Chapter 2544: 【2544】Duration control is very important
"Does the doctor on your side have any requirements for our side?" Ye Chuanguang asked.
When Xie Wanying was talking on the phone, she pulled out the ballpoint pen in her hand.
Seeing this, Wei helped her take out a notebook so that she could write on it.
Xie Wanying wrote that she wanted to coordinate with the other party for Teacher Cheng to see.
Dr. Cheng Yuchen nodded while watching.
After obtaining the teacher's approval, Xie Wanying said, "First of all, the distance for the heart to be transported is relatively long and the journey takes a long time. Some preparations require the cooperation of Teacher Ye."
"You're welcome." Ye Chuanguang said frankly, "If you don't call, we also wanted to ask what your plans are. Do we need to refill the donor heart with cardioplegic fluid from the aortic root for preservation?"
"Yes." A great teacher, you don't need to say a word to understand it in seconds.
"But you must be clear that the cold ischemia time of the heart should not exceed five or six hours." Ye Chuanguang reminded him, don't think that everything will be fine with more preparation steps, and it will take a little longer at most. .
Cold ischemia can be said to be a proper term in organ transplantation technology. Before talking about cold ischemia, let’s talk about another similar technical term: warm ischemia.
The period of operation before the organ is removed from the donor's heart after cardiac arrest for cold preservation is called warm ischemia. Cold ischemia corresponds to the time period from when an organ leaves the donor to when it is transplanted into the recipient, and here mainly refers to the transport time on the road.
Each organ has an upper limit of warm ischemia and cold ischemia time. For example, the upper limit of warm ischemia and cold ischemia of the heart are the shortest, at ten minutes and eight hours, respectively. The ten minutes and eight hours here are super caps, the equivalent of big adventures. No one can take this risk lightly. Therefore, Dr. You Ye said that the cold ischemia time should not exceed five or six hours. The warm ischemia time for heart extraction in their hospital will be controlled to within five minutes.
What's the matter with the infusion of cardioplegia? Here again, when the organ is removed from the donor, the cells are not dead and continue to metabolize. Since the blood flow is interrupted and there is no blood to nourish, the organs that are taken out will inevitably suffer from metabolic damage of self-consumption. It can be imagined that the warm ischemia time period causes the most damage to the donor organ, and a skilled professional doctor is required to do this to shorten the operation time as much as possible.
How to protect the donor heart during the cold ischemia stage. In terms of medical technology, it is either the most ideal state, using a mechanical simulation of a normal human body to continuously perfuse the donor heart, so that the damage is minimal. The problem is that long-distance transportation cannot do this at all, and we can only retreat and use other methods to reduce the metabolic rate of the donor heart and reduce the damage. Therefore, there must be low temperature and other components in the general organ preservation solution to inhibit the metabolism of organ cells.
The energy consumption of the heart is mainly composed of systolic and diastolic movements of the heart and the metabolic composition of cardiomyocytes. The former accounted for 90% of the total consumption. The use of cardioplegia can stop the mechanical activity of the heart, and the low temperature reduces the metabolism of cardiomyocytes. The combination of the two is equal to one plus one, and the effect of reducing the loss is doubled.
Protecting the heart muscle is one aspect.
On the other hand, because the heart is not like the liver and has a special structure, the donor heart and the recipient need multiple ports for anastomosis.
(end of this chapter)