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166 Kozol
It is not uncommon to encounter patients taking anticoagulant medications for a
variety of conditions. The most common example would be patients taking coumadin for
atrial fibrillation or for deep venous thrombosis or pulmonary embolism. In such cases,
the physicians who care for the patient must determine a perioperative plan for the
patient’s anticoagulation. If the indication for the anticoagulation is questionable, the
anticoagulant may be stopped indefinitely. If however, anticoagulation is a necessity, as
in protection of a prosthetic heart valve; the following procedure is frequently followed.
The patient is instructed to stop taking coumadin 1 or 2 d prior to admission. The patient
is admitted the day prior to surgery and is given intravenous-iv-heparin. The purpose of
this regimen is to convert from anticoagulation, which is slow to reverse (coumadin) to
anticoagulation, which is rapidly reversible (heparin).
The intravenous heparin is then stopped about 2 h prior to surgery. The heparin is
restarted 4–8 h postoperatively depending on the magnitude of the operation. Finally, the
patient resumes his/her coumadin prior to discharge.
PROCEDURE
Elective colon surgery requires bowel preparation. The goal of bowel preparation
is to diminish the bacterial load logarithmically. The mechanical portion of the prep
is accomplished by oral laxatives, which have replaced old-fashioned enema preps.
The oral prep may be performed with a high volume solution of polyethylene glycol
plus electrolytes, with Fleets phospho-soda solution, or with magnesium citrate. Additional antimicrobial preparation is achieved via the oral intake of poorly absorbed
antibiotics such as neomycin and erythromycin base. Preoperative bowel preparation
has lowered infectious complications of colon surgery from double-digit rates to singledigit rates.
As with many operations, a picture or a diagram may be worth a thousand words for
understanding the operation. The following description will allow better understanding of the diagrams. Most colon surgery is performed via a vertical midline incision.
The colon receives its blood supply from arteries, which originate from the anterior
surface of the aorta. The arteries are the superior mesenteric and the inferior mesenteric arteries. The SMA branches supply 80–90% of the colon with arterial blood and
the IMA 10–20%. The anastomosis between SMA and IMA branches occurs along the
left side of the colon. The ascending and descending colon are fixed by peritoneal
attachments. The transverse colon and sigmoid colon are mobile. The blood supply
and lymphatics to the colon are contained in a sheet of fibrofatty tissue known as
the mesocolon.
Any colon resection involves mobilization of the colon. To mobilize the ascending or the
descending colon involves dividing peritoneal attachments laterally and lifting the colon into
a midline position, with the colon still attached to the aorta by the mesocolon (3).
The resection margins are selected. At this point, the surgeon may choose to divide
the colon at the proximal and distal resection margin or to divide the mesocolon first.
The division of the mesocolon involves clamping and tying off branches of the mesenteric arteries and veins. The colon may be divided at resection margins by use of a
linear stapler or using a scalpel between bowel clamps. Once these two steps are
accomplished, intestinal continuity is reestablished by using suturing or stapling tech-
Chapter 15 / Colonic Resection 167
Fig. 2. (A) Schematic diagram of an end colostomy. (B) A mucus fistula.
niques. Regardless of technique chosen, there are three technical requirements for a
successful colonic anastomosis:
1. An adequate lumen.
2. An adequate blood supply.
3. Lack of tension on the anastomosis.
Attention to these technical requirements during the operation may prevent postoperative complications such as leakage and stricture formation.
If the colonic resection is an emergency procedure and the colon is not “prepped” as
aformentioned, or there exist extraordinary intraoperative problems, a colostomy may
need to be performed. A colostomy involves bringing the colon to the anterior abdominal
wall. A hole is created in the anterior abdominal wall. There are two common ways to
create the colostomy. One way is to divide the colon. With this technique, the proximal
end is brought through the hole in the abdominal wall as an “end colostomy” (Fig. 2A).
In these cases, the distal colon is either closed and dropped back in the abdomen “the
Hartman procedure” (Fig. 3A and B), or, it also is brought through the abdominal wall
as a mucous fistula (Fig. 2B).
The second type of colostomy is a “loop colostomy.” With a loop colostomy, the colon
is not divided. Instead, a loop of colon is brought through a hole in the anterior abdominal
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Fig. 3. (A) The Hartman operation. Resection of tumor containing bowel. (B) Creation of a
colostomy, and oversewn blind rectal stump (Adapted from Shackelford’s Surgery of the Alimentary Tract, Vol IV, 5th ed. WB Saunders, Philadelphia, PA, 2002).
Fig. 4. Schematic diagram of a loop colostomy.
Chapter 15 / Colonic Resection 169
Fig. 5. Anatomy after right hemicolectomy. The terminal ileum is then anastomosed to the
transverse colon.
Fig. 6. Anatomy after sigmoid colectomy. The descending colon is then anastomosed to the rectum.
170 Kozol
wall (Fig. 4). The anterior surface of the loop is opened allowing egress of stool. With
either type of colostomy, an appliance is placed over the ostomy for collection of stool.
As with colectomy with primary anastomosis, colectomy with colostomy may be associated with complications (4). The normal configuration of the colon is seen below in
Fig. 1. The anatomy after right hemicolectomy and sigmoid colectomy are seen in Fig.
5 and 6, respectively. The anatomy after left hemicolectomy is seen in Fig. 7.
COMPLICATIONS
Complications of colonic surgery may be considered in two groups, generic complications and complications specific to intestinal surgery. Generic complications include
atelectasis, pneumonia, deep venous thrombosis, urinary retention, wound infection,
fascial dehiscence, and myocardial infarction. The incidence of any of these complications varies according to risk factors such as age, cigarette smoking, obesity, and presence of comorbid conditions such as diabetes mellitus. Some complications are
preventable with proper perioperative care. Examples include proper bowel preparation
and prophylactic antibiotic use to reduce the risk of wound infection. Another example
is the use of mechanical compression stockings and/or mini-dose heparin to prevent deep
venous thrombosis. A detailed discussion of generic complications is beyond the scope
of this chapter.
Complications specific to bowel surgery include anastomotic leak and anastomotic
stricture. Anastomotic leak can be caused by a variety of factors, most commonly
errors in technique (5). Leaks may also be caused by an inadequate blood supply or by
undue tension on the anastomosis. Anastomotic leaks are generally serious complications and usually present with signs of sepsis. These signs include oliguria, tachycardia, fever, and leukocytosis. The patient may also develop abdominal or pelvic pain
beyond expected postoperative pain.
If an anastomotic leak is suspected, it may be confirmed with a gastrografin enema or
with a CT scan with rectal contrast. Minor leaks that have sealed may be treated with
percutaneous drainage, a nasogastric tube, and iv antibiotics. However, most commonly
the patient will require diversion of the fecal stream with a proximal colostomy or
ileostomy plus drainage of any abscess cavity (6). The use of an ostomy under these
circumstances is usually temporary. The patient may then have restoration of the GI tract
with colostomy takedown 6 wk–3 mo postoperatively. Anastomotic leaks occur in approx
5% of colonic resections. The leak rate is higher with rectal (low-pelvic) anastomoses.
Anastomotic stricture is a late complication, presenting 6 mo to years postoperatively.
These strictures are usually caused by low-grade ischemia at the anastomosis or a subclinical leak. In the latter case, the inflammatory response results in fibrosis over time
strictures present with constipation, cramping discomfort, bloating, or narrow caliber
stools. Strictures occur in less than 10% of colonic resections. They may be treated with
endoscopic dilatation in some cases. Significant strictures often require surgical revision
of the anastomosis.
The complication rates for colectomy are very well established and are reflected in
Table 2.
All other complications such as myocardial infarction, deep venous thrombosis and
pulmonary embolism occur in only 1–3% of cases. The 30-d postoperative mortality for
colonic resection is 1–6% depending on the series reviewed.
Chapter 15 / Colonic Resection 171
Table 2
Common Complications
After Colon Resection
Generic Complications in a Large
Series of Colonic Resections
Prolonged ileus 7.5%
Pneumonia 6.2%
Respiratory failure 5.7%
Urinary tract infection 5.0%
Table 3
Bowel Function After Coletomy
Extent of Resection Early (1–3 mo) Bowel Changes Long-Term Bowel Changes
Segmental Colectomy 2–4 BMs/d may be “loose” No discernible change
(1–2 ft)
Hemicolectomy 2–4 BMs/d may be liquid. 1–3 BMs/d
(1/2 of colon)
Subtotal Colectomy Diarrhea in form & frequency. 2–4 BMs/d
(only rectum left)
Total Colectomy with Diarrhea with potential incontinence. 4–8 BMs/d
ileo-anal anastomosis
There are two complications specific to colostomy, parastomal hernia and colostomy prolapse. Parastomal hernias occur in about 10% of cases. Colostomy prolapse
is slightly less common. Both of these complications may require reoperation for
correction of the problem (4).
Changes in Physiology and Potential Side Effects Caused by the Procedure
Patients vary greatly in what they consider normal bowel function. Some patients
regularly have one bowel movement per day. Others go 3–4 d without a movement. As
expected then, the physiologic outcome from patient to patient after colectomy is variable (7). Table 3 provides a rough outline of expectations based on experience with
hundreds of patients. Patients will undergo physiologic accommodation to the resection
for weeks to months. Patients with long-standing diarrhea may get relief with the use of
bulking agents, adjustments in diet, or antidiarrheal medications.
ALTERNATIVE PROCEDURES
Colonic resections have been performed laparoscopically since the early 1990s. The
technical limitations of the procedure have largely been overcome. The procedure is
performed with four or five trocars placed through the abdominal wall. Some resections
can be preformed completely laparoscopically. Others can be performed “hand-assisted.”
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Fig. 7. Schematic diagram of anatomy after a sigmoid colectomy. The left or descending colon
is then anastomosed to the rectum.
With the hand-assisted approach, a 5–8-cm incision is made that allows the surgeon to
introduce one hand into peritoneal cavity. The procedure is still viewed entirely via the
intraperitoneal camera.
Surgical authorities accept laparoscopic colectomy for benign indications. There have
been two major concerns voiced regarding laparoscopic colectomy for cancer. First are
the many reports of trocar site recurrences of cancer in the abdominal wall. As larger
volumes of data have been examined, this concern has waned. The second concern is
focused on the question of lymph node dissection. Specifically, can a surgeon safely and
routinely resect as much mesocolon (containing lymph nodes) using laparoscopic techniques compared to standard open resection. There is at least one study showing equivalence of lymph nodal resection between open and laparoscopic colectomy.
Ongoing prospective trials will answer the most important question. That is, are
survival rates ultimately different using laparoscopic compared to open techniques?
Preliminary reports suggest equal survival rates. It is the author’s opinion that laparoscopic colectomy will supplant the standard operation by 2005.
COSTS
The upfront costs for laparoscopic colectomy are greater than for the standard open
operations. This is because of the many disposable instruments used in laparoscopic
surgery. Disposable instruments may range in cost from a $50 trocar to a $500 intestinal
stapler. Total disposable costs could reach $2000–$3000 for a major procedure. This
increase in upfront costs may be overcome by a diminished hospital length of stay in
patients undergoing laparoscopic surgery. If an 8-d stay is converted to a 4-d stay, the
Chapter 15 / Colonic Resection 173
entire disposable instrument cost could be overcome. Analysis of cost to society would
have to include consideration of time out of work. In theory, minimally invasive procedures will allow for an earlier return to work.
SUMMARY
1. The majority of colonic resections are performed for adenocarcinoma of the colon.
2. Colon resections are major operations, which require general anesthesia. Patients require
bowel preparation preoperatively. The hospital stay ranges from 4–10 d based on a
number of variables.
3. Because the colon is involved primarily in water absorption and waste storage, patients
adapt well to resections of portions of the colon.
4. As a trend, laparoscopic colectomy will probably replace open colonic surgery during the
current decade.
REFERENCES
1. Zuckerman GR, Prakash C. Acute lower intestinal bleeding. Gastrointest Endosc 1999;49:228–238.
2. Allan A, Andrews H, Hilton CJ, et al. Segmental colonic resection is an appropriate operation for short
skip lesions due to Crohn’s disease in the colon. World J Surg 1989;13:611–614.
3. Zollinger RM. Atlas of Surgical Operations. McGraw-Hill, New York, NY, 1993.
4. Allen-Mersh TG, Thompson JP. Surgical treatment of colostomy complications. Br J Surg 1988;75:
416–418.
5. LongoWE, Virgo KS, Johnson FE, et al. Risk factors for morbidity and mortality after colectomy for
colon cancer. Dis Colon Rectum 2000;43:83–91.
6. Mileski WJ, Joehl RJ, Rege RV, et al. Treatment of anastomotic leakage following low anterior colon
resection. Arch Surg 1988;123:968–971.
7. Desai TK, Kinzie JL, Silverman AL, et al. (1988) Life after colectomy. Gastro Clin North Am 1988;17:
905–915.
174 Kozol
Chapter 16 / Surgery of the Rectum 175
16 Surgery of the Rectum and Anus
Mark Maddox, MD and David Walters, MD
CONTENTS
INTRODUCTION
LOW ANTERIOR RESECTION
ABDOMINO-PERINEAL RESECTION
TOTAL PROCTOCOLECTOMY WITH END-ILEOSTOMY
TOTAL PROCTOCOLECTOMY WITH ILEO-ANAL ANASTOMOSIS
SURGERY FOR RECTAL PROLAPSE
ANORECTAL PROCEDURES
LATERAL INTERNAL SPHINCTEROTOMY
HEMORRHOIDECTOMY/BANDING
RUBBER BAND LIGATION
OPERATIVE HEMORRHOIDECTOMY
REFERENCES
INTRODUCTION
Surgery of the rectum and anus has evolved significantly and is quite commonly
performed. The following procedures are representative of the more commonly performed operations in this area.
LOW ANTERIOR RESECTION
Low anterior resection (LAR) is generally performed for carcinoma of the mid-and
proximal rectum. With the training of more surgeons specializing in operations on the
colon and rectum, the extent of resection has been extended to some lesions in the lower
third of the rectum, less than 6 cm from the anal verge. The operation does not require
a special center per se, but Rosen (1) has shown that better outcomes are obtained when
it is performed by a surgeon trained in colon and rectal surgery.
Indications
Apart from rectal carcinoma, complicated diverticular disease or high rectovaginal
fistula secondary to radiation may occasionally require LAR.
From: Clinical Gastroenterology: An Internist's Illustrated Guide to Gastrointestinal Surgery
Edited by: George Y. Wu, Khalid Aziz, and Giles F. Whalen © Humana Press Inc., Totowa, NJ
175
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