Transcript CT Criteria for Management of Blunt Liver Trauma

CT Criteria for Management
of Blunt Liver Trauma:
Correlation with Angiographic
and Surgical Findings
From the Departments of Diagnostic Radiology and Interventional
Radiology University of Maryland Medical Center and Shock Trauma
Cente
Pierre A. Poletti, MD, Stuart E. Mirvis, MD,
Kathirkamanathan Shanmuganathan, MD
Karen L. Killeen, MD,Douglas Coldwell, MD
Radiology 2000; 216:418–427
Preface
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In previously published studies (1–7), 50%–
96% hemodynamically stable patients with
blunt hepatic traumacan be successfully
treated without surgery
The quantity of hemoperitoneum by initial
CT initially considered --indicator of hepatic
trauma severity (8,9) .
several subsequent studies (6,10–12) : the
quantity of hemoperitoneum does not
correlate with failed nonsurgical
management.
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A CT-based grading
system has been
adapted from the
American
Association for the
Surgery of Trauma
classification of
blunt hepatic injury.
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the direct application of such a CT classification, although
reflective of the extent of parenchymal liver damage, cannot
reliably predict the need for angiographic assessment of the
liver or the probable clinical outcome of attempted
nonsurgical management (6,12).
Even major hepatic injuries with a severity of up to CT grade
4 typically can be managed without surgery in those patients
who maintain hemodynamic stability (6,12–18).
Some authors have described wide discrepancies between the
CT injury grade and the injury severity determined at surgery
(19), with CT generally yielding an underestimation of the
extent of injury.
the advent of spiral CT and improvements in image quality
have led to an increasing role of and reliance on CT for
evaluating acute traumatic hepatic lesions (6,7,20 –25).
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The value of the periportal blood track as a CT sign to help
guide the management of liver trauma remains uncertain and
controversial (26,27).
The pooling of contrast material locally in the liver
parenchyma or freely in the peritoneal space has been
recognized as a specific sign of active bleeding that warrants
embolization or celiotomy (28).
Early detection of arterial contrast material extravasation is
clearly important for improving the success of nonsurgical
management, because it allows arterial embolization to be
performed before the patient becomes hemodynamically
unstable and thus potentially prevents the need for urgent
surgery.
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Intrahepatic vascular injuries have been reported more
frequently in association with liver injuries of a higher CT
grade than in association with those of a lower CT grade (4).
Some authors (4,29) advocate performing mandatory hepatic
angiography in all patients with hepatic injuries of CT grade 3
or higher to avoid the risk of missing arterial bleeding at CT.
In the present study, our aim was to further determine the
value of CT for assisting in decisions regarding the treatment
of hemodynamically stable patients with blunt hepatic trauma.
The accuracy of CT in depicting hepatic arterial hemorrhage
was determined by comparing the CT findings with the results
of angiography and surgery.
MATERIALS AND METHODS
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From 1995.6 to 1999.4, 20,537 patients to the University of
Maryland Shock Trauma Center. Of these patients, 7,188 (35%) were
with blunt abdominal trauma.
During this period, admission CT of the abdomen and pelvis depicted
hepatic injury in 420 (6%) of the patients admitted with blunt-force
abdominal trauma.
All patients who underwent both hepatic CT and angiography during
their acute imaging assessment were included in the study.
Seventy-two patients (37 female, 35 male; mean age, 37.5 years;
age range, 14–93 years; with 29.5% of all CT-depicted hepatic
injuries) met these criteria and formed the study population.
mechanisms of injury : motor vehicle collision (n = 64), pedestrian
struck by vehicle (n = 4), fall (n =2), impact with a falling beam (n =
1), and jet ski accident (n = 1).
In 47 (65%) of the 72 patients, more than one CT scan was obtained
at admission.
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All initial abdominal CT scans were obtained within 24 hours after
admission— typically in less than 2 hours.
CT was performed from the lung bases to the pelvis with 8-mm
contiguous sections.
The indications for hepatic angiography included confirmation of and
potential embolization for CT signs of contrast material extravasation
(ie, CT blush) in hemodynamically stable patients.
Hepatic angiography was performed also to exclude hepatic arterial
injury in patients with CT evidence of liver injury without direct CT
findings of vascular injury who had unexplained transient
hypotension (ie, peak systolic pressure equal to or below 100 mm
Hg).
Hepatic angiography was performed within 12 hours after CT in 59
patients and within 24 hours after CT in 11 patients; it was delayed
in two patients for 4 and 7 days after CT.
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Figure 1. Active
bleeding in the liver of
a 77-year-old man
struck by a bus.
Transverse CT scan
shows a grade 3 liver
injury (arrows) with
areas of high
attenuation
(arrowheads) within
the laceration.
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Active bleeding in a 17year-old male patient
admitted following
blunt abdominal
trauma. (a) Transverse
CT scan shows a grade
4 liver laceration
(arrows) in the right
lobe of the liver with
two high-attenuating
areas (arrowheads),
which represent active
bleeding.
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(b) Selective right
hepatic arterial
angiogram obtained
after embolization
of one bleeding site
(solid arrow)
confirms the second
area of active
bleeding (open
arrow), as seen in a.
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Angiographies were assessed for the presence or
absence of hepatic vascular injuries, including
localized retention of contrast material (ie,
parenchymal extravasation), pseudoaneurysm,
occlusion or luminal irregularity of hepatic arteries,
devascularized hepatic segments, arteriovenous or
arteriobiliary fistulas, and major portal venous
perfusion abnormalities.
Embolizations were performed for evidence of
arterial bleeding, fistula, or major hepatic arterial
vascular abnormality (ie, occlusion or marked focal
luminal irregularity)
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The medical and surgical records of all the patients, as well as
the radiologic reports of the 47 patients who underwent
follow-up CT, were examined to determine the outcome of
surgical or nonsurgical management and the prevalence and
types of liver-related complications that occurred.
The surgical report for each patient who underwent surgery
was reviewed to determine the indication or indications for
surgery, the presence and location of any bleeding site or
“oozing,” and whether surgical treatment (ie, packing,
suturing, and/or resection) was required.
Our study data were analyzed to determine the value of
admission CT in predicting the need for hepatic angiography
and the potential for early and late complications among all
grades of blunt liver injury.
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(e)
the following factors were assessed:
the association between CT injury grade and injury to specific
anatomic sites;
the relationship between specific anatomic sites of hepatic
injury at CT and angiographic findings, need for surgery, or
failed nonsurgical management;
the sensitivity, specificity, negative and positive predictive
values, and accuracy of CT findings of vascular injury with
angiography and surgery as the reference-standard methods;
the clinical outcome versus initial treatment (ie, early surgery,
angiographic intervention, or observation);
the relationship between delayed hepatic trauma
complications that occurred more than 10 days after
admission and initial CT findings.
Statisitcal Analyses
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Each CT criterion was compared with the
angiographic and surgical results in two by
two tables by using statistical software
(Stata, College Station, Tex).
The x2 or Fisher exact test was used, when
appropriate, to evaluate the univariate
association between the tested parameters.
P value <0.05 was considered to be
indicative of a statistically significant
difference between two different sample
populations.
Results
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CT Hepatic Injury Grade and
Involvement of Specific Anatomic
Landmarks
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The liver was the major abdominal visceral
injury in 51 (71%) of the 72 patients.
Splenic injury (n = 16 [22%]) was the most
common major associated intraabdominal
injury, followed by diaphragmatic tear (n =2
[3%]), renal contusion (n = 1 [1%]), colon
tear (n =1 [1%]), and mesenteric contusion
(n =1 [1%]).
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Liver lacerations extending
into major hepatic veins in
a 25-year-old man
admittedfollowing a motor
vehicle collision.
Transverse CT scan shows
right lobe liver lacerations
(arrows) extending to the
right and middle hepatic
veins at their confluence
with the inferior vena cava.
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Correlation of Specific CT Injury
Findings with Hepatic Angiographic
Findings and Clinical Management
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Major hepatic venous involvement was also seen in all six CT
studies that were false-negative for arterial bleeding when
compared with the hepatic angiographic studies (P =.01)
Among the 13 patients with both these CT findings, 11 (85%)
had arterial bleeding that was confirmed at angiography or
surgery and two were considered to have false-positive CT
studies for arterial bleeding
None of the 25 patients who had no CT finding of arterial
vascular injury or major hepatic venous involvement had
active bleeding at angiography or surgery.
the absence of both these findings was considered to be the
most reliable CT evidence to exclude hepatic arterial bleeding,
with a sensitivity of 100% (25 of 25 patients), specificity of
92% (25 of 27 patients), and accuracy of 95% (36 of 38
patients) (P <.001).
Hepatic Arterial Contrast
Material
Extravasation at CT
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In two patients, the CT finding
probably did represent active
bleeding, which retrospectively
was found to be extrahepatic
in origin and thus did not
originate from a branch of the
hepatic artery.
In another patient, the
common hepatic artery was
not selectively catheterized for
anatomic reasons, and,
therefore, the angiographic
study was suboptimal because
the contrast material injection
was limited to the celiac trunk.
However, because the
angiographic examination was
considered to be a reference
standard for the present study
and because the patient was
treated successfully without
surgery, that CT study also was
considered to be false-positive.
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Transverse CT scans falsepositive for active bleeding in
the liver of a 17-year-old
female patient admitted
following a motor vehicle
collision show a grade 4 liver
injury (solid arrows) involving
the bare area of the liver and
the porta hepatis (open arrow
in b).
Two focal areas of
hemorrhage (arrowheads in a)
are seen within the hematoma.
The selective hepatic
angiogram (not shown) did not
show evidence of hepatic
hemorrhage.
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Normal enhancing hepatic
parenchyma within a hepatic
laceration mimicking active
bleeding in a 20-year-old woman
admitted following a motor vehicle
accident. Transverse
CT scan shows a focal area of
normally enhancing hepatic
parenchyma (straight arrow) within
a grade 4 right liver lobe laceration
(curved arrows) mimicking a site
of active hemorrhage.
The selective hepatic angiogram
(not shown) did not show evidence
of hepatic bleeding.
Branch of the portal vein mimicking a
hepatic pseudoaneurysm in a 31-yearold man admitted following a blunt
abdominal trauma.
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At initial interpretation of the transverse
CT scan, a well-circumscribed focal area
of high attenuation (arrow) seen within
a grade 4 hepatic laceration
(arrowheads) was falsely considered to
be a hepatic pseudoaneurysm.
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The selective hepatic angiogram (not
shown) did not demonstrate a hepatic
arterial pseudoaneurysm.
At retrospective review of this scan, these
findings were found to be a branch of
the normal right portal vein traversing
through the hepatic laceration.
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Hepatic venous injury in a 14-yearold girl admitted following a blunt
abdominal trauma. (a, b)
Transverse CT scans show a
wedge-shaped, low-attenuating
area (open arrows) in the right
hepatic lobe drained by the middle
hepatic vein.
A hepatic laceration (solid arrow in
a) extends into the region of the
middle hepatic vein (curved arrow
in b), which is thrombosed and not
enhancing at CT.
Free intraperitoneal blood
(arrowheads) is seen around the
inferior vena cava and the liver.
At surgery, the middle hepatic vein
was avulsed from the inferior vena
cava and actively bleeding.
Evaluation of Initial Treatment:
Surgical versus Nonsurgical
Management
Angiographic Results versus
Outcomes
Conclusion
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our data indicate that CT-based criteria can be used to guide the
diagnostic management of blunt hepatic trauma in hemodynamically
stable patients.
Such criteria, including CT gradeof hepatic injury, CT evidence of
arterial vascular injury, and presence or absence of hepatic venous
involvement within the hepatic injury, can help in the selection of
patients who should undergo hepatic angiography and possibly
embolization.
These criteria appear to be useful in identifying high-risk patients—
that is, those prone to persistent or delayed hepatic bleeding or who
may develop delayed complications and thus need closer observation
and CT follow-up.
If supported by further studies, our observations should help in
adapting the current CT-based injury classifications to improve their
usefulness in selecting patients for initial nonsurgical management of
blunt hepatic injury.
Thanks for your attention