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420 The ASCRS Manual of Colon and Rectal Surgery
Clinical Presentation
• As previously described, the patient is typically a male nursing home resident, on psychotropic medications, with a history
of chronic constipation. These patients may not complain of
pain, but rather a caregiver notices an extremely long interval
between bowel movements, associated with signifi cant abdominal distension.
• It has been reported that 40–60% of patients will give a history
of having had similar episodes.
• On presentation, the distension is often dramatic. Unlike the
patient with fecal impaction, the rectal ampulla is empty.
• Plain abdominal fi lms typically show massive colonic distension, with or without small bowel dilatation (depending on the
competence of the ileocecal valve). The very large sigmoid
loop will be orientated toward the right upper quadrant. The
adjacent walls of the sigmoid will appear to be thickened, arising out of the left lower quadrant, giving the classical “bent
inner tube” sign (Fig. 19.6A ).
• Plain abdominal X-rays alone are diagnostic in 60–75% of
cases. However, the massive distension may, occasionally,
make the diagnosis diffi cult to establish with certainty. In those
cases, a contrast enema should be obtained. This study will
show the obstruction at the rectosigmoid junction, with the
classical bird’s beak confi guration (Fig. 19.6B ).
• The addition of barium enema to the plain abdominal X-rays
may increase the diagnostic yield to near 100%.
• The major diagnosis from which sigmoid volvulus must be distinguished is colonic obstruction caused by neoplasm.
– Usually the abdominal X-rays can distinguish one from
the other; however, in the presence of truly massive distension, differentiation may be diffi cult.
– At the time of attempted sigmoidoscopic detorsion, the
obstructing neoplasm will hopefully be visualized and
the true diagnosis will be apparent.
• The other condition that may cause clinical confusion is colonic
megacolon associated with abnormal colonic motility. This
condition also presents in elderly, constipated nursing home
patients. The X-rays can look remarkably similar. Because
rectal tube decompression will generally rapidly and successfully relieve the distension associated with this form of megacolon, distinction from volvulus can be diffi cult.
19. Colonic Volvulus 421
ba
Fig. 19.6. ( a ) Plain abdominal X-ray of a sigmoid volvulus indicating the “bent
inner tube” sign. ( b ) Barium enema study of a sigmoid volvulus indicating the
bird’s beak deformity and complete obstruction to retrograde fl ow of contrast.
Treatment/Outcome
• The patient with sigmoid colon volvulus should be hydrated
and resuscitated.
• The mainstay of emergency therapy has generally been detorsion and decompression.
• Detorsion of sigmoid volvulus has been described using
several techniques, including rigid proctoscopy, fl exible sigmoidoscopy or colonoscopy, blind passage of a rectal tube, and
use of a column of barium during barium enema examination.
Successful decompression using one of these techniques is
generally reported in the range of 70–80%.
• A signifi cant concern is that the sigmoid may already be
gangrenous.
• If ischemic mucosa is visualized, attempts at detorsion should
be immediately abandoned and operative intervention should
be undertaken emergently.
• For this reason, the authors strongly recommend using only
those detorsion techniques that visualize the mucosa before
422 The ASCRS Manual of Colon and Rectal Surgery
detorsion. Attempts at detorsion via blind passage of a rectal
tube should be avoided.
• The major complication associated with attempted detorsion is
inadvertent perforation. This is more likely in the presence of
gangrene, but can occur with viable bowel as well.
• Once decompression has been accomplished, there is usually
forceful evacuation of fl atus and stool (frequently all over the
clothes and shoes of an unsuspecting novice) and visible defl ation of the patient’s abdominal distension.
• A rectal tube should then be gently inserted into the colon
to a point proximal to the site of the twist (which is usually
within 20 cm of the anus). The tube should then be fi xed in
place, to allow continued decompression and prevention of
recurrence.
• A plain abdominal fi lm should be obtained to document
decompression and the patient should be admitted to the hospital.
• Successful detorsion provides the advantage of converting a
surgical emergency to an elective situation.
• Over the next several days, bowel function is likely to return
to normal. Medical conditions (cardiac, pulmonary, renal, etc.)
should be addressed, electrolyte abnormalities should be corrected, and the patient’s condition optimized.
• Colonoscopy, to rule out a proximal lesion, should be performed, and then a decision must be made. The rectal tube can
be safely removed and the patient could be discharged from
the hospital; however, it is well established that the rate of
recurrent sigmoid volvulus is in excess of 25%. In fact, most
authors document a recurrence rate of greater than 50%, and
some report recurrences as high as 80–90%.
• The standard elective surgical procedure is sigmoid resection with primary anastomosis; however, a number of
nonresective techniques have been described, including
nonsurgical endoscopic sigmoidopexy with or without tube
fi xation, extraperitoneal sigmoidopexy, sigmoidopexy to the
transverse colon and/or the parieties, mesosigmoplasty, colopexy with banding, mesenteric fi xation, and laparoscopic
fi xation.
• Although several authors have reported excellent results using
pexy without resection, others have reported recurrence rates
in excess of 25%.
19. Colonic Volvulus 423
• The technique of mesosigmoidoplasty deserves discussion.
This procedure is performed by incising the elongated sigmoid
mesentery vertically along its axis. Peritoneal fl aps are then
created which are then approximated transversely (Fig. 19.7 ).
– This procedure thereby creates a shortened, broad mesen-
tery precluding future bowel rotation.
– Although one author has reported a recurrence of 28%,
most report recurrences of less than 2%. Mortality ranges
from 0 to 7%.
• Resection with anastomosis, therefore, should currently be
considered the standard of care for elective cases. However, in
circumstances in which continence is an issue, an end stoma
may be a better alternative.
• Laparoscopic techniques have also been applied, but in general,
because the redundant distended colon obscures the working
space and the incision required to deliver the specimen is also
large enough to exteriorize the redundant sigmoid colon and
Fig. 19.7. Mesosigmoidoplasty. ( a ) A longitudinal peritoneal incision is made
in the elongated, narrow mesentery. ( b ) The incision is then closed transversely,
broadening the mesenteric base and shortening the height of the sigmoid loop.
424 The ASCRS Manual of Colon and Rectal Surgery
perform an adequate resection and anastomosis, there is little
to be gained by the use of laparoscopy.
• If decompression is not possible, if the patient has signs and
symptoms of peritonitis or colonic ischemia, or if gangrenous
mucosa is visualized during attempted decompression, the situation becomes a surgical emergency.
• The volvulus should be manually reduced if the bowel is viable,
and the redundant, twisted sigmoid should be resected. However, when gangrenous bowel is encountered during laparotomy,
detorsion should not be performed. Accumulated toxins and
bacteria may be released into the circulation, resulting in sepsis
and cardiovascular collapse.
• Generally, an anastomosis should be avoided if the proximal
colon is massively dilated and loaded with feces.
• A single prospective, randomized trial comparing primary
anastomosis to the Hartmann’s procedure in 14 patients
with gangrenous bowel, revealed a 50% anastomotic leak
rate. In addition, mortality was more than double in those
patients in whom an anastomosis was performed (33 vs.
13%).
• Overall mortality rates for the treatment of sigmoid volvulus
range from 14 to 45%.
• Elective surgery, after detorsion, is currently associated with
mortality rates below 10%, despite the fact that these are generally patients with multiple comorbidities.
• Finally, operative detorsion with or without pexy carries a similar mortality to elective resection and anastomosis (8–14%).
Therefore, one must consider the overall risk of recurrence as
well as the risk of mortality.
• As expected, any nonresectional procedure carries a substantial risk of recurrence. For decompression alone it ranges from
25 to 70%, whereas detorsion, with or without pexy, has been
associated with recurrence rates of 23–40%.
• Most authors indicate that the risk of recurrence after resection
approaches zero.
• The only prospective randomized trial comparing elective
resection and primary anastomosis with mesosigmoidoplasty
confi rms these fi ndings. None of the resected patients and 29%
of the plastied patients experienced recurrence. However, there
was no mortality in the plasty group as compared with 10% in
the resection group.
19. Colonic Volvulus 425
F. Ileosigmoid Knotting
Incidence and Epidemiology
• Ileosigmoid knotting, also called compound volvulus, is a rare
form of volvulus in the West. It is, however, comparatively
more common in certain areas of Africa, Asia, and the Middle
East. In particular, large series are reported from Turkey, Russia, Scandinavia, Uganda, and India.
• The geographic distribution corresponds with regions of the
world where diets high in bulk and carbohydrates are consumed with large volumes of liquid. The incidence is highest in groups in which one single large meal is consumed
daily.
Pathogenesis/Etiology
• Theories of the pathogenesis of ileosigmoid knotting focus on
a large volume diet high in bulk and carbohydrates, associated
with large volumes of concomitant liquid ingestion. This may
lead to an elongated abnormally mobile small intestinal mesentery, in addition to a long narrow pedicled sigmoid mesentery
(Fig. 19.8 ).
Clinical Presentation
• The presentation of ileosigmoid knotting is one of acute onset,
often with a fulminant course.
• At surgery, gangrenous intestine is found in 70–100% of
cases.
• Clinically, the patient’s condition presents as a small bowel
obstruction, but radiographic evaluation is more consistent
with a large intestinal obstruction.
Treatment/Outcome
• Because of the high incidence of ischemia and gangrene at the
time of presentation, after an initial period of rapid resuscitation and antibiotic administration, patients should be taken for
emergent abdominal exploration.
426 The ASCRS Manual of Colon and Rectal Surgery
Fig. 19.8 Ileosigmoid knotting: these schematic illustrations indicate the four
forms of knotting. The active ileum may rotate around the sigmoid colon in either
a clockwise ( a ) or counterclockwise ( b ) direction. Much more infrequently, the
sigmoid colon may act as the active loop and rotate in either a clockwise ( c ) or
counterclockwise ( d ) direction around the ileum.
• Because of the high likelihood of gangrenous bowel, most
authors advocate en bloc resection of both segments of intestine without attempts to untwist the bowel.
• Although most perform a primary ileoileal or ileocolic anastomosis in patients with gangrenous small bowel, a Hartmann’s
procedure is usually performed when the sigmoid is found to
be nonviable.
• Overall surgical mortality generally ranges from 30 to 50%.
20. Lower Gastrointestinal
Hemorrhage
A. Introduction
• Lower gastrointestinal hemorrhage refers to a spectrum of
intestinal bleeding that arises distal to the ligament of Treitz.
It may range from occult bleeding or occasional spotting of
blood to massive lower intestinal hemorrhage.
• True massive intestinal hemorrhage typically involves hemodynamic compromise or acute symptomatic anemia.
• Multiple sources defi ne massive bleeding to include patients
with an acute drop in their hematocrit to less than 30%, patients
with transfusion requirements (up to 3–5 units of blood/blood
products), or orthostasis requiring resuscitation.
• Melena typically suggests bleeding from a more proximal
source in the colon or small intestine.
• Hematochezia suggests left colonic, rectal, or anal sources.
• Overall, it is believed that upper sources may present with lower
gastrointestinal bleeding symptoms in 10–15% of cases.
• Most often the intestinal bleeding resolves spontaneously often
while undergoing supportive hospital care.
• In clinical scenarios in which the bleeding resolved spontaneously, the diagnostic evaluation may only unmask potential
sources. Without associated attached clot or active bleeding,
the true site of hemorrhage may never be elucidated.
• Current treatment regimens incorporate remediating the impact
of long-term anticoagulants and antiplatelet agents for underlying cardiovascular conditions. Hemorrhage in these patients
proves more life-threatening.
D.E. Beck et al. (eds.), The ASCRS Manual of Colon and Rectal Surgery, 427
DOI: 10.1007/978-0-387-73440-8_20, © Springer Science + Business Media, LLC 2009
428 The ASCRS Manual of Colon and Rectal Surgery
B. Etiologies
• Common causes for lower gastrointestinal hemorrhage include
colonic diverticula, angiodysplasia, ischemic colitis, and
infl ammatory bowel disease. Hemorrhage may also stem from
intestinal tumors or malignancies.
• Unusual causes include nonsteroidal antiinfl ammatory drug
(NSAID)-related nonspecifi c colitis, Meckel’s diverticulum,
and anorectal diseases.
Diverticular Disease
• The precise mechanism of diverticular hemorrhage is
unknown.
• It is generally accepted that thinning of the media in the vasa
recta predisposes to intraluminal rupture: focal injury may
occur from trauma related to a fecalith.
• It is unclear how frequently diverticula are the true cause of
hemorrhage.
• Diagnostic evaluations, such as colonoscopy, often do not
identify a precise source for the hemorrhage without the presence of witnessed bleeding or an adherent clot.
• Despite being considered a major source for colonic hemorrhage, bleeding from diverticula is a relatively rare event
affecting only 4–17% of patients with diverticulosis.
• In most cases, bleeding ceases spontaneously, but in 10–20%
of cases, the bleeding continues unabated in the absence of
intervention.
• The risk of rebleeding after an episode of bleeding is approximately 25% but increases to 50% among patients who have
had two or more prior episodes of diverticular bleeding.
• Right sided colonic diverticula occur less frequently than left
sided or sigmoid diverticula but are thought to be responsible
for a disproportionate incidence of diverticular bleeding. This
fi nding is not well established, however, and there is often
diffi culty distinguishing between bleeding from an arteriovenous malformation or angiodysplasias and bleeding from
diverticulosis.
• Operative management of diverticular bleeding is indicated
when bleeding continues unabated and is not amenable to angiographic or endoscopic therapy.
20. Lower Gastrointestinal Hemorrhage 429
– It also should be considered in patients with recurrent
bleeding localized to the same colonic segment.
– In a stable healthy patient, the operation consists of a
segmental bowel resection (usually a right colectomy or
sigmoid colectomy) followed by a primary anastomosis.
Angiodysplasia
• Angiodysplasias are thin-walled arteriovenous communications
located within the submucosa and mucosa of the intestine.
• Angiodysplasias may be congenital or, more typically, acquired.
• In the acquired form, distortions of the postcapillary venules
may arise as a degenerative lesion associated with increases in
intraluminal pressure. The intraluminal pressure occurs from
loss of the precapillary sphincter and a resultant increased
pressure transmitted through the capillary bed into the
venules. As these vessels respond to the arterial fl ow, it results
in thickening and ectasia. The vessels eventually entangle as
tufts within the submucosa and erode into the mucosa proper.
• No one is quite certain precisely why angiodysplasias occur.
Current hypotheses suggest a loss of vascular integrity related
to loss of transforming growth factor (TGF) b signaling cascade or
from a defi ciency in mucosal type IV collagen.
• Angiodysplasias are uncommon before age 60, increase with
age, and are associated with aortic stenosis (Heyde’s syndrome),
chronic renal failure, and von Willebrand’s disease.
• Osler-Weber-Rendu (hereditary hemorrhagic telangiectasias)
is a hereditary condition with telangiectasias of the lung, nervous
system, skin, and intestine.
• When angiodysplasias are noted during angiography or colonoscopy, unless a hemorrhagic blush is seen during the
angiogram or colonoscopy, it is diffi cult to accurately accuse
this malady as the source of hemorrhage.
• Angiography remains the gold standard for the diagnosis of
angiodysplasia.
• In the arterial phase, the radiographic fi ndings of angiodysplasia
demonstrate early venous fi lling which normally occurs in later
phases.
• When angiography identifi es a bleeding angiodysplasia, treatment
with embolization therapy or directed infusion of vasopressin
will decrease or stop the bleeding.
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