Loop Colostomy and Colostomy Closure
A loop colostomy is the easiest colostomy to make and to take down. It is used in situations in which temporary (often emergency) decompression or diversion of colonic contents is required. In many situations, a loop ileostomy (see Chapter 92) is preferred and used. In this chapter, the construction and closure of a right transverse colostomy is illustrated. The equivalent laparoscopic procedure is shown in Chapter 98e.
SCORE™, the Surgical Council on Resident Education, classified colostomy and colostomy closure as “ESSENTIAL COMMON” operations.
STEPS IN PROCEDURE—LOOP COLOSTOMY
Short transverse right upper quadrant incision
Deliver transverse colon into incision
Remove greater omentum from selected segment of colon
Create a window under the colon, at the antimesenteric border
Tack the loop to the fascia
Pass a colostomy bridge under the loop and secure it
Close skin around loop, if necessary
Open and mature colostomy by suturing mucosa to skin
Place appropriate colostomy bag
HALLMARK ANATOMIC COMPLICATIONS—LOOP COLOSTOMY
Failure to divert
Prolapse of defunctionalized limb
LIST OF STRUCTURES
Greater omentum
Transverse colon
Hepatic flexure
Middle colic artery
Marginal artery (of Drummond)
Rectus abdominis muscle
Anterior rectus sheath
Superior epigastric artery
The conventional terminology for various parts of the colon is shown in Figure 97.1A. The hepatic and splenic flexures are the points at which the relatively fixed ascending (sometimes called the right) colon and descending (sometimes called the left) colon transition to the mobile transverse colon. They are anchored by peritoneal bands. The transverse colon is normally covered by the greater omentum, which hangs down like a large fatty apron. The greater omentum must be lifted to expose the transverse colon. The relationships of the omentum, stomach, and transverse colon are shown in Figure 97.1B.
Isolation of Loop (Fig. 97.2)
Technical Points
Make a short (about 10 cm in length) transverse incision in the right upper quadrant. Do not make the incision too far laterally. The transverse colon becomes deeper and higher in the vicinity of the hepatic flexure (lateral) and more mobile in the midsection (medial).
Identify the colon by its overlying greater omentum. Mobilize a greatly distended and dilated colon with caution to avoid spillage of enteric contents. If the incision is not large enough to deliver the loop comfortably, enlarge the incision. Observe the character of the peritoneal fluid. If it is turbid or purulent, a colonic perforation may have occurred. In this case, proceed with a full laparotomy.
Divide the omentum to expose the colon by serially clamping and tying it. Develop a mesenteric window under the colon by passing a clamp or finger through an avascular portion of the mesocolon. Pass a Penrose drain under the colon and use it to elevate the colon.
