along with a margin of healthy colon and surrounding tissue.
If your intestine needs extra time to rest and heal, your surgeon may perform a colostomy. Although this is not routinely done when a colon resection is performed to treat cancer, it may be necessary if your cancer is complicated by an infection or severe inflammation.
When a colostomy is needed, the lower end of your intestine is sewn shut, and the other end is pulled through an opening created in your abdomen. This opening, called a stoma, will allow the contents of the colon to come out into a collection pouch, or ostomy bag. In most cases, the colostomy is temporary.
If a colostomy is not required, your surgeon will sew the two loose ends of the colon together using one of a number of techniques.
After your surgeon has completed the procedure, he or she will insert one or two drains to collect fluid that may accumulate around the surgery site, close the wound with sutures or staples, and cover it with bandages. If a colostomy was performed, an ostomy bag will be attached to the opening in your abdomen.
Risks and Benefits
Possible complications of a colon resection include: damage to the remaining colon, small intestine, or other neighboring organs, accumulation of blood or fluid in the area of the surgery, wound infection, blood clots in the legs that may travel to the lungs, a hernia at the incision site, intestinal blockage from excess scar tissue, adverse reaction to general anesthesia.
Possible benefits of colon resection include: removal of colorectal cancer and other life-threatening conditions, decreased risk of colorectal cancer coming back, removal of diseased areas of the colon caused by other serious conditions, relief of intestinal blockage.
If the cancer has already spread beyond the inside lining of your colon, a colon resection would not necessarily eliminate all of the cancer from your body. For this reason, additional treatment such as chemotherapy and/or radiation is often recommended.
In a colon resection, or any procedure, you and your doctor must carefully weigh the risks and benefits to determine whether it is the most appropriate treatment choice for you.
After the Procedure
After your procedure, you will: be taken to the recovery area for close observation; be given antibiotics and pain medications as necessary; receive fluids and nutrition through an IV, then gradually progress from a liquid to a solid diet over several days; be encouraged to get out of bed and move about as soon as possible; most colorectal resection patients remain in the hospital for 5-7 days.
If you had a colostomy, a health care professional will teach you how to care for the opening and bag. You may be advised to avoid high fiber foods in the first weeks after your operation. It is important to drink eight 8-ounce glasses of liquid a day and avoid using laxatives.
In most cases the ostomy bag is left in place for several months while your intestine heals. Occasionally, however, it is permanent. If and when your surgeon determines the bag can be removed, you will undergo another surgical procedure to reconnect the two ends of the colon and close the opening in your abdomen. This will restore the original flow of stool through your colon and rectum.
After you leave the hospital, you should contact your doctor promptly if you experience: signs of infection, such as fever or chills, increasing or persistent abdominal pain or bloating, increased or persistent swelling, redness, or discharge from the wound, nausea and vomiting, blood in your stool, or black tarry stools, constipation, weakness or dizziness, cough, chest pain, or shortness of breath, pain and/or swelling in your feet, calves, or legs, pain, burning, urgency, or increased frequency of urination, persistent bleeding in the urine.
In addition, if you have a colostomy, be sure to contact your doctor promptly if: you need to change the ostomy bag more than twice or three times a day, there is bleeding from the opening, there is no stool in the ostomy bag, you notice irritation, moistness, redness, swelling, or sores around the abdominal opening.
- American Gastroenterological Association. Colorectal cancer: treatment. Mayo Foundation for Medical Education and Research website. Available at: http://www.mayoclinic.com/invoke.cfm?objectid=13D504C5-40A0-40DA-9F61138EEAAE162F&dsection=7. Accessed September 10, 2004.
- General information about colon cancer. Colon Cancer (PDQ):Treatment. National Cancer Institute website. Available at: http://www.cancer.gov/cancertopics/pdq/treatment/colon/Patient. Accessed September 10, 2004.
- National Digestive Diseases Information Clearinghouse. The Clinical Outcomes of Surgical Therapy Study Group. A comparison of laparoscopically assisted and open colectomy for colon cancer. New England Journal of Medicine. 2004;350:2050-2059.
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