Trauma and Post-treatment Complications of the Pancreas

Active pancreatic bleeding

Pancreatic laceration or facture

Pancreatic contusion or hematoma

Focal or diffuse enlargement or edema of the gland

Low or heterogeneous pancreatic attenuation

Dilatation or discontinuity of the pancreatic duct

Edema and stranding of peripancreatic fat

Thickening of the anterior pararenal fascia

Fluid in the lesser sac, transverse mesocolon, and anterior and posterior pararenal spaces or surrounding the SMA

Pseudocyst or abscess

Fluid between the posterior pancreas and splenic vein

Injuries to adjacent structures

Free intraperitoneal fluid

SMA superior mesenteric artery

Conventionally, ERCP has been regarded as the gold standard in the evaluation of pancreatic duct. However, due to the invasive nature of ERCP, it is not widely accepted as an appropriate screening test for pancreatic trauma. MRCP has been reported as attractive alternative modality to evaluate the patency of pancreatic duct. Some investigators demonstrated that the use of secretin stimulation improved the delineation of ductal morphologic features on MRCP; therefore it could provide additional useful information about duct integrity. However, the exact usefulness of MRCP in acute pancreatic injury has not yet been established since most studies on the topic had limitations of small sample size and retrospective nature. More experience and studies are required to confirm the usefulness of MRCP in acute pancreatic injury.

21.1.1.1 Grading of Pancreatic Injury

Among various classification systems proposed for pancreatic injury, a grading scale proposed by the American Association for the Surgery of Trauma (AAST) is the most widely accepted (see Table 21.2). This scheme addresses the significance of more complex injuries to the pancreas according to the location of the injury and the integrity of the ampulla and main pancreatic duct. It also enables to correlate with other organ injury scales which allow the prediction of a patient’s prognosis.

Table 21.2

American Association for the Surgery of Trauma pancreatic injury scale

Grade^a	Type of injury	Description of injury
I	Hematoma	Minor contusion without duct injury
I	Laceration	Superficial laceration without duct injury
II	Hematoma	Major contusion without duct injury or tissue loss
II	Laceration	Major laceration without duct injury or tissue loss
III	Laceration	Distal transection or parenchymal injury with duct injury
IV	Laceration	Proximal (to right of SMV) transection or parenchymal injury involving ampulla
V	Laceration	Massive disruption of pancreatic head

^aAdvance one grade for multiple injuries up to grade III. SMV superior mesenteric vein

21.1.2 Differential Diagnosis: Pseudopancreatitis

Several studies have been published to report an abnormal CT finding of intra- and peripancreatic fluid in patients without clinical and laboratory evidence of pancreatic injury, pancreatitis, or pancreatic disease. The reported causes of this phenomenon comprise severe trauma of extremities, major burn injury, and hypovolemic shock. Although the exact mechanism of pseudopancreatitis was not well known, a hypothesis was proposed that it might be a consequence of mild ischemic pancreatic injury caused by hypovolemic shock and followed by overhydration.

21.2 Post-treatment Complication

21.2.1 Post-operative Complication

For the past two decades, with technical advances and centralization of care, pancreatic surgery has progressed into a safe procedure with mortality rates of less than 5 %. However, postoperative complication rate with reported range from 30 to 50 % is still considerable. Pancreatic surgery has similar complications which confront to other major abdominal surgery, e.g., anastomotic leakage, intra-abdominal abscess, wound infection/dehiscence, hemorrhage, and medical complications such as cardiac problems, cerebrovascular accidents, respiratory distress, and renal and hepatic dysfunction. Common and relatively specific complications that attend pancreatic surgery include pancreatic fistula and delayed gastric emptying.

Pancreatic fistula occurs in 5–30 % of patients undergoing pancreaticoduodenectomy. This wide range is probably due to different definitions used. Although most pancreatic fistula runs a benign course, it potentially leads to postoperative mortality if it results in retroperitoneal sepsis with abscess formation and/or destruction of the surrounding tissues and blood vessels. A fluid collection seen on CT around the pancreaticojejunostomy site and in the pancreatic bed and depiction of air bubbles in the fluid are known to be feasible findings for diagnosing pancreatic fistula. Since pancreatic leakage is basically a clinical diagnosis of persistent drainage of amylase-rich fluid, clinico-radiologic correlation should always be followed when there is a suspicion of pancreatic leakage.

Delayed gastric emptying is also a common complication of which incidence ranges from 20 to 60 % of patients. It is notable that delayed gastric emptying is closely associated with other postoperative pathologic conditions such as pancreatic fistula and postoperative acute pancreatitis. However, the radiologic evaluation of postoperative delayed gastric emptying has not been well established in the literature.

21.2.2 Post-procedural Complication

Several diagnostic and therapeutic procedures might cause complications in the pancreas. Acute pancreatitis is one of the most common complications of ERCP. Although ultrasonography-guided percutaneous or endoscopic biopsy has been established as a feasible and safe method to confirm the unresectable pancreatic cancer, it can also result in complications such as fever, hemorrhage, acute pancreatitis, and pseudocyst formation.

21.3 Summary

Blunt traumatic pancreatic trauma is uncommon accounting for less than 2 % of all cases of blunt abdominal trauma.

Since coexisting injuries can affect various organs adjacent to the pancreas, careful examination should be accompanied for injuries.

The diagnostic performance of CT in detecting pancreatic trauma is still on debate.

Repeated scan in 12–24 h should always be considered if there is a suspicion for pancreatic injury.

ERCP is the gold standard in the evaluation of pancreatic duct.

MRCP might be useful in the evaluation of acute pancreatic injury although more experience and studies are required.

As various iatrogenic procedures might affect the pancreas, radiologists should always concern the possibility of the pancreatic injury in image interpretation.