Cutting Edge: The iKnife
If a cancer involves a solid tumour, removal of cancer in surgery is often the treatment with the best outcome. However, during surgery it is often impossible for surgeons to tell where the cancerous tissue ends and the healthy tissue begins. Misjudging either can be dangerous for the patient, whether it be removing too much or not enough. Before the creation of the ‘iKnife’ there was nothing to do but send tissue to the lab and sit back and wait while the patient remained under anaesthesia.
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Surgeons have been using electricity to cut tissue for over a century. Electrosurgical knives use an electrical current to rapidly heat tissue, cutting through it while minimising blood loss. A major by - product of their use is smoke which previously had no purpose other than to irritate the rooms inhabitants.
The inventor of the iKnife, Dr Zoltan Takats of Imperial College London, realised that this smoke would be a rich source of biological information. To create the iKnife, he connected an electrosurgical knife to a mass spectrometer, and used it to identify what chemicals are present in a sample. During surgery, the iKnife matches the chemicals in the smoke to a reference library giving a result, for the tissue being cut, in three seconds.
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When tested on a variety of tumours, in all 91 tests, the tissue type identified by the iKnife matched the post - operative diagnosis based on traditional methods. While the iKnife was being tested, surgeons were unable to see the results of its readings. In the future it will be interesting to see how it effects patients
outcomes if surgeons are given the answers.
While the iKnife has the potential to improve cosmetic and functional outcomes by minimizing surgical trauma and the unnecessary removal of healthy tissue there are some limitations. Currently building the chemical library is a costly and time - consuming procedure and may never be able to include rarer tissue types. Furthermore, it is associated with significant carbonization and chemical
contamination, which are related to the high temperature of smoke at which many molecules become unstable. More recently low temperature units are being shown to help overcome this problem.
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The iKnife has potential uses beyond cancer diagnosis. It has recently been used to detect bacteria, micro-organisms and even the authenticity of beef burgers. Overall, the invention of the iKnife highlights that surgeons of the future may have something the surgeons of today don’t; certainty that as they remove tissue they are doing more good than harm.
