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25 Colonic Obstruction 269
You should choose either an anastomosis or a colostomy. The proximal
“protective” ostomy for an anastomosis is a hybrid of disputable value. Should
the anastomosis break, the protective colostomy is of little help because the colon
was not clean and will leak all the residual feces distal to the protective stoma.
Usually, a reoperation becomes necessary anyway. There is no study that proves
that the proximal stoma prevents anastomotic failure.
A Word About Stents
In recent years, endoscopically placed flexible, self-expanding stents have
been developed and are increasingly applied in many hospitals as the preferred
means of relieving the obstruction. There is a significant learning curve before the
stent can be safely placed, so most surgeons will not have acquired the necessary
skills. However, the technique may be available in your hospital, in which case it
certainly should be considered in patients who do not require an urgent operation.
The stents are used for two indications:
As the definitive treatment in patients who have metastatic disease and
therefore will not benefit from surgery or oncology treatment. This is for purely
palliative treatment in patients with a short expected survival time.
As a bridge to surgery in patients who have resectable cancer sometimes
associated with resectable liver metastases.
Stenting requires that a CT scan is done to allow pretreatment staging of
the cancer. Palliation can be excellent, avoiding an operation and its associated
risks. The bridge-to-surgery option is less established, and there is yet much to
learn about its advantage over operative resolution of the obstruction. However,
if the obstruction can be safely relieved with the stent, it will allow an elective
treatment pathway for the cancer. Stents are not an option for benign disease like
diverticulitis.
Our Preferences
We believe that resection of the obstructing lesion and a primary anastomosis can and should be achieved safely in most patients. For sigmoid lesions,
we opt for a sigmoidectomy and colorectal anastomosis; if the proximal colon is
excessively loaded or appears compromised, we proceed with a subtotal colectomy and an ileorectal anastomosis. The latter is also our preference for lesions
in the proximal descending colon and the transverse colon. We reserve the
Hartmann procedure for high-risk patients and those who appear poorly
nourished.
270 Per-Olof Nyström
Acute Colonic Pseudo-obstruction (Ogilvie’s Syndrome)
William Heneage Ogilvie (1887–1971) was not only a great British surgeon but also
a keen surgical aphorist. For example, “Personal statistics are at the bottom of all
unsound teaching; they are either too good to be true or too true to be good.”
This is an important differential diagnosis of colonic obstruction. Pseudoobstruction has the same symptoms, signs, and radiographic appearances of acute
large bowel obstruction, but there is no mechanical blockage. The X-ray films are
suggestive, but a contrast study or colonoscopy finds no obstruction. This pseudoobstruction can be so intense that the right colon becomes ischemic and perforates due to the high intramural pressure. The distension may be extreme, resulting
in acute abdominal compartment syndrome.
The mechanisms behind pseudo-obstruction are not known. It has been
proposed that the condition may be due to sympathetic overactivity, parasympathetic suppression, or both. Most patients are already in the hospital for other
reasons when the pseudo-obstruction develops. It is a rare but well-recognized
sequel to giving birth, but more commonly is seen after major nonintestinal surgery or trauma or on the background of serious medical illnesses. Some patients
may be sent directly from the nursing homes with this problem.
This entity is the reason why you should not operate on a suspected colonic
obstruction without a preoperative colonoscopy, contrast enema, or CT. Taking
an elderly patient with multiple premorbid conditions for a laparotomy to find
“only” a distended colon, without an obstructing lesion, is a cardinal error. Avoid
it. These patients should not have surgery but should be treated medically or
decompressed with colonoscopy.
For medical treatment, it is suggested that neostigmine (2 mg) intrave-
nously will effectively induce bowel movements and colonic emptying within a
few minutes. There are side effects to the neostigmine, including bradycardia,
salivation, nausea, and abdominal cramps. The patient should therefore be under
close surveillance during the treatment. We have tried this a few times; it does
not always work, but when it does you look like a superstar.
If medical treatment is ineffective, a careful colonoscopy may decompress
the bowel. The target is decompression of the grossly distended cecum; occasionally, repeated colonoscopic decompressions may be needed. A large and long rectal tube can be left in situ after the colonoscopy for a few days. The diagnostic
Gastrografin enema may occasionally also be therapeutic, with the hyperosmolar
contrast medium promoting colonic peristalsis.
Surgical treatment is required if the cecum perforates or, very rarely, if medical
treatment fails and the cecum reaches gigantic size, sometimes even producing an
abdominal compartment syndrome! If the cecum becomes necrotic or perforates, a
25 Colonic Obstruction 271
right hemicolectomy is necessary. Because the functional obstruction must be in the
left colon, a primary anastomosis is inappropriate. It is better to fashion an end ileostomy and bring out the distal end of the colon through the same colostomy hole, fashioning a “double-barrel” stoma. This arrangement makes it easy to restore bowel
continuity later at the site of the colostomy without the need to reopen the abdomen.
When at laparotomy the cecum is distended but viable, most surgeons
would opt for a cecostomy. Tube cecostomy is messy; it is associated with a high
incidence of local complications, such as a fecal leak around it or even into the
abdomen. To minimize these risks, use a soft, large-bore tube and surround its
insertion site in the cecum with a double purse-string suture; the cecostomy site
should then be carefully attached to the abdominal wall (as you do with a gastrostomy). Cecostomy tubes tend to obstruct with fecal matter and need regular
flushing. A viable alternative to tube cecostomy is the formal—“matured”—cecostomy: simply exteriorize a portion of the cecum above the skin level and
suture it to the surrounding skin. This, in medically ill patients with pseudoobstruction, can be performed under local anesthesia.
Volvulus of the Colon
Though sometimes in a person who is fat
The diagnosis is not clear as that
‘Tis then you get help from plain X-ray
Which gas within the gut should well display
So that the coil you see in the radiogram
Reaching from pelvis to the diaphragm.
(The Acute Abdomen in Rhyme. Zachary Cope, 1881–1974)
While volvulus accounts for only one-tenth of all instances of colonic obstruction, we tend to remember those patients. It is probably because of the spectacular appearance on abdominal X-rays and the equally spectacular way it is
treated. Volvulus of the sigmoid colon is by far the most common, followed
by that of the cecum. There is also volvulus of the transverse colon, but it is so
rare that you will probably not see a case during your surgical life.
Sigmoid Volvulus
In affected patients, the sigmoid is long, with a redundant mesentery that
allows the sigmoid to rotate around its mesenteric axis, usually counterclockwise.
It usually occurs after patients have reached seniority. It does happen at younger
ages but then typically in an institutionalized patient. The rotation must be at least
272 Per-Olof Nyström
180° to be symptomatic for obstruction, but if the rotation is 360° there is also a
risk of strangulation. These circumstances account for two types of volvulus: a
“slow” form in which obstruction develops gradually and a “rapid” form in which
strangulation dominates. As the obstructing point is distally at the rectosigmoid
junction, the propulsion of the proximal colon will blow up the obstructed sigmoid loop to impressive dimensions.
The typical patient presents with a history of recent onset of constipation
and lack of flatus and a grossly distended belly. Because half of the patients have
recurrent episodes of volvulus, the diagnosis may already be known. A plain abdo-
minal film will suggest the diagnosis: a tremendously large loop of colon fills the
abdomen from the pelvis to the upper abdomen. A contrast enema with Gastrografin
will show the obstruction at the rectosigmoid junction. Typically, the contrast ends
in a “beak-of-a-bird” sign that is very characteristic. It is the lower twist that causes
this image. And of course, a CT would show the huge loop of sigmoid, including the
“whirl sign”—typical for an intestinal volvulus—developing at the twisting point
of the mesentery.
Treatment of Sigmoid Volvulus
Non-operative Approach
Until around 1950, the treatment of sigmoid volvulus was surgical and associated with significant mortality. Then, it was demonstrated that the volvulus
could be decompressed with much lower morbidity and mortality by passing a
tube through the rectum. There are three ways of doing the procedure. If you are
lucky to work in a hospital where the radiologist treats the patient, this is what
they do. A large-bore, flexible but rather stiff tube, size 30–36 and 50 cm long, is
passed through the anus and rectum to the site of obstruction. A bag of barium,
or water-soluble contrast, is connected to the tube, and by letting in a little contrast, the hydrostatic pressure will open the twisted bowel sufficiently to pass the
tube into the obstructed sigmoid. A flush of gas and feces signifies successful decompression. The whole procedure is done under X-ray imaging. Whether the
tube should be left in place for a day or withdrawn immediately is a matter of
debate (> F ig. 25.1).
You might have to do the procedure yourself without the assistance of imaging. Then, use a rigid sigmoidoscope and pass it to the twist, which should be
seen. The lubricated tube is introduced through the sigmoidoscope and carefully
manipulated into the sigmoid. A third method is by means of a flexible colonoscopy and maneuvering the scope itself into the sigmoid. The eventual success of
your manipulations is usually announced with a sudden rush of flatus and liquid
feces at your face (watch out).
25 Colonic Obstruction 273
Fig. 25.1. Non-operative management of sigmoid volvulus
Operative Treatment
These non-operative methods are successful in the vast majority of cases
because strangulation is uncommon. If strangulation and necrosis of the sigmoid are suspected on clinical grounds (evidence of peritonitis) or if attempts
at nonoperative decompression fail, then an emergency laparotomy is required.
At operation (modified lithotomy position), you will encounter a hugely distended sigmoid colon that has to be decompressed. This is best achieved by gently untwisting the sigmoid and advancing a prepositioned rectal tube into the
dilated segment. Today, in most patients who undergo an emergency operation
for sigmoid volvulus, the bowel will be nonviable or compromised. Thus, the
procedure of choice is sigmoid resection, with either a colorectal anastomosis
or as a Hartmann’s procedure. The selection of what to do is essentially the same
as discussed with regard to malignant colonic obstruction. Finally, we have to
mention the option of sigmoidopexy, the fixation of the sigmoid to the lateral
abdominal wall. This is a theoretical option when the sigmoid is viable and well
decompressed, and you think that sigmoid resection with anastomosis is too
much for the individual patient.
After Successful Non-operative Decompression
Elective sigmoidectomy to prevent recurrence, on the other hand, is very
simple. It is done with a small transverse incision through which the hypertrophied
mobile sigmoid loop is delivered and resected. There is no general agreement when
patients should be offered a sigmoidectomy to prevent a recurrence. About half of
the patients will have only one episode, but those with two episodes will frequently
have a third. Most surgeons therefore offer resection after the second episode.
274 Per-Olof Nyström
Anecdotally, a fragile lady in her mid-80s suffered one episode after another, but
each time she was thought unfit for an elective operation on a benign condition.
After her 12th volvulus, she had proved her case and was subjected to sigmoidectomy from which she recovered uneventfully and was discharged after 5 days.
Volvulus of the Cecum
Volvulus of the cecum is much less common; you probably will not see more
than a few cases during your career, but these will usually require an operation.
The diagnosis is not as straightforward as that of the sigmoid volvulus. These
patients have clinical and radiographic signs of SBO. In addition, typically the
cecal “shadow” is absent from the right lower quadrant. Instead, the poorly attached and redundant cecum, which has flipped to the left and upward, is visualized in the epigastrium or the left hypochondrium, with its concavity pointing to
the right lower quadrant. A single fluid level may be seen, representing the dislo-
cated cecum and often confused with the gastric shadow. If in doubt, and in the
absence of peritoneal signs, you may order a Gastrografin enema, which will demonstrate the characteristic “beak” in the right colon. Today, a CT would be the
easiest and most accurate route to a diagnosis.
There are isolated reports of colonoscopic decompression of cecal volvulus,
but the complexity of such a procedure and its doubtful results suggest that operation is the treatment of choice. What to do? There is an eternal controversy—
probably never to be solved— between the proponents of cecal fixation-cecopexy
and the advocates of mandatory resection. This is our selective approach: first,
detort the cecum; the torsion is clockwise, so derotate the mobile cecum. If after
detorsion the bowel appears gangrenous or of doubtful viability, then proceed
with a right hemicolectomy. A primary anastomosis should usually be permissible, but occasionally circumstances suggest that a stoma is preferable. If so, bring
out the small bowel as an end ileostomy and a corner of the closed colon end
through the same hole. This combined double-barrel stoma allows simple closure
and restoration of bowel continuity through the site of the stoma.
If the cecum is viable, we see no point in resecting it. Why remove a healthy
organ that can be fixed? To prevent recurrence of the volvulus, fix the mobile
cecum to the lateral abdominal wall (cecopexy). Start with decompression of the
cecum by milking its contents toward a rectal tube for sutures hold poorly in a
distended bowel wall. Cecopexy is accomplished by suturing the entire length of
the cecum to the lateral abdominal wall. Use nonabsorbable material and take
big seromuscular bites on the bowel and big deep bites on the abdominal side.
Some surgeons elevate a flap of parietal peritoneum that is sutured to the anterior wall of the cecum.
25 Colonic Obstruction 275
Cecostomy, either a tube or matured to the skin, is an option that is mentioned in the literature as an alternative to cecopexy. However, we think that it is
a bad idea: why convert a simple and clean procedure (i.e., cecopexy) to a contaminated and potentially complicated one (i.e., cecostomy)?
“Sometimes a bowel-coil gets out of place
By twisting round a narrow base
With gradual strangulating of the blood supply
And danger that th’ affected coil will die.
This is a VOLVULUS which you should learn
Is from the Latin – volvere – to turn.”
(The Acute Abdomen in Rhyme, Zachary Cope, 1881–1974)
Reference
SCOTIA Study Group. (1995). Single-stage treatment for malignant left-sided colonic ob-
struction: a prospective randomized clinical trial comparing subtotal colectomy with
segmental resection following intraoperative irrigation. Br J Surg 82:1622–1627.
Acute Diverticulitis
1
Per-Olof Nyström
Think about acute diverticulitis as a left-sided acute appendicitis which is,
however, usually treated without an operation.
Diverticula of the colon are not “true” diverticula but herniations of the
mucosa through a weak spot of the muscular bowel wall. They can occur in all
parts of the colon but are most abundant in the sigmoid colon. The mucosa bulges
out through the points of entry for the blood vessels, which transgress the bowel
wall on each side, where the mesentery joins the bowel. It is thought that the pressure inside the sigmoid colon, which can be very high, causes expulsion of the
mucosa. The smooth muscle of the affected sigmoid colon, unlike that of the rest
of the colon and rectum, is often hypertrophied. This thickening is always located
at the summit of the sigmoid loop and rarely extends for more than 15 cm. The
diverticula mainly appear within this thickened segment of the sigmoid but are
not restricted to it. The thickening may reach the rectosigmoid junction but never
extends into the rectum proper (15 cm from anal verge). However, it is common
to find diverticula extending into the descending colon. Be aware that diverticu-
losis—the mere presence of sigmoid diverticula—is extremely prevalent in persons consuming a Western-type diet, while acute diverticulitis, inflammation of
the diverticula-bearing segment of the colon, is relatively much rarer.
26
Surgical Pathology
A wide spectrum of pathological conditions is covered by the term acute
diverticulitis, each correlating with a specific clinical scenario, which in turn
necessitates selective management.
1
A comment by the editors is found at the end of the chapter.
Per-Olof Nyström
Department of Surgical Gastroenterology, Karolinska University Hospital, Huddinge, 141 86 Stockholm,
Sweden
M. Schein et al. (eds.), Schein’s Common Sense Emergency Abdominal Surger y,
DOI: 10.1007/978-3-540-74821-2_26, © Springer-Verlag Berlin Heidelberg 2010
277
278 Per-Olof Nyström
At operation for acute diverticulitis, the sigmoid usually feels like a thick
fusiform tumor, with only a few diverticula. There are also cases of minor thickening with many diverticula, one of which has perforated and is the cause of the
acute inflammation. Such observations make one think about the basic pathology of acute diverticulitis.
Basil Morson, the famous pathologist at St. Mark’s, London, highlighted
the hypertrophy of the bowel wall as the primary pathology, and we are inclined
to accept this, with the addition that the mesenteric fat tissue also plays a role. It
is this fat that creeps up the bowel wall, becomes inflamed, produces the phlegmon or abscess, and heals with fibrosis. In our experience, many cases of acute
diverticulitis might better be termed acute sigmoiditis, recognizing that it is an
acute inflammation of the thickened bowel wall and mesentery. When it is a diverticulum that has been eroded by a fecalith, one finds a localized inflammation, which identifies the site of the perforation. In cases of free fecal peritonitis,
a perforated diverticulum is the cause, although more often it has been walled off
by the mesentery or epiploic appendices to produce a pericolic abscess. Sometimes,
the perforation occurs entirely within the mesentery, forming a mesenteric
phlegmon or abscess. The latter may secondarily perforate into the free peritoneal cavity, but usually this variety only gives rise to minor abdominal and systemic signs but can occasionally produce septicemia in a patient who is unable to
contain and isolate the perforation.
There is a strong tendency for diverticulitis and sigmoiditis to adhere
locally and fistulate. The formation of fistulas has an obscure mechanism as
most patients with such a fistula present as nonemergency cases and often do
not even give a history of previous attacks of acute diverticulitis. Most often,
the fistulas are into the bladder. The patient seeks attention for pneumaturia or
persistent urinary tract infection. Fistulas can also communicate with the fallopian tubes, uterus, small bowel, or skin. It is usually thought that the fistula
is the sequela of an abscess, but commonly there is no sign of an associated
abscess; if there had been one, it must have been silent or drained spontaneously via the fistulous tract.
Clinical Features, Diagnosis, and Approach
It is clinically pragmatic to think about acute diverticulitis or sigmoiditis as
a “left-sided acute appendicitis.” Unlike appendicitis, however, most episodes of
acute diverticulitis are successfully managed without an operation. [As most episodes of acute appendicitis might be. See > Chap. 28.—The Editors]
26 Acute Diverticulitis 279
Practically, we find it convenient to think about the clinical scenarios of
acute diverticulitis in order of increasing severity:
Simple-Phlegmonous diverticulitis
and COMPLICATED FORMS:
Pericolic abscess
Free perforation with purulent peritonitis
Free perforation with fecal peritonitis
Phlegmonous Diverticulitis
Most patients admitted to the hospital with acute diverticulitis harbor a
phlegmon; they are still capable of mounting an anti-inflammatory response that
quenches the inflammation. Such patients are in good condition but suffer from
acute pain and tenderness in the left lower quadrant and above the symphysis
pubis. A mass may be felt on abdominal or rectal examination. There are signs of
systemic inflammation with fever, increased CRP (C-reactive protein) and leukocytosis with left shift. For this stage, the diagnosis is clinical. The patient is treated
conservatively and usually responds.
Conservative Treatment of Acute Diverticulitis
Traditionally, patients with “mild” phlegmonous diverticulitis are admitted
to the hospital; they are kept on nothing by mouth (nil per os, NPO) and on intravenous fluids. Wide-spectrum antibiotics are given and continued until local and
systemic inflammatory manifestations subside. The colon, however, contains feces
and will contain feces even after a few days of starvation. So, what is the rationale
of the “traditional” regimen? We contend that in the absence of an associated intestinal ileus you may feed your patient or at least provide the patient with oral
fluids instead of intravenous fluids. The same is also true concerning antibiotics:
A perfectly adequate “coverage” of anaerobic and aerobic colonic bacteria can be
achieved using oral agents such as metronidazole and ciprofloxacin. So, if intravenous therapy is not necessary, why admit the patient at all? And, in fact mild acute
diverticulitis can be managed with oral antibiotics on an outpatient basis. Indeed,
the necessity of any antibiotics for this condition is questioned. There are no randomized studies to demonstrate its advantage, but there are comparative studies
that find no benefit with antibiotic treatment.
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