Synthetic trachea save the lives of dying patients
Is it possible to manufacture organs that work just as well as donations? Yes - and it has already been done. So far, the surgeon Paolo Macchiarini has given five patients new trachea made from nanotechnology and the patient's own stem cells.
The first two operations performed using these techniques were reported worldwide in 2011. In both cases, the patients were young men under 40, with late-stage tracheal cancer. In order to survive, both patients needed their cancerous trachea removed immediately - a task which was not possible, as no replacement donor organs were available.
"They had, in effect, been given a death sentence. As a last resort, they elected to try this method. Seeing them get a new chance to live their lives was fantastic, a great experience", says Paolo Macchiarini, Guest Professor of Regenerative Surgery at Karolinska Institutet, and responsible for the surgery.
However, less than four months later in March 2012, one of the patients died; a man from the USA who was operated on at the Karolinska University Hospital in Huddinge. The death occurred suddenly at a hospital in the USA.
"Of course it was shocking to discover that the man died. I'm not at liberty to discuss the more in-depth details behind his death, due to patient confidentiality, but it was not linked to our interventions. Nevertheless, we have evaluated everything and looked to what we can improve. Naturally this must be done, as we are dealing with previously untested technology. Each operation provides us with further important knowledge. We must always be humble and try to do better", says Paolo Macchiarini.
As a result of this evaluation, Paolo Macchiarini and his team have chosen a new material for the manufacture of the synthetic trachea. Nanotechnology is still being used, but hopefully the structure of the new material will encourage the stem cells to bond even better than previously. With this new, fine-tuned technology, a further three patients have received new trachea. All of these patients were operated on during the summer of 2012; two in Russia and one at the Karolinska University Hospital in Huddinge. These patients are doing well, as is the very first patient to receive the transplant, a man from Ethiopia. The three new patients, however, received the surgery under different circumstances than previously, as they did not have cancer. Instead they are patients whose trachea had been damaged by other incidents, such as accidents.
Synthetic materials and tissues have previously been used in many other areas; for example, it is relatively common to use synthetic blood vessels. The technique of covering an organ donated from a deceased person with a patient's own stem cells has also been used previously. Both trachea and urinary bladders have been transplanted. In 2008, for example, Paolo Macchiarini gave a new trachea to a Spanish woman with tuberculosis - a donor organ covered in her own stem cells. The new aspect of these well observed operations is that two previously known techniques have been combined; it is a synthetic organ that is covered in the patient's stem cells.
The result is a partially synthetic body part that develops biological functions. For example, the new trachea have fully functioning phlegm production and are completely flexible when the patient turns their head. It is possible to "tickle" the trachea and produce a coughing reflex, to name just a few examples that were impossible to achieve with trachea made from solid plastic. Furthermore, biopsies from the new constructed trachea have shown that they partially comprise of cells that are unique to the airways and were not present when the trachea was transplanted. Therefore they must have developed from the stem cells that covered the artificial trachea, or they developed as a consequence of the presence of stem cells. Nevertheless, new, healthy cells have developed where the patients previously had a cancerous trachea and these healthy cells have grown after the operation.
Paolo Macchiarini believes that it is possible to develop this discovery, in the best case into a ground-breaking innovation. He believes that it may eventually be possible to place tissues covered in stem cells in areas of a heart severely damaged by a heart attack. Here, the tissues will then begin to build healthy cells to replace those damaged. It could work as a cure for patients who are currently waiting for a donor organ.
"I am pretty sure that we will have achieved this within ten years. It should be possible to use the technique on different types of tissue, such as liver and lungs", says Paolo Macchiarini.
Do you mean that this could replace organ donations?
"That would be the best option. An organ transplant is an aggressive procedure for the body and it would be wonderful if a patient could avoid this."