Organ transplantation, also known as grafting, is now a major treatment in modern medicine. It allows a severely, irreversibly and vitally damaged organ to be replaced or supplemented, offering an alternative to heavy and chronic treatments, and even the only chance of survival for some patients.
Beyond the surgical procedure itself, transplantation is a complex process involving major medical, biological, logistical and ethical issues.
What is a transplant?
A transplant involves implanting an organ, tissue or cells from a donor into a patient in order to restore a vital function or significantly improve quality of life.
It can:
- save the life of a patient in critical condition,
- or enable a person with a serious chronic illness to regain a more independent life, avoiding heavy and restrictive treatments (dialysis, repeated hospitalisations, palliative care).
The different types of donors
There are two main categories of donors:
- Living donors, who account for around 10% of donors. They enable the donation of a kidney or part of the liver, under strictly controlled conditions.
- Deceased donors, who account for the majority of available transplants and make multiple transplants possible.
The three main types of transplants
Transplantation does not only concern organs. We distinguish between:
- Tissues (cornea, skin, valves, bones, etc.)
- The organs (kidney, liver, heart, lung, pancreas, etc.)
- Cells (haematopoietic stem cells in particular)
Each of these grafts has specific indications and involves different storage and transport requirements.
The graft: an organ subjected to major stress
Between removal and transplantation, the graft undergoes intense physiological stress.
The various stages are critical:
- Upon the donor's death, the organ is suddenly deprived of oxygen, nutrients and warmth.
- it is then collected and stored at low temperature,
- it is then collected and stored at low temperature,
These successive phases lead to molecular, cellular and tissue alterations that can impair organ function and increase the risk of early failure or rejection.
The importance of conservation techniques
Preservation techniques aim to minimise damage caused by this stress by protecting the graft.
The organs are placed in hypothermia at approximately 4 °C, in a preservation fluid, in order to:
- slow down the organ's metabolism,
- reduce cell damage,
- attenuate the alloimmune reaction,
- ensure complete washing of residual blood,
- ensure even distribution of cold air.
Organ preservation solutions
Several generations of preservation solutions are used in clinical practice:
- 1st generation – Euro-Collins
Intracellular solution, still used in particular for its low cost. - 2nd generation – UW (Belzer)
Intracellular solution, widely considered to be the gold standard and the most commonly used in France for abdominal organs. - 3rd generation – Celsior / HTK (Custodiol)
Solutions characterised by a lower potassium concentration. - 4th generation – IGL-1, Macobiotech Transplant
Extracellular solutions using a polymer (PEG) as a colloid, aimed at improving cell protection.
Securing transport: a vital requirement
The transport of organs is subject to strict recommendations. International guidelines, particularly those issued by Eurotransplant, recommend a triple sterile and leak-proof barrier:
- three successive sterile bags,
- placed in a dedicated cooler.
This organisation aims to preserve the integrity, sterility and viability of the graft until it is implanted.
A global shortage of transplants
Despite medical advances, transplantation faces a chronic shortage of organs.
Transplantation is now indicated as a last resort for a growing number of diseases, and demand is increasing faster than the number of available transplants.
In the European Union, approximately 4,000 patients die each year due to a lack of available organs.
Two major avenues for addressing this shortage
In response to this public health challenge, two approaches are emerging:
1. Improve transport and storage conditions
Optimise graft protection to reduce losses related to transport and ischaemic stress, and increase the number of organs that can be effectively transplanted.
2. Develop alternatives
Artificial organs and new biomedical technologies represent a promising avenue for expanding long-term therapeutic resources.
In conclusion
Organ transplantation is much more than a surgical procedure: it is a chain of critical decisions and practices, from donation to transport and preservation, which directly determine the survival of the graft and the patient.
In a context of global shortage, every technical improvement counts towards maximising the chances of success and saving more lives.