Duodenal injury

　　There are two main causes of duodenal injury, namely abdominal trauma and iatrogenic injury. The former is divided into two categories: closed injury and open injury. The latter often occurs due to accidental injury during endoscopic examination and treatment, as well as during operations such as right hemicolectomy, cholecystectomy, and right nephrectomy.

　　The mechanism of closed duodenal injury caused by abdominal contusion is generally believed to be that external force directly compresses the duodenum between the lumbar vertebral bodies, resulting in injury. The site of injury is mainly the descending part of the duodenum. At the junction of the duodenum and jejunum, the duodenum is in a fixed position, while the jejunum connected to it is mobile. When the superior end of the jejunum is abruptly pulled during injury, the shearing force causes a rupture at the distal end of the duodenum. Some people believe that the duodenojejunal flexure is acute, and if the pyloric sphincter is tightly closed during injury, the duodenum may form a closed loop. External force on the intestinal tract can suddenly increase intracavity pressure, causing the intestinal tract to burst.

　　Pathogenesis

　　The degree of external force exerted on the duodenum can result in different types of injuries:

　　1. Mild cases are characterized by contusions of the intestinal wall forming a hematoma

　　Hematoma between the duodenum may exist under the mucosa, in the muscle, or under the serosa, with the subserosal hematoma being the most common. Larger hematomas can block the duodenum, causing symptoms of high intestinal obstruction such as vomiting bile, leading to dehydration and electrolyte imbalance.

　　2. Severe cases may result in rupture or perforation

　　Due to the anterior half of the duodenum being inside the peritoneal cavity and the posterior half being outside the peritoneum, a rupture or perforation can occur both inside the peritoneal cavity and outside the peritoneum. A rupture or perforation occurring inside the peritoneal cavity is caused by a large amount of intestinal contents spilling into the peritoneal cavity, leading to peritonitis, with obvious clinical symptoms and signs; a rupture or perforation occurring outside the peritoneum causes retroperitoneal space infection, with symptoms and signs being either not apparent or delayed, and the pancreas and biliary tract often sustain injuries due to their anatomical relationship. Some cases may damage the major blood vessels of the duodenum, resulting in severe hemorrhage. Many of these reasons can lead to shock in patients.

　　Duodenal injury is generally caused by trauma or iatrogenic injury. If not treated in a timely manner, it may cause the following two complications:

　　1. Duodenal fistula

　　It is a common serious complication after duodenal injury, with an incidence rate of about 50% according to statistics. Its occurrence is related to factors such as missed diagnosis and treatment, inappropriate surgical methods, poor blood circulation at the anastomosis, tension, and infection around the duodenum. It usually occurs 5 to 7 days after surgery, and once it occurs, it is often accompanied by abdominal or retroperitoneal infection and sepsis, with a mortality rate of up to 50% to 70%.

　　2. Obstruction

　　Narrowing caused by the suture after duodenal injury, mainly manifested as vomiting.

　　Due to the different locations, degrees of injury, and the presence of associated injuries, the clinical manifestations of duodenal injury vary. The following are common symptoms of duodenal injury:

　　1. Intraperitoneal duodenal rupture

　　Clinical manifestations are prominent. It is mainly characterized by sudden, severe abdominal pain, more severe on the right side, accompanied by nausea and vomiting. With the increase of peritoneal effusion and the aggravation of peritonitis, abdominal distension and cessation of flatus occur. There is tenderness in the upper abdomen and muscle tension, with the disappearance of bowel sounds and the descent of the liver dullness.

　　2. Interstitial hematoma of the duodenal wall

　　Early clinical manifestations are generally mild, mainly characterized by upper abdominal pain and tenderness, followed by obstruction symptoms, mainly recurrent biliary vomiting. With the aggravation of vomiting, there may be imbalances in water, electrolytes, and acid-base balance. If a large hematoma compresses the second and third segments of the duodenum after trauma, widespread duodenal necrosis and perforation may occur.

　　3. Extra-peritoneal duodenal rupture

　　It often occurs after severe blunt trauma in the upper abdomen. There may be temporary loss of consciousness, but it recovers within a few minutes without any special discomfort, and can even continue with activities and work. After a period of time, a persistent abdominal pain may be felt, and nausea, vomiting may occur, with blood in the vomit. Abdominal pain is generally localized to the upper right abdomen or back and gradually worsens. Due to the stimulation of the posterior abdominal wall testicular nerve and the sympathetic nerve accompanying the spermatic artery by the intestinal effluent, testicular pain and penile erection symptoms may occur occasionally. During physical examination, tenderness may be felt in the upper right abdomen or back, and subcutaneous emphysema may be visible. Early there may be mild abdominal distension, with no significant muscle tension, and intestinal sounds may be weak or absent. Body temperature, pulse, and respiration do not change significantly in the early stage. However, as the course progresses, the above clinical manifestations gradually intensify or become more obvious, and tenderness may extend to the right kidney area, the inner edge of the right psoas muscle, and the dullness of the right abdominal percussion may gradually expand.

　　Duodenal injury is caused by trauma or iatrogenic injury, and prevention requires attention to avoid abdominal trauma. It is also important to avoid damaging the internal organs during treatment and examination. Early diagnosis and treatment are crucial once duodenal injury occurs.

　　Prognostic evaluation of duodenal injury

　　1, Cure: After surgical treatment, symptoms and signs disappear, wounds heal, and there are no complications.

　　1, Cured: After surgical treatment, symptoms and signs disappear, wounds heal, and there are no complications.

　　2, Improved: After surgery, the general condition improves, and there is wound infection or sinus tract formation.

　　For patients with duodenal injuries caused by trauma, attention should be paid to blood pressure, pulse, respiration, signs of shock, whether there is bleeding or ecchymosis on the abdominal wall skin, whether it is a closed or open injury, and whether there is any internal organ prolapse or organ content leakage inside the wound. Pay attention to whether there is limitation of abdominal breathing movement, abdominal distension, abdominal muscle tension, tenderness, mobile dullness, decreased or absent bowel sounds, and other signs of visceral injury and intra-abdominal hemorrhage. Digital rectal examination for tenderness or mass, and whether there are blood stains on the gloves. All abdominal penetrating injuries (open injuries穿透 abdominal membranes) should be considered as having the possibility of visceral injury. Any injury to the chest, lumbar sacral, buttocks, and perineum (especially firearm injuries) should be carefully examined for the abdomen. In addition to detailed medical history and physical examination, duodenal injury patients should also pay attention to auxiliary examinations:

　　1, Blood routine

　　White blood cell count is elevated.

　　2, Serum amylase

　　Serum amylase levels are elevated.

　　3, other auxiliary examinations

　　(1) Diagnostic abdominal puncture or lavage

　　If light yellow biliary fluid is aspirated, it is often a sign of duodenal or biliary tract injury.

　　(2) X-ray examination

　　Abdominal X-ray films show free gas under the diaphragm, hazy shadow of the psoas muscle, free air or fluid accumulation outside the duodenal lumen and (or) right renal preperitoneal interspace, hazy shadow around the right kidney, duodenal dilatation, and the diagnosis can usually be confirmed.

　　When duodenal rupture occurs, gas often enters the mesentery of the transverse colon. To avoid confusion with gas in the transverse colon, take multiple X-rays at regular intervals. If there is gas accumulation in the mesentery of the transverse colon, the position of the gas does not change much.

　　(3) Gastrointestinal contrast examination

　　For patients with mild conditions and unclear diagnosis, oral water-soluble contrast agents can be used for duodenal contrast examination, which can usually clarify the diagnosis. If there is a duodenal rupture, after injecting water-soluble contrast agent through a gastric tube, contrast agent can be seen to leak out from the rupture.

　　(4) Duodenoscopy

　　If diagnosis cannot be confirmed and the condition allows, duodenoscopy can be performed to facilitate accurate diagnosis.

　　(5) CT scanning

　　Some authors report that abdominal CT scanning is more sensitive in the early diagnosis of retroperitoneal duodenal rupture than conventional X-ray films and believe it can be used as a method of early diagnosis. Its CT features include free air or fluid accumulation outside the duodenal lumen, right renal preperitoneal interspace, hazy shadow around the right kidney, duodenal dilatation, and contrast agent interruption without entering the distal duodenum.

　　Patients with duodenal injuries generally require fasting and immediate rescue. After the patient's body recovers basically after surgery, and the anus starts to排气, they can start to eat according to the doctor's instructions. The patient's diet should be light and easy to digest, with an emphasis on eating more vegetables and fruits, properly balancing the diet, and ensuring adequate nutrition. In addition, patients should also pay attention to avoiding spicy, greasy, and cold foods.

　　The treatment of duodenal injury should be diagnosed and surgically managed early, regardless of the type of perforation or rupture. Duodenal wall hematoma, which does not respond to non-surgical treatment within 2 to 3 weeks, or duodenal obstruction symptoms that cannot be relieved, should also be treated surgically immediately. Delaying the operation time can significantly increase the mortality rate.

　　1. General management

　　For patients suspected of having duodenal injury, immediate treatment should include:

　　① Refrain from eating and apply gastrointestinal decompression.

　　② Administer intravenous fluids.

　　③ Use effective antibiotics.

　　④ Perform blood and urine routine tests, amylase tests, and blood cross-matching.

　　⑤ Monitor hemodynamic and other vital signs changes, and monitor central venous pressure if necessary.

　　⑥ If shock occurs, active anti-shock treatment should be carried out, and a catheter should be placed for urinary drainage.

　　⑦ For penetrating injuries, drainage and collection of intestinal effluent should be performed, the wound should be debrided and bandaged, and appropriate protection should be provided for visceral prolapse.

　　⑧ For difficult diagnosis, abdominal puncture and peritoneal lavage can be performed.

　　⑨ Make adequate preoperative preparations.

　　2. Principles of surgical management

　　In recent years, with the improvement of clinical management of abdominal complex, severe, or multi-organ injuries, as well as the control of severe infections and the understanding of abdominal compartment syndrome, the understanding and requirements for laparotomy in patients with severe duodenal injuries have been updated. For patients presenting with the 'death triad', that is: hypothermia (35℃), metabolic acidosis (alkali loss of 15mmol/L), and coagulation mechanism disorders (platelet count 75×10^9/L, PT 15 seconds), clinical practice does not require the treatment of injuries to be completed in one operation.

　　(1) For patients with stable hemodynamics

　　Principally, the primary treatment of the focus and gastrointestinal reconstruction surgery should be performed. Methods:

　　① If it is a simple duodenal injury, repair surgery, duodenal-jejunal anastomosis, or pedicled jejunal tube repair surgery, pyloric septum excision, or duodenal diverting surgery can be performed.

　　② If there is associated pancreatic injury, duodenal repair or resection and anastomosis, pyloric septum excision, or diverting surgery, or resection of the distal part of the injured pancreas can be performed. A few cases may require pancreaticoduodenectomy (use with caution).

　　(2) For patients with hemodynamic instability

　　Principally, focus on treating the injury and controlling the source of contamination. Methods:

　　① Apply gauze pads to stop bleeding, quickly close the openings of the digestive tract, and temporarily close the skin incision.

　　② Continue to place the patient in the ICU for resuscitation and emergency treatment, stabilize the circulation, correct hypothermia and acidosis, and coagulation mechanism disorders, etc., generally requiring 36 to 48 hours.

　　③ After the parameters of the 'death triad' are basically normal, proceed with gastrointestinal reconstruction surgery. The basic surgical principles for duodenal trauma.

　　3. Surgical methods

　　The choice of surgical method depends on the patient's overall condition, the time of trauma, the location, type, and severity of duodenal injury, as well as the presence of associated injuries, especially pancreatic injuries. Most duodenal injuries can be cured by repair surgery, but when accompanied by complex injuries such as pancreatic, biliary, and large vascular injuries, especially when diagnosis is delayed, the condition is not only complex but also very difficult to manage, requiring comprehensive consideration and determination.

　　During laparotomy, if it is found that there is a retroperitoneal hematoma around the duodenum, air in the retroperitoneal lateral edge of the duodenum and a crepitus can be felt, the mesenteric colon has ecchymosis, edema, and shows hyaline swelling, fat necrosis, and the appearance of saponification spots, the retroperitoneal tissue changes (bile-like fluid turns green, bleeding turns dark black, etc.), and there is a history of duodenal trauma, Kocher incision should be performed, open the retroperitoneum, widely mobilize the duodenum and the head of the pancreas, and it is possible to find the site of the injury. Then, the surgical plan is determined according to the general and local conditions.

　　(1) Simple repair surgery

　　Applicable to cases with small incisions, good blood supply, and no tension after suture. However, there should be duodenal internal and external decompression measures to prevent duodenal fistula. There are the following methods for duodenal decompression

　　① Place the gastrointestinal decompression tube into the duodenal cavity and perform continuous aspiration.

　　② Duodenal gastrostomy, continuous aspiration. The gastrostomy tube should be led out through another puncture hole in the duodenal wall, rather than directly from the break suture site, as the latter is prone to form a duodenal fistula. The method of continuous aspiration and decompression through duodenal gastrostomy is the most direct and reliable, widely used in clinical practice, and effective.

　　③ Continuous aspiration of gastrostomy, at the same time, perform a jejunal upper segment gastrostomy, insert the catheter retrogradely into the duodenum, and perform continuous aspiration, also known as retrograde duodenal decompression, which can be used alone. The above duodenal decompression often requires the use of extraintestinal drainage in conjunction to further prevent duodenal fistula. In addition, after duodenal decompression, an enteral gastrostomy tube can be placed at the same time to maintain postoperative nutrition.

　　(2) Repair with jejunal loop serosal layer coverage or pedicle seromuscular layer flap coverage

　　For cases with large defects but still suitable for approximation and suture, a transverse suture can be used to prevent intestinal stricture. To prevent poor healing after repair and suture, the above technique can be added. During repair and suture, it is as far as possible to remove necrotic intestinal wall tissue, cover the repair site completely, and as far as possible suture it to the normal intestinal wall to ensure the healing of the injured site. In the operation of duodenal旷置术 and gastric antrum resection by Pi Zhi Min, a seromuscular pedicle flap is made from the gastric antrum, or a seromuscular pedicle flap from the jejunum is used to repair large duodenal defects in more than 30 cases without duodenal fistula in only 1 case due to infection. It is noteworthy that even though effective coverage reinforcement has been adopted, effective duodenal cavity decompression and external drainage are still needed.

　　(3) Duodenal anastomosis

　　Applicable to cases with complete or partial transverse transection or large perforation of the duodenum, due to the risk of stricture after simple repair, anastomosis at the opposite or side side should be performed after local debridement. Before the anastomosis, the duodenum must be fully mobilized to avoid excessive tension after anastomosis, which may lead to the rupture of the anastomosis and the formation of a high-position enteric fistula. The anastomosis site should be large enough to avoid stricture and obstruction.

　　(4) Roux-en-Y anastomosis of duodenojejunum

　　Applicable to cases with large defects, unsuitable for anastomosis or direct repair, Roux-en-Y anastomosis of duodenojejunum can be performed. The jejunum is cut about 15cm from the Treitz ligament, and the distal jejunum is elevated from behind the colon to in front of the colon and anastomosed to the duodenum in a side-to-side or end-to-side Roux-en-Y anastomosis.

　　(5) Duodenal segment resection and anastomosis

　　It is often used when the injury cannot be repaired, and it can be resected and end-to-end anastomosis can be performed, especially for the fourth segment injury, the damaged part should be resected as much as possible. If the tension is too great to be anastomosed, the distal end can be closed, and an end-to-side anastomosis can be performed between the proximal end and the jejunum, or both ends can be closed and a duodenal-jejunal side-to-side anastomosis can be performed, but in either case, an ileal end-to-side Y-shaped anastomosis must be added.

　　(6) Duodenal diverticulectomy or pyloric exclusion surgery

　　Duodenal diverticulectomy, also known as duodenal旷置术. Its main purpose is to prevent the repaired duodenum from contacting the contents of the stomach, in order to achieve early and good healing.

　　Pyloric exclusion surgery, first introduced by Summers in 1930. However, Jordan first applied it to clinical practice in the early 1970s. Vanghan reported 128 cases in 1983, with a duodenal fistula incidence of 5.5%. The operation includes:

　　① Repair of duodenal injury.

　　② Pyloric ring suture closure (through the gastric incision, using non-absorbable sutures or a suture device, or using 7号线交锁胃全层缝合).

　　③ Gastrojejunostomy.

　　(7) Pancreaticoduodenectomy

　　This surgical method is highly traumatic, and it is performed in emergency situations, so there are many postoperative complications and a high mortality rate, and it is only suitable for a few cases of severe second segment duodenal fragmentation and injury to the pancreatic head, which cannot be repaired and has stable hemodynamics. Therefore, the author believes that this surgical method should be used with extreme caution.

　　(8) Serosal incision hematoma removal and hemostasis

　　Applicable to interduodenal hematoma, with peritoneal irritation signs or persistent obstruction, which is ineffective after conservative treatment. Under normal circumstances, the mucosa is intact, and only the hematoma, hemostasis, and repair of the serosal rupture are cleared, but it should establish intestinal decompression and drainage at the damaged site to prevent possible duodenal rupture.

　　In summary, although there are many surgical options for duodenal injury, the surgeon should choose according to the patient's injury condition, vital signs, postoperative rehabilitation conditions, and the surgeon's own proficiency in surgery. Regardless of the type of surgery chosen, effective intestinal decompression and complete drainage are the key to healing.