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Blunt Abdominal Trauma: Injury to the Epigastrium
Mária
Némethy, Harvard Medical School, Year IIIGillian Lieberman, MD
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
2
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
3
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
http://www.emedicine.com/EMERG/topic1.htm
4
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
Adrenal
–
Bowel
Bladder (intraperitoneal)
5
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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.
6
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Abdominal Retroperitoneum
Netter FH. Atlas of Human Anatomy, 2nd ed.
PancreasDuodenum(retroperitoneal)
Right kidneyLeft kidney
Inferior vena cava Abdominal aorta
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Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Epigastric
region
Netter FH. Atlas of Human Anatomy, 2nd ed.
IVC
Right adrenal
Right kidney
Duodenum
Transverse colon
Abdominalaorta
Left adrenal
Pancreas
Left kidney
8
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
9
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Options for evaluating BAT•
CT – gold standard for BAT evaluation–
MDCT: high-resolution images and reconstructions allow improved detection and management of soft-
tissue 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
10
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
11
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Initial plain films were normal
Images from PACS, BIDMC
12
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
CT: the diagnostic modality of choice in initial evaluation of
blunt abdominal trauma
13
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
CT: pre-contrast
Images from PACS, BIDMC
Mesenteric hematoma
Blood attenuation induodenal wall
14
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Post-contrast: Pancreatic injury
Images from PACS, BIDMC
Fluid surrounding pancreas
Blood surrounding pancreatic head
15
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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 intervention
16
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
17
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Image from PACS, BIDMCImage from PACS, BIDMC
Ischemic kidney
Extravasation
of IV contrast
Renal injury
18
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Renal injuryRight kidney Left kidney
Images from PACS, BIDMC
Ischemic kidney
19
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
20
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
21
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Duodenal hematoma
Image from PACS, BIDMC
22
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
23
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
24
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Intraperitoneal
bleedingUterus
Air in rectum
Intraperitoneal
bloodin Douglas’
pouch(HU = 50)
Image from PACS, BIDMC
25
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
26
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
27
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
How extensive was the pancreatic injury?
…The role of MRI…
28
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
29
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Pancreatic injury: characterization with MRI
Images from PACS, BIDMC
Lacerations in head of pancreas
Pancreatic headcontusion
Laceration in bodyof pancreas
30
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Duodenal hematoma on MRI
Image from PACS, BIDMC
31
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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…?
32
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
10-day follow-up: Pancreatic pseudocyst
Image from PACS, BIDMC
Pseudocyst
Pancreatic tissue
33
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Pancreatic pseudocyst
Image from PACS, BIDMC
34
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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…
35
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Bilateral accessory renal arteries
Image from PACS, BIDMC
36
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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
37
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 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….
38
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
PICC line terminating in L jugular vein
Image from PACS, BIDMC
39
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
The PICC line was repositioned, and subsequently revealed some more
interesting anatomy….
40
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
A Left-sided SVC!
Image from PACS, BIDMC
41
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
Acknowledgements
•
Michael Goldfinger, MD•
Gillian Lieberman, MD
•
Pamela Lepkowski•
Larry Barbaras, Webmaster
42
Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
References•
Becker CD, et al. Blunt abdominal trauma in adults: role of CT in the diagnosis and management of visceral injuries. Eur
Radiol
1998;8:772-80.•
Bradley EL III, et al. Diagnosis and initial management of blunt pancreatic trauma. Ann Surg
1998;227(6):861-9.•
Bruce LM, et al. Blunt renal artery injury: incidence, diagnosis, and management. Am Surg
2001;67(6):550-5.•
Dodds
WJ, et al. Traumatic fracture of the pancreas: CT characteristics. J Comp
Assist Tomography 1990;14(3):375-8.
•
Fischer JH, Carpenter KD, O’Keefe GE. CT diagnosis of an isolated blunt pancreatic injury. AJR 1996;167:1152.
•
Fuchs WA and Robotti
G. The diagnostic impact of computed tomography in blunt abdominal trauma. Clin
Radiol
1983;34:261-5.•
Klausner
JM, et al. Intramural haematoma
of the duodenum following blunt abdominal injury –
the place for conservative treatment. Injury 1986;17:131-2.•
Kunin
JR, et al. Duodenal injuries caused by blunt abdominal trauma: Value of CT in differentiating perforation from hematoma. AJR 1993;160:1221-3.
•
Lupetin
AR, Mainwaring BL, Daffner
RH. CT diagnosis of renal artery injury caused by blunt abdominal trauma. AJR 1989;153:1065-8.
•
McGehee
M, et al. Comparison of MRI with postcontrast
CT for the evaluation of acute abdominal trauma. J Comp Assist Tomography 1993;17(3):410-3.
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Mária Némethy, HMS IIIGillian Lieberman, MDNovember 2004
References•
McKenney
KL. Ultrasound of blunt abdominal trauma. Radiol
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•
Mirvis
SE and Shanmuganathan
K. Abdominal computed tomography in blunt abdominal trauma. Sem
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http://www.emedicine.com/EMERG/topic1.htm