A systematic approach for an improved patient-device-connection to allow a long-term lung assist (ConnLA)

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Aim of SPP 2014 is to enable research to support the development of long-term implantable lung assist systems. The cannulation of Extracorporeal Lung Assist (ECLA) systems is still a source of undesired complications such as recirculation due to a malposition of the cannula, ischemia of the averted body parts, and formation of (micro-)thrombi at the cannula tip due to non-physiologic flow conditions. These complications can result in an ineffective and possibly harming treatment and a reduction of the operating time of the ECLA system due to clotting and clogging. The latter requires a higher frequency of component changes which adds to the risks for the patient.Therefore, a new systematic approach to connect the ECLA system to the patient is necessary, which addresses these complications and thus may represent an important step towards a long-term stable and implantable artificial lung system. The present project aims for an alternative to conventionally used cannula such as hemodynamically optimized grafts directly connected to blood vessels. The intention is to provide a reliable blood flow into the extracorporeal circuit without (micro-)thrombi formation and/or prevention of suction of the cannula tip to the vessel wall on one hand and a return of the oxygenated blood on the other hand, which causes low shear stress to the vessel wall, provides a good mixing with the natural blood flow and no recirculation to the withdrawal point.In order to accomplish this aim, the minimal and maximal demand of extracorporeal blood flow needs to be determined for therapy concepts tailored to different entities of lung disease (e. g. lung assist with mere CO2 removal or combined oxygenation and CO2 removal with venovenous ECLA). Suitable blood vessels will be identified with the support of imaging methods and the optimal graft shape and optimal positioning, regarding angle of flow, mixing, shear stresses, and spatial position relative to other anatomic structures, will be investigated using numerical simulation and flow visualization methods. Based on these data, novel graft designs will be explored and tested in vitro. Finally, these in-vitro test results will be validated in an acute animal test series. Further in-vivo testing in a chronic animal test series is planned for a second grant period.Planned project duration: 36 month followed by a continuative application for 36 month