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Treatment and decision making is best reviewed in light of injury severity. The classification system most commonly used for injury stratification is the AAST Organ Injury Scale (OIS) (Tables 32-7 and 32-8).53 Injuries are graded on a I–V scale in ascending order of severity. Of note, this scale adds associated pancreatic injury as a major morbidity cofactor in duodenal injury.
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Duodenal intramural hematomas are more common in children than adults and may be identified at the time of exploration, or may be detected on CT scanning (Fig. 32-8). If duodenal hematoma is discovered at initial operative exploration, the duodenum must be thoroughly mobilized and examined to rule out perforation. Hematomas can range from serosal staining to obstructing masses. Whether or not to open and evacuate the hematoma is debated: almost all hematomas resolve in this setting, and opening of the duodenum risks conversion of a closed to open injury. A selective approach is favored by many. Small hematomas with minimal luminal compromise are managed expectantly, with initial nasogastric suction and advancement of oral diet as tolerated. Distal feeding jejunostomy is placed for enteral nutritional support in the setting of luminal compromise up to 50%, or severe associated injuries. Incision and clot evacuation is reserved for larger hematomas with mass effect and luminal compromise more than 50%. Following evacuation of the hematoma and meticulous hemostasis, the incision is closed with single-layer running absorbable closure.
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For those without indications for laparotomy, expectant management is appropriate. Treatment generally consists of IV hydration, parenteral nutrition, and nasogastric tube suction. Nearly all duodenal hematomas will resolve spontaneously within 2–3 weeks, but the clinical course may be marked by progressive gastric outlet obstruction with or without bilious emesis. Obstruction can develop as fluid is sequestered into a hyperosmotic hematoma. For patients who continue to manifest complete obstruction after 10–14 days, repeat CT scan should be done to reevaluate the obstructive process, and operative management should be considered.54,55 Operative approaches for evacuation of the hematoma include open or laparoscopic drainage procedures.56
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Most duodenal lacerations occur as a result of penetrating trauma (see Table 32-1). Simple duodenal lacerations with minimal tissue destruction often result from either stab wounds or small caliber gunshot wounds. The vast majority can be safely repaired primarily with a meticulous single layer closure if adequate blood supply is ensured.12 Duodenotomies can be repaired with running or interrupted sutures; a monofilament repair is preferred. Repair in the direction in which the injury is formed is generally recommended. Although earlier reports advocated transverse repair of select longitudinal injuries to minimize luminal compromise, current use of single layer monofilament closure has eliminated this concern in most cases.57 Avoidance of tension is paramount. In rare situations of laceration to the pancreatic side of the duodenum, mobilization may not be possible for repair. In such situations, an antimesenteric duodenotomy may be performed, with repair of the injury from the inside.
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Some grade III lacerations may be repaired by simple duodenorrhaphy, as long as a tension-free repair may be achieved. In those that are judged too extensive for primary repair after mobilization and debridement, other options must be considered. If a segment is removed and the ends can be mobilized without tension, end-to-end duodenoduodenostomy may be performed. Such a repair is rarely feasible in the second portion of the duodenum due to the intimate attachments to the pancreas and thus difficulty with mobilization. In this area, careful identification of the ampulla of Vater is essential to avoid injury at the time of repair. Injuries to the second portion of the duodenum distal to the ampulla can be repaired with division of the duodenum and end-to-end duodenojejunostomy using a Roux-en-y limb of jejunum passed through the transverse mesocolon to the proximal duodenum. In these situations, the distal duodenal stump is oversewn and a jejunojejunostomy is created for intestinal continuity (Fig. 32-9). In the setting of extensive tissue loss but without the need for resection, the duodenum may be similarly reconstructed with a Roux-en-y duodenojejunostomy. Although jejunal mucosal patches and interposition grafts based on a vascular pedicle of the jejunal mesentery have been described, they are rarely used.55 Repair of injuries to the third and fourth portion of the duodenum may be compromised by the short mesentery, with limited ability to mobilize the bowel. If it appears the blood supply is compromised, resection and primary duodenojejunostomy is recommended. An intriguing potential alternative to create a tension-free repair while avoiding extensive anatomic reconstruction is to apply a patch graft, analogous to patch angioplasty techniques employed in vascular surgery. Encouraging results have been reported from preclinical studies with nonabsorbable materials such as expanded polytetrafluoroethylene58 as well as bioprosthetic materials59; further controlled study is warranted.
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“Protecting” the Duodenal Repair
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When confronted with a patient with a tenuous duodenal repair or an intermediate grade duodenal injury and associated pancreatic injury, the pyloric exclusion procedure as described by Vaughan et al8 has been promoted (Fig. 32-10). This procedure is simpler than the original “diverticulization” technique described by Berne et al,60 as it does not require gastric antrectomy, vagotomy, biliary T-tube drainage, or tube duodenostomy. In the pyloric exclusion procedure, the duodenal injury is repaired primarily and is “protected” by gastric diversion. To accomplish this, a gastrotomy is created along the greater curve of the stomach adjacent to the pylorus; the pylorus is oversewn from the inside; and a gastrojejunostomy is created with a loop of jejunum. A long jejunal limb should be created to prevent reflux of enteric contents to the duodenum. If a fistula develops, it is a functional end duodenal fistula, which is usually easier to manage than a higher output lateral fistula. A feeding jejunostomy is employed in this setting to ensure a route for enteral nutrition.61 Some authors additionally advocate a retrograde tube passed into the duodenum for decompression.9 The patient will often tolerate an oral diet after 10–14 days. The incidence of marginal ulceration may be reduced by the performance of vagotomy; however, significant bleeding is an infrequent (3%) complication.8,62 Furthermore, the pylorus has been documented to reopen within 3–7 weeks in over 90% of patients. Thus, routine vagotomy is not justified.8,62
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Although there are no prospective studies to prove the benefit of either diverticulization or pyloric exclusion, several reports from the 1970s and 1980s suggested that the introduction of the pyloric exclusion procedure was associated with a reduction in duodenal leak/fistula and its incumbent morbidity and mortality.8,12,24,62,63 On the other hand, recent series have questioned the necessity of this adjunct, pointing out that most injuries may be managed safely and successfully by primary repair.55,64,65,66,67,68 It should be noted that these recent publications are retrospective reviews of patients whose injuries were severe enough that the trauma surgeon felt a pyloric exclusion was necessary—that is, there is selection bias. Regardless, it is clear that (1) the vast majority of injuries are appropriately managed by repair or resection, without gastric diversion; and (2) morbidity and mortality related to duodenal injuries has decreased in the last two decades. This is likely due in part to contemporary application of damage control principles, allowing duodenal repair under better physiologic conditions.69 Ultimately, the surgeon must exercise his or her judgment based on the patient’s overall condition and that of the duodenal tissue, and associated injuries. This author generally favors pyloric exclusion in patients with grade III duodenal injuries and associated grade III-IV pancreatic injuries, or grade IV duodenal injuries not requiring resection. If the procedure is employed, the method of closure is an important consideration. If the pylorus opens too early, the benefit of diversion is lost. In animal studies, pyloric patency was re-established within 2 weeks with polyglycolic acid sutures, while polydioxanone (PDS) held for 4–5 weeks. Of note, pyloric closure with polypropylene did not reopen in one of four animals by 6 weeks.70 Further, Martin and colleagues62 reported one patient with an intact polypropylene closure at 53 days. In a rat study, external closure with polypropylene was associated with the lowest rate of pyloric patency at 21 days (57%).71 Reopening of the pylorus after stapled exclusion has not been well-documented. Thus, in order to close the pylorus for an adequate interval, while anticipating reopening within 6 weeks, PDS appears to be optimal. The use of periduodenal drains is debated, and there is no level I evidence supporting either routine use or nonuse. In general, drains are unnecessary after repair of grade I or II, or straightforward grade III injuries, unless there is an associated pancreatic injury (see below). Drains should be placed in any case in which repair is felt to be tenuous enough that a “protective” maneuver such as pyloric exclusion is employed. The advantage is that in case of leak, there will be a controlled fistula. If a drain is to be utilized, a closed suction drain is preferred over other types of drains.72
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These injuries involve major disruption or devascularization of the second portion of the duodenum with avulsion of the ampulla of Vater or distal CBD (grade IV) or massive disruption of the pancreaticoduodenal complex (grade V). In general, these injuries are caused by blunt trauma or large caliber/high-velocity gunshot wounds, and are associated with other significant injuries. In the face of significant hemorrhage, acidosis, hypothermia, and coagulopathy, a damage control approach is indicated. This entails hemostasis, debridement, and drainage, with subsequent definitive operative management after physiologic derangements are corrected.69 If the patient with a grade V injury survives and is brought back for reconstructive surgery, complex repairs and/or resections are generally necessary. If the duodenum can be repaired utilizing reconstructive techniques as described above, then the bile duct may be reimplanted into the duodenum or a Roux-en-Y hepaticojejunostomy created. If the duodenum cannot be repaired, and/or the pancreatic head is destroyed, a pancreaticoduodenectomy is necessary (see discussion below regarding grade V pancreas injuries).55
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The AAST OIS for pancreatic injury reflects the fact that the major determinant of morbidity following pancreatic trauma is the integrity of the main pancreatic duct (Table 32-9 and Fig. 32-11).53
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With liberal application of sensitive MDCT imaging, many low-grade injuries are diagnosed in patients who have no other indications for laparotomy. Nonoperative management (NOM) is currently recommended for low-grade injuries.73 This has been practiced for the past two decades in children, with good results.74,75 There is not a great deal of literature in adults, but the approach appears safe. Duchesne et al29 suggest that patients with apparent grade I or II injuries could be managed nonoperatively if ductal disruption is excluded by MRCP or ERCP. Of 35 patients managed in this way, 5 (14%) failed—three with pancreatic abscess, and 2 with missed bowel injuries. In the multicenter trial of New England trauma centers,27 Forty-nine patients with grade I or II pancreatic injuries and another 17 with combined pancreatic and duodenal injuries (both grade I or II) were managed nonoperatively. Four (6%) failed; three had pancreatic drainage at laparotomy, and it is not clear that any of them had prolonged LOS or morbidity related to the pancreatic injury. The recurring themes in the reports of nonoperative management are that (a) it is safe to manage patients with grade I and grade II injuries nonoperatively; (b) it is important to exclude main pancreatic ductal disruption (ie, grade III injury); and (c) main ductal disruptions may be best managed operatively, to avoid pancreatic duct-related complications (see below).
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When grade I and grade II injuries are discovered intraoperatively, the vast majority can be treated with no more than surgical hemostasis and drainage.3,6,14,19,25,32 Even capsular tears that are not bleeding are not repaired and may be simply drained with closed suction drainage. Drainage is employed liberally as many minor appearing injuries will drain for several days. Unnecessary attempts at repair of lacerations without evidence of ductal disruption can result in late pseudocyst formation, whereas the vast majority of controlled, minor pancreatic fistulae are self-limited and easily managed with soft closed suction drains. The drains are usually removed within a few days, as long as the amylase concentration in the drain is less than that of serum. If amylase levels are elevated, drainage is continued until there is no further evidence of pancreatic leak. Prolonged gastric ileus is common with even minor pancreatic injuries, so distal enteral access with jejunostomy should be considered in such cases. As the composition of most standard tube feeding increases the pancreatic effluent volume and amylase concentration, lower fat and higher pH (4.5) elemental diets are less stimulating to the pancreas.76
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Differentiating grade II from grade III injuries can be challenging, as described above. The nonsurgical diagnosis often requires MRCP or ERCP. In contrast to grade I and II injuries, NOM of grade III injuries is controversial.73 Several reports have addressed this in pediatric patients. Wood and colleagues77 reported that after operative management of grade II–IV injuries, the rate of pancreatic complications was significantly lower than after NOM; length of stay and readmission rates were lower although differences were not statistically significant. In larger single- and multi-institutional series, patients with grade III or higher injuries managed nonoperatively have longer LOS, higher overall morbidity rates, higher rates of pseudocyst formation, and longer time to a regular diet.78,79,80 At this time, data on NOM in adults are sparse.
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While ERCP has an established role in managing complications of pancreatic injuries (see below), its role in primarily managing grade III injuries is unclear. Some authors suggest that stenting in the acute phase may allow NOM.48,49,81 However, there are no prospective data comparing this with surgical treatment. At this time, it is probably advisable only for selected patients with minimal duct disruption. As noted above, verification of ductal injury may require ERCP. To help refine decision making, Takishima et al82 proposed a classification of pancreatic ductal injuries based on pancreatography. They suggested that class 1 (normal ducts) and 2a (branch injuries without extraparenchymal extravasation) injuries could be managed nonoperatively, while class 2b (branch injuries with leak into the retroperitoneum), 3a (main duct injuries in the body or tail), and 3b (main duct injuries in the head) injuries require surgical drainage.
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In patients undergoing emergent laparotomy without the benefit of preoperative imaging, assessment of pancreatic ductal integrity is pivotal to decision making. As described above, a simplified management guideline based on intraoperative clinical assessment of the duct has largely obviated the need for intraoperative ERCP or surgeon-performed pancreatography.3,32 Indicators of ductal injury include direct visualization of ductal injury, complete transection of the gland, laceration of more than 50% of the gland, central perforation, and severe maceration.3,32,52 In indeterminate cases, probability of ductal injury is based on the wound location and the operating surgeon’s assessment of high versus low probability. If the surgeon’s assessment is low probability, closed suction drainage is recommended. If there is clear indication of high suspicion of ductal injury, the management is based on the location of the injury. Injuries to the head should be drained, while injuries to the body and tail are treated by distal pancreatectomy.3,32,37,73 In the vast majority of patients, distal resection should leave no concern for later pancreatic endocrine or exocrine function.37 If there is any concern for injury to the proximal duct (grade IV), a proximal pancreatogram can be performed through the end of the transected duct; such situations are rarely encountered. The pancreas is divided at the injury location, and the proximal stump is closed. The optimal method of closure is debated. Roux-en-y pancreaticojejunostomy is rarely employed and does not appear to be justified. The primary options are sutured and stapled closures. A recent meta-analysis reported that a stapled closure was superior to sutured closure.83 The addition of direct suture closure of the ductal orifice was not superior to stapled closure alone. Of note, this meta-analysis was dominated by observational studies. In the largest prospective randomized trial performed to date, pancreatic fistula rate was 28% following hand-sewn closure and 32% following stapled closure; this difference was not statistically significant.84 The preference of many surgeons is to perform a stapled resection using a TA-type stapler with 4.8 mm staples, which generally avoids excessively crushing the gland. In young trauma patients, the pancreatic duct is small but can usually be identified; individual ligation of the duct is again a matter of preference.25 In the hemodynamically stable patient, the distal pancreatectomy can generally be performed without splenectomy.37,85 While the risk of overwhelming postsplenectomy sepsis is very low in the trauma population, the ability of the host to combat encapsulated organisms may be compromised and so it is considered a worthwhile exercise. Efforts should be made to establish enteral access at the time of initial laparotomy in virtually all patients with grades III–V injuries.
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Trauma to the pancreatic head and neck represents the most challenging of pancreatic injuries. If ductal status cannot be determined, wide external drainage and postoperative ERCP evaluation of the duct is recommended; stenting is reasonable if there is ductal disruption.3,32,73 In the setting of major disruption at the pancreatic neck, careful assessment of the remaining pancreatic tissue and consideration of future function should be weighed when contemplating an extended distal pancreatectomy. Roux-en-y pancreaticojejunostomy to the distal pancreatic fragment has been recommended to preserve functioning pancreatic tissue, as resection of greater than 85–90% has been felt to be associated with a significant risk of pancreatic insufficiency.86 However, as Yellin et al86 pointed out, it has been demonstrated that 95% pancreatectomy can be performed without creating a diabetic individual. For destructive injuries of the pancreatic head without associated duodenal injury the surgeon should consider the duodenum-preserving pancreatic head resection (Beger procedure).87 Current trends emphasize the effectiveness of closed suction drainage alone even for extensive proximal gland injuries. It is important to remember that hemorrhage control and drainage can allow planning of the optimal reconstructive option, including enlisting a surgeon with appropriate expertise.
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Pancreaticoduodenectomy is rarely performed for trauma, and a recent analysis of data from the National Trauma Data Bank suggests it was performed for inappropriate indications in as many as 21% of cases.88 Indications for the procedure include massive unreconstructable injury to the head of the pancreas, including the intrapancreatic bile duct and proximal main pancreatic duct; and avulsion of the ampulla of Vater from the duodenum with destruction of the second portion of the duodenum. As described above, these injuries are usually encountered with the patient in poor physiologic condition, so the principles of damage control apply (see above). A recent large series from Seattle emphasized that this procedure should be done in a staged manner, after initial damage control, to optimize the patient’s physiologic status.89 In addition to improved physiologic status, there are tissue changes that facilitate reconstruction, such as dilation of the biliary and pancreatic ducts.90 Delcore and colleagues91 previously suggested that pancreaticogastrostomy reconstruction is preferable to pancreaticojejunostomy in these circumstances, for physiologic as well as anatomic reasons. A recent meta-analysis supports a lower rate of pancreatic as well as biliary fistulae when pancreaticogastrostomy is performed.92
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Complications of Pancreatic and Duodenal Trauma
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Two-thirds of deaths associated with pancreatic and duodenal injuries occur in the first 48 hours (Table 32-6). The other deaths are generally due to late sepsis and multiple organ failure, often attributable at least in part to complications of the pancreatic or duodenal injury and/or repair. The morbidity related to duodenal injuries varies with the grade, ranging from 7 to 55%.12,13,27,28 The morbidity related to pancreatic injuries is consistently higher, ranging from 24 to 52%.3,6,27,37 Patients with combined pancreaticoduodenal injuries have morbidity rates between 50% and 87%.88,89 The risk of complications can be predicted by the AAST injury grade, associated injuries, combined pancreaticoduodenal injuries, hypothermia, and packing without drainage during initial damage control laparotomy.
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Exsanguination is the most common cause of early death associated with pancreatic and duodenal injuries. Early application of damage control maneuvers is therefore necessary for successful management. Damage control techniques such as packing of hemorrhage and stapling or drainage of intestinal leaks will allow for deferred debridement and reconstruction. Correction of coagulopathy and hypothermia, and optimization of oxygen delivery may be lifesaving, followed by definitive operative treatment upon return to the operating room.69,89,93
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Recurrent (Secondary) Hemorrhage
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Postoperative hemorrhage is a common concern after laparotomy for pancreatic and duodenal injuries, especially given the extent of associated injuries, which can be a source of bleeding. Approximately 10% of patients after pancreatic and duodenal trauma will sustain some degree of hemorrhage. Transfusion therapy should be guided by evaluation of the patient’s hemodynamic and coagulation status with attention to oxygen delivery. As in a patient presenting with initial trauma, it is important to resuscitate the patient with efforts to correct associated acidosis, coagulopathy, and hypothermia prior to embarking on a reexploration.69 In a stable patient with recurrent hemorrhage, angiography may identify the bleeding point for treatment with embolization. Other causes of postoperative hemorrhage late in the treatment course include progressive pancreatic necrosis or intra-abdominal infection/abscess. Serial CT scan evaluation of pancreatic necrosis with aspiration and culture will predict the need for subsequent invasive radiological intervention and drainage. Many patients can be spared complicated and difficult reoperation with these techniques. Hemorrhagic pancreatitis is a rare complication, which may be indistinguishable from postoperative hemorrhage, and has a reported 75% mortality.14,16
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Pancreatic fistula is a significant complication, with an incidence in current series of 11–37%.3,6 In a multicenter review of distal pancreatectomy for trauma, the postoperative fistula rate was 14%; 89% closed within 8 weeks.37 A recent review of posttraumatic biliary and pancreatic fistulae calculated that a pancreatic fistula was responsible for 27 additional hospital days and $191,000 in additional costs.94A pancreatic fistula may be diagnosed in a patient with a measurable drain output with an amylase level greater than three times the serum level, on or after postoperative day 3.95 A “benign” pancreatic fistula is defined as output less than 200 mL/d, and most will resolve spontaneously if adequate drainage without obstruction is established.94 High output lateral fistulae (>700 mL/d) are rare. They are severe management challenges, and many will require long periods of drainage, nutritional support, or late surgical intervention.94 Early ERCP with sphincterotomy and/or stenting may accelerate resolution, but more data are needed to clarify its role.81 Stoma therapists can offer creative solutions for skin protection in these patients. Given the frequency of this complication, liberal enteral access is advised at the time of initial surgery (see above). In the 1990s there was some enthusiasm for the somatostatin analogue octreotide in decreasing the volume of fistula drainage in patients with prolonged high-output fistulae; however, current meta-analysis of randomized trials does not demonstrate any benefit in fistula closure rates.96 A somatostatin analogue with a longer half-life and broader binding profile than octreotide was recently found to decrease the rate of clinically significant postoperative pancreatic fistula, leak, or abscess following pancreatic surgery.97 Future investigation in trauma is warranted.
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Duodenal Fistula and Stricture
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Duodenal fistula generally results from failure of surgical repair due to suture line dehiscence, sometimes with distal duodenal obstruction from stricture. Patients with duodenal obstruction in the postoperative period should be evaluated with CT scan to rule out extrinsic compression from associated phlegmon or abscess. Avoidance of tension at the time of duodenal repair is essential to avoid subsequent stricture formation. With careful attention to these principles, duodenal stricture is rare. The incidence of duodenal fistula is generally less than 5%.37 However, it is still recommended to consider protecting the surgical repair with pyloric exclusion in high-risk injuries. If a fistula develops, the diversion results in a less morbid end versus lateral fistula, and if a duodenal stricture or obstruction occurs, drainage is protected via the gastroenterostomy. Most such fistulae heal within several weeks. Once again, it is advisable to establish enteral access at the time of initial repair in high-risk injuries.
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Abscess formation should be considered in patients who develop sepsis after pancreatic or duodenal injury. The best predictors of postoperative abscesses are inadequate debridement or drainage during the initial operative management. Reexploration in this setting carries significant morbidity and mortality and should be avoided whenever possible. Image-guided drainage is preferable, and often is required more than once. Control of infections is important top avoid progression to multiple organ failure.
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Pancreatic Pseudocyst and Pancreatitis
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Early pseudocyst formation may be indistinguishable from abscess; percutaneous aspiration may be helpful from both a diagnostic and therapeutic standpoint. Delayed pseudocysts may be managed surgically or endoscopically. In the setting of a pseudocyst, ERCP may be employed to evaluate the continuity of the pancreatic duct. If the duct is intact, percutaneous drainage will often resolve the problem. Endoscopic stenting has been described, but there is a paucity of data on late outcomes.81 Occasionally, pseudocyst formation is the presenting symptom of missed blunt pancreatic trauma.
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Transient hyperamylasemia is common in patients after laparotomy for pancreatic trauma; true acute pancreatitis with clinical abdominal pain is much less frequent. A CT scan should be performed to rule out associated abscess, pseudocyst, or other complications. If the diagnosis is confirmed, treatment includes nasogastric suction, bowel rest, and nutritional support. Elemental enteral formulas appear to be tolerated well and should be provided. Most cases will resolve spontaneously. Chronic pancreatitis has been reported after pancreatic trauma; its treatment would follow the same principles as chronic pancreatitis due to other causes.98
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Pancreatic Insufficiency
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This is a concern when resecting more than 80% of the pancreas, for grade IV or V injuries (see above). With careful attention to injury patterns as described, both exocrine and endocrine insufficiency should be rare after pancreatic trauma. In the trauma setting, it may be assumed that any resection distal to the mesenteric vessels will preserve adequate pancreas for normal function.37