Chapter 2138 【2138】Decided by Oneself

Given this, there can be no preoperative factors that suggest that physicians fail to take into account the patient's own physical needs.

The first time the doctor used a mechanical valve for this patient, there was only one reason: there was no choice.

Biological valves are more expensive, and patients with money can afford them, but helpless patients may not be able to accept them physically. It's like buying an expensive piece of clothing, if it doesn't fit you, it doesn't matter how expensive it is. Once again, it shows that the disease treats people regardless of whether the patient is rich or poor.

The compatibility of biological valves is much better than that of mechanical valves, and the postoperative anticoagulant medication only needs to be taken for half a year, which has advantages over mechanical valves in this regard. It is more friendly to women who want to get pregnant. The problem is that the manufacturing process of biological valves is subject to physical limitations such as material science, and the finished products are often not as good as mechanical valves, resulting in limited use conditions.

The simplest example, when the aortic root of the patient in front of me is too thin to be less than 19 mm in diameter, only a mechanical valve can achieve such a perfect fit for a valve with a small diameter. If the bioprosthesis can be made with the same diameter of less than 19 mm, there will be fewer manufacturers with such a manufacturing process, and the range of patients and doctors who want to carefully select the best products will become smaller. Not only that, even if the size of less than 19 mm can be placed in the original diameter of the mitral valve, the effective valve area of ​​the biological valve is much smaller than that of the mechanical valve.

What a valve really plays a key role in the human heart is the effective area of ​​the valve rather than others. To describe it specifically, it refers to the leaflet area of ​​the valve except the opening and closing joints.

What is the advantage of a large effective area of ​​the valve? The daily work of the valve leaflet is to continuously withstand the impact of blood flow from the heart and large blood vessels.

When the leaflets are closed, the large leaflets are tightly closed in the face of the blood flow of the torrential waves, which can withstand the impact of huge blood flow like a solid large-scale dam.

The hemodynamics when the leaflets open are more important. At this moment, the blood rushes out of the heart to nourish other organs in the whole body. The best effect needed should be the opening of the dam to release the flood. The effective area of ​​the valve leaflet is large, and the gate is opened wide enough, so that the blood flow in the heart, which is like stored in a reservoir, can flow for thousands of miles, avoiding remaining in the heart and increasing the burden on the heart, and at the same time, it will not cause insufficient nutrition for blood flow in other organs of the body.

What if the effective area of ​​the valve is not enough? From the above principle, it can be deduced that what is the cause of various physical symptoms caused by valvular insufficiency and stenosis in clinical practice.

The human heart has four valves.

Among them, the mitral valve and the aortic valve bear the hemodynamic pressure of the systemic circulation on the side of the left atrium and the left ventricle, which can be described as a huge pressure. Compared with the pulmonary valve and the tricuspid valve of the pulmonary circulation, the task is heavier, and the position follows the important position. some.

Compared with the aortic valve, the mitral valve is more important and prone to failure, because it is located in the middle of the left atrium and left ventricle, at the root of the aorta, and its location is relatively tricky. Many patients here have a smaller caliber than the aortic valve. The position diameter is large, resulting in less choice of valve models.

At the moment, what the chief surgeon said is not very good. Based on Zhang’s words, it should be that the doctor opened the patient’s heart during the operation and took a look: Oh, this patient’s physical structure is not very good. It is estimated that the only way to change it is to replace it with a mechanical valve.