Colectomy (removal of the colon)

Indications:

• Cancer: Removal of the colon and rectum is the main stay of treatment for cancer. It can be curative or palliative at which time the surgery is performed to relieve symptoms. Colon surgery for cancer may be combined with other forms of treatment including radiotherapy and chemotherapy
• Polyps: Removal of the colon is performed for a condition called Familial Adenomatous Polyposis that is associated with numerous polyps in the colon at a young age. It carries a very high incidence of colon cancer and hence requires the removal of the entire colon to prevent malignancy
• Colitis: Colon resection may be performed in patients with inflammatory bowel disease (ulcerative colitis and Crohn's disease) with persistent, intractable pain and failure of medical treatment, intestinal obstruction, fistulae, bleeding, perforation, and marked dilatation of the colon
• Diverticular disease: Colon surgery is performed in patients with diverticulitis (acute inflammation of the diverticuli) with or without abscess formation, persistent profuse bleeding, or perforation of the bowel wall

Other conditions that may necessitate removal of the colon include ·

• intestinal obstructions
• perforation of the colon wall
• ischemic colon (lack of blood supply to the colon)
• toxic megacolon (massive dilatation of the colon)
• fistulae between the colon and other organs such as the bladder or vagina

Removal of the colon may be carried out as a scheduled procedure or as an emergency in life saving situations such as severe bleeding or perforation of colon. The extent of removal of the colon varies depending on the site of the disease. In the removal of the colon for cancer, all the lymph nodes that drain the tumor are also removed.

Preparation:

Before surgery, the bowel must be prepared to decrease the incidence of infection. Preparation begins a few days prior to colon surgery. The patient is placed on a low residue diet for 2-3 days prior to surgery and on liquids the day before surgery, with complete fasting from the midnight before surgery. The patient is usually admitted to the hospital on the day before surgery and is given some purgatives to cleanse the large bowel along with antibiotics. Intravenous fluids are given on the night before surgery to avoid dehydration resulting from the diarrhea due to the cleansing action of the purgatives. Intravenous antibiotics are usually administered just before surgery to reduce the incidence of infections--they may be continued after surgery.

Procedure:

The procedure is usually done under general anesthesia. An incision is made in the abdomen and is carried through the wall of the abdomen to expose the bowel. The diseased portion of the colon is identified and that part of the colon and its blood supplied is divided and removed. Care is taken to identify the ureters, small intestine and other organs so as to avoid injury to these organs.

In the last ten years, special instrumentation has greatly simplified the procedure. A stapler placed across the colon seals the colon on each side of the stapler and then cuts the colon between the staples. Likewise, a different type of stapler staples the anastomosis together. The anastomosis may also be sutured together by hand with individual sutures.

After surgery, the abdominal wound is usually closed although in cases with colon perforation, the wound may be left open and closed at a later date.

Sometimes, an emergency operation may need to be performed to remove the colon in cases with perforation of the colon, bleeding or diverticulitis. In such cases, a colostomy is usually performed. When a colostomy is performed the colon is brought out through a separate incision in the abdominal wall and sutured to the skin. Feces are then excreted in to a bag attached to the skin. This may be temporary or permanent.

Tumors or lesions in the ascending colon can be treated by an operation to remove the last part of small bowel, the ascending colon, hepatic flexure, and a small part of transverse colon (right hemi-colectomy). In a similar fashion, lesions of the descending colon and sigmoid are dealt with by left hemi-colectomy (removal of descending colon and adjoining parts of sigmoid colon, splenic flexure and part of transverse colon) and sigmoid colectomy respectively. After removal of a segment of colon, the two ends of the bowel are joined together (called an anastomosis). Tumors in the upper part of rectum and lower part of sigmoid colon are dealt with by an operation called an anterior resection, wherein the rectum and sigmoid colon are removed and lower end of the rectum is joined to the colon. Removing the entire rectum and part of the sigmoid colon (abdomino-perineal resection) is used in the treatment of tumors low in the rectum. The end of the remaining colon is brought out as a colostomy. Polyps or tumors that are very low in the anal canal can sometimes be resected from below, through the anus (transanal resection of the tumor).

Complications:

In addition to the routine complications of any general anesthetic, there can be complications as a result of the colon surgery. These include:

• postoperative bleeding
• dehiscence or breakdown of the anastomosis
• recurrence of tumor
• wound infection
• urinary or respiratory infections
• deep vein thrombosis with or without pulmonary embolism
• urinary retention
• adhesions with bowel obstruction
• injury to the ureter
• obstruction at the anastomosis site

Recovery:

The recovery period after colon surgery is widely variable. It usually involves a stay in the hospital from 3-10 days in uncomplicated cases. The patient will have a catheter in the urinary bladder for a few days and will be given adequate pain relief, intravenous fluids, antibiotics etc. For patients who do not have any oral intake for several days, nutrition may be provided intravenously or through a tube in the stomach or bowel. The function of the bowel is monitored closely to await the passage of gas and stool after surgery. The patient then gradually begins to take liquids by mouth and solid food later on, following which they will be discharged home.

After discharge, the patient resumes normal activity in 1-3 weeks. Heavy exertion and lifting weights is avoided for 4-6 weeks. If a colostomy is required, the patient receives instruction on its care.

Laparoscopic Colon Surgery

Because of recent advances in instrumentation, colon surgery can also be performed using the laparoscope. This method employs the use of a long tube containing a light and lens system for visualization and special instruments for manipulating the bowel through small incisions in the skin called ports. This surgery, however, is still in its development phase and is not widely done.