CT Criteria for Management of Blunt Liver Trauma: Correlation with Angiographic and Surgical Finding

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CT Criteria for Managementof Blunt Liver
TraumaCorrelation with Angiographicand
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 216418427

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Preface

• In previously published studies (17), 5096
  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 (6,1012) 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 (6,1218).
• 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.

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MATERIALS AND METHODS

• 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, 1493 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 17-year-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.

12

• 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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• 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.

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Statisitcal Analyses

• 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 lt0.05 was considered to be indicative of
  a statistically significant difference between
  two different sample populations.

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Results

• CT Hepatic Injury Grade and Involvement of
  Specific Anatomic Landmarks

17

• 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 lt.001).

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Hepatic Arterial Contrast MaterialExtravasation
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 false-positive 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.

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• Branch of the portal vein mimicking a hepatic
  pseudoaneurysm in a 31-year-old man admitted
  following a blunt abdominal trauma.
• 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.
• 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-year-old 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.

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• Evaluation of Initial TreatmentSurgical versus
  NonsurgicalManagement

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• Angiographic Results versus
• Outcomes

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Conclusion

• 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 patientsthat 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.

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Thanks for your attention