Patients
Cell-free Allografts
Cell-free allografts are tissue donations from which the donor's cells have been removed. Physico-chemical methods are used for this purpose. The process is also called "decellularization". What remains is the stable connective tissue. And this is what matters. The body cells make up only a very small proportion of heart valves and vessels. The heart valves and vessels act mainly mechanically as valves, or as blood conduits. These properties are provided by the connective tissue, which is completely preserved. Immediately after implantation, the cell-free allografts fulfill their purpose.
Acceptance by the body
Cell-free allografts are very rarely recognized as "foreign" by the patient's immune system. The connective tissue is immunologically silent. In contrast to the cells, whose surface markers are different in every person and are therefore recognized. Since the cells were washed out before implantation, they do not provoke the patient's immune system. The cell-free connective tissue offers the patient's body cells a natural environment for colonization. Different cell types gradually settle down and thus promote healing and regeneration. The natural shape and elasticity of the cell-free allograft facilitate the undisturbed blood flow.
Tissue Donation
Each individual cell-free allograft is derived from a tissue donation. The tissue can be removed many hours after complete cardiac arrest and therefore does not compete with organ donation. The tissue donation is carried out by independent, non-profit organizations with which corlife cooperates.
Sizes and availability
Although many people already donate tissue after they passed away, the need is greater. In addition, the geometry of the tissue donation must fit the recipient: a large person usually needs large allografts, a smaller person small. This is why there are regular waiting periods, which can last for months. The employees of corlife dedicate their full attention and care to each donation. With our Xellfree technology, we ensure the highest possible safety for patients.
The German competent authorities have approved these cell-free allografts for therapy:
Xellfree®-Technology
The process to a cell-free allograft takes about 50 days.
What happens during this time?
Discover more in this slideshow.
Tissue donation
Many people have decided to donate tissue. Relatives, friends and family can say their leave in peace, as the tissue is not removed until hours after the cardiac arrest. The maximum age for cardiovascular donation is 70 years.
Before the removal, a physician of the donation institution makes sure that the decision to donate tissue is still valid. During the conversation with close relatives, the circumstances of the deceased are also asked about in order to exclude possible risks for the transplantation. For this purpose, the medical records are checked and consultations are held with the treating physicians.
Once all consents have been obtained and risks have been excluded, the body is examined, opened and the heart and adjacent vessels are removed. A blood sample is tested for infection parameters. During the collection and examinations, signs of disease (e.g. infections) or signs of aging (e.g. arteriosclerosis) can be detected. In this case the donation will be discontinued.
A corlife employee checks and documents each tissue upon receipt.
Processing
Body cells are surrounded by a fat layer. The cells are dissolved in several washing cycles without destroying the connective tissue.
During the washing process the genetic material is released from the cells. The human genome consists of very large molecules, the DNA. The DNA is biochemically cut into many small pieces and thus completely inactivated.
In a further processing step, germs that were introduced during tissue donation are chemically deactivated.
Numerous washing steps follow to remove all remaining cell components and processing chemicals.
Release for Implantation
Finally, samples are taken from each processed allograft and examined for freedom from fungi and bacteria and freedom from cells. In addition, it is checked whether the connective tissue has a healthy structure. The examination period lasts for two weeks. If all specifications are met, we consider it a cell-free allograft.
The cell-free allograft is securely packed and labelled. Cell-free allografts are medicinal products. The "Xellfree Process" meets very high requirements, which have been approved by the German competent authorities and are continuously monitored.
Allocation
The donation institution, the clinics and corlife coordinate the distribution of the cell-free allografts. Usually the donation institution coordinates this allocation.
Testimonials
Thank donors
After receiving a tissue donation, there is often a wish to thank the donor. This gratitude can be expressed in different ways and each of these ways has its dignity and justification.
In most cases, the donor will have passed away before the tissue is donated. In a few cases, the donors are still alive. They are people who have had a heart transplant themselves. The heart valves can be taken from the explan-ted heart as a tissue donation. We are not allowed to tell you which donation you have.
One way to say thank you is to write a letter of comfort and appreciation to the donor family. When you write this letter and what you write is up to you. There is no such thing as "too early" or "too late". For example, tell what tissue donation means to your daily life and how you feel when you think of the donor.
However, you should keep one very important rule in mind: This letter must be written in anonymous form. It is not allowed to reveal your identity. Therefore, avoid any information that allows you to draw direct conclusions about yourself. For example, the letter must not contain any information about your name (or your relatives), your address, your email connection, your presence in social media, the name of the treating clinic or the treating doctors. If the anonymity criteria are not met, your letter must not be forwarded.
The thank-you letter takes the reverse route of the tissue donation:
- Give your thank-you letter in an open envelope to your attending doctor. Your letter must be accompanied by the "Consent form for forwarding an anonymous thank-you letter to the tissue retrieval organisation". We have also written a cover letter to support your intention. The thank-you letter will be addressed with the 40-digit SEC, the identification number of the tissue donation you received. This number can be found on the "Implant Identification Card" that was given to you after the surgery.
- Your letter will then be forwarded to the tissue retrieval organisation by your attending physician. The tissue retrieval organisation will check whether your letter was written anonymously, whether your consent form is enclosed for forwarding and whether the donor family wishes to receive your letter. If these conditions are met, your thank-you letter can be sent to the donor family.
An anonymous response letter from the donor family can also be forwarded to you. Please do not interpret a lack of response as rejection or disinterest. It is sometimes very difficult for donor families to write a letter. Whether you want to receive a reply letter from the donor family is also your free decision. You can indicate on the consent form whether you would like to receive such a letter.
The procedure of saying thank you is not formally established and might be inhibited by laws at domestic and international level. There are therefore no guarantees that your thank-you letter will ever reach the donor's family. However, it is our experience that those involved are committed and will go out that extra mile to fulfil your wish.