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.