Pancreatic Trauma

　　1. In traffic accidents, especially when drivers are driving at high speeds, the car suddenly hits an object, and the strong inertia causes the driver's upper abdomen to collide with the steering wheel of the car, resulting in pancreatic injury. Sometimes when a person falls from a high place, the waist is in an excessive curvature, and both sides of the ribs are extremely retracted. In a moment of explosive force, they are compressed on the pancreas, causing varying degrees of pancreatic injury.

　　2, The location of pancreatic injury varies with the direction of external force, with the head and body of the pancreas being common. When the external force acts on the right upper abdomen or the right side of the spine, the pancreatic head is prone to be compressed, and it often combines with duodenal, biliary, and liver injuries, which have serious consequences and a high mortality rate of up to 70-80%; when the external force acts directly on the middle of the upper abdomen, the injury is mostly partial or complete rupture of the pancreatic neck and body, and it is often accompanied by superior mesenteric artery injury; when the external force acts on the left side of the spine, the tail of the pancreas is often injured, and it is often accompanied by splenic rupture.

　　3, The pathological changes of closed pancreatic injury are progressive. Surgeons often pay great attention to treating pancreatic rupture injuries with concentration of efforts. However, they often do not pay enough attention to local pancreatic contusions. This is mainly due to the lack of sufficient understanding of the characteristics of the pathological changes - progressive.

　　Although relatively reasonable treatment has been given after pancreatic injury, the mortality rate is still very high. Death is often caused by injuries to major blood vessels or surrounding organs, which often exceed the death caused by the injury itself. More than 30% of survivors have complications: such as massive hemorrhage, pancreatic abscess, pseudopancreatic cyst, pancreatic fistula, and so on.

　　1. Massive hemorrhage:It is one of the most dangerous complications after pancreatic injury, often leading to death due to difficulty in treatment.

　　2. Pancreatic abscess:It is less common and often secondary to severe pancreatic contusion areas, where the injured pancreatic tissue undergoes necrosis and further forms an abscess.

　　3. Pancreatic fistula:It is the most common complication of pancreatic trauma. It can reach 20-40%, with the incidence of pancreas head contusion being the highest.

　　1, In the early stage, injury to the pancreas itself often does not lead to immediate death. Early death is often due to combined injury of other solid organs or massive hemorrhage from major vascular injury.

　　2, In the case of simple pancreatic injury or mild combined injury, there are often no obvious symptoms or specific signs in the early stage. Delayed treatment increases the incidence of complications.

　　3, Necrosis and hemorrhage of surrounding tissues, and the digestive action of pancreatic enzymes cause necrosis and hemorrhage of surrounding tissues, making the incidence of complications after injury reach 30-50%.

　　4, Multiple organ failure often occurs due to tissue necrosis and contamination, hemorrhage, shock, and decreased immunity, leading to the frequent occurrence of multiple organ failure, with a high mortality rate.

　　5, In the early stage of moderate injury, in addition to the temporary inhibition of pancreatic secretion after injury, or the release of pancreatic enzymes has not been activated, so the early symptoms are not typical.

　　6, The incidence of combined injury of the pancreas and other organs after pancreatic injury is very high. Open pancreatic injury combined with other organ injuries includes liver injury, gastrointestinal injury, duodenal injury, spleen injury, kidney injury, small intestine injury, colonic injury, vascular injury, and so on. Closed pancreatic injury combined with other organ injuries includes liver injury, stomach injury, duodenal injury, spleen injury, small intestinal injury, vascular injury, and so on.

　　This disease is caused by external force, so there is currently no preventive measure. In traffic accidents, especially when car drivers are driving at high speed and the car suddenly collides with an object, the strong inertia causes the driver's upper abdomen to collide with the steering wheel of the car, resulting in pancreatic injury. Therefore, driving safety should be paid attention to, and seat belts should be worn. Sometimes when a person falls from a high place, the waist is excessively arched, and both sides of the ribs are extremely retracted. In a moment of explosive force, the pancreas is compressed, causing varying degrees of pancreatic injury. Therefore, high-risk workers should pay close attention to this issue.

　　1. Laboratory tests:Serum phospholipase A2 (SPLA2), C-reactive protein, α1-antitrypsin, α2-macroglobulin poly(c)-specific ribonuclease (poly-(c)-specifiRNAase), serum methemoglobin, plasma fibrinogen, and other tests have good reference value, but have not been widely used.

　　2. B-ultrasound and CT examination:There may be small omental bursa effusion, pancreatic edema, etc., because the pathological changes of pancreatic injury are progressive. Therefore, imaging examinations should also be done dynamically, but sometimes they are easily confused with retroperitoneal hematoma.

　　3. Abdominal lavage or abdominal puncture:In the early stage of pancreatic injury, the intra-abdominal fluid may be very little, and puncture is often negative. Therefore, in addition to mastering the time of abdominal puncture, multiple punctures are needed to achieve an accurate diagnosis.

　　1. Fat-free high carbohydrate fluid substances can be given, such as fruit juice, jelly, lotus root starch, rice gruel, vegetable juice, protein water, mung bean soup, and other foods. Foods such as strong chicken soup, strong fish soup, meat soup, milk, soy milk, and egg yolk should be avoided. During this period, the diet is unbalanced in terms of nutritional components, with low energy and low content of various nutrients, and should not be used for a long time.

　　2. Avoid foods high in fat and irritants, such as chili, coffee, strong tea, etc., and absolutely avoid alcohol.

　　3. Maintain a regulated diet, with fixed timing and quantity, and avoid overeating and overdrinking, especially not to overindulge in fatty and greasy foods. Try to avoid adverse mental stimulation, prevent excessive tension, and think broadly when faced with things. For those with loss of appetite or poor digestion, medication and diet therapy can be combined.

　　Emergency treatment for pancreatic injury

　　After pancreatic injury, the main manifestations are intra-abdominal hemorrhage and acute pancreatitis, followed by water, electrolyte, and acid-base imbalance. Therefore, it is necessary to immediately counter shock, actively expand blood volume, and appropriately input albumin to reduce exudation. Under active anti-shock treatment, regardless of whether the blood pressure is stable or not, there should be no waiting and surgery should be performed immediately. If the injury is severe and the bleeding is large, shock should be counteracted while surgery is performed, and it should not wait for the blood pressure to rise before surgery.

　　The treatment of pancreatic injury is difficult, with many complications and a high mortality rate. During the treatment process, the following principles are often neglected, leading to treatment failure.

　　1. Pancreatic injury with surrounding major vascular injuries is serious. After laparotomy, these major vascular injuries should be explored quickly and treated accordingly. Pancreatic tissue with bleeding cannot be clamped for hemostasis, nor can it be sutured (especially deep suture), in order to avoid injury to large pancreatic ducts.

　　2. Correctly estimate the degree, scope, and whether there is a rupture of the pancreatic duct.

　　3. Reasonably resect the damaged area to reduce the impact on endocrine and exocrine functions.

　　4. Prevent the activation of pancreatic enzymes due to the overflow of pancreatic juice.

　　5. Properly apply internal and external drainage.

　　6. Prevent complications such as pancreatic fistula and formation of pancreatic cysts.

　　The pancreas is deep and long, extending from the duodenum to the hilum of the spleen. Therefore, inappropriate surgical incisions will bring great inconvenience to surgical exploration, and sometimes, due to poor exposure, the injured site can be missed.

　　There are many incisions for pancreatic surgery. If it is for exploration, the median upper abdominal incision is preferable. For cases with clear diagnosis, pancreatic projection incisions or upper abdominal curved incisions can be selected, which can completely expose the head, body, and tail of the pancreas. Obviously, these two types of incisions have good exposure, but they cause large damage to the abdominal wall and have a long operation time. Therefore, in emergency situations, a median incision can also meet the requirements for the exploration of the entire pancreas.

　　Second, emergency treatment of different types of pancreatic trauma:

　　1. Pancreatic contusion

　　It can be divided into two types: intact capsule and damaged capsule. The former is a simple pancreatic injury, and the so-called 'traumatic pancreatitis' is mostly of this type. For pancreatic contusion with capsule rupture, cigarette drain and double lumen drain can be used. If there is no pancreatic juice leakage from the drain tube, it can be removed after a few days, even if only a small amount of pancreatic juice leaks out, the tube should not be removed. To reduce bile reflux into the pancreatic duct, bile duct fistula can also be added. For pancreatic injuries with intact capsules, it is not appropriate to not drain them, as small capsule ruptures can be missed even after meticulous exploration, especially the capsule rupture on the posterior surface of the pancreas is more likely to be missed.

　　2. Pancreatic rupture

　　The rupture of the tail of the pancreas is generally uncontroversial, and the distal portion can be resected, and the proximal residual surface can be sutured. The rupture of the neck and body of the pancreas is not appropriate for anastomosis of the pancreatic duct, as the anastomosis of the pancreatic duct is difficult to perform correctly, and complications such as pancreatic fistula and stricture often occur. Therefore, distal pancreatic resection should be adopted. This not only reduces the incidence of pancreatic fistula but also prevents endocrine deficiency due to the resection of the distal segment of the pancreas. Furthermore, since there is no intestinal anastomosis, it avoids the introduction of pancreatin activator and thus prevents pancreatitis. Although the number (density) of islets is higher in the tail of the pancreas than in the head and body, generally, the removal of 80-90% of the pancreas will not cause pancreatic endocrine dysfunction. If the resection range is increased further (to the right of the mesenteric artery), pancreatic insufficiency will occur. When a large amount of pancreatic tissue is resected, appropriate insulin should be administered postoperatively to prevent denaturation due to the large secretion of insulin by the remaining small amount of pancreatic cells (islets).

　　After partial resection of the pancreas, whether the remaining pancreas has the ability to regenerate, the conclusion is different from that of the liver, and its spontaneous regeneration ability is limited. Parekh reported the results of a group of experiments on white rats using a synthetic trypsin inhibitor (FOY-305), which can stimulate the normal growth of the pancreas of white rats by increasing the release mechanism of endogenous cholecystokinin (CCK). The experimental results show that after pancreatectomy (66% distal resection), the pancreas can show significant regeneration ability when stimulated by FOY-305 through enteral feeding, and the regeneration process increases in size first and then proliferates with the increase of treatment time. The degree of proliferation of the pancreatic mass is only after 27 days of treatment, which exceeds that of the normal non-resected pancreatic mass. Although this result is still at the research stage, it has provided a new field of启示 for the treatment of pancreatic dysfunction after subtotal pancreatectomy and acute necrotizing pancreatitis.

　　3. Head injury of pancreas

　　The treatment of head injury of the pancreas is difficult. Draining alone will fail, and if the distal segment is resected, it will result in pancreatic insufficiency. Therefore, both of these treatment methods are not appropriate. The correct treatment principle is:

　　(1) If it is merely a crush or laceration, the site can be anastomosed with the jejunum;

　　(2) If the duodenum is already broken, the lateral break of the duodenum should be closed, and the distal pancreatic remnant should be anastomosed with the jejunum to preserve pancreatic function. It is also possible to insert a segment of jejunum between the two ends of the pancreas, and perform a double-ended jejunojejunal anastomosis to preserve pancreatic function;

　　(3) If the injury is very close to the duodenum or there is a duodenal rupture, the duodenum should be removed together with the injury, and the distal pancreatic断面 should be anastomosed with the jejunum.

　　4. Combined injury to the head of pancreas

　　Duodenal rupture combined with head of pancreas injury is relatively common, and it can also be accompanied by injuries to the inferior vena cava, portal vein, and superior mesenteric artery. Those with major vascular injuries often die immediately. The mortality rate of combined injuries to the head of pancreas and duodenum is very high.

　　The treatment for duodenal rupture and head of pancreas contusion can include partial gastrectomy, end-to-side gastrojejunostomy, duodenal stenting, suture of the duodenal rupture, vagotomy, choledochojejunostomy, 'diverticulization' of the duodenum with rubber tube drainage and double-lumen catheter drainage. To prevent reflux, the gastrojejunostomy should be at least 60cm away from the injured duodenum. However, some hold different opinions, suggesting that merely repairing the injury, using jejunal stenting, and high-price deep venous nutrition (total parenteral nutrition TPN) is sufficient.

　　Pancreatic head injury often occurs with biliary tract injury, especially in cases of pancreatic duct injury close to the duodenum. Intraoperative biliary tract angiography should be performed to understand the condition of the common bile duct. The junction of the bile duct and the duodenum needs to be checked carefully to avoid missing anything. The resection of the pancreatic head and duodenum is a highly destructive surgery and should not be used lightly. Generally, it should be performed under the following conditions:

　　(1) Severe head injury or pancreatic duct rupture, which is impossible to anastomose with the intestine;

　　(2) Severe duodenal contusion and laceration, or irregular edges, or long rupture, or already involving the Vater ampulla and difficult to repair;

　　(3) Pancreatic head injury with rupture of the portal vein;

　　(4) The pancreas is torn from the duodenum.

　　Regarding the issue of whether the residual pancreas needs to be connected with the jejunum after the resection of the head and duodenum in the case of contusion and laceration of the pancreatic head, some people have compared it with the conventional Whipple operation. The author believes that after the resection of the duodenojejunal and biliary enteric reconstruction, without connecting the pancreatic duct with the jejunum, the pancreatic duct at the断面 of the residual pancreas can be ligated, and an external drain can be placed around it. After comparing the two groups, the author believes that there is no significant statistical significance in terms of mortality and complications, and in cases of severe trauma to the patient, it is simpler and easier for the patient to accept to ligate the pancreatic duct without connecting it with the jejunum.

　　The treatment of common complications of pancreatic injury

　　1. Massive hemorrhage:

　　Massive hemorrhage is often due to the pancreas being damaged after the overflowed pancreatic juice is not timely drained out of the body, then the pancreatic enzymes digest and corrode the surrounding large blood vessels, causing the vessel wall to溃烂 and massive hemorrhage. It is often difficult to handle, and surgical hemostasis is also very difficult. Because the entire peripancreatic area is in a state of 'digestive rot', it is not easy to ligate. Even if it is temporarily ligated to stop the bleeding, if the pancreatic juice cannot be completely drained out of the body, it will continue to erode and hemorrhage. The only good way is to prevent it before it happens - strengthen drainage, so that the peripancreatic area is in a 'dry' environment.

　　2. Pancreatic abscess:

　　The method to prevent it is still to strengthen effective drainage, leading necrotic tissue out of the body. Pancreatic abscess is the result of pancreatic contusion. In some cases, there are abdominal symptoms after surgery, with varying degrees of fever. At this time, attention should be paid to observe whether there is regional necrotic abscess formation in the pancreas. Through pancreatic hemodynamic angiography (Dynamic Pancreatography), it is possible to predict whether there is necrosis in the pancreas. The method is to inject contrast agent intravenously, measure the density of the contrast agent in the pancreas, and at the same time, measure the density in each aortic imaging as a reference for pancreatic contrast. The average contrast agent density without pancreatic necrosis, the density of the contrast agent in the head, body, and tail sections of the pancreas is basically consistent, with a density greater than 50Hu. When there is necrosis in the pancreas, the density is

　　3. Pancreatic fistula:

　　The treatment methods can be divided into local and systemic treatment. Local treatment is mainly to enhance drainage. Systemic treatment: on the one hand, it is to supplement water, electrolytes, and various nutrients, and reduce the secretion of pancreatic juice through body fluid pathways.

　　TPN provides the patient with the calories and nutrients needed for metabolic balance during fasting. The high osmotic glucose in TPN can inhibit exocrine secretion of the pancreas by increasing plasma osmotic pressure. After 30 minutes of amino acid input, the concentration of pancreatic juice and HCO3- decreases significantly, and the volume of pancreatic juice can be reduced by 60%. It was previously thought that the input of fat emulsion could increase (promote) the excretion of pancreatic juice, but recent research has found that the input of fat emulsion has no effect on the exocrine secretion of the pancreas. When TPN is given, the gastrointestinal tract is in a 'resting' state, reducing the stimulatory effect of intestinal diet on the exocrine secretion of the pancreas.

　　Somatostatin octapeptide (Sandostatin) is a peptide hormone that is widely distributed in the central nervous system, gastrointestinal tract, and neuroendocrine organs, and has various inhibitory functions. Somatostatin can significantly reduce the secretion of pancreatic juice. The mechanism may be direct (or indirect) inhibition of exocrine secretion. Research has found that there are somatostatin receptors on the surface of pancreatic cells, which have strong affinity for somatostatin. When they bind directly, they inhibit the activity of the cell adenylate cyclase, inhibit the synthesis of intracellular cAMP, and reduce the exocrine secretion of the pancreas. Somatostatin can also reduce the activity of the vagus nerve, reduce the release of acetylcholine, and thereby inhibit neurogenic exocrine secretion of the pancreas.

　　Feedback effect of pancreatic enzymes: There have been successful reports on the use of oral pancreatic enzyme treatment for pancreatic fistula. Garcia et al. reported that after the use of a pancreatic enzyme mixture, the volume of pancreatic juice and the concentration of trypsin decreased rapidly, and the flow of pancreatic juice stopped between 1 to 12 days after treatment, and the sinus tract healed.

　　Pancreatic fistula can heal in most cases through TPN, somatostatin, pancreatic enzyme feedback, and local enhanced drainage. If there is a persistent fistula that does not heal, after imaging it is found that the fistula comes from the pancreatic duct, and there is significant stenosis or blockage at the proximal end, after 3 to 4 months of palliative treatment, surgical treatment is performed after the surrounding edema and inflammation subside. The surgical method should be determined according to the situation.