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Colostomy is the operation of opening into the colon, or lower portion of the intestine. This procedure is one of the most important in abdominal surgery. It is sometimes necessary as a life- saving measure. It may be temporary or permanent as an artificial anus in the radical treatment of rectal cancer. Because of its appearance, its inconvenience and the very thought of an artificial opening in the abdominal wall a great deal of care is necessary to allay the anxieties of patients and their relatives when colostomy is necessary.
In some cases of acute intestinal obstruction the surgeon explores the abdomen and finds perhaps a large mass in the region of the pelvic colon or rectum that cannot be removed. An emergency colostomy is then performed in the transverse colon with the immediate purpose of saving life and with the further objective of providing temporary drainage should the growth be removable at a later date. In some such cases, when at first sight the primary cause of the obstruction seems beyond any possibility of surgical removal, after several weeks of colostomy drainage the infection subsides and the affected portion of bowel may then be removed. Colostomy may be necessary as a preliminary to other operations involving removal of the large bowel. Such an occasion arises if diverticulitis has produced vesico-colic fistula (between the colon and bladder). In some cases of severe incontinence due to abnormality or injury to the anus, a left iliac colostomy enables the patient to be free of the terrible inconvenience of perpetual soiling in the perineum. Injuries or abnormalities of the spinal cord produce paralysis of the anal sphincter mechanism and sometimes colostomy is essential. Congenital absence of the rectum or anus requires an emergency colostomy within a day or so of birth.
There are two main forms of colostomy. First is the loop colostomy which has two limbs. The opening is at the apex of the loop and the bowel has not been divided completely across. A variation of the loop colostomy is the double- barrel form in which the two limbs of the loop are separated by a piece of skinrafter complete division. This is also described as a defunctioning colostomy as it prevents the spill of faeces from the proximal to the distal loop. A second variety is the spur colostomy where a spur is formed by suturing the two ends together for several centimeters inside the abdomen. This is of particular value if the colostomy is temporary as the spur can be destroyed by a crushing clamp without risk of peritonitis or perforation since the limbs have become sealed together. When the spur breaks down, the artificial opening on the surface shrinks and sinks back below the skin level. The aim is that this should close spontaneously without further operation. The third type is the terminal colostomy in which the distal portion of bowel is removed completely or in the case of excision of rectum the lower end is closed to form a blind end. In grave emergencies the simplest form of colostomy is performed in which a loop of colon is brought out through the abdominal wall, where it is held by the insertion of a glass rod passed through a small hole in the mesentery. The ends of the glass rod are connected by a loop of rubber tubing which forms a 'bucket handle' . The abdominal wall is closed around the protrusion of the colostomy. Exteriorisation is another way of performing a colostomy. If a growth is present in a part of the bowel which can be brought readily through the abdominal wall (e.g. transverse or pelvic colon) the affected loop containing the growth is left outside and the peritoneum, muscles and skin are closed around the base of the loop where the two limbs converge. The loop of colon containing the growth is then removed, leaving two open ends of
el which can later be joined by crushing the spur between them. This operation avoids the handling of growth or unprepared bowel while the peritoneal cavity is open and so diminishes the risk of peritonitis. A formal operation for closure is required if a spur has not been made.
At the end of the operation a small incision is usually made in the apex of the loop to allow the immediate discharge of gas and faecal material which is collected as cleanly as possible before the patient leaves the theatre. A dressing of petroleum jelly gauze or tulle gras is applied on the exposed bowel. The skin incision may be sealed with Whitehead's varnish and a pad of cellulose tissue and wool is bandaged lightly over the opening. For fear of contaminating the abdominal wound before the peritoneal cavity has become sealed, the former practice was to leave the colostomy unopened for 48 hours. The initial opening may be enlarged by the surgeon two or three days after the colostomy has been raised. The bowel is usually divided (without anaesthetic) by an electric cautery which seals the blood vessels and prevents bleeding from the very vascular mucous membrane and muscle wall of the bowel. A method of draining the colostomy is by the use of Paul's tube. This is an angled wide glass tube which is inserted through a hole in the colostomy loop. It is tied in position in the same way as the caecostomy catheter and connected to a bedside jar with wide, thin, latex tubing.
 Research Colostomy
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