The Management of Pancreatic Trauma in the Modern Era Surgical Clinics of North America Volume 87, Issue 6 (December 2007)

1. The Management of Pancreatic Trauma in the Modern Era Surgical Clinics of North America Volume 87, Issue 6 (December 2007)

2. Epidemiology Injuries to the pancreas occur in approximately 5% of patients with blunt abdominal trauma , 6% of patients with gunshot wounds to the abdomen, and 2% of patients with stab wounds to the abdomen. Most patients with pancreatic injuries sustain multiple other significant injuries, which compounds an already high mortality rate. There was an average of 2.7 associated nonvascular injuries and 0.89 associated vascular injuries per patient.

3. Diagnosis Grading system Serum amylase levels CT Endoscopic retrograde cholangiopancreatography (ERCP) Dynamic secretin-stimulated (DSS) magnetic resonance cholangiopancreatography (MRCP) Exploratory laparotomy

4. Pancreas Organ Injury Scale of the American Association for the Surgery of Trauma Data from Moore EE, Cogbill TH, Malangoni MA, et al. Organ injury scaling II: pancreas duodenum, small bowel, colon, and rectum. J Trauma 1990;30:1427–9.

5. Serum Amylase Levels Initial serum levels of amylase are neither sensitive nor specific for predicting an injury to the pancreas. Jones reported that up to 35% of patients with complete transection of the main pancreatic duct may have normal serum amylase levels. If the amylase level is abnormal, further investigation with CT or ERCP is warranted. Takishima reported that all their 73 patients with blunt injuries to the pancreas had elevated serum amylase levels when drawn at least 3 hours after the initial trauma.

6. CT A contrast-enhanced CT scan is the initial imaging study of choice, realizing that the overall accuracy of CT for diagnosis of pancreatic injuries is only fair. Ilahi demonstrated an overall sensitivity of only 68% with a correct injury grade in less than 50% of the 40 patients in their series. Findings suspicious for an injury to the pancreas include the following: a hematoma surrounding the pancreas, fluid in the lesser sac, or thickening of the left anterior Gerota's fascia. CT scans can also demonstrate parenchymal lacerations or transections of the main pancreatic duct.

7. ERCP If CT scan is equivocal or a small parenchymal laceration is present, ERCP is the most reliable method to define continuity of the main pancreatic duct accurately . ERCP can precisely localize the site of a ductal injury by demonstrating extravasation or a cutoff, especially in patients with delayed presentations. An advantage of this modality is that in addition to being diagnostic, ERCP-placed stents may be useful as an adjunct to non-operative management of proximal pancreatic duct injuries in the appropriate setting. Disadvantages of ERCP include the risks of endoscopy, exacerbating a smoldering pancreatitis, and sepsis from overfilling of a disrupted duct.

8. Classification of pancreatic injuries by ERCP Data fromTakishima T, Hirat M, Kataoka Y, et al. Pancreatographic classification of pancreatic ductal injuries caused by blunt injury to the pancreas. J Trauma 2000;48:745–52.

9. DSS MRCP Like ERCP, DSS MRCP provides dynamic information as to whether there is continuing leakage from an injured main pancreatic duct. Unlike ERCP, this imaging modality is noninvasive; however, it can illustrate the entire pancreatic parenchymal and ductal anatomy as well as pathologic fluid collections and ductal disruptions. Its disadvantages include the time needed for a study to be completed and the inability to perform therapeutic maneuvers. It is not considered suitable for multiply injured patients.

10. Exploratory Laparotomy In those patients who are taken emergently to the operating room for abdominal trauma, pancreatic injuries are diagnosed at exploration. When evaluating an injury to the pancreas, it is important to establish the continuity of the main pancreatic duct. In the authors’ experience, simple examination of the area of injury for several minutes with loupe magnification reveals clear pancreatic fluid leaking in most injuries that involve the pancreatic duct. Intra-operative ultrasound (IOUS) can be used to help diagnose a parenchymal or ductal laceration. Intra-operative pancreatographymay also be used to detect an injury to the main pancreatic duct.

11. Nonoperative Management If there is no evidence of a ductal injury on fine-cut CT, non-operative management is acceptable, although it may be wise to perform ERCP to establish normal ductal anatomy definitively. As with non-operative management of blunt injuries to the liver or spleen, serial physical and laboratory examinations (ie, hemoglobin, amylase, lipase) are required. A continued increase in serum amylase levels or change on physical examination mandates an abdominal operation or repeat imaging with CT or ERCP.

12. Endoscopically Placed Stents Endoscopically placed stents have been used occasionally as definitive management of isolated injuries to the proximal pancreatic duct in hemodynamically stable patients.

13. Operative Treatment Indications Peritonitis on physical examination Hypotension and a positive (anechoic fluid present in the abdomen) focused surgeon-performed ultrasound examination of the abdomen Evidence of disruption of the pancreatic duct on fine-cut CT or on ERCP

14. Isolated injuries to the pancreas without ductal involvement General principles and exposure Simple external drainage Pancreatorrhaphy and drainage

15. General principles and exposure During laparotomy, the initial priorities are control of active hemorrhage and control of gross gastrointestinal contamination. Once a pancreatic injury is identified, the principles for management are well established and include hemostasis, debridement of dead tissue with anatomic resection as appropriate, and wide drainage. After exposure, the choice of management technique depends on the following: the presence or absence of injury to the main pancreatic duct the location of the ductalinjury the presence or absence of a concomitant duodenal injury hemodynamic status

16. Treatment options for isolated pancreatic injuries based on the American Association for the Surgery of Trauma pancreas Organ Injury Scale

17. Simple external drainage In the hemodynamically stable patient, pancreatic contusions (AAST grade I), minor capsular injuries, and traumatic pancreatitis can be treated without drainage. Most other injuries require drainage of some sort.

18. Pancreatorrhaphy and drainage Pancreatic lacerations not involving the duct (AAST grade I and grade II) are often associated with parenchymal bleeding. In cases in which the edges of the lacerations have been oversewn, however, repeat laparotomy generally reveals necrosis of these suture lines. This necrosis can lead to late complications, such as fistulas or pseudocysts. Wide drainage should be performed because of the obvious risk for a fistula from a minor pancreatic duct .

19. Isolated pancreatic injuries with ductal involvement General principles Ductaltransection in the neck, body, or tail of the pancreas Distal pancreatectomy Roux-en-Y distal pancreatojejunostomy Anterior Roux-en-Y pancreatojejunostomy Ductaltransection of the head of the pancreas Resection Endoscopically placed stents

20. General principles All hematomas overlying the pancreas should be explored because they may obscure a transection of the main pancreatic duct . In rare cases, if a ductal injury is unable to be confirmed by local examination, some centers recommend intraoperative ERCP or some form of surgeon-performed pancreatogram.

21. Ductal transection in the neck, body, or tail of the pancreas Distal pancreatectomy In a case of transection of the pancreas to the left of the mesenteric vessels (AAST grade III), a distal pancreatectomy should be performed. Ideally, an attempt at splenic salvage should be considered, but this is not often feasible in multiply injured patients.

22. In the hemodynamically stable patient with an isolated pancreatic injury, especially a child 10 years of age or younger, splenic salvage should be considered. If the patient is hemodynamically unstable, an expeditious distal pancreatectomy with splenectomyshould be performed.

23. Ductal transection in the neck, body, or tail of the pancreas Roux-en-Y distal pancreatojejunostomy A Roux-en-Y distal pancreatojejunostomy is an alternative to distal pancreatectomy, but it is rarely performed. The most appropriate indication is in the hemodynamically stable patient who has a transection of the pancreas at the neck or just to the right of the mesenteric vessels and few associated injuries.

24. Ductal transection in the neck, body, or tail of the pancreas Anterior Roux-en-Y Pancreatojejunostomy In the rare patient, a penetrating wound through the pancreatic duct at the head of the pancreas preserves the parenchyma posterior to the transected duct. In these cases, several investigators have recommended performance of an anterior Roux-en-Y pancreatojejunostomy.

25. Ductal transection of the head of the pancreas Resection Endoscopiclly placed stents Endoscopically placed stents have been inserted in hemodynamically stable patients with isolated proximal ductal injuries.

26. Combined pancreatoduodenal injuries General principles and exposure Simple primary repair and drainage Complex repair Diversion procedures Duodenal diverticulization “Triple-tube” approach Pyloric exclusion with gastrojejunostomy Resection

27. Combined pancreatoduodenal injuries General principles and exposure Control of hemorrhage and gastrointestinal contamination must occur first. After adequate exposure and identification of the injuries, a decision must be made on the choice of procedure based on the extent of the pancreatic and duodenal injuries, the hemodynamic status of the patient, and the expertise of the surgeon.

28. Combined pancreatoduodenal injuries Simple primary repair and drainage In approximately 25% of the patients with combined pancreatoduodenal injuries, small duodenal injuries can be repaired primarily and moderate injuries to the pancreas can be widely drained.

29. Combined pancreatoduodenal injuries Complex repair The pancreatic injury can be treated with the omentalpancreatorrhaphy, distal pancreatectomy, or a Roux-en-Y distal pancreatojejunostomy. A duodenal injury may require a transverse duodenorrhaphy, resection with end-to-end anastomosis, or Roux-en-Y jejunal limb to repair (mucosa-to-mucosa) a large defect in the wall of the duodenum.

30. Combined pancreatoduodenal injuries Diversion procedures When there is significant concern about the possibility of a postoperative fistula from the injured pancreas or duodenum, a diversion procedure is probably wise. Duodenal diverticulization Six-part procedure includes the following: truncalvagotomy antrectomy with gastrojejunostomy duodenal closure tube duodenostomy drainage of the common bile duct external drainage

31. Combined pancreatoduodenal injuries Diversion procedures “Triple-tube” approach Primarily indicated for duodenal drainage in a combined pancreatoduodenal injury, it involves: placement of a gastrostomy tube for proximal decompression retrograde duodenostomy tube inserted by way of the jejunum for decompression of the repaired duodenum antegradejejunostomy tube for enteralfeeding

32. Combined pancreatoduodenal injuries Diversion procedures Pyloric exclusion with gastrojejunostomy The pyloric muscle ring is closed with a number 1 polypropylene suture through a dependent gastrotomy. An antecolicgastrojejunostomy is then performed using this gastrotomy.

33. Combined pancreatoduodenal injuries Resection Pancreatoduodenectomy is indicated when there is extensive trauma to the head of the pancreas, a severe combined pancreatoduodenal injury, or destruction of the ampulla of Vater. In the hemodynamically stable patient, this procedure can be performed at the time of the original trauma laparotomy. In most of the patients who are hypothermic, acidotic, or coagulopathic, a damage control procedure is indicated. In this instance, the pancreatoduodenectomyor the reconstruction after a prior pancreatoduodenectomy should be performed at the reoperation.

35. Complications and outcome Complication rates after operative treatment of pancreatic injuries range from 26% to 86%. The most common postoperative infectious complication and the leading cause of morbidity in patients with injuries to the pancreas is an intra-abdominal abscess. A pancreatic fistula is the most common “pancreatic” complication after operative repair of a major injury . The literature reports an incidence of pancreatic fistulas after trauma ranging from 5% to 37%. Most series report spontaneous closure within 4 months in 50% to 100% of patients. Conservative management of pancreatic fistulas includes initial bowel rest and TPN.

36. Complications and outcome A postoperative fistula may also lead to a pseudocyst. In addition, pseudocysts can form as a late complication of a missed injury to the pancreatic duct. Persistent pseudocysts should be treated to prevent hemorrhage, perforation, infection, or obstruction of the bowel or bile duct . Percutaneous drainage is safe, effective, and an acceptable option for initial management of fluid collections or traumatic pseudocysts. If a fluid collection or a suspected pseudocyst persists after percutaneous drainage, investigation by means of ERCP to rule out injury to the main pancreatic duct is recommended.

37. Complications and outcome Patients may present with late posttraumatic pancreatitis. Treatment, like any other form of pancreatitis, includes proximal bowel rest and TPN or jejunal feeds. Complication of stents placed in the main pancreatic duct is stricture. Lin and colleagues recommend using Teflon stents, which have multiple lateral holes for drainage of side branches and exchanging them every 3 weeks.

38. Summary ERCP has been used more frequently to assist in diagnosis and, on occasion, for definitive management of ductal discontinuity in patients with contraindications to laparotomy. Early operative intervention is warranted in most patients with confirmed or suspected ductal injury. The integrity of the main pancreatic duct is key in the management and outcome of patients with pancreatic trauma.

39. Summary Simple external drainage and distal pancreatectomy are commonly performed operative procedures and have a favorable outcome most of the time. Pancreatoduodenectomy is indicated in those select patients with extensive combined pancreatoduodenal injuries who are hemodynamically stable with few associated injuries. Post-operative complications after repair of major pancreatic injuries include intra-abdominal abscesses, postoperative fistulas, and an occasional pancreatic pseudocyst. Many of these complications may be treated successfully without re-operation.