Pulmonary embolectomy

Acute pulmonary embolism (pulmonarpulmonary embolism) refers to sudden mechanical obstruction in the pulmonary artery or its branch lumen. The obstruction is usually a thromboembolism, 90% of which is caused by a thrombus in the deep vein of the lower extremity and then falls off. Due to the mechanical obstruction of the pulmonary artery, the reflex and fluid delivery factors caused by the embolus caused vasospasm, the resistance of the pulmonary vascular bed increased rapidly, and the right ventricular afterload suddenly increased. If the pulmonary artery obstruction range exceeds 50% (large pulmonary embolism), there will be obvious hemodynamic disorders: the right ventricular and pulmonary arterial pressure and central venous pressure rise, while the pulmonary capillary wedge pressure decreases, the cardiac output decreases sharply, and the heart rate Increased, decreased blood pressure, produces a special type of shock-obstructive cardiogenic shock. The dead space ventilation of the embolized lung and the ventilated blood flow of the unembolized lung cause imbalance of moderate to severe hypoxemia. About 10% to 30% of patients can die within 1 hour, and the third cause of death in Europe and America. The disease. There is no exact statistics on the incidence rate in China, but there is data showing that the incidence rate has a rapid growth trend. According to the size of the embolus, the hemodynamic changes and clinical symptoms are very different, from mild urgency, chest pain, or difficulty breathing, collapse, shock to cardiac arrest. Therefore, the treatment methods are also very different, from general symptomatic treatment, circulatory breathing support, or anticoagulant therapy, thrombolytic therapy, until the emergency cardiopulmonary bypass or normal temperature block circulation down the pulmonary artery thrombectomy. Most patients are treated with thrombolytic therapy. Only a few (about 5% of the total number of cases) are in a tight condition, the circulation is difficult to maintain, time is not allowed to wait for thrombolytic drugs, or patients who have already had cardiac arrest must Do emergency surgery. The mortality rate of surgical emboli before and after the occurrence of cardiac arrest was 10% to 30% and 60% to 70%, respectively. The mortality rate of surgery was performed before shock and without shock. 17% and 42% respectively, it can be seen that the problem related to the treatment of this disease is mainly due to timely and appropriate surgical decisions. As early as 1908, Trendelenberg proposed the use of pulmonary plug for the treatment of pulmonary embolism. After 1924, Kirschner had successfully performed one case, but due to the level of understanding and technical conditions at that time, in the future. Most of the patients in the repeated practice failed. In 1961, Sharp and Cooley succeeded in the successful removal of the pulmonary plug in the extracorporeal circulation. After that, Lewis, Clarke and others underwent the operation under the simple blocking cycle. As for various transvenous interventional pulmonary embolectomy procedures, the technology and understanding have not been consistent, and it has not been widely applied. Treatment of diseases: pulmonary embolism indications The problem of pulmonary embolization surgery has not been consistent. Some people think that about 2/3 of patients with pulmonary embolism die within 2 hours after the onset of illness. It is difficult to send the patient to a conditional hospital in such a short time and determine the diagnosis. It is difficult to decide to perform surgery. In the early stages of this crisis, there are many possibilities for rescue under active medical treatment. Therefore, surgical treatment is considered to have no status in this disease. Those who are positive believe that emergency surgery can make part of the hopeless, even patients who have had cardiac arrest, resurrected. In patients who continue to deteriorate under medical treatment, there is no other way to save them. Moreover, medical treatment, especially thrombolytic therapy, also has contraindications. Therefore, it is considered that the value of surgical emboli is still used. Moreover, patients who do not have severe circulatory dysfunction should undergo surgery, the so-called prophylactic embolectomy. In short, pulmonary plug resection is a rescue operation. There is no mature and unified format for the decision of surgery. It is necessary to carefully analyze each patient, treat it differently, and comprehensively weigh the pros and cons and risks of surgery, and make it cautiously and actively. Make a decision. In general, surgery should be performed in one of the following situations: 1. Obvious circulatory breathing: blood pressure <90 mmHg, urine volume per hour < 20 ml, arterial oxygen partial pressure < 60mmHg, there was no improvement in the positive treatment after about 1h. 2. Thrombolytic therapy failed to achieve early results (short-time thrombolysis before surgery did not increase the risk of surgical bleeding). 3. Thrombolytic therapy has contraindications (active gastrointestinal bleeding; recent brain and spinal cord trauma, surgery; brain tumors; liver and kidney dysfunction; coagulation mechanism disorders; recent childbirth or major surgery, etc.) . 4. Pulmonary angiography showed that the pulmonary artery occlusion range was more than 50%. 5. Emergency arrest due to sudden cardiac arrest due to pulmonary embolism. Contraindications The diagnosis was not established, especially when acute myocardial infarction was not clearly identified. Preoperative preparation 1. Pulmonary angiography and/or lung scan are generally required to determine the diagnosis and to understand the location and extent of the embolus. However, patients who have been diagnosed with deep venous thrombosis in the lower extremities, or who are unable to perform angiography in a situation, may be relieved after partial extracorporeal diversion. 2. Intravenous infusion of isoproterenol 0.5~5μg/min to increase cardiac output. In the case of massive pulmonary embolism, the drug also reduces pulmonary vascular resistance and relieves bronchospasm. The role. 3. Enter the colloidal solution to dilate blood volume to increase blood pressure. 4. High concentration oxygen inhalation to increase arterial oxygen partial pressure. Surgical procedure 1. Emergency part of extracorporeal circulation: in severe shock, respiratory and circulatory function has been difficult to maintain vital vital organs for oxygen supply or cardiac arrest has been stopped, urgent Partial diversion to rapidly improve circulation and blood oxygenation. Because the blood can not fully flow into the pulmonary artery for oxygenation, all other resuscitation measures will not be effective, and the heartbeat has been stopped, and can be performed while the other group is doing cardiac resuscitation. The thigh is slightly externally rotated, starting from the upper part of the inguinal ligament, along the femoral artery and vein, making a 10 cm long longitudinal incision to the distal side, dissecting the femoral artery and vein and respectively on the near and far side. The blood flow is temporarily blocked around the block. The femoral vein was cut transversely to half of the circumference, and the F32-36 intravenous catheter with a side hole was inserted, and the proximal side was inserted into the inferior vena cava, the blocking band was tightened, and the catheter was fixed. The femoral artery was cannulated with a catheter of suitable caliber, and the tip of the catheter was placed in the common iliac artery. Partial diversion begins after heparinization. When the flow rate is only 1000ml/min, the patient's condition will be significantly improved, and the general anesthesia can be intubated at this time. 2. The midline incision of the chest, open the sternum, reveal the heart, and establish extracorporeal circulation as usual. Blocking the ascending aorta with coronary artery cardioplegic perfusion and myocardial local cooling arrest. Patients who have undergone partial bypass may not have aortic and inferior vena cava intubation, and only block the aorta and vena cava to establish complete extracorporeal circulation. 3. Make a longitudinal incision of the anterior wall of the pulmonary artery about 2 cm above the pulmonary valve annulus. After retracting the incision, use a common bile duct stone clamp or a small sponge forceps to extend into the bilateral pulmonary artery to remove the embolus and blood clot. . 4. Cut the bilateral pleural cavity, squeeze the lungs by hand to help the discharge of deep emboli, or use the Fogarty balloon catheter to extend into the bilateral pulmonary artery to pull out the remaining emboli. Cut the right atrium and right ventricle, check for emboli or wall thrombus and blood clots that remain in the heart chamber, remove them, and rinse the heart chamber. 5. Continuously suture the pulmonary artery incision with a 4-0 polypropylene thread. The right atrium and right ventricular incision were sutured. 6. Auxiliary transfer, gradually reduce the perfusion flow, and stop after the cycle is stable. 7. Conventional drainage and suturing the incision such as the chest.

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