Advanced Perfusion Techniques - Flow versus Pressure

Abstract

Cardiac operations which require Cardiopulmonary bypass (CPB) are considered the most common procedures in cardiac surgery, performed for more than half a century, especially in Europe and North America. Despite that new technologies are being incorporated in CPB as long as the development of new techniques in CPB, some debates still remain. These debates regard the achievement of the needed optimal perfusion during CPB and the relation between perfusion pressures and the optimal blood flow during extracorporeal circulation. Blood flow and blood pressure during Cardiopulmonary bypass are very important factors. Although more studies are in favor of a minor superiority of the optimal blood flow requirements, compared to the corresponding optimal blood pressure needs, their role is quite interdependent. The usage of contemporary electronic Data Management Systems (DMS) led to a significant evolution of the perfusion science. Adequate perfusion can now be judged by its results in real time, while information from DMS, such as venous saturation, levels of haemoglobin and lactate, may be used as the markers of optimal perfusion and additionally for the development of the perfusion protocols in the future.

Organ Preservation into the 2020s: The Era of Dynamic Intervention

“…Ultimately, these new technologies are trying to create an appropriate environment to preserve the organ in the best possible way, outside of its usual environment, and maintain this situation until the organ is implanted. However, many debates still remain, dealing with the ways of achieving the optimal perfusion, but mainly with the relationship between perfusion pressures and the optimal preservation solution flow during extracorporeal circulation [154]. For instance, roller pumps by their design produce a pulsatile wave pattern of flow, which by producing the appropriate pulsatile wave could serve to overcome the opening pressure for the capillary bed, sufficient to allow brief but ongoing “bursts” of perfusion, whilst avoiding continuous exposure to this higher pressure, which is recognized as a contributing factor to develop a deleterious tissue edema [140].…”