What Is an Embolectomy?

Circulating pulmonary arterial embolectomy at room temperature is a surgical operation that belongs to cardiovascular surgery.

Blocking Circulating Pulmonary Embolization at Room Temperature

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Circulating pulmonary arterial embolectomy at room temperature is a surgical operation that belongs to cardiovascular surgery.

Removal of Circulating Pulmonary Embolism at Normal Temperature; Removal of Circulating Pulmonary Embolism at Normal Temperature

Cardiovascular Surgery / Pulmonary Embolism / Surgical Treatment of Acute Pulmonary Embolism

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Due to the critical condition of pulmonary embolism, patients who need surgery to remove emboli often cannot quickly transfer to a cardiac surgery hospital to perform surgery under extracorporeal circulation. Even in some qualified hospitals, they may not be able to respond quickly. Extracorporeal circulation requires an intensive period of time, including machine preparation, and this short time is of course extremely valuable to the patient. In a group of 36 patients who underwent thrombus removal at room temperature before cardiac arrest, the mortality rate was 11.2%. Compared with the 60% mortality rate of thrombus removal under cardiopulmonary bypass after cardiac arrest, it is better to fight for time before execution. It is a surgical procedure, and do not wait for the operation in the extracorporeal circulation after the cardiac arrest during preparation. Therefore, pulmonary embolization under off-pump has its application value. Because blocking pulmonary arterial embolectomy at normal temperature does not require any special equipment and preparations, once the decision is made, the operation can be performed quickly, and there is no need for a specialist. Physicians with basic knowledge of general cardiac surgery are qualified to perform the operation. Implemented earlier, the treatment effect is similar to that of extracorporeal circulation. Therefore, even in conditional specialist hospitals, this surgical method is still used, and it is even considered to be more preferable than extracorporeal circulation.

Blocking Circulating Pulmonary Embolism at Room Temperature is Suitable for:

Pulmonary embolization is a rescue operation. There is no mature and unified format for surgical decision-making. Each patient must be carefully analyzed and treated differently. The pros and cons and risks of the operation must be fully weighed, and the decision must be made cautiously and actively. . In general, surgery should be performed in one of the following situations:

1. Obvious circulation disorder: blood pressure <90mmHg, urine volume per hour <20ml, partial pressure of arterial oxygen <60mmHg, cases that have not improved after 1 hour of active treatment.

2. Thrombolytic therapy fails to achieve early results (short-term thrombolytic therapy before surgery does not increase the risk of surgical bleeding).

3. Thrombolytic therapy is contraindicated (active gastrointestinal bleeding; recent brain and spinal cord trauma, surgery; brain tumors; liver and kidney dysfunction; coagulation mechanism disorders; recent delivery or major surgery, etc.).

4. Pulmonary angiography showed that the range of pulmonary artery occlusion was over 50%.

5. Sudden cardiac arrest due to pulmonary embolism, emergency surgery.

The diagnosis is not established, especially if it is not clearly distinguished from acute myocardial infarction.

1. Pulmonary angiography and / or lung scan are generally required to confirm the diagnosis and understand the location and scope of the emboli. However, in patients who have been diagnosed with deep vein thrombosis of the lower extremity, or those who cannot be performed under urgent circumstances, they can be relieved after partial external bypass.

2. Intravenous infusion of isoproterenol 0.5 5g / min to increase cardiac output, the drug can also reduce pulmonary vascular resistance and relieve bronchospasm during massive pulmonary embolism.

3. Enter colloidal solution to expand blood volume to raise blood pressure.

4. High concentration oxygen inhalation to increase partial pressure of arterial blood oxygen.

General anesthesia tracheal intubation, supine position, the left body is slightly raised by 15 °, the upper part of the body is raised by 20 °, so that the root of the pulmonary artery is at the highest position, so that the air is easily discharged when the incision is sutured.

1. A midline incision in the chest, saw the sternum, reveal the front of the heart, dissect the upper and lower cavities of the static cavity and wrap around to block the band. Auricular ear forceps were used to clamp a part of the anterior wall of the pulmonary artery slightly above the annulus of the pulmonary artery, and cut about 2 cm longitudinally. Use two 4-0 silk sutures on both sides of the incision to prepare for distraction.

2. Prepare to block the circulation anesthesiologist to perform excessive ventilation, speed up the drip rate of positive inotropic drugs, and avoid blood pressure drop. Tighten the strap to block the inferior vena cava, and the anesthesiologist stops assisting breathing. Block the superior vena cava, at the same time, the timekeeper starts timing and reports the time twice every half minute. After a few heartbeats, the surgeon releases the ear-clamps that clamp the pulmonary artery. Incision traction line, the operator quickly used the common bile duct stone clamp to extend into the pulmonary artery and its bilateral branches to clamp the embolus.

The first assistant uses the catheter to extend into the pulmonary artery for suction and irrigation, while the anesthesiologist pressurizes the trachea to help expel deeper residual emboli.

Open circulation: When the surgeon determines that the emboli has been removed, the second assistant is asked to lift and pull the pulmonary artery traction line, the first assistant releases the superior vena cava blocking band, and the anesthesiologist applies intratracheal pressure to squeeze out the pulse The arterial blood was exhausted side by side, and the surgeon immediately clamped the pulmonary artery incision with auricular forceps, and the anesthesiologist assisted in breathing. After the heart beats for more than 10 times, the inferior vena cava blocking band is gradually released gradually after a strong heart beat.

3. Suture the pulmonary artery incision with 4-0 silk suture.

4. After the heart rate and blood pressure have recovered well, the incision and drainage tube are sutured layer by layer.

1. Maintain the stability of circulatory function. In patients without other important cardiopulmonary diseases without cardiac arrest, the effect of emboli removal is satisfactory, and they can quickly restore circulatory breathing function and maintain stability. However, about 15% of patients, especially those who have suffered asystole, have not recovered their cardiogenic shock in time, which is the number one cause of postoperative death. Postoperative arterial blood pressure, heart rate, heart rhythm, and central venous pressure should be closely monitored, and positive inotropic drugs should be used to support circulation. When drugs are difficult to maintain the function of the heart pump, intra-aortic balloon counterpulsation support or assisted circulation should be considered.

2. Prevention and treatment of ARDS Due to severe preoperative shock, hypoxia, ischemic damage to the embolized lung, and serotonin and other fluid-transmitting substances produced by the embolus, the alveolar epithelium and the alveolar-capillary membrane are damaged, and the embolus is removed. After reperfusion injury, the incidence of ARDS after surgery is above 10%. After the operation, the airway should be kept open and humid, and appropriate oxygen therapy should be maintained. Strict breathing monitoring, including respiratory system signs, chest X-rays, blood gas analysis and calculation of oxygenation index, alveolar-arterial oxygen partial pressure difference, etc., should be detected early. ARDS. Once it appears, it should be treated with high-dose hormones, vasodilators, diuretics, and restricted fluid intake, as well as mechanically assisted breathing and positive end-expiratory pressure ventilation. Because the pathogenic factors have been removed, the prognosis of ARDS after pulmonary embolism is better than general ARDS.

3. Pulmonary hemorrhage may occur during and early postoperative pulmonary hemorrhage, and even the amount of bleeding is uncontrollable, becoming the second leading cause of postoperative death. As its mechanism of occurrence is unclear and difficult to predict in advance, there is no effective preventive countermeasure. Symptomatic treatment to keep the airway open, use hemostatic drugs, PEEP and other measures. If necessary, a double-lumen bronchial catheter can be inserted, and a Fogarty catheter can be inserted into the bleeding side for tamping. After the bleeding stops, remove it. During surgery, care should be taken not to remove the emboli from the site where the pulmonary infarction is suspected. If there is a large amount of pulmonary hemorrhage after the emboli is removed during the operation, the pulmonary artery and bronchi can be clamped. If the pulmonary hemorrhage stops, the lobectomy can be performed.

4. Patients with hypoxic brain damage and effective resuscitation before cerebral resuscitation for more than 4 to 5 minutes will inevitably develop symptoms of brain damage. Patients who fail to recover for other reasons after surgery should promptly perform brain resuscitation treatment measures such as cooling, dehydration, and application of hormones, and strengthen corresponding nursing to avoid brain edema, avoid secondary damage, and strive for brain function. Full recovery.

5. Prevention and treatment of acute renal failure Shock has occurred before surgery, especially those who have failed to quickly restore stability to circulatory function after surgery, which is prone to acute renal failure. Postoperative attention should be paid to the supplementation of effective circulating volume, to observe changes in urine volume, and to perform renal function tests in a timely manner. Once acute renal failure occurs, it should be treated accordingly.

6. There is no consensus on whether it is necessary to block all or all types of inferior vena cava during the prevention of pulmonary embolism at the same time or after surgery to prevent the re-shedding of thrombus in the inferior vena cava system. Some people think that the additional inferior vena cava blocking surgery has more disadvantages: the mortality rate of surgery has increased significantly; about 1/3 of patients have sequelae of lower limb venous insufficiency; Pulmonary embolism can still occur in a few patients through collateral circulation. On the other hand, under effective drug control, the recurrence rate of pulmonary embolism is at least not higher than that of those who have had inferior vena cava obstruction. Therefore, such surgery is not routinely used.

In order to prevent recurrence of pulmonary embolism, anticoagulation must be performed after surgery. Generally, after 24 hours of surgery, heparin anticoagulation treatment can be started when the blood component of the drainage fluid has been significantly reduced and there is almost no bleeding in each incision. Pay attention to keeping the test tube method clotting time extended to about 2 times normal, which can be safe. After 5 to 7 days, the transition to oral anticoagulants was gradually applied, and the dose was controlled according to routine monitoring for 3 to 6 months. Those who have already established deep vein thrombosis of the lower limbs and want to undergo thrombolytic therapy should wait 10 days after the operation to avoid the risk of incision bleeding in various parts.

7. After the circulation is ready, the surgeon should check whether the various instruments and medicines are prepared. It is clear whether the operation division of each person and the collaboration of the anesthesiologist are clear after the circulation is interrupted. , Calmly and quickly complete each step of taking the emboli.

8. The safety time limit for blocking the circulation at room temperature is 3 minutes. In this short time, the plug removal operation can be completed with good cooperation without having to be nervous.

9. If the emboli have not been removed within 3 minutes or if there is any doubt, repeat the operation once when the heartbeat is strong and the blood pressure is not low after 15 minutes of recovery.

10. It should not be too early to open the inferior vena cava, so as to avoid excessive blood returning to the heart too quickly and causing ventricular fibrillation or apnea. The heartbeat should be stronger after opening the superior vena cava, and gradually open when the right atrium is not overfilled Inferior vena cava, sometimes need to wait for about 1min. However, if the diameter of the superior vena cava is small, the inferior vena cava should be opened earlier when the amount of return blood is small.

11. The situation generally improves quickly after the open cycle. If the original hypotension does not recover quickly, a booster medication should be dropped. At this time, because the emboli has been removed, the pulmonary circulation resistance will become normal; you can drop dopamine or dobutamine first, and after the blood pressure stabilizes, apply vasodilators such as sodium nitroprusside or phentolamine and replenish blood volume to improve the heart Blood output and blood pressure, as well as reducing pulmonary vascular resistance, -receptor agonist-based drugs can be used if necessary. Such as bradycardia, below 60 beats / min, when the color of the heart is dark or there is conduction block, the pre-prepared isopropyl adrenaline should be injected into the right ventricle, so that the heart rate increases, the pulse is strong, and the blood pressure rises. In case of ventricular fibrillation, a cardiac massage should be performed promptly, and electric shock defibrillation should be performed when the tremor wave appears coarse.

12. Mild metabolic acidosis usually occurs after recovery of circulation, and basic drugs such as sodium bicarbonate can be appropriately administered intravenously.

13. Except for the occasional permanent left superior vena cava that enters the coronary sinus before blocking the circulation, if it is found, it should be temporarily clamped, otherwise, a large amount of blood will be lost when the pulmonary artery is cut.