Biomed Imaging Interv J 2006; 2(1):e4
doi: 10.2349/biij.2.1.e4
© 2006 Biomedical Imaging and
Intervention Journal
 LEARNING
POINTS
Lower gastrointestinal bleed
M Adan1, MRad, BJJ Abdullah1,
FRCR, S Mohd Amin2, FRCS
1 Department of Biomedical Imaging (Radiology), University
of Malaya Medical Centre, Kuala Lumpur, Malaysia
2 Department of Surgery, University of Malaya Medical Centre,
Kuala Lumpur, Malaysia
CASE REPORT
A 78-year-old woman was admitted with a history of melaenic
stool and associated fresh per-rectal bleeding for five days.
She also presented with appetite and weight loss. There were
symptoms of lethargy, palpitation and shortness of breath.
Besides history of melaena, she did not have any epigastric
pain or haemetesis. Patient was a known case of chronic renal
failure on regular haemodialysis and frequent blood transfusion
since 2000. She also suffered from long-term hypertension
and atrial fibrillation, which were controlled by medications.
Apart from pallor, the other vital signs were stable with
heart rate of 88 beats per min and blood pressure of 160/80
mmHg. Cardiovascular examination showed that patient still
had atrial fibrillation but with good pulse volume. Ejection
systolic murmur of the heart was noted. Respiratory and abdominal
examination was unremarkable. Per rectal examination revealed
some fresh blood. No rectal mass or haemorrhoids detected.
Haemoglobin level on admission was only 8 g/L. The renal function
was deranged as expected. Coagulation profiles were normal.
No other alarming signs were obtained from the rest of the
laboratory results.
Colonoscopies were done twice for this patient. The initial
colonoscopy done two days before admission showed several
diverticulae in the right side of colon. No active bleeder
was detected. Three days after admission, a repeat colonoscopy
was carried out as the bleeding still persisted. Fresh and
clotted blood was seen throughout the whole colon making identification
of the source of bleeding not possible.
CT scan of the abdomen and pelvis (Figure 1) was performed
using a 16-slice multidetector CT scanner (Siemens Somatom
Sensation 16, Erlangen, Germany).
QUESTIONS
- What is the abnormality demonstrated and
what is the diagnosis?
- What measures should be taken to optimize the visibility of
the pathology?
- What are the other common causes of this clinical condition
and how is it managed?
- What is the current role of MDCT compared with the other modalities
in the diagnosis and management of this condition?
ANSWERS
Lower gastrointestinal bleed from
a right-sided colonic diverticulum detected by multidetector
CT
Answer 1
In Figure 1a, the CT scan shows a small diverticulum in the
ascending colon as well as delineated small, rounded pockets
of air outpouchings from the bowel wall. In Figure 1b, the
diverticulum in the caecum, contains high density material
within it (reformatted MDCT in Figure 2). As there was no
history of previous barium enema, this represents extravasation
of contrast into the diverticulum indicating presence of an
active bleeder within it. The diagnosis is that of a bleeding
diverticulum. The bleeding diverticulum characteristically
shows peri-diverticular stranding, but this is not always
present.
[View this figure] |
Figure 2 Reformatted coronal
CT image of the bleeding from a caecal diverticulum
(arrow). |
|
Answer 2
Plain water should be used instead of oral and rectal contrast
to have a clear visualization of the possible site of bleeding
since dense contrast will obscure presence of blood within
the bowel lumen. In addition current MDCT allows accurate
visualization of the enhancing mucosal wall and thus mucosal
and submucosal disease can be better visualized.
In addition a dual or triphasic CT should be performed i.e.
unenhanced, 30-40 second followed by a delayed scan at 1-2
minutes [1].
Answer 3
Acute gastrointestinal bleeding is a common disorder (hospitalization
for severe or continuous bleeding occurs in 20.5 per 100 000
adults per year) with lower gastrointestinal bleeding being
one of the common medical emergencies in elderly patients.
It is a potentially dangerous and life-threatening situation.
Initial haemodynamic assessment and resuscitation are critical,
followed by localization of the bleeding site in order to
plan for a definitive treatment.
Approximately 70% of lower GI bleeding is due to diverticular
diseases, neoplasms, angiodysplasia and haemorrhoids [1]
with diverticular disease being responsible for approximately
40% of cases because diverticula are intimately related to
small arteries. Most of such diverticular haemorrhages have
a benign outcome, which nearly always stops spontaneously.
A vast majority of these patients can be treated conservatively
with overall mortality of 2.8%. If an active bleeder is detected
during colonoscopy, endoscopic treatment can be carried out
either by thermal contact probes, laser, monopolar electrocauthery
or injection sclerotherapy. Angiography also offers interventional
treatment. A selective infusion of vasoactive drugs (e.g.
vasopressin) or embolisation through an angiogram catheter
was reported to be effective in 36-90% of cases [2].
The most widely accepted surgical indications are based on
haemodynamic stability, transfusion requirements and the presence
of persistent bleeding. Segmental colectomy is best performed
when the site is accurately identified. In this case patient
was transfused two pints of blood and recovered well with
no signs of early recurrent haemorrhage.
However the increased presence of cerebrovascular and cardiovascular
diseases, malignancy, polypharmacy and the use of non-steroidal
anti-inflammatory drugs in elderly patients affect the outcome
of lower GI bleed.
Answer 4
There are various imaging techniques to demonstrate gastrointestinal
bleed. With the emergent of a multidetector helical CT scanner,
CT angiogram can be used as an imaging technique to detect
an active bleeder. An experimental study demonstrated that
helical CT could detect arterial of 0.07 ml/min [2],
suggesting that helical CT could be more sensitive than angiography.
The positive rate for detecting active GI haemorrhage may
reach 80% [1]. The high sensitivity of CT
is attributed by CT does not only show contrast extravasation
and vascular abnormalities but it is also able to demonstrate
contrast enhancement of the bowel wall and other anatomic
lesion (polyps, tumours, diverticulae) that can cause gastrointestinal
bleeding. It is also fast, safer, less expensive, minimally
invasive and less demanding than angiography. CT scan has
evolved into an important tool in diagnosing GI haemorrhage.
Upper tract endoscopy is helpful in ruling out bleeding
source from upper GI tract. An unprepared colonoscopy can
be performed; however, bowel cleansing improves visualization
and allows a more accurate diagnosis of the bleeding source.
Colonoscopy is adequate for many cases; but fails in 32% of
the cases [2], mainly because of technical
difficulties due to blood clots and stools, and the time required
for a prepared colonoscopy, which was the case presented.
Furthermore, colonoscopy is unable to depict small intestine
bleeding.
Traditionally, angiography is used for localization of a bleeding
source for surgical resection, but it is an invasive technique.
For an angiogram to be positive, it is estimated that arterial
bleeding of at least 0.5 mls per minute is necessary. The
limitations of angiography is its variable sensitivity of
13.6-86%, a complication rate of about 8.5-10% (stroke, renal
failure, femoral artery thrombosis, lower extremity immobilization,
haematoma) and higher costs [3] especially
in view of the elderly population. Advances in transcatheter
technique have allowed for haemorrhage control through embolisation
of bleeding points, without the need for emergent laparotomy.
It is a relatively safe and effective procedure with a success
rate ranging between 70% and 100% [4].
If bleeding rate is less than 0.5 ml per minute, technetium-labelled
red blood cell scans may be useful in demonstrating the lesion,
which can detect rates as low as 0.1 ml per minute. The source
of the active bleeding can be identified in up to 85% of cases.
However, in cases of inactive bleeding, the study is accurate
in only 40-60% of patients [5]. The procedure
is however time consuming and not widely available.
Magnetic resonance angiography (MRA) had been reported to
be able to diagnose an active lower GI bleeding [6].
Contrast enhanced MRA is a non-invasive, three-dimensional
imaging technique that delivers high spatial resolution and
high contrast between exogenous contrast and native tissue.
MRI can identify an extravasated blood pool with 100% sensitivity
and specificity, compared with 78% specificity for nuclear
scintigraphy [6]. The excellent results
for MRI could be achieved only in an idealized and controlled
environment; therefore this investigation is not applicable
in our situation. However, the procedure is time consuming
and requires patient’s cooperation.
REFERENCES
- Yamaguchi T, Yoshikawa K. Enhanced CT for initial localization of active lower gastrointestinal bleeding. Abdom Imaging 2003;28(5):634-6.
[ Medline ]
- Ernst O, Bulois P, Saint-Drenant S, et al. Helical CT in acute lower gastrointestinal bleeding. Eur Radiol 2003;13(1):114-7.
[ Medline ][ CrossRef ]
- Buttenschoen K, Buttenschoen DC, Odermath R, et al. Diverticular disease-associated hemorrhage in the elderly. Langenbecks Arch Surg 2001;386(1):8-16.
[ Medline ][ CrossRef ]
- Gady JS, Reynolds H, Blum A. Selective arterial embolization for control of lower gastrointestinal bleeding: recommendations for a clinical management pathway. Curr Surg 2003;60(3):344-7.
[ Medline ][ CrossRef ]
- Bokhari M, Vernava AM, Ure T, et al. Diverticular hemorrhage in the elderly--is it well tolerated? Dis Colon Rectum 1996;39(2):191-5.
[ Medline ]
- Chan FP, Chhor CM. Active lower gastrointestinal hemorrhage diagnosed by magnetic resonance angiography: case report. Abdom Imaging 2003;28(5):637-9.
[ Medline ]
- Messmann H. Lower gastrointestinal bleeding--the role of endoscopy. Dig Dis 2003;21(1):19-24.
[ Medline ][ CrossRef ]
Received 19 July 2005; received
in revised form 4 September 2005; accepted 20 September
2005
Correspondence: Department of Biomedical Imaging
(Radiology), Faculty of Medicine, University of Malaya,
50603 Kuala Lumpur, Malaysia. Tel.: +603-79502069; Fax.:
+603-79581973; E-mail: basrij@ummc.edu.my
(Basri J.J. Abdullah).
Please cite as: M Adan, BJJ Abdullah, S
Mohd Amin, Lower gastrointestinal bleed, Biomed Imaging
Interv J 2006;2(1):e4
<URL: http://www.biij.org/2006/1/e4/>
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