Part 1: Precardiac surgery, increasingly minimally invasive
What is the difference between this surgery and the previous open-heart surgery, radiation-guided percutaneous interventional occlusion and ultrasound-guided transthoracic occlusion? Dr. Pan Xiangbin, Department of Pediatric Cardiac Surgery, Fu Wai Hospital, Beijing
Dr. Pan Xiangbin: First of all, let’s briefly introduce the development of congenital heart disease treatment model
I. Conventional open-chest surgery. In the 1950s, the conventional surgery was performed by cutting through the front or side of the chest, inserting a tube for extracorporeal circulation, stopping the heart first, then finding the hole and sewing it up, with the disadvantage that the heart had to be cut and traumatized.
Second, percutaneous interventional blockage under radiation. It has obvious advantages over the first method, as it is very traumatic and the heart can beat during the whole process without stopping. The disadvantage is that the operation will use radiation and contrast agent, which will have some effects on the patient’s liver and kidney, and the radiation has some effects on the eyes, bone marrow, thyroid, breast and gonad.
Third, trans-thoracic interventional occlusion under esophageal ultrasound. In this method, an opening about the size of a thumb is made in the glabella, and the blocker is put in through this position under the guidance of esophageal ultrasound. The biggest advantage of this method is that it does not require the use of radiation and contrast agent, but rather esophageal ultrasound to observe the heart, but the disadvantage is that the esophageal ultrasound has to be inserted through the mouth into the esophagus, which is more painful for the patient.
Fourth, transthoracic interventional blockage under ultrasound. The tube is sent in through the leg as usual, and the wound is very small, but no radiation or contrast is used, instead, transthoracic ultrasound is used for guidance, and esophageal ultrasound is not needed.
Trans-thoracic ultrasound is the most common ultrasound examination that people usually do in the hospital, putting the ultrasound probe in the chest to see, it does not open, no radiation, and no tracheal intubation, as long as local anesthesia, and the patient himself is awake; if the patient can cooperate, he can also communicate awake during the operation, truly realizing the maximum benefit to the patient with the least trauma.
Part 2: What are the advantages of percutaneous interventional occlusion under ultrasound?
What is the significance of the difference between ultrasound-guided percutaneous interventional occlusion and radiation-guided percutaneous interventional occlusion, the former is ultrasound and the latter is radiation?
Dr. Xiangbin Pan: There are several differences between the two.
Difference one: whether there is radiation. Ultrasound guidance does not require the use of radiation, contrast agents, do not need to wear protective clothing, which not only protects the doctor, but also protects the patient; because radiation-guided surgery, in order to prevent radiation, the surgeon to wear more than ten kilograms of radiation-resistant clothing (including hats, glasses and clothing), but the patient is no way to such protection, and the rays themselves are certain hazards; at the same time, after the contrast agent hit the body, need At the same time, after the contrast agent hits the body, it needs to be metabolized by the liver and kidneys, mainly excreted by the kidneys, so if the patient’s liver function or kidney function is abnormal, it will also have an effect. In addition, because the contrast agent is more expensive, if ultrasound guidance is used, the overall cost will also be reduced because the contrast is eliminated.
Difference 2: Ultrasound guidance will not have the allergic reactions that may be caused by contrast. Since ultrasound guidance does not require the use of contrast agents at all, there is certainly no risk of allergy from the use of contrast agents.
Difference 3: The ability to change to a conventional surgical procedure in a timely manner if needed is also the most important difference. The ultrasound-guided percutaneous intervention technique is in the surgical room, which means that if the blockage does not work (for example, if the defect is large and the blocker reaches the hole before it affects the motion of the mitral valve or septum or affects the heart rate), the blocker can be retrieved directly and immediately converted to conventional surgery, so the patient does not need to be transferred back and forth. The approach may be adjusted in time as needed.
I often joke with the patient’s family, who is very nervous before the surgery, “This time we will definitely cure the child in the operating room, just like when you go to buy a lottery ticket, you will definitely win 5 million, but we will try to see if we can win 10 million, if we can make percutaneous blockage, of course, the best, less trauma, no heart stop, and low cost.
Part 3: Children are more suitable for transthoracic occlusion
Compared with ultrasound-guided transthoracic occlusion, what is the difference between percutaneous interventional occlusion and transthoracic occlusion, also under ultrasound guidance?
Dr. Xiangbin Pan: There are three main differences between the two.
First, the degree of wound concealment is different. Transthoracic occlusion is a third-generation method and percutaneous occlusion can be a fourth-generation method, but the most obvious advantage of percutaneous occlusion is that the wound is very hidden, because transthoracic occlusion will leave a scar on the chest, while percutaneous intervention from the leg is very little trauma, and the key is that there is no scar on the chest.
Second, the diameter of the wound is different. The wound of percutaneous blockage is five millimeters, and transthoracic blockage is usually in two centimeters, although the wound is also very small, but the percutaneous blockage wound is smaller.
Third, whether the muscle or bone is injured. Transthoracic occlusion can damage muscles or bones, but percutaneous occlusion enters the heart from blood vessels and does not hurt muscles or bones at all.
For example, if a child weighs 5-8 kg, the blood vessels in his legs are thin, so percutaneous blocking may break the blood vessels, which is a higher risk. Different methods are suitable for different people and need to be chosen according to the patient’s condition.
Ultrasound-guided percutaneous interventional occlusion is a new technology, so does it mean that the newest procedure is the best? What is the relationship between the various surgical methods?
Dr. Xiangbin Pan: In general, the more the 1st to 4th generation blocking methods, the less traumatic and risky the later methods are, and the greater the overall benefit; but for each patient, there is no best method, only the most suitable method, and different methods are chosen according to different patients.
If the child is older, weighs about ten kilograms, and the location of the defect is appropriate for both size, then the choice of percutaneous occlusion is the least invasive and risky. However, if the child is very young, 5-6 kg, transthoracic occlusion is more suitable and safest at this time.
Part 4: For whom is percutaneous interventional occlusion under ultrasound suitable?
Which patients are suitable for ultrasound-guided percutaneous interventional occlusion?
Dr. Xiangbin Pan: The suitability of ultrasound-guided percutaneous interventional occlusion is based on the following two considerations.
First, the location, size and shape of the defect are determined by ultrasound examination. A professional ultrasonographer will determine whether percutaneous occlusion is suitable. The chief of the department personally performs the preoperative ultrasound assessment of the child, and the experts of the department also assist in the measurement and decide together whether the child is suitable for percutaneous occlusion.
Secondly, all the preoperative examinations are just an assessment, and the final determination of whether the blocker really fits is still made after the blocker is put in. For example, you wear size 40 shoes, but not all size 40 shoes can be worn, you have to put them on your feet to determine whether they are suitable. The biggest advantage of performing ultrasound-guided percutaneous interventional occlusion in the surgical suite is that if the occluder does not fit, for example, if there is a possibility of pressure on the mitral valve or a change in heart rate, the occluder can be retracted and immediately replaced with a conventional surgical procedure for occlusion.
What are the chances that ultrasound-guided percutaneous occlusion will “fail to occlude”? Is it possible to assess the chance of “non-occlusion” before surgery?
Dr. Xiangbin Pan: Compared with radiographic guidance, ultrasound guidance is dynamic and can directly see the effect of the blocker on the valves and heartbeat, which is more intuitive to the doctor.
It is understood that one of the risks of ultrasound-guided percutaneous block is the possibility of third-degree AV block, under what circumstances is it likely to occur?
Dr. Xiangbin Pan: All procedures that place blockers have the risk of causing AV block, but the probability is very low. In the Department of Cardiac Surgery at Fu Wai Hospital, we have only encountered one case of second degree AV block, not yet third degree, but the child recovered on his own after a period of drug treatment.
In general, the probability of third degree AV block by ultrasound-guided percutaneous block is very low, and if it does occur, the blocker can be removed by conventional surgery.