The Diagnosis and Management of Traumatic Pancreatic Duct Injury SJ Co, CJ Yong-Hing, S Galea-Soler, DJ Hou, A Eftekhari, Buckley AR, L Louis, S Nicolaou Department of Radiology, Vancouver General Hospital, University of British Columbia INTRODUCTION Blunt pancreatic injury is relatively uncommon but associated with high morbidity [1-2]. Poor outcomes are due to delay in recognition of ductal injury because of absence of specific symptoms, minimal physical findings, and nonspecific laboratory findings [3-4]. The absence symptoms may be due to the pancreas’ retroperitoneal location and possibly due to transient decrease in pancreatic secretions immediately after trauma which leads to minimal pancreatic inflammation and edema [5]. Delay in diagnosis can result in grave complications, such as pseudocysts, necrotizing pancreatitis, pancreatic fistula, abscess, bleeding, persistent pancreatic pain, and even death [6-8]. The broad spectrum of injuries complicates management of each case. Although surgical intervention is often warranted, less invasive alternatives, such as endoscopic retrograde cholangiopancreatography (ERCP) stent placement, percutaneous drainage, and conservative measures, are very effective treatment options depending on the severity of injury [9-11]. FIGURE 3: CLASSIFICATION OF INJURY American Association for the Surgery of Trauma (AAST) Grade III Injury Cont. On axial CT (A) the pancreatic duct is poorly visible in a patient with hepatic and splenic lacerations. Axial and coronal MR (B) and (C) reveal high signal that extends through the duct just to the left of the SMV and is consistent with pancreatic laceration involving the duct. A B C Images by Michael Liston Non-contiguous axial CT images demonstrate complete pancreatic transection through the distal body. A B A B Grade I Grade II Grade III Grade IV Grade V Grade Description I Hematoma Minor contusion without duct injury Laceration Superficial laceration without duct injury II Major contusion without duct injury or tissue loss Major laceration without duct injury or tissue loss III Transection or parenchymal injury with duct injury to the left of the SMV IV Transection or parenchymal injury to the right of SMV V Massive disruption of pancreatic head ERCP images of two patients with grade 3 injuries. Abrupt termination of contrast in the distal pancreatic duct can be appreciated in the first patient (arrow) (A). ERCP images show contrast extravasation from the mid to distal pancreatic duct in the second patient (B-C). A B Figure 1: Intraoperative photos following pancreatic trauma of (A) pancreatic neck injury and (B) pancreatic laceration associated with jejunal tear and rupture of Ligament of Treitz. Grade IV Injury On axial CT (A) transection is visible through the pancreatic tail (arrow). Duct involvement is confirmed on axial MR (arrowhead) (B). On follow-up axial MR (C) the laceration has resolved but a large pseudocyst has developed. A B C ROLE OF IMAGING The status of the main pancreatic duct (MPD) is paramount in predicting morbidity and guiding treatment [12-14]. The American Association for the Surgery of Trauma (AAST) classifies pancreatic injuries based on location of the injury with respect to the duct, the superior mesenteric vein (SMV) and evidence of duct involvement (Figure 1). Imaging modalities that can accurately localize pancreatic injury with respect to the SMV and identify duct involvement guide management. CURRENT IMAGING MODALITIES MDCT Multidetector CT (MDCT) has revolutionized the quality and accuracy of CT scans [15] and has significantly improved pancreatic imaging. The course of the pancreatic duct is visualized and can thus provide important information for assessing pancreatic injury and disease [16-19]. With these improvements in accuracy, some groups are beginning to question the necessity of invasive ERCP and MRCP as diagnostic steps in the investigation of blunt pancreatic trauma [20]. ERCP  Endoscopic retrograde cholangiopancreatography (ERCP) provides detailed images of the pancreatic duct and clearly defines the nature of the injury [13, 21]. The site of duct disruption and the grade of injury can be ascertained [10]. However, ERCP is invasive and there are associated complications so it is now reserved for those cases in which pancreatic injury is equivocal on MDCT or when the imaging and clinical findings are discordant. MRCP While magnetic resonance cholangiopancreatography (MRCP) is used in the assessment of chronic duct disease, it has little role in the acute trauma setting [22]. Contiguous axial CT images demonstrate transection of the pancreatic head (arrows). A B FIGURE 2: PANCREATIC TRAUMA IMAGING ALGORITHM A B C ERCP images with abrupt termination of the contrast column at the proximal main pancreatic duct (arrow) with contrast extravasation (arrowhead). All Stable Patients With Blunt Abdominal Trauma Axial (A) and coronal (B) CT show complete transection of the head of the pancreas. A B A B Enhanced MDCT MDCT Evidence of pancreatic injury Equivocal on MDCT or discordant clinical findings Non-contiguous axial CT images show two transections of the pancreatic body (arrows). Confident on MDCT Grade V Injury Axial (A) and coronal (B) CT show traumatic pancreatic pseudocyst anterior and inferior to the head of the pancreas (arrows). A B Repeat MDCT ERCP or MRCP BLUNT PANCREATIC INJURY: A PICTORIAL REVIEW Non-contiguous axial CT images with massive disruption (arrowheads) of the pancreatic head and an adjacent fluid collection in the anterior pararenal space (arrows). A B Axial CT in 3 patients with pancreatic contusion. (A) Irregularity of pancreatic tail and stranding in the anterior pararenal space. (B) Enlargement of the pancreatic tail with adjacent stranding in a patient with hepatic laceration. (C) Stranding around the pancreatic head.   Grade I Injury A B C Axial CT with pancreatic head enlargement and stranding in the anterior pararenal space consistent with pancreatic contusion. Grade II Injury AAST Grade of pancreatic injury No evidence of MPD injury Evidence of MPD injury MPD injury to left of SMV MPD injury to right of SMV Grade I or II CONCLUSION MDCT plays a major role in assessing patients with pancreatic injuries.  MDCT accurately localizes the injury with respect to the duct and identifies evidence of duct involvement, which allow accurate classification and subsequently guides management.  Understanding radiographic classification of traumatic pancreatic injuries is helpful in patient triage. Our pancreatic trauma imaging algorithm demonstrates how imaging findings are integrated with clinical findings to determine which patients require invasive intervention. Conservative management Grade III No massive disruption of pancreatic head Massive disruption of pancreatic head Grade III Injury Distal pancreatectomy +/- Splenectomy Axial (A) and (C) and coronal (B) CT with pancreatic tail transection (arrow) with peripancreatic and free intraperitoneal fluid (arrowhead). A B C Grade IV Grade V REFERENCES 1. Bradley, E.L., 3rd, et al., Diagnosis and initial management of blunt pancreatic trauma: guidelines from a multiinstitutional review. Annals of Surgery, 1998. 227(6): p. 861-9. 2. Stone, H.H., et al., Experiences in the management of pancreatic trauma. Journal of Trauma-Injury Infection & Critical Care, 1981. 21(4): p. 257-62. 3. Ryan, S., et al., Pancreatic enzyme elevations after blunt trauma. Surgery, 1994. 116(4): p. 622-7. 4. Wright, M.J. and C. Stanski, Blunt pancreatic trauma: a difficult injury. Southern Medical Journal, 2000. 93(4): p. 383-5. 5. Lucas, C.E., Diagnosis and treatment of pancreatic and duodenal injury. 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