Download Blunt Abdominal Trauma: Injury to the Epigastrium

Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Blunt Abdominal Trauma:
Injury to the Epigastrium
Mária Némethy, Harvard Medical School, Year III
Gillian Lieberman, MD
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Blunt Abdominal Trauma (BAT)
• Trauma is the leading cause of death in the
United States in persons under 45 years of
age
• Because it primarily affects the young, trauma
causes more lost years of productive life than
cancer and cardiovascular disease combined
• Blunt trauma accounts for 2/3 of all injuries
• Majority of abdominal injuries are due to blunt
trauma; 10% of trauma fatalities are due to
abdominal injury
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Mechanisms of injury
• Compression: direct blow or against a fixed object
(seat belt, spinal column)
– Generally results in tears or subcapsular hematomas in
solid organs
– Increased intraluminal pressure can cause rupture of
hollow organs
• Deceleration: stretching and linear shearing
between fixed and movable structures
– Rupture of supporting elements at junction between fixed
and free segments of organs
– Thrombosis of vessels contained within supporting
elements
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http://www.emedicine.com/EMERG/topic1.htm
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Injuries resulting from blunt
abdominal trauma
• Common:
– Liver – most commonly injured in all abdominal trauma
(blunt and penetrating)
– Spleen – most commonly injured organ in blunt trauma
– Kidney – increasing frequency (increased detection)
– Bladder (extraperitoneal)
• Rare:
– Pancreas
– Bowel
 Adrenal
 Bladder (intraperitoneal)
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
First, a brief review of retroperitonal
anatomy.
Note the crowding of the numerous soft
organs in the epigastrium, with little
bony protection. Unlike small bowel,
these organs are fixed in place, and
so cannot move out of the path of
blunt traumatic forces.
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Abdominal Retroperitoneum
Inferior vena cava
Abdominal aorta
Pancreas
Duodenum
(retroperitoneal)
Left kidney
Right kidney
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Netter FH. Atlas of Human Anatomy, 2nd ed.
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Epigastric region
IVC
Right adrenal
Abdominal
aorta
Right kidney
Left adrenal
Pancreas
Duodenum
Left kidney
Transverse colon
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Netter FH. Atlas of Human Anatomy, 2nd ed.
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Options for evaluating BAT
• Plain film
– Difficult to evaluate soft-tissue injury
– May reveal free intraperitoneal air or signs of
bowel obstruction
• Deep peritoneal lavage
– Rapid detection of hemoperitoneum
– Invasive
– Risk of visceral and vascular injury
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Options for evaluating BAT
• CT – gold standard for BAT evaluation
– MDCT: high-resolution images and reconstructions
allow improved detection and management of softtissue injury, hemorrhage, etc
• Ultrasound – increasing use
– Safe for unstable patients; decreased costs
– Limitations: fluid-filled bowel versus hemoperitoneum;
extraperitoneal fluid versus intraperitoneal fluid; cystic
masses can look like fluid collections; obesity
• MRI – not used in initial evaluation of BAT
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Our Patient
JO, a 23-yr-old woman kicked in the
stomach by a horse
● Imaging at outside hospital
suggested pancreatic injury; JO was
transferred to BIDMC for more
complete evaluation
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Initial plain films were normal
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Images from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
CT: the diagnostic modality of
choice in initial evaluation of
blunt abdominal trauma
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
CT: pre-contrast
Mesenteric hematoma
Blood attenuation in
duodenal wall
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Images from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Post-contrast: Pancreatic injury
Blood surrounding pancreatic head
Fluid surrounding pancreas
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Images from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Pancreatic injury in BAT
• Epi: uncommon – seen in 0.2-12% of blunt trauma
– associated visceral injuries are very common (50-90% of
patients)
• Mechanism:
– compression against vertebral column
– shear across pancreatic neck
• Sequelae: Ductal leakage  pancreatitis, which can
lead to pseudocysts, fistulas and abscesses (20%
mortality)
• Grading: based on injury to main pancreatic duct:
– minor injuries usually heal spontaneously and are treated
conservatively
– injuries involving main pancreatic duct require surgical
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intervention
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
CT findings in pancreatic injury
• CT sens/spec for pancreatic injury over 80%;
dependence on interpreter experience and timing of
evaluation
• Contusion: areas of low attenuation with
heterogeneous foci and diffuse enlargement of
pancreas
• Laceration: areas of linear, irregular low attenuation
within normal parenchyma
• Nonspecific: thickening of anterior pararenal fascia;
blood/fluid tracking along mesenteric vessels; fluid in
lesser sac; fluid between pancreas and splenic vein
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Renal injury
Extravasation of IV contrast
Ischemic kidney
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Renal injury
Left kidney
Right kidney
Ischemic kidney
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Images from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Renal injury in BAT
• Epi: Seen in 10% of trauma patients; blunt trauma
accounts for 80% of renal injuries
– Left-sided predominance (1.3:1) – thought to be due to
anatomic protection of right renal artery beneath inferior
vena cava and duodenum
• Mechanism:
– sudden deceleration/direct blow can cause renal
dislocation
– stretching of renal arteries can cause immediate avulsion
or delayed thrombosis
• Sequelae: 80% are contusions/minor lacerations
that heal spontaneously; persistent bleeding or
complete infarction require surgical intervention
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
CT findings in renal injury
• CT important in both diagnosis and patient
management: provides both functional and
morphologic information
• Absence of contrast nephrogram reveals
devascularized areas
• Helical CT can image specific renal artery injury
• Contusion: delayed and non-homogenous excretion
of contrast material
• Laceration: linear or wedge-shaped hypodensity
• Fracture: involvement of full depth of renal
parenchyma + disruption of collecting system
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Duodenal hematoma
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Duodenal injury in BAT
• Epi: Bowel injury seen in 4-5% of major BAT;
associated non-bowel injuries in 50%
– Retroperitoneal duodenum most common site of injury
– Duodenal hematomas are very uncommon!
• Mechanism:
– Compression between spine and impacting body;
– Shearing at fixed points (e.g. ligament of Treitz)
• Sequelae:
– Duodenal hematoma: resolves in 1-3 weeks
– Duodenal perforation: surgical intervention required
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
CT findings in duodenal injury
• Nonspecific (perforation vs. hematoma):
– Thickening of duodenal wall
– Presence of fluid in right anterior pararenal space
• Specific to perforation: Extraluminal gas and/or
oral contrast in right anterior pararenal space
• Duodenal hematoma:
– Initial heterogeneous, high attenuation region in
duodenal wall due to blood accumulation
– Isodensity, then hypodensity as clot resolves
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Intraperitoneal bleeding
Uterus
Intraperitoneal blood
in Douglas’ pouch
(HU = 50)
Air in rectum
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Intraperitoneal fluid in BAT
• Is often sole finding on CT in blunt
abdominal trauma
• Tracks down right and left paracolic
gutters into pelvic reflection of peritoneum
• Large amounts of blood can accumulate in
pelvis without significant hemoperitoneum
apparent in upper abdomen
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
CT: detection of intraperitoneal fluid
• CT very sensitive for detecting even small
amounts of intraperitoneal fluid or hemorrhage
• “Sentinel clot” sign: with multiple sites of
hemoperitoneum, blood with highest CT
attenuation is in proximity of site of hemorrhage
• Blood attenuation on CT:
– Free blood: 20-45 HU
– Clotted blood: 40-100 HU
– Active bleeding: within 10 HU of contrast density
inside adjacent major vessel
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
How extensive was the pancreatic
injury?
…The role of MRI…
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
MRI: characterization of soft tissue injury
• MRI is more sensitive for soft tissue
anatomy and pathology
• No advantage over CT in initial evaluation,
but can be invaluable in characterization of
subtle soft tissue injury, as in the pancreas
• Role of MRCP: evaluate damage to
pancreatic duct – key factor in surgical
versus conservative treatment
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Pancreatic injury: characterization with MRI
Lacerations in head
of pancreas
Pancreatic head
contusion
Laceration in body
of pancreas
Images from PACS, BIDMC
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Duodenal hematoma on MRI
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Sequelae
• JO was admitted to BIDMC one day after the injury
• Her intra-abdominal injuries were managed
conservatively (MRCP did not show laceration of
pancreatic duct)
• PICC line was placed on day two post-injury; initial
inappropriate placement corrected on day three
• Follow-up CT imaging was performed 10 days after
initial CT
– the findings…?
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
10-day follow-up: Pancreatic pseudocyst
Pseudocyst
Pancreatic tissue
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Pancreatic pseudocyst
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Why did the kidney not infarct completely??
• Initial work-up demonstrated ischemic
lower pole in left kidney
• Extravasation of IV contrast into peritoneal
cavity would suggest transection of renal
artery
• Follow-up CT indicated improved
perfusion of lower renal pole
• Interesting anatomy…
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Bilateral accessory renal arteries
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Accessory renal arteries
• Transection of inferior accessory renal
artery originating from common iliac artery,
leading to contrast extravasation and
infarct of inferior renal pole
• Development of collateral perfusion from
main renal artery and remaining accessory
renal artery
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Our patient’s course
• JO had a stable hospital course, and was
discharged home 13 days after admission
• Incidental note: JO received a PICC line
for parenteral nutrition. Initial follow-up
CXR revealed inappropriate positioning of
the line….
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
PICC line terminating in L jugular vein
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
The PICC line was repositioned, and
subsequently revealed some more
interesting anatomy….
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
A Left-sided SVC!
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Image from PACS, BIDMC
Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
Acknowledgements
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Michael Goldfinger, MD
Gillian Lieberman, MD
Pamela Lepkowski
Larry Barbaras, Webmaster
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
References
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Mária Némethy, HMS III
Gillian Lieberman, MD
November 2004
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