LAUSR

Purpose Nowadays borders between cardiac surgery and interventional cardiology are fading and more hybrid procedures are being performed. A hybrid cardiac catheterization lab (hCCL) is needed combining optimal image quality, reduction of patient radiation dose and ultra clean air. The practical standard for a high-tech OR has been the laminar flow (LAF) principle. In a hCCL, a complete C-arm is attached to the ceiling together with multiple other ceiling mounts. LAF works as designed only when there is no or very low disturbance of the air streamlines, which is not the case in most procedures. Moreover the air cleanliness is only guaranteed in the area beneath the plenum. In practice instrumentation tables are placed outside the plenum. The purpose of this work was to compare the air cleanliness of LAF with a novel technique of smart controlled- dilution flow (SCDF) for a state-of-the art hCCL. Methods The complete deployment for a TAVI (Transcatheter Aortic Valve Implantation) procedure including personnel, devices and a state-of-the-art new monoplane imaging system was modelled in the new room. This complex procedure was analysed by Computational fluid dynamics (CFD) simulations. A set of steady state 3D analyses with particle tracking were executed, the focus being on cleanliness in three critical zones (wound area and two instrumentation tables). Results The C-arm is blocking the LAF causing air to stagnate and even create turbulences underneath the obstacle. Contaminations are not pushed away, so there is no cleaning effect of the LAF. Moreover critical areas outside the central area are not protected. In the critical zones LAF is not capable of producing ultra clean ( Conclusions All challenges of patient safety must be examined when designing and building a new hCCL. One should rethink the applicability of LAF in a hCCL with large obstacles and need for clean conditions in different areas of the room. CFD calculation is necessary. SCDF technology gives good air quality even in complex hCCL with multiple critical zones.