Pancreatic Trauma

 Secondary signs of pancreatic injury are usually present (peripancreatic fat stranding and fluid, thickening of pararenal fascia, peripancreatic hematoma)

– Peripancreatic signs of traumatic pancreatitis often subtle; more evident in 24-48 hours


image Pancreatic contusion: Ill-defined focal hypoattenuation at site of injury (not linear like laceration)

image Pancreatic laceration: Discrete linear hypodense cleft through pancreas

image Pancreatic fracture: Large laceration with clear separation of 2 ends of gland

image CT insensitive for pancreatic duct injury (usually inferred by laceration extending through duct)


• MR: MRCP (± secretin) is a useful tool in determining presence of pancreatic ductal disruption

• ERCP: Best modality for pancreatic ductal injury
image Transection of pancreatic duct: Abrupt duct termination or contrast extravasation




PATHOLOGY




• May result from either penetrating or blunt trauma
image Blunt traumatic injury usually results from anterior/posterior compression force to abdomen

• Pancreatic injuries almost never isolated and usually associated with polytrauma


CLINICAL ISSUES




• Blunt pancreatic injuries often clinically occult and unrecognized on initial evaluation

• Clinical presentation often due to traumatic pancreatitis: Upper abdominal pain, abdominal distention

• Serum amylase/lipase levels: Elevated in 90% of patients, but may be normal immediately after trauma

• Treatment: Penetrating trauma generally requires immediate laparotomy
image AAST grades I and II: Conservative management

image AAST grades III, IV, and V: Typically require surgery (including possible pancreatic resection)

image
(Left) Axial CECT shows subtle laceration of the pancreas image with fluid in the lesser sac image as well as retropancreatic fluid image.


image
(Right) Axial CECT in the same patient reveals fluid image tracking posterior to the pancreas along the splenic vein from extravasated pancreatic juice. Secondary signs of injury, such as peripancreatic fluid, hematoma, or fat stranding, are almost always present as a clue to the diagnosis.

image
(Left) Axial CECT in a patient with pancreatic fracture shows a fracture plane image through the neck of the pancreas. The pancreatic duct was disrupted, and the body and tail of the pancreas were resected at surgery.


image
(Right) Axial CECT 48 hours after trauma shows a pseudocyst image in the lesser sac in this pancreatic transection image.The fluid collection developed as a result of leakage of fluid from the site of the transected pancreatic duct.


TERMINOLOGY



Synonyms




• Traumatic pancreatic injury


Definitions




• Inflammatory disease of pancreas secondary to trauma


IMAGING


General Features




• Best diagnostic clue
image Enlarged, heterogeneous pancreas with peripancreatic fluid or hematoma in patient with history of trauma

• Location
image Most commonly involves pancreatic body > head > tail

• Morphology
image Spectrum of injury: Acute pancreatitis, contusions, deep lacerations, fractures with ductal disruption


Radiographic Findings




• ERCP
image Normal in cases of pancreatic contusion

image Best modality to identify pancreatic duct (PD) injury
– Transection of PD: Abrupt duct termination or contrast extravasation

– Communication of pseudocyst with PD

image May cause pancreatitis


CT Findings




• Secondary signs of pancreatic injury or post-traumatic pancreatitis usually present even in absence of discrete contusion/laceration
image Peripancreatic fat stranding and fluid with loss of normal peripancreatic fat planes almost always present
– Fluid separating pancreas from splenic vein is sensitive (60-90%) for pancreatic injury

– Fluid or hematoma is often seen in lesser sac, left anterior pararenal space, transverse mesocolon, adjacent to spleen, and mesenteric root

image Thickening of anterior pararenal fascia

image Peripancreatic or intrapancreatic hematoma: Intrapancreatic hematoma is more specific for pancreatic injury

image Peripancreatic signs of traumatic pancreatitis are often subtle: May be more evident in 24-48 hours

• Pancreatic contusion: Ill-defined focal hypoattenuation at site of injury 
image Appearance ranges from subtle contour deformity of pancreas to rounded mass-like enlargement of pancreas several cm in diameter

image Often associated with focal or diffuse pancreatic enlargement

• Pancreatic laceration: Discrete linear cleft of hypoattenuation running through pancreas (usually perpendicular to long-axis of gland)
image Much more likely to be associated with PD injuries than contusion

image Often associated with distortion or irregularity of contour of pancreas and hypoenhancement of gland upstream from laceration

image Lacerations may produce subtle parenchymal density changes and may be undetectable on CT in some cases 
– 20-40% of pancreatic injuries not visible on initial imaging

– May only be faintly visible on initial imaging, and become more conspicuous on follow-up imaging

image CT is not sensitive for detection of PD injury (∼ 40%):  Inferred by presence of laceration extending through duct (> 50% of pancreatic thickness)

• Pancreatic fracture: Linear low attenuation running through pancreatic parenchyma with clear separation of 2 ends of gland
image Most often through pancreatic neck

• Pancreatitis secondary to ERCP (± papillotomy, etc.) usually more severe in/around pancreatic head


MR Findings




• Variably decreased signal on T1WI at sites of contusion or laceration ± high T1 signal related to hematoma

• High signal on T2WI at sites of contusion or laceration

• Heterogeneous enhancement on T1WI C+ images with areas of nonenhancement related to fluid collections, pseudocysts, necrosis, laceration, or severe contusion

• MRCP useful tool to determine PD disruption
image Secretin stimulation may improve diagnostic sensitivity

image Ductal injury suggested by discontinuity in PD, along with direct communication to adjacent pseudocyst or fluid collection

image 


Ultrasonographic Findings




• Not sensitive for pancreatic injury or complications

• Findings similar to pancreatitis (enlarged, hypoechoic gland)


Imaging Recommendations




• Best imaging tool
image CECT for initial evaluation after trauma

image Emergency ERCP: Investigate pancreatic injuries when CT positive and status of PD uncertain

• Protocol advice

• Repeat CT at 24-48 hours may identify pancreatic injuries not appreciated on original examination


DIFFERENTIAL DIAGNOSIS


Shock Pancreas




• Part of hypoperfusion complex seen in severe traumatic injuries or in setting of severe hypotension

• Abnormally intense enhancement of pancreas, bowel wall, and kidneys, with decreased caliber of aorta and inferior vena cava, and diffuse dilatation of intestine with fluid
image Findings resolve spontaneously after fluid resuscitation

• Moderate to large peritoneal fluid collections

• Pancreas appears edematous, enlarged, and hyperenhancing with surrounding fluid and fat stranding, mimicking post-traumatic pancreatitis or injury

• Differentiate from direct traumatic injury by looking for other imaging features of hypoperfusion complex


Duodenal Injury Without Pancreatic Injury




• Duodenal injury (including rupture or hematoma) may simulate or coexist with pancreatic injury

• Duodenal hematoma appears as focal high-attenuation thickening of duodenal wall
image Picket-fence appearance on fluoroscopy from hemorrhage

image Smooth intramural mass causing incomplete bowel obstruction

Only gold members can continue reading. Log In or Register to continue

Stay updated, free articles. Join our Telegram channel

Nov 16, 2016 | Posted by in GASTROINTESTINAL IMAGING | Comments Off on Pancreatic Trauma

Full access? Get Clinical Tree

Get Clinical Tree app for offline access