Review Br. J. Surg. 1991, Vol. 78, October, 1I 96-1 202

R . H. Wilson and R . J. Moorehead Department of Surgery, Institute of Clinical Science, The Queen's University of Belfast, Grosvenor Road, Belfast BT12 6BJ, UK Correspondence to: Mr R. J. Moorehead

Current management of trauma t o the pancreas This review examines pancreatic trauma and its management in the light of recent experience. The incidence, mechanism, classijication, diagnosis, treatment and complications of pancreatic trauma are discussed. The dificulty in establishing the diagnosis is addressed and possible solutions are provided. The case for conservative surgery in the absence of pancreatic duct damage is outlined. The importance of draining all pancreatic injuries is emphasized.

Incidence and mechanism of injury

Experimental pancreatic trauma

Injuries to the pancreas are uncommon. A recent study from Sweden' reported an incidence of only 0.4 per 100000 population. Despite these figures, the serious nature of the injuries together with the relatively young age of most victims means that all surgeons should have at least a basic knowledge of the management of pancreatic trauma. There is a marked predominance of young men among those with pancreatic injury. A representative series of 93 patients with pancreaticoduodenal trauma revealed that 83 per cent of injuries involved men and that 78 per cent were in people less than 40 years old2. Damage to the pancreas is caused by either blunt or penetrating trauma. The blunt trauma mechanism of injury can be understood by considering the relationship of the pancreas to the vertebral column. Injury over the vertebral bodies tends to result in transection of the pancreas just to the left of the superior mesenteric vessels. Injuries to the right of the vertebrae may produce crushing of the pancreatic head and duodenum against the spine. Blunt injury to the left of the vertebrae may result in damage to the pancreatic tail and the spleen. In the UK, blunt trauma to the pancreas and duodenum is usually caused by road traffic accidents3. This region may be injured by direct contact with the steering wheel when the driver is unrestrained, or by incorrectly fitted lap components of seat belts. Handlebars may inflict similar injuries to motorcyclists and to children on bicycles. In view of the difficulties in clinical diagnosis, a high index of suspicion is necessary when a history of these forms of injury is obtained. In North American cities, gunshot wounds and knife wounds are the two common causes of pancreatic trauma. In the UK, penetrating injuries are less common and pancreatic trauma usually arises after road traffic accidents. Because of this geographical variation in aetiology, there is also a wide variation in the incidence of pancreatic damage in abdominal trauma. This may range from under 1 per cent to 12 per cent.

The literature on experimental pancreatic trauma is scanty. In 1943, Dragstedt showed that 8&90 per cent distal pancreatectomy in dogs resulted in neither endocrine nor exocrine insufficiency". This correlates well with observations in humans after pancreatic resection. Most authors advise against reconstruction of transected pancreatic ducts. This is felt to be too difficult and time consuming to be of use in patients with severe associated injuries, and it has a high complication rate". Lamesch and Dociu experimentally divided pancreatic ducts in dogs and then reconstructed them using microsurgical techniques". There were no complications and all anastomoses remained patent. They attribute failure of conventional techniques of ductal reconstruction to failure to obtain a microscopically accurate anastomosis.

Classification of injuries A number of classifications exist to describe pancreatic injuries. The system suggested by Lucaslg is probably the most popular: 1. Simple superficial contusion with minimal parenchymal damage. Any portion of the pancreas can be affected but there is no damage to the pancreatic duct. 2. Deep lacerations, perforations or transection of the body or tail of the pancreas. The pancreatic duct may be damaged. 3. Severe crushing, perforation or transection of the head of the pancreas with or without ductal injury. 4. Combined pancreaticoduodenal injuries, subdivided into: (a) those with mild pancreatic injury (b)those with severe pancreatic injury and duct disruption.

A classification such as this is useful because surgical management varies with the type of injury.

Diagnosis

Isolated injuries to the pancreas are uncommon. There is a very high incidence of associated injuries, with figures of 50-98 per cent widely reported4-I5. It is usual to find many organs injured in the same patient; the mean number5*I3may range from 3.5 to 4.3. These associated injuries lead to most of the morbidity and mortality linked with pancreatic trauma. The liver, spleen, stomach, duodenum and colon are the organs most commonly injured7. Colonic injuries are more common after penetrating than after blunt trauma (27 uersus 2 per cent), and are associated with a high incidence of postoperative sepsis. These penetrating injuries may also result in damage to retroperitoneal vessels in 50 per cent of cases".

The diagnosis of pancreatic injury can be extremely difficult. Early diagnosis of blunt pancreatic injury is hampered by the retroperitoneal location of the organ. This diminishes the typical clinical features of peritonitis and thereby causes diagnostic delay. This in turn results in delay in laparotomy, which is the most important cause of increased morbidity and mortality rates. The minimal abdominal pain and tenderness presenting immediately after injury often decreases over the next 1-2 h only to worsen again within 6 h (Reference 19). This feature will result in a missed diagnosis unless a high index of suspicion is associated with recognition of the mechanism of injuries and repeated subsequent examination is carried out. In all gunshot wounds and some stab wounds to the abdomen a laparotomy is mandatory. Patients with abdominal stab wounds, without overt signs of visceral injury, undergo selective

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Associated injuries

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Trauma to the pancreas: R. H. Wilson and R . J. Moorehead

Figure 1 Pancreatic haematoma with division of the main duct

laparotomy based on local wound exploration and peritoneal lavage2'. In these cases the diagnosis of pancreatic trauma should be made during operation. However, even at laparotomy, injuries to the pancreas may be missed, with potentially disastrous consequences. If pancreatic trauma is a possibility, there should be good visualization, mobilization and thorough examination of the gland and the adjacent duodenum. If a haematoma around the pancreas is encountered it must be e x p l ~ r e d ~ *Failure ~ ' * ~ to ~ .do so can result in missed injuries to the pancreatic duct2' (Figure I). The inexperienced surgeon should seek help before exploring such retroperitoneal haematomas as their release may result in uncontrollable haemorrhage. Although contusions and lacerations to the pancreas are readily diagnosed, ductal damage can easily be missed even with thorough exploration. Because of this, some surgeons advocate intraoDerative DancreatograDhv to outline the main Two &methods;xiit for doing this. One is pancreatic to amputate the tail of the pancreas and insert a cannula into the main duct. The more popular method is to cannulate the ampulla of Vater through a duodenotomy using a 5 Fr gauge paediatric feeding catheter. Sodium diatrizoate, 2-5 ml, is then injected to visualize the duct. No significant force should be used as this may produce postoperative pancreatitis. Advocates of this procedure claim a significant reduction in postoperative morbidity and mortality rates as duct injury will not be missed. In the series reported by Berni et al.', the rate of major complications dropped from 55 to 15 per cent and deaths from 11 to 0 per cent after the introduction of ductography. Despite the obvious advantages of this technique, many are unhappy about performing a duodenotomy and risking potential fistulae. We believe that the theoretical risk of a duodenal fistula is outweighed by the real risk of late complications of missed ductal injuries. Although this remains controversial' 1 q 1 2 , 2 3 we recommend the use of intraoperative pancreatography . The diagnosis of pancreatic injury after blunt trauma can be particularly difficult. The presence of associated injuries may dictate management in the form of an exploratory laparotomy, when the procedures already outlined should be followed. It is when laparotomy is not necessarily required that the diagnosis of possible pancreatic injury becomes a problem. Because of the retroperitoneal site of the pancreas, physical signs may be unhelpful. A plain abdominal radiograph should be taken to identify retroperitoneal air, which may be present in duodenal rupture. However, interpretation may be difficult and the yield of positive findings was only 18 per cent in a series of 152 cases17. Serum amylase measurement is generally

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unreliable as a diagnostic test; it may be more useful after operation as an indication of the development of complications'. In penetrating injuries, amylase levels may be elevated in only 8-23 per cent of c a ~ e s ~ ' ~Levels ' ' ~ . tend to be higher after blunt trauma, but the wide ranges reported (14-71 per cent) suggest that it is not a reliable indicator of '. Even with complete pancreatic transection, amylase levels may be normal in 3&35 per cent of patients4.I2. Hyperamylasaemia may also be caused by trauma to the head, face and chest, rupture of the stomach, duodenum or small bowel, acute alcohol intake, small bowel infarction, and hypotensive shock. The use of amylase isoenzymes has not resulted in an improvement in the diagnosis of pancreatic traumaz4. Diagnostic peritoneal lavage, a useful tool in blunt abdominal trauma, is of little value in diagnosing pancreatic injury. False negative results are common, and so the investigation is limited to the detection of associated visceral injuries which frequently occur. However, a positive result from injury to another abdominal organ will allow identification of the pancreatic injury at subsequent laparotomy. Computed tomography (CT) scanning is of more value in assessing the stable patient, but again its usefulness is limited. If the patient is scanned soon after injury, major trauma such as pancreatic fracture may not show up25. A CT scan may appear normal in 40 per cent of significant pancreatic injuries26. If scanning is performed, meticulous attention to detail is required to reduce false positive results. Unexplained thickening of the anterior renal fascia should alert the examiner to possible pancreatic trauma25. CT scanning in the acute stage may be more useful for diagnosing associated injuriesz7. Endoscopic retrograde cholangiopancreatography (ERCP), although advocated by some for stable patient^^^,^^.^^, probably has no place in the acute situation because of its invasive nature3'. ERCP and ultrasonographic scanning are of more value in the diagnosis of late problems arising from missed injuries' 5 , 2 7 . Apart from intraoperative evaluation, most other means of detecting pancreatic trauma are unsatisfactory. A high index of suspicion is mandatory if pancreatic injury is not to be missed,

operative management The approach to patients with pancreatic trauma is similar to that used for any patient with serious abdominal injury. The history of injury and physical examination are exceedingly important and should proceed simultaneously with resuscitation. The ABC of primary survey must be performed: airway management, breathing, and circulatory evaluation. The upper airway must be cleared and protected, as must the cervical spine. If breathing is inadequate, the cause must be established while ventilation allowing adequate oxygenation is maintained. Venous access must be established and volume replacement carried out. Routine blood tests should include haemoglobin concentration, white cell count, packed cell volume, group and crossmatch, urea and electrolytes, and arterial blood gas estimation. A nasogastric tube will empty the stomach and prevent gastric dilatation. A urethral catheter is mandatory unless urethral injury is suspected, when the suprapubic route is used. The last two measures are essential before either peritoneal lavage or laparotomy is carried out. A laparotomy through a long midline incision is needed. As with all trauma cases, the first priority is to arrest haemorrhage and then to limit any further gastrointestinal contamination, should any have occurred. When there are no other serious injuries, the pancreas is then examined. The pancreas is best approached through the lesser sac via the gastrocolic omentum. The presence of retroperitoneal air, particularly around the head and duodenum, or free bile should be sought. Haematomas around the pancreas and duodenum should alert the operator to possible pancreaticoduodenal injury and these must be explored. The duodenum is fully

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Kocherized, allowing examination of the pancreatic head and the retroperitoneal areas of the duodenum, where injuries can easily be overlooked. The whole of the pancreas must be fully visualized and thoroughly examined. Division of the gastrocolic omentum just outside the gastroepiploic arcade allows thorough inspection and palpation of the anterior surface and superior and inferior margins of the pancreas. Two approaches may be used to mobilize the tail of the pancreas. If the spleen is injured, the spleen and pancreas are mobilized medially by dividing the lienorenal ligament and areolar tissue along the superior and inferior margins of the pancreas. If the spleen is intact, the retroperitoneal tissue along the inferior margin of the pancreas is incised. The gland is then elevated, exposing its posterior surface. Prophylactic antibiotics should be administered in cases of abdominal trauma6.'.' 1,20.2'323. In many American series these are given in the emergency room according to a management protocol. Although the choice of specific antibiotic differs, there is broad agreement on the indications. These include all patients with penetrating trauma (from either gunshot or stab wounds), and most authors include patients with blunt trauma who require laparotomy. Broad-spectrum antibiotics which will cover contamination from organisms present in the gut are uszd. One dose before operation should be followed by two doses thereafter unless there is colonic injury, in which case a therapeutic course for 5 days should be used2'. If a splenectomy is performed with a distal pancreatectomy, prophylactic penicillin should be taken along with pneumococcal vaccine to reduce the risk of pneumococcal sepsis3'. Management of the pancreatic wound depends on the type of injury. Grade I and I1 injuries Simple drainage alone is all that is necessary for grade I injuries. Sump drains are widely advocated as there is some evidence that these reduce postoperative complications5. They should be left in place for around 10 days". In a series reported by Wynn et a/., 14 patients with grade I injuries were all treated by drainage3'. There was no morbidity o r mortality and the average hospital stay was 14 days. In another series of 23 patients, of whom 87 per cent were treated with drainage, there were four minor complications and no deaths''. Sorensen et a/. reported 17 patients after penetrating trauma; there were seven complications in five patients and no deaths after drainage33. External drainage provides an excellent means of removal of pancreatic secretions. These contain activated proteolytic enzymes and may be destructive. Adequate drainage will diminish the formation of both fistulae and abscesses. Passive drains fail to prevent formation of pancreatic juice collections5. Straight suction drains become ineffective because of plugging by collapse of adjacent tissues. Sump drains provide almost complete evacuation of secretions and avoid local autodigestion. Several studies show marked falls in the complication rate on changing from routine use of passive drains to active sump drainage. Cogbill et aL6 noted a fall from 64 per cent morbidity with passive drains to 36 per cent with sump drains. Stone et aL5 demonstrated an even more marked fall in complication rate, from 39 to 2 per cent. Some combine the use of passive and active drainage and remove the sump drains at an earlier stage than the passive onesg3". There are two main problems associated with the use of sump drains. First, they are rapidly colonized by hospital pathogens and may thus increase the rate of abscess formation. The use of a bacterial filter for the air going into the drain before it enters the body may decrease this risk5. Alternatively, a soft catheter may be placed down the formed tract of the sump drain after its removal at 10 days or later. This second tube is gradually withdrawn, allowing closure of the wound from below. Secondly, sump drains are rigid and may erode adjacent viscera or vessels. This risk may be diminished by the use of softer materials in drains or interposition of a leaf of omentum between the drain and surrounding tissues".

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Drainage alone is adequate for grade I1 injuries if the main duct is intact. Suturing the parenchyma and capsule, although suggested by some surgeons2'S2', is unnecessary and may be dangerous. Capsular repair in the presence of a missed ductal injury may result in the development of a pseudocyst". There is lower ultimate risk from the controlled fistula that would have been the outcome after drainage. A variety of options exist to deal with pancreatic duct damage when it occurs in the body or tail, to the left of the mesenteric vessels. Repair of the duct should not be considered". The best method for dealing with this problem is distal pancreatectomy and drainage4-9~'2~'4~21.22.30.32 (Figure 2 ) . Some suggest splenic p r e ~ e r v a t i o n ~but ~ , this involves a tedious dissection and added operation time, which could be considered inappropriate in an acute situation. There is also the possible late complication of splenic vein thrombosis. Wynn et a / . reported on 26 patients with grade I1 injuries32. Drainage was performed in 42 per cent, and 58 per cent underwent distal pancreatectomy. There were nine major complications in five patients and an 11 per cent mortality rate. The average hospital stay was 33 days. In 18 patients reported by Smego et a/. there was one death; three fistulae and three intra-abdominal abscesses also occurred' '. Their management was by drainage in 73 per cent and resection in 27 per cent. In contrast, Sorensen et a/. used resection in 17 patients, 10 (59 per cent) of whom suffered a total of 24 complications. A solitary patient treated by drainage had no complication^^^.

Figure 2 a Division of the main pancreatic duct. b Distal pancreatectomy and drainage

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reported overall mortality rate is 3WO per cent. A Whipple’s procedure should therefore be performed only in the most severe injuries where the missile has effectively performed the resection and the operation is essentially debridement of devitalized tissue. The incidence of such procedures is no more than 2 per cent6. Several less radical and more satisfactory options exist to deal with these sorts of injury:

Figure 3 a Combined pancreaticoduodenal injury. b Onlay Roux-en-Y loop 10 cover both injuries

Grade III and IV injuries

Major injuries to the pancreatic head without ductal damage are best treated conservatively by sump drainage. If the duct is damaged, an onlay Roux-en-Y loop is probably the best procedure2’. Smego et a/. reported 14 patients with grade 111 injuries”. All had resections performed and there was one death; four fistulae and one intra-abdominal abscess also occurred. Wynn et a / . 3 2reported six patients of whom one died. One patient underwent a pancreaticoduodenectomy without complication, and the only patient treated by drainage developed a fistula. Three patients survived total or near-total pancreatectomy with duodenal diversion and had satisfactory long-term outcomes. The average hospital stay was 31 days. Sorensen et al. treated one patient with resection33. There were three major complications, but the patient survived. Their 6-year review contained 41 patients with penetrating abdominal trauma. Overall, 20 patients were treated with drainage, with an 11 per cent mortality rate and two pancreatic and six non-pancreatic complications. Twenty-one patients underwent resection, with a resultant 19 per cent mortality rate and 18 pancreatic and 16 non-pancreatic complications. The differences in morbidity and mortality rates could not be accounted for by the severity of the injury. They recommend drainage for the majority of penetrating pancreatic injuries and suggest that resection be reserved for injuries requiring debridement and for haemostasis. Pancreaticoduodenectomy for grade IV injuries carries an unacceptably high mortality rate in the acute situation3’. The

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1. Onlay Roux-en-Y loop to cover the damaged areas of adjacent pancreas and duodenum” (Figure 3 ) . 2. Duodenal diversion. There are two ways of achieving this: After repair of the (a) Pyloric exclusion4~6~s~’0~20.35. duodenotomy a 4 cm gastrotomy is made along the distal greater curve. Through this the pylorus is approached and a polyglactin (VicryP, Ethicon Ltd., Edinburgh, UK) pursestring suture is inserted to close the pylorus. A gastrojejunostomy is then constructed using the same gastrotomy (Figure 4 ) . Vagotomy is not required because the pylorus should re-open and function normally after 3 weeks. It is the first 3 weeks after surgery that carry the high risk of fistulae35. Vaughan et al. reported 75 patients undergoing pyloric exclusion for pancreaticoduodenal injury. The mortality rate was 19 per cent and there was a 12 per cent fistula rate. The complications attributable to the technique were two suture line bleeds and one case of gastric outlet o b s t r ~ c t i o nThere ~~. was free passage of contrast medium on 25 late follow-up radiological studies and 4 per cent had marginal ulcers. Cogbill et al. used the same technique but substituted polyglactin for chromic catgut sutures6. They reported one death among eight patients, two fistulae which closed spontaneously in 21 days, and no ulcers. (b) Duodenal diverticulization. This is a more extensive procedure requiring duodenal repair, vagotomy, antrectomy, gastrojejunostomy and tube duodenostomy (Figure 5 ) . Although it has its supporter^^^^^^^, it is a complex operation which may have no advantage over the simpler procedure of pyloric exclusion. Berne et a / . described 50 trauma patients who underwent duodenal divertic~lization~’.They had a 16 per cent mortality rate, and all their fistulae at the site of the tube duodenostomy closed spontaneously. The results of duodenal diversion offer a significant improvement over primary repair and drainage. Fistula rates as low as 3 per cent have been reported using this

Figure 4 Duodenal diversion with pyloric exrfusiun and feeding jejunostomy

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effect on pancreatic secretions as intestinal rest and TPN43. A comparison between enteral and parenteral hyperalimentation using the same solution has been reported in 24 patients44. This showed that enteral feeding requires less insulin than TPN to maintain normoglycaemia and that it is more efficient for nitrogen utilization, both advantageous features for those with pancreatic trauma. The enteral route may also be more effective in restoring immune competence. Kudsk et al. reported that enteral feeding was more effective than parenteral feeding in preventing septic complications in protein-depleted rats45. Mansour et al. suggest that a feeding jejunostomy may be used for feeding in outpatient management of a persistent pancreatic fistula35 .

Complications Morbidity rates are high and vary according to the nature of associated injuries. Complication rates range from 30 to 64 per cent6.7.9.11-15.20.32 . Spay has described the long-term surveillance of 23 patients after isolated pancreatic injury46. There were five cases of diabetes, two of exocrine insufficiency and two of combined endoexocrine insufficiency.

/ Figure 5 Duodenal diveriieulization

technique”. Both pyloric exclusion and duodenal diverticulization are designed to divert the stream of gastric contents away from the duodenum. This should allow healing and decrease pancreatic and biliary secretions. They offer the advantage of a quicker and technically easier operation, lower mortality rate and no loss of pancreatic tissue in comparison with pancreaticoduodenectomy. Duodenal diversion should be used unless the pancreas and duodenum are devitalized. Sorensen et al. described five patients with grade IV injuries33. Two underwent drainage with only one complication; a patient treated by simple drainage needed reexploration for bleeding, and a patient treated by duodenal diversion had no complications. Three patients with resections had seven major complications. One of the two who had a total pancreatectomy died at operation, but the other, and a patient who had a pancreaticoduodenectomy, survived. There was a 100 per cent mortality rate in six patients reported by Wynn et al.32.Three patients exsanguinated in theatre, and the other three survived an average of45 days. One patient with duodenal diverticulization died from a pulmonary embolus after suffering a duodenal fistula. Both patients who had a pancreaticoduodenectomy died, one from sepsis and bleeding and the other after an anastomotic breakdown. Drainage of pancreatic injuries is particularly important. Whatever the type of injury, a sump drain should always be u ~ e d ~ 1*20*32935*3B. *~.’

Nutritional support

Fistula This is the commonest complication arising from pancreatic trauma. The incidence may be from 7 to 20 per ~ e n t ~ , ” * ~ ’ , rising to 26 per cent after combined pancreaticoduodenal injury”. Most develop within the first 3 weeks and can be anticipated if a major duct injury is not properly dealt with. Generally, fistulae are more common after injuries to the pancreatic head. Stone et al. noted that, of their 19 fistulae in 275 patients, 58 per cent were in the head, 26 per cent in the body and 16 per cent in the tail5. Smego et al. demonstrated that the frequency of pancreas-related complications increased with the grade of injury”. Abscess or fistula was seen in 9 per cent of grade I injuries, 17 per cent of grade I1 injuries, 36 per cent of grade 111 injuries and 50 per cent of grade IV injuries. The rate of fistula formation also varies with the method of management. In a series of 450 patients reported by Jones, fistulae were seen in 3 per cent of those treated by drainage, 4 per cent of those treated by distal pancreatectomy and 20 per cent of those treated by duodenal diverticulization”. Fistulae may drain up to 1000 ml/day depending on size. If the diagnosis is in doubt, the amylase content of the fluid should be measured. Most fistulae can be managed conservatively. This involves good drainage, protection of the skin, and nutritional support. There must be careful attention to fluid and electrolyte balance. A biochemical assay of the electrolytes in fistulous losses is useful. Each litre of fluid lost must be replaced with a litre of normal saline. Supplemental replacement of potassium, bicarbonate and (in prolonged cases) zinc and magnesium may be necessary. Of the 28 fistulae reported by Feliciano et 70 per cent closed in 2 weeks, and the slowest in 12 weeks. Recently, a somatostatin analogue has been used to hasten the closure of external pancreatic fistulae. This may be administered either as an intravenous infusion with TPN4*, or as a twice-daily subcutaneous injection4’. The patients involved all had fistulae resulting from pancreatic surgery. We recommend a trial of somatostatin use in fistulae of traumatic origin. Surgery is rarely necessary to deal with this problem. In many series all fistulae closed spontaneously, and the maximum rate of reoperation was 7 per ~ e n t ~ 1*12320-23.35. .~.’ If operation is necessary, a Roux-en-Y loop to the offending area of the pancreas is the best treatment.

Nutrition after surgery is important in the management of pancreatic injuries, particularly combined pancreaticoduodenal ones. It may be some considerable time before normal oral feeding can be reintroduced. The average time that nutritional support was required in the series reported by Wynn et al. was 14 days (range 2 4 3 days). Some use total parenteral nutrition (TPN), with its combined effect of providing nutrition and Abscess reducing pancreatic secretion3*. Most, however, advocate feeding jejunostomies in the postoperative p e r i ~ d ~ , ~ ’ , ~ ’The incidence of abscess formation after pancreatic trauma 1,12920,22.23,32,35. Abscesses ranges from 10 to 25 per (Figure 4). Enteral nutrition is safer3’, cheaper4’, more physiologica141, and associated with less stress ulceration and fewer usually develop as a result of associated injuries to adjacent other complications than TPN42. Enteral provision of an viscera, and their frequency is dependent on which other organs elemental diet distal to the pylorus has the same suppressant are damaged6,’2,23.This complication carries a high risk of

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death unless it is diagnosed and drained early6. In a series of 84 patients with pancreatic trauma, Wynn et al. reported postoperative abscesses in 19 patients, of whom 11 required exploration and drainage3’. Ultrasonography and C T scanning were very useful in the early detection and localization of these abscesses. The mortality rate in this group was 20 per cent and the average hospital stay was 42 days. Feliciano et al. described 108 patients, of whom 18 (17 per cent) developed intra-abdominal abscesses. They all required percutaneous drainage or reoperation. Five patients subsequently died from multiple organ failure. There was a mean of 5.2 intra-abdominal visceral or vascular injuries in this group. Pancreat it is The development of pancreatitis after pancreatic trauma is a common and serious complication and may carry a high risk of death5,6.1’*20. Stone et al. reported a series of 283 patients in which pancreatitis resulted in eight of 39 deaths and 11 of 54 local complications5. The mortality rate varies depending on the severity of the pancreatitis. One series reported six cases of pancreatitis in 32 patients, all of which resolved”, whereas five of six patients with haemorrhagic pancreatitis died in a series reported by Jones”. The treatment is the same as for any patient with pancreatitis, consisting of nasogastric suction, bowel rest and nutritional support.

reported by Stone et al., the overall mortality rate was 14 per cent5. Shotgun wounds carried a 67 per cent mortality rate, blunt injuries 17 per cent, other gunshot wounds 11 per cent and stab wounds 6 per cent. Trauma to the pancreatic head had a mortality rate of 20 per cent, compared with 12 per cent for the body and 10 per cent for the tail. This is probably because of the higher incidence of trauma to the duodenum and major vascular structures associated with wounds adjacent to the pancreatic head. The number of associated injuries also affects the mortality rate. Balasegaram reported a 2.5 per cent mortality rate with no or one associated injury, 13.6 per cent with two or three, and 29.6 per cent with four or morel7. The mean mortality rate from reports over the last 10 years is 19 per cent with a range of 9-34 per cent4.6-9.12-l 5 . 2 0 . 2 2 . 3 5 , 4 7 . M ost deaths are due to haemorrhage and shock and occur within the first 24-48 h. In the series reported by JonesI2, 68 of 104 deaths (65 per cent) from pancreatic trauma occurred within 48 h. Later deaths are usually caused by sepsis o r pulmonary complications.

Diagnosis and management of late presentations of pancreatic injury

Late complications of undetected trauma may present months to years after injury and can be difficult to Chronic pancreatitis usually arises because of either overlooked pancreatic trauma or missed ductal injury even Pseudocyst when trauma was recognized. A careful history is needed to With early diagnosis and treatment of pancreatic trauma, the incidence of pseudocyst should be only 2 per ~ e n t ~ ~ ~ ~ identify ’ ~ ~trauma ~ ~ as*the~ aetiological ~ * ~ ~factor, . as presentation up to 21 years after injury has been reported”. Diagnosis of the The rate depends on the adequacy of control of pancreatic extent of the pancreatitis and the integrity of the duct is best secretions achieved by internal or external drainage or made by a combination of ultrasonography, C T scanning and resection. In the series reported by Stone et al., the incidence ERCP’ 5 , 2 8 . A definitive operation to avoid further compliof pseudocyst varied from 7 per cent in patients treated with cations may then be planned. Satisfactory results were obtained passive drainage, through 3 per cent in patients treated with by distal pancreatectomy in four such patients reported by distal resection, to 1 per cent in those treated with sump Leppaniemi et a1.” and four reported by Carr et ~ 1 . ’ ~ . drainage5. Pancreatic fistulae, abscesses and pseudocysts are well documented complications of blunt and penetrating trauma. Postoperative haemorrhage The failure of a disrupted ductal system to heal will result in This occurs in 5-10 per cent of cases6,20,35.Injuries to the ongoing leakage of activated proteolytic enzymes and tissue pancreas alone d o not generally result in major haemorrhage. damage. After trauma, leakage of pancreatic juice or abscess Incomplete duct transection may also result in a stricture development may result in erosion of an adjacent vessel, after fibrous healing. Carr et al. reported a series of 11 patients resulting in major haemorrhage. Emergency operative interwith late complicationsz8.These included five pseudocysts, one vention was required in 75-100 per cent of cases of bleeding fistula, one abscess and four cases of recurrent pancreatitis. Ten reported in two series6.”. of these patients had either strictures or disruptions of the main duct demonstrated on ERCP, ultrasonographic scanning or Wound sepsis exploration. Pseudocyst accounted for 45 per cent of the late The incidence of this is between 10 and 39 per cent. The rate complications referred to this specialist unit, all of which varies according to the nature of any associated injuries and is required distal pancreatectomy after investigation revealed a particularly common with colonic involvement6,”. disrupted ductal system”. Exocrine and endocrine insuficiency

Either problem is unusual after pancreatic trauma. The amount of residual pancreatic tissue required to maintain exocrine and endocrine function is around 10-20 per cent in humans and in animal model^^,'^. In a series of 30 patients reported by Balasegaram, no pancreatic insufficiency occurred after up to 90 per cent r e ~ e c t i o n ’ ~ .

Acknowledgements We thank Mrs G. Johnston for typing the manuscript and the Medical Photography Department, Royal Victoria Hospital, Belfast for preparing the illustrations.

References 1.

Death Isolated pancreatic injuries are uncommon and carry mortality rates of between 3 and 10 per cent5-’’. Mortality rates are generally higher when associated injuries are present. The magnitude varies considerably in the literature. Some report rates as high as 22 per cent with penetrating injuries, compared with 19 per cent for blunt injuriesJ2.The type of injury to the pancreas, presence and type of associated injuries, and the cause of injury (e.g. high-velocity gunshot wound compared with stab wound) are important variables to consider when making any literature comparison. In a 30-year review of 283 patients

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Nilsson E, Norrby S, Skullman S, Sjodahl R. Pancreatic trauma in a defined population. A c ~ aChir Scand 1986; 152: 647-51. Levison MA, Petersen SR, Sheldon GF ef al. Duodenal trauma: experiences of a trauma center. J Trauma 1984; 24: 475-80. Flint LM, McCoy M , Richardson JD et a/. Duodenal injury: analysis of common misconceptions in diagnosis and treatment. Ann Surg 1980; 191: 697-702. Dickerman RM, Dunn EL. Splenic, pancreatic and hepatic injuries. Surg Clin North Am 1981; 61: 3-16. Stone HH, Fabian TC, Satiani B, Turkleson ML. Experiences in the management of pancreatic trauma. J Trauma 1981; 21: 257-62. Cogbill TH, Moore EE, Kashuk JL. Changing trends in the management ofpancreatic trauma. Arch Surg 1982; 117: 722-8.

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Berni GA, Bandyk DF, Oreskovich MR, Carrico CJ. Role of intraoperative pancreatography in patients with injury to the pancreas. Am J Surg 1982; 143: 602-5. Henarejos A, Cohen DM, Moossa AR. Management of pancreatic trauma. Ann R Coil Surg Engl 1983; 65: 297-300. Sims EH, Mandal AK, Schlater T, Fleming AW, Lou MA. Factors affecting outcome in pancreatic trauma. J Trauma 1984;

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Paper accepted 6 June 1991

Br. J. Surg.,Vol.78, No.IO,Octoberl99l