Transcript Abdominal Trauma - University of Toronto

Abdominal Trauma
Modified by: Sanjay
Gupta
Original by Steve
Gazzola
Outline
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FAST Scans
Mechanisms
• Blunt vs Penetrating
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Hemoperitoneum
Solid Organ
• Liver
• Spleen
• Kidney
• Pancreas
Outline
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Hollow Organ
• Bowel and Mesentery
• Bladder
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Hypovolemic Shock Complex
FAST
FAST: Focused Assessment with
Sonography in Trauma
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a decision-making tool to help
determine the need for transfer to
the operating room, CT scanner or
angiography suite.
FAST
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FAST examines four areas for free
fluid:
• Morrison’s Pouch
• Perisplenic
• Pelvis
• +/-Pericardium
Morrison’s Pouch
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probe is placed in the right mid- to posterior
axillary line at the level of the 11th and 12th
ribs
Perisplenic
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transducer is
placed on the left
posterior axillary
line region
between the 10th
and 11th ribs.
Pelvic
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transducer is
placed midline just
superior to the
symphysis pubis.
Pericardial
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transducer is
placed just to the
left of the
xiphisternum and
angled upwards
under the costal
margin
How good is FAST?
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As a decision making tool for
identifying the need for laparotomy
in hypotensive patients (Systolic BP
< 90), FAST has:
a sensitivity of 92%,
specificity of 96%
Accuracy 93%
Blunt vs Penetrating
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Important to know the mechanism.
It will tell you where to look
Penetrating Trauma i.e. stab wound
requires you to carefully look at the
wound tract.
Blunt trauma: knowing what side
was injured or seeing subcutaneous
edema helps you focus your search
Hemoperitoneum
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When seen in a trauma setting the
search is on for the source.
Specific signs may point out the
source:
• Sentinel clot
• Extravasation of IV contrast
• Location
Peritoneal Spaces
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Supine abdomen: most dependant
location is
• Hepatorenal fossa (Morrison’s pouch)
• Pelvic cul-de-sac (Pouch of Douglas) or
retrovesicular fossa*
*May be the only location you find blood
without hematoma around the source
organ.
Hemoperitoneum
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Unclotted blood usually has a
measured attenuation of 30-45 HU.
Attenuation can be significantly less
in a patient with anemia or older
hemorrhage.
Blood will settle and will get a
hematocrit level.
Hematocrit Effect
Sentinel Clot
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Highest attenuation hematoma aka
Sentinel clot is that closest to the
site of bleeding.
Sentinel Clot Sign
Mesenteric Fluid
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Hemorrhage from bowel or
mesentery typically flows between
bowel loops.
Mesenteric fluid has a
characteristically triangular shape
due to the leaves of the mesentery.
Mesenteric Tear
Solid Organs
Liver
Spleen
Kidney
Pancreas
Liver
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commonly injured in both blunt and
penetrating trauma
Most are self limiting and are often
watched by the surgeon.
• Especially if stable and no other injuries
are found on CT
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Look for vascular injury (especially
venous- active extravasation)
Liver
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Clincal Findings:
RUQ pain
R shoulder pain
Hypotension
Shock
Classification of Hepatic Injuries
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Grade I
• Capsular avulsion, superficial laceration(s) <1cm deep,
subcapsular hematoma <1cm in maximum thickness,
periportal blood tracking only
Grade II
• Laceration(s) 1-3 cm deep, central-subcapsular hematoma(s)
1-3 cm in diameter
Grade III
• Laceration >3 cm deep, central-subcapsular hemotoma(s)
greater than 3 cm in diameter
Grade IV
• Massive central-subcapsular hematoma >10 cm, lobar tissue
destruction (maceration) or devascularization
Grade V
• Bilobar tissue destruction (maceration) or devascularization
Traumatic Liver Imaging
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Plain film: not useful
US: hemoperitoneum
CT: imaging modality of choice
Angiography: to detect vascular
complications and for therapeutic
embolization
CT Imaging of Liver Injury
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Spectrum of injury:
• Contusions
• Subcapsular hematoma
• Intraparenchymal hematoma
• Linear or stellate lacerations
• Complete hepatic fracture
Contrast Enhanced CtIntraparenchymal Hematoma
Liver Contusions
Subcapsular Hematoma with Liver Laceration/Periportal
Edema
Hepatic Lacerations
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Most common liver injury
Intact vs. disrupted capsule
• Disrupted capsule often accompanied by
hemoperitoneum
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Differentiate from hepatic fissures by
their irregular edges, location and
blood density (30-40 HU)
Typically runs parallel to hepatic vein
or posterior segment of R portal vein
Hepatic Lacerations –cont’d
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Stellate pattern:seen in massive trauma,
complex multiple lacerations
Fluid in R paracolic gutter if ant surface
lacerated
Extraperitoneal hemorrhage if laceration
involves bare liver surface between the
coronary ligaments (“Halo sign”)
Hepatic fracture: laceration extending
from one liver surface to other
Liver Laceration
Liver Lacerations with Active Extravasation
Injury to Intrahepatic Biliary Tree
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Mechanism: laceration extending into
bile duct
Intrahepatic and intaperitoneal fluid
can represent bile (0-5HU)
Biloma (collection of bile)
Hepatic Vascular Complications
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Pseudoaneurysm & contrast
extravasation
Juxtahepatic venous injury: incl tear
of IVC or hepatic veins
Hepatic avulsion: devascularization,
no contrast enhancement of liver on
contrast-enhanced CT
Spleen
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Most frequently injured organ in blunt
trauma
Injury may be hematoma, laceration or
infarction.
Traditionally treated with splenectomy
now a selective approach is used
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Single system injury
Hemodynamically stable
No anticoagulation
Compliant patient
Traumatic Splenic Injury
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Imaging
• Plain film: not useful
• US: hemoperitoneum
• Contrast-enhanced CT: imaging
modality of choice
• Angiography: therapeutic embolization
Classification of Splenic Injury
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Grade I
• Small capsular laceration and/or parenchymal laceration
smaller than 1 cm
• Small subcapsular hematoma smaller than 1 cm
Grade II
• Parenchymal laceration 1-3 cm
• Central or subcapsular hematoma 1-3 cm
Grade III
• Parenchymal laceration deeper than 3 cm
• Central or subcapsular hematoma larger than 3 cm
Grade IV
• Devascularization of the spleen (no contrast
enhancement)
• Fragmentation of the spleen
Splenic Laceration
Splenic Rupture with Perisplenic hematoma
Splenic Rupture with Active Extravasation
Splenic Rupture with active Extravasation
Renal Trauma
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Kidney is most common structure in
GU tract injured.
10% of blunt traumas will involve
injury to the kidneys
Majority >80% nonsurgical
Renal Trauma
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2 mechanisms of trauma:
• Compressive forces: direct blows or
external force causing compression
against a fixed object
• Deceleration forces: shearing between
relatively fixed and free objects which
tends to rupture at the junction
Radiological Classification
Category 1 Renal Injuries
Renal Contusion/Hematoma
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Ill-defined, round
or ovoid
hypoattenuating
areas; occasionally
sharply defined
Subcapsular Hematoma
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round or elliptical
hyperattenuating
fluid collection
indenting or
flattening the renal
margin
Attenuation varies
by age of clot
Small Renal Infarcts
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small, sharply
demarcated,
wedge-shaped
areas of decreased
contrast
enhancement
Cortical Laceration
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MINOR lacerations
appear as defects
in the periphery of
the renal
parenchyma
without
involvement of the
collecting system
Category 2 Renal Injuries
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MAJOR lacerations through the
cortex extending to the medulla or
collecting system
+/- urinary extravasation
deep clefts that fill with hematoma
+/- devascularized parenchyma
perirenal hematoma
Deep Renal Lacerations: No
Urinary Extravasation
Deep Renal Lacerations:
With Urinary Extravasation
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Delayed views will
demonstrate the
urinary
extravasation.
Segmental Renal Infarcts
Category 3 Renal Injuries
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Include:
Multiple renal lacerations
 Vascular injuries involving the renal
pedicle
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Multiple severe renal lacerations –
“shattered kidney”
Also includes lacerations of the renal
pelvis and collecting system
Shattered Kidney
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Multiple renal
lacerations with
urinary contrast
extravasation.
Renal Artery Thrombosis
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Deceleration
causes tearing of
the intima
Intimal flap
initiates
thrombosis which
quickly propagates
Cortical Rim Sign
late finding (days)
Cortical Rim Sign
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Late sign vascular
occlusion
1- to 3-mm rim of
subcapsular
enhancement,
paralleling the renal
margin, can be seen
as a result of
preserved perfusion of
the outer renal cortex
by capsular
perforating vessels.
Category 4 Renal Injury
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UPJ injuries are rare in blunt trauma
Caused by sudden deceleration which
creates tension on the renal pedicle
CT reveals excretion of contrast into an
intact intrarenal collecting system but
medial perinephric urinary extravasation
A circumferential urinoma may be seen
around affected kidney
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UPJ injuries classified into two
groups:
• Avulsion (complete transection) Surgical
• Laceration (incomplete tear) stented
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Presence or absence of urinary
contrast in distal ureter differentiates
UPJ Disruption
UPJ Disruption
Perinephric Fluid.
No laceration.
medial contrast
material
extravasation
(arrow).
No ureteral
filling noted.
UPJ Laceration
Pancreas
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Rarely Injured
• Usually injured in penetrating trauma
• Crush injuries (hitting handlebars)
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early diagnosis is crucial, since
delayed complications such as
fistula, abscess, sepsis, and
hemorrhage may lead to significant
mortality
Traumatic Pancreatic Injury
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Imaging:
• US: limited use
• Contrast-enhanced CT: modality of
choice
• ERCP: to demonstrate pancreatic duct
anatomy prior to pancreatic surgery
• MRCP
Classification and Management of
Pancreatic Injuries
Grade
Description
Management
I
Parenchymal contusion or
minor hematoma
Conservative or minimal
surgical treatment
(drainage)
II
Sml parenchymal
laceration
Conservative or minimal
surgical treatment
(drainage)
III
Parenchymal laceration
with rupture of the main
pancreatic duct
Surgical
IV
Severe crush injury
Surgical
Pancreatic Neck Fracture
Pancreatic Neck Fracture with
Active Extravasation