Professor Jaak Kals, University of Tartu
Professor Urmas Lepner, University of Tartu
Professor Mihkel Zilmer, University of Tartu
Professor Joel Starkopf, University of Tartu
Professor Anne Lejay, University of Strasbourg (France)
Surgical procedures have health risks that depend in addition to its nature also on physiology and health condition of the individual. Until now no effective and safe solutions have been found to undo these risks. To reduce possible damage human organism has got natural protection mechanisms, that are activated by factors endangering the system, like ischaemia. These protection mechanisms are used in remote ischaemic preconditioning (RIPC) by suspending briefly blood flow to the upper limb, activating thus the corresponding mechanisms that reduce the possible damage coming from the absence of blood supply. Yet, the blood flow will be restored before the damage occurs and the tissues being temporally left without blood supply create signals that spread elsewhere in the system and prepare other organs, like for example heart or kidneys to the possible damage. Hence it is possible to get protection for the remote organs that could suffer from the surgery by activating the natural protection mechanisms of the system in advance. This doctoral thesis has studied the RIPC methodology in individuals that suffer from high risk in connection with surgery, that is in individuals that need vascular surgery procedures. RIPC was performed to these patients directly before the surgery, by suspending blood flow to their upper limb for five minutes by five minute intervals. By using this method kidney and heart damage biomarkers, but not arterial stiffness, diminished showing that RIPC reduces the possible damage of kidneys and heart resulting from the surgery. Besides it was discovered that this method has an effect on the metabolism of acylcarnitines that could be one of the intermediating mechanisms providing protection. RIPC is considered to be a harmless procedure, and this research did not find any serious negative side effects. In conclusion, given the safety of RIPC and the easiness of the procedure, the method has great potential to find a way to clinical use to reduce organ damage associated with surgery.