Xenon safe in heart surgery
New study shows xenon gas could help stop nerve damaging illnesses
Each year over 28,000 patients have coronary artery bypass grafting, a surgical treatment which improves blood flow to the heart through the coronary arteries. Heart disease can often cause the arteries to narrow, restricting the amount of oxygen reaching the heart. During a coronary artery bypass healthy blood vessels are taken from another part of the body, for example the leg, which are used to take over from the narrowed arteries. 98% of first time operations occur without fatalities but there are also postoperative risks such infection, kidney failure and brain damage.
A recent successful clinical trial on 12 coronary artery bypass grafting patients found that giving xenon to patients can safeguard against postoperative brain damage from occurring. Research published in Anesthesiology shows how the team safely gave xenon to patients undergoing coronary artery bypass grafting while on cardiopulmonary artery bypass, during this form of bypass cardioplegia is administered to arrest the heart and the function of the heart and lungs are assumed by a pump and oxygenator. This research could eventually lead to new treatments for people who suffer from illnesses that damage nerve cells such as strokes, and brain and spinal cord injuries. It was found in earlier preclinical work that xenon acts as a neuroprotectant, a protector of the nerve cells, by stopping processes that occur during strokes or brain and spinal cord injuries that damage the nerve cells. The xenon was found to be capable of blocking the effects of a particular type of glutamate receptor, which plays a role in the process by which neurons communicate with each other. This particular glutamate receptor however is the same receptor in the pathway that leads to the death of nerve cells, thus xenon can prevent damaged nerve cells from dying. The discovery of the neuroprotectant property of xenon was made by Professor Nick Franks, a biophysicist from Imperial College London, whilst he was investigating molecular targets which could be responsible for the effects of different anaesthetics. Professor Mervyn Maze, an anaesthetist also from Imperial who collaborated with Professor Franks in his xenon research, said "We knew from our earlier studies that xenon was effective in stopping damaged nerve cells from dying, but this study is of tremendous importance as it shows that it is feasible to administer xenon safely to a population of patients at risk for developing brain damage. What we need now is a clinical trial to test the efficacy of xenon in large numbers of patients." The discovery also has huge implications on the treatment of nerve damaging illnesses, "Although we can stop people dying from these illnesses, there is not much we can do to stop the nerve damage that ultimately leads to devastating longterm disability. Xenon could provide a whole new way of treating nerve damaging illnesses." Other positive aspects of xenon include that it is naturally occurring and has a lack of toxicity, making it appealing for use as a neuroprotectant in humans. It is hoped that xenon could become part of standard medical treatment, administered to stroke, brain-injured and spinal cord injured victims to stop ongoing nerve cell death and prevent any more damage to the patient.
