Transfusion medicine

In patients with contraindications to oral anticoagulants; a left atrial appendage occluder (LAAO) is often implanted to prevent blood flow entering in the LAA. But this strategy is not without problems and often the success of the  depends on the clinician’s experience. Implementation can even lead to blood clots outside the device; therefore eventually leading to stroke if not treated.

Often implanted to prevent

Blood clotting, or coagulation, is an important process that prevents excessive bleeding when a blood vessel is injured. Platelets (a type of blood cell) and proteins in your plasma (the liquid part of blood) work together to stop the bleeding by forming a clot over the injury. Typically; your body will naturally dissolve the blood clot after the injury has healed. Sometimes, however, clots form on the inside of vessels without an obvious injury or do not dissolve naturally.

These situations can be dangerous and require accurate diagnosis and appropriate treatment. Clots can occur in veins or arteries; which are vessels that are part of the body’s circulatory system. While both types of vessels help transport blood throughout the body The aim of a study; published in March in Frontiers in Physiology, was to develop tools based on biophysical models and interactive interfaces to optimize LAAO device therapies.

Body’s circulatory system

The study was led by Òscar Camara, a researcher with the Physense Research Group; which is a part of the BCN MedTech Unit at the UPF Department of Information and Communication Technologies (DTIC). “A study that summarizes the good work of our research team over the past three years and is part of the bachelor’s degree final project in Biomedical Engineering by Ainhoa M. Aguado, first author of the study;” explains Camara.

To obtain the most appropriate LAAO configurations for a given patient-specific LAA morphology; the researchers created a web-based 3-D interactive virtual implantation platform called VIDAA. Then, based on the features of the shape of the patient’s appendage; the researchers calculated the most promising LAAO device.

Virtual implantation platform

Using the geometric and anatomic data of the patient’s left atrial appendage, together with the most suitable adhoc device, volumetric meshes were built to run computational fluid dynamics simulations. Thus the researchers were able to assess estimated blood flow patterns after device implantation.

Thus, by combining the VIDAA platform with computational simulations it has been possible to identify the LAAO configurations associated to a lower risk of thrombus formation and also to reveal that the positioning of the device is a key element in the creation of regions with turbulent blood flows after implantation.