ruptured abdominal aortic aneurysm
Introduction
Introduction to rupture of abdominal aortic aneurysm Although the mortality rate of elective surgery for abdominal aortic aneurysm has been reduced to 5% or less, the rupture of abdominal aortic aneurysm is an extremely critical state. Patients often die from hemorrhagic shock before coming to the clinic. The operative mortality rate is as high as 31%. 70% is the main cause of death in patients with abdominal aortic aneurysm. Early diagnosis, emergency surgery to control bleeding is essential. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: Hemorrhagic shock
Cause
Abdominal aortic aneurysm rupture
(1) Causes of the disease
Abdominal aortic aneurysm rupture is the elastin failure of the abdominal aortic wall. After the pressure load is transferred to the collagen, the collagen becomes the main anti-tension component, which ultimately leads to the inevitable result of collagen failure under various factors. In the abdominal aortic aneurysm In the evaluation of risk factors for rupture, the main factors are tumor diameter, expansion rate, diastolic blood pressure and chronic obstructive pulmonary disease (COPD). The diameter of the tumor is considered to be the decisive factor. It is reported that the diameter of the tumor is 5-6 cm. The rupture rate was 6.6%, and the diameter was 7% when it was 7 cm. It was reported that the 5-year rupture rate of abdominal aortic aneurysm with a maximum tumor diameter of 4 cm was 10% to 15%, about 20% at 5 cm, and about 33% at 6 cm. When it is 7cm or more, it is 75%-90%, which indicates that the risk of rupture is large when the tumor diameter is more than 6cm. It is an absolute indication for surgery. The expansion speed of the tumor is 0.21 below the diameter of 6cm according to CT and B-ultrasound observation. ~0.52cm / year, and 0.69cm / year at 6 ~ 7cm, if the abdominal aortic aneurysm enlarges the diameter of 0.5cm or more within 3 months, it is easy to rupture, it is advisable to have early surgery, and the diastolic blood pressure is increased. Increased in pressure, the presence of COPD makes collagenase and leukocyte protein Increased enzyme activity, accelerate the destruction of the tumor wall and rupture, in addition, it is found that the tumor is usually oval, the lateral expansion speed is faster, and the side wall rupture of the abdominal aortic aneurysm is more common in clinical, Inzoli et al. It is suggested that in addition to the above factors, thrombosis, atherosclerotic plaque and pressure from the vertebral body also determine the pressure distribution of the tumor wall. Local pressure concentration is easy to cause abdominal aortic aneurysm rupture. Thrombosis reduces the internal aortic aneurysm. The cavity also reduces the maximum pressure on the aneurysm wall (Laplace's law), indicating that the thrombus has a certain protective significance. Surgery confirmed that the abdominal aortic aneurysm rupture often occurs near the extraperitoneal spine, where the tumor wall usually lacks thrombus and The pressure of vertebral body contact is related to increase, in addition, the aneurysm wall caused by atherosclerotic plaque is unevenly stressed, which is a factor that can not be ignored in the rupture of small abdominal aortic aneurysm.
(two) pathogenesis
According to the location of the bleeding, the extent of expansion, and the general condition, Szilagyi divides the ruptured abdominal aortic aneurysm into three cases:
1. Open type: Abdominal aortic aneurysm is broken into the abdominal cavity, and the shock occurs rapidly.
2. Restricted type: Abdominal aortic aneurysm breaks into the retroperitoneal cavity, forming a retroperitoneal hematoma, causing temporary filling.
3. Closed type: The abdomen aortic aneurysm has a small rupture hole, and the bleeding is limited by the posterior peritoneal tissue or the fibrous tissue membrane formed, and the closure is closed.
According to statistics, only about 20% of patients broke into the abdominal cavity, a large number of bleeding and rapid death; about 80% of patients broke into the retroperitoneal cavity and more common on the left side, in addition, there are still abdominal aortic aneurysm broke into the adjacent vein or intestine It is rare to form aortic vena cava, or abdominal aortic fistula, which have special manifestations.
Prevention
Prevention of rupture of abdominal aortic aneurysm
You should first focus on and improve those factors that are closely related to our lives, such as quitting smoking, eating properly, exercising regularly, and losing weight. Appropriate exercise, enhance physical fitness and improve your disease resistance. Anyone who follows these simple and reasonable lifestyles can reduce their chances of developing cancer. Pay attention to personal and environmental hygiene, avoid drug abuse, and pay attention to personal protection when working in a harmful environment.
Complication
Abdominal aortic aneurysm rupture complications Complications, hemorrhagic shock
The main complication of this disease is hemorrhagic shock. Secondly, after blood loss, it can cause insufficient blood supply to the whole body tissue, and the body is deficient in oxygen and causes metabolic acidosis. At the same time, accompanied by a drop in blood pressure, hypoxia of brain cells can cause a decrease in the activity of the "sodium-potassium pump" on the brain cell membrane, and Na ions in the cells cannot be pumped out of the cell to cause cerebral edema. This disease is critically ill and needs immediate Surgery, otherwise it can directly endanger the patient's life.
Symptom
Abdominal aortic aneurysm rupture symptoms Common symptoms Liver nausea nausea abdominal tenderness jaundice dyspnea abdominal pain low blood pressure
The clinical manifestations of abdominal aortic aneurysm rupture are serious and complicated. For those with obvious major bleeding in a short period of time, there may be a "triple sign", namely: severe abdominal pain or low back pain, hypotension and even shock and abdominal pulsation mass, about 80%~ 90% of abdominal aortic aneurysms have sudden abdominal pain when they rupture, which may be associated with low back pain. The pain is often released to the lateral abdomen or groin, which is more common on the left side. The patient may rapidly deteriorate the circulation due to major bleeding. Shock state, dizziness, loss of consciousness, thirst, cold hands and feet, decreased urine output, etc., may have blood pressure drop, pulse count, pale conjunctiva and other performance, such as broken into the retroperitoneal cavity due to hematoma filling, blood pressure once decreased There may be recovery afterwards, so it is necessary to note that a small number of patients may have no shock performance at the time of initial diagnosis.
Patients may have nausea, vomiting, bloating, hematemesis and blood in the stool. It is a manifestation of abdominal aortic aneurysm breaking into the digestive tract to form aortic fistula. Usually there is a small amount of bleeding (also known as aura of hemorrhage) followed by massive hematemesis and/or blood in the stool. The patient quickly entered the state of shock and died. In the First Affiliated Hospital of China Medical University, 2 cases of abdominal aortic aneurysm broke into the duodenum and produced hemorrhagic hemorrhage. If a large amount of fresh blood was found, the possibility of breaking into the colon should be considered.
Abdominal aortic aneurysm broke into the inferior vena cava and formed aortic vena cava caused by high cardiac output dysfunction, tachycardia, dyspnea, lower extremity edema, venous congestion, varicose and other manifestations.
In addition, when the retroperitoneal hematoma involves the iliopsoas muscle, there may be femoral neuralgia; closed rupture compresses the extrahepatic biliary tract with obstructive jaundice; the hematoma expands downward to form a mass in the groin, which needs to be differentiated from the painful inguinal hernia.
About 70% of patients with ruptured abdominal aortic aneurysm can touch the abdominal pulsatile mass, mostly on the left side, but may have tenderness, but not very severe. If the abdominal aortic aneurysm is not large, obesity or abdominal distension is obvious. Touching the pulsatile mass, some people will have sudden severe abdominal pain and/or low back pain, lower blood pressure or shock, and abdominal pulsatile mass as a triad of ruptured abdominal aortic aneurysm, but only about 50% occur at the same time.
70% of patients may have abdominal tenderness, but the muscle tension is lighter, the patient may have abdominal distension, abdominal distension, due to intra-abdominal hemorrhage or retroperitoneal hematoma caused by secondary paralytic ileus, such as continuous vascular murmur in the abdomen should be heard Considering the possibility of abdominal aortic aneurysm breaking into the inferior vena cava, iliac vein, and left renal vein, such as the presence of congestive heart failure, it is more helpful for diagnosis.
In addition, retroperitoneal blood to the lateral abdomen, lumbar back extravasation can appear ecchymosis, similar to the acute pancreatitis when the Grey-Turney sign.
Examine
Examination of rupture of abdominal aortic aneurysm
First, do a good blood type, test the clotting time and blood interlacing test to detect the coagulation mechanism. If there is abnormality, it should be corrected before surgery to avoid DIC.
It is only suitable for patients with completely stable systemic conditions, and should be prepared for emergency rescue under strict supervision. If the condition is unstable, the operation should not be delayed for a clear diagnosis. The patient should be immediately sent to the operating room for rescue.
1. chest, abdominal X-ray film: can understand whether there is a thoracic and abdominal aortic aneurysm or aortic dissection aneurysm, abdominal positive, lateral slices can be observed whether there is eggshell calcification, if the shadow of the psoas muscle disappears, side The posterior segment of the intestine should be considered to cause retroperitoneal hematoma due to rupture of the abdominal aortic aneurysm.
2. Abdominal B-ultrasound: can be carried out at the bedside, more commonly used, can effectively understand the size and extent of abdominal aortic aneurysm, and the presence and extent of intra-abdominal and retroperitoneal hemorrhage, and can be used for differential diagnosis.
3. CT examination: can be identified as the presence of abdominal aortic aneurysm, tumor wall defects and hematoma formation, etc., can be used to differentiate from inflammatory abdominal aortic aneurysm.
4. Other examinations: Electrocardiogram examination (including limb lead) can exclude myocardial infarction, pulmonary embolism and other diseases, angiography is generally not used.
Diagnosis
Diagnosis and diagnosis of abdominal aortic aneurysm rupture
For those over the age of 50, with symptoms and signs of ruptured abdominal aortic aneurysm, especially those with triple syndrome, combined with the necessary examination, the diagnosis is not difficult to establish, the state is very poor, then the diagnosis and rescue are combined, only the open exploration No delay in diagnosis and treatment.
Sometimes it needs to be differentiated from peptic ulcer perforation, kidney or ureteral calculi. In addition, abdominal aortic aneurysm combined with other abdominal lesions may sometimes have symptoms similar to rupture. It is reported that ruptured non-ruptured abdominal aortic aneurysm died after emergency operation. The rate is similar to elective surgery.
