Traumatic retroperitoneal hemorrhage or hematoma

　　First, etiology

　　The retroperitoneal space has three areas, and the tissues and organs contained differ, leading to different direct causes of bleeding.

　　1. The median area contains organs such as the abdominal aorta, inferior vena cava, superior mesenteric artery, pancreas, and duodenum. Forceful blows to the back and anterior abdomen can easily cause these organs to be damaged and bleed heavily. Compression of the spine due to vertebral fracture in the back can also cause bleeding at the fracture ends, making it a hematoma.

　　2. There are kidneys and adrenal glands, ascending colon and descending colon on both sides (perirenal area). The lateral crushing and collision is prone to cause injury to the kidneys and colon.

　　3. There are fractures and vascular injuries of the pelvis, common iliac artery and vein, external iliac artery and vein, and their branches and tributaries in the pelvic area. Bleeding at the fracture ends and ruptured bleeding from vascular rupture can all cause massive hematomas, even persistent bleeding and progressive enlargement of the hematoma.

　　Second, pathogenesis

　　The vast majority of retroperitoneal hemorrhages and hematomas are caused by retroperitoneal structural injury, with pelvic fracture and lumbar vertebral fracture being the most common causes, accounting for about 2/3. The second most common cause is retroperitoneal vascular or organ injury, often seen in abdominal trauma from vehicles traveling at high speed, causing retroperitoneal organ or vascular injury, such as renal, pancreatic, and duodenal injury. Due to the loose tissue of the retroperitoneum, bleeding is prone to spread widely in the retroperitoneal space, forming a large hematoma, which can also seep into the mesentery, with blood loss of up to 2000-4000ml.

　　Hypovolemic shock:Hypovolemic shock is a decrease in blood pressure and microcirculatory disorder caused by a sudden decrease in effective blood volume due to a large loss of blood, plasma, or body fluids in the body or blood vessels. This includes severe diarrhea, severe vomiting, large-volume urination, or extensive burns leading to significant loss of water, salt, or plasma; esophageal variceal rupture, gastrointestinal ulceration causing massive internal hemorrhage; traumatic shock caused by muscle contusion, fracture, liver or spleen rupture, and plasma extravasation due to extensive burns, all of which belong to hypovolemic shock.

　　Retroperitoneal hematoma, due to different primary injured organs and varying degrees of injury severity, presents with diverse clinical manifestations, lacking fixed typical symptoms. Small bleeding may form a small hematoma, often with no obvious symptoms and signs and is absorbed spontaneously. The main manifestations of clinically larger hematoma include:

　　1. Symptoms of hematoma compression: Compression of nerves and internal organs by a hematoma can cause neuralgia and dysfunction of the gastrointestinal or urinary system. About 60% of patients have abdominal pain, 40% have symptoms and signs of shock, and 25% have back pain.

　　2. Abdominal pain and intestinal paralysis are relatively indistinct, which can be generalized abdominal pain or localized pain at the hematoma site. There is often varying degrees of intestinal paralysis. In cases where retroperitoneal hematoma has not渗入 the peritoneal cavity, there may only be abdominal tenderness without significant muscle tension or rebound pain. If the blood spreads into the peritoneal cavity, it can cause abdominal muscle tension, tenderness, and rebound pain, exacerbating intestinal paralysis.

　　3. When there is a large hematoma in the lateral abdominal area and ecchymosis, the lateral abdomen may appear full and swollen, with occasional subcutaneous ecchymosis and occasionally palpable tender masses.

　　4. When there is a large retroperitoneal hematoma, the patient may have rectal irritation symptoms.

　　4. When there is a large retroperitoneal hematoma in the pelvis, the patient may have rectal irritation symptoms. Palpation of the lateral abdomen may show fullness and swelling. Percussion may sometimes reveal dullness in the lumbar or back area that does not change with body position. Retroperitoneal hematoma in the pelvis, and rectal examination can palpate a mass.

　　Pay attention to the protection of the abdomen in daily life to prevent injuries from playing, fighting, kicking, and scratching. Actively prevent infection to prevent peritonitis. The prognosis of traumatic retroperitoneal hemorrhage or hematoma depends on the speed, amount, cause, and timing of discovery of the hemorrhage. Aortic rupture has a very high mortality rate. Pregnancy complicated with retroperitoneal hemorrhage poses serious risks to both the mother and the child. The prognosis of bleeding caused by other reasons is better.

　　1. Blood routine

　　Reduced hematocrit and hemoglobin levels.

　　2. Urinalysis

　　Sometimes red blood cells can be seen in the urine.

　　3. Ultrasound examination

　　Emergency abdominal ultrasound examination can, to some extent, show the condition of intra-abdominal solid organ injury, such as the condition of abdominal hemorrhage and effusion.

　　4. X-ray film

　　If there are findings such as pelvic fracture, lumbar spine fracture, blurred shadows of the psoas muscle, or mass shadows, it suggests retroperitoneal hemorrhage. Due to intestinal bloating and ileus, the manifestations may include displacement of the gaseous intestine.

　　5. Intravenous pyelography

　　There may be manifestations such as compression or displacement of the renal pelvis, with contrast medium渗漏 from the kidney outward, indicating renal injury and retroperitoneal hemorrhage.

　　6. CT examination

　　General hematomas are manifested as abnormal soft tissue density, accompanied by occlusion and displacement of the retroperitoneal space. The density of hematomas varies with the duration of bleeding. Acute hematomas have increased density, subacute hematomas have a central high-density area surrounded by low-density areas (Figure 1), and chronic hematomas show non-specific low-density areas, accompanied by thickened环形 walls, with enhancement visible in the wall on contrast-enhanced scans. Late stages may also calcify. The location of the hematoma is helpful in diagnosing the source of bleeding.

　　7. MRI examination

　　Its manifestations depend on the duration of the hematoma, the pulse sequence, and the magnetic field strength. In the hyperacute phase of hematomas at high field strength (0.5-2.0T), the signal on T1-weighted images can be slightly lower, slightly higher, or equal to that of muscle, and the signal on T2-weighted images is usually high. Acute phase hematomas: on T1-weighted images, peripheral high signal and central low signal; on T2-weighted images, very low signal. Subacute phase hematomas: both T1 and T2 weighted images show high signal, surrounded by a black low signal ring.

　　8. Abdominal puncture

　　If there is no posterior peritoneal rupture and blood does not flow into the abdomen, abdominal puncture is often negative. However, some retroperitoneal hematomas can extend to the abdominal wall, and clotted blood can also be aspirated from punctures in the right or left lower abdomen without injury to abdominal organs. Therefore, further analysis of positive abdominal puncture is also required to avoid negative laparotomy.

　　9. Abdominal lavage

　　Abdominal lavage is helpful in distinguishing between intra-abdominal hemorrhage and retroperitoneal hematoma, and in dynamically observing the condition of intra-abdominal hemorrhage.

　　The method is: under local anesthesia, insert the lavage tube into the peritoneal cavity at the point above the umbilicus as the puncture point, and stop lavage and perform laparotomy if gastrointestinal contents or more than 10ml of unclotted blood is aspirated. Lavage is carried out by infusion, with rapid infusion of 1000ml of normal saline, Ringer's solution, or sodium lactate Ringer's solution within 10 to 15 minutes. If the lavage reflux fluid has any of the following, it indicates abdominal bleeding or intra-abdominal organ injury rather than retroperitoneal hematoma.

　　1. Present with a hemorrhagic appearance.

　　2. Contains bile or gastrointestinal contents.

　　3. Red blood cell count exceeds 0.1×10^12/L.

　　4. Amylase determination > 175U/L (Karowan).

　　5. The smear microscopic examination found a large number of bacteria.

　　Engran reported that if the red blood cell count in the peritoneal lavage fluid exceeds 0.1×10^12/L, the possibility of intra-abdominal organ injury is 85%, and when it is (0.05～0.1)×10^12/L, it is 59%.

　　Early in the injury, the affected area has ecchymosis and swelling, meridians are blocked, and Qi and blood are obstructed. The treatment during this period focuses on promoting blood circulation and removing blood stasis, and dissipating Qi. According to traditional Chinese medicine, 'If the blood stasis does not go away, the bone cannot grow' and 'if the blood stasis goes away, new bone can grow'. It can be seen that removing swelling and blood stasis is the primary requirement for fracture healing. The principle of diet coordination is to maintain a light diet, such as vegetables, eggs, soy products, fruits, fish soup, lean meat, etc. in the middle stage (when most of the swelling is absorbed): the treatment during this period focuses on harmonizing the营, alleviating pain, removing blood stasis, and promoting the formation of new tissue. In terms of diet, it shifts from light to moderate high-nutrition supplementation, with dishes such as bone soup, Cordyceps chicken stew, animal liver, etc., to provide more vitamin A, D, calcium, and protein.

　　First, treatment

　　The treatment of retroperitoneal hematoma should be individualized, and it is wrong to decide on conservative treatment or surgery in general; in surgical treatment, whether to incise the retroperitoneum should also be decided according to specific circumstances.

　　1. Non-surgical treatment

　　(1) Indications: Patients with good overall condition, stable hemodynamics, and estimated less retroperitoneal bleeding after clinical examinations, or only pelvic or spinal fracture end bleeding without major vascular or visceral injury. In this case, the amount of bleeding or hematoma is not large, and it can be absorbed spontaneously most of the time.

　　(2) Treatment measures:

　　①Closely observe the changes in the basic vital signs of the patient such as blood pressure, pulse, respiration, and body temperature, and refer to the anatomical location of the fracture and the degree of injury to comprehensively estimate the amount of internal bleeding.

　　Blood transfusion and fluid resuscitation for shock treatment, maintaining electrolyte balance. In recent years, anti-shock treatment often adopts the

　　③ Preventive use of antibiotics.

　　④ Fast and gastric decompression.

　　⑤ Do not use analgesics when the diagnosis is unclear.

　　⑥ Prevent and treat complications of respiratory, urinary and other systems.

　　If the hemodynamics is unstable and there is a suspicion of internal organ injury during the treatment and observation period, reoperation should be performed.

　　2. Surgical treatment

　　(1) Indications: Retroperitoneal hematoma from major retroperitoneal blood vessel injuries such as abdominal aorta, inferior vena cava, and iliac vessel injuries; retroperitoneal hematoma from pancreatic, duodenal, and renal rupture; retroperitoneal hematoma with liver, spleen, uterus, and abdominal blood vessel injuries; retroperitoneal hematoma with injury to the colon, small intestine, and other hollow organs.

　　(2) Surgical methods: The surgical method is determined according to the different parts of the injury during surgery. In some cases, for patients with pelvic fracture and retroperitoneal hemorrhage, bilateral internal iliac arteries can be ligated to control bleeding, or selective internal iliac artery catheterization can be performed to embolize the artery with absorbable gelatin sponge. In addition, vasoconstrictor drugs can be infused to reduce bleeding and hemostasis. For patients suspected of having internal organ injury, laparotomy should be performed, and attention should be paid to the presence of multiple injuries to abdominal and retroperitoneal organs. If retroperitoneal hemorrhage with gas collection and jaundice is found, the possibility of duodenal injury should be considered, and corresponding measures should be taken.

　　Postoperative exploration of retroperitoneal hematoma without injury to abdominal internal organs showed different opinions on whether to incise the retroperitoneum, but if the hemodynamics is stable, no injury to abdominal internal organs is found, the retroperitoneal hematoma is not large, and there is no progressive enlargement, it can be ruled out that the patient who does not need to incise the retroperitoneum does not have injury to blood vessels and retroperitoneal organs. However, if the hemodynamics is unstable, the retroperitoneum should be incised to find the cause of retroperitoneal hemorrhage. After reliable ligation of large blood vessels, it is confirmed that there is no further bleeding, and traditional Chinese medicine and Chinese herbs can be applied to promote the absorption of hematoma.

　　Second, prognosis

　　Good prognosis and recovery.