A novel toolkit to improve percutaneous subxiphoid needle access to the healthy pericardial sac.

INTRODUCTION: The current practice of percutaneous subxiphoid needle access to the "healthy" pericardial sac has significant limitations. We sought to examine the feasibility of a novel toolkit designed to improve this procedure. METHODS AND RESULTS: The toolkit included a pericardial access needle and a virtual imaging platform. The needle had a 0.036 inch outer diameter, abbreviated 25° bevel, and was electrically insulated except for two small surfaces recessed from the tip. Radiofrequency energy was delivered via these surfaces to facilitate pericardial perforation. The virtual imaging system demonstrated the needle in real time and in its entirety within the thoracic anatomy of the individual animal, which was reconstructed from computed tomographic images obtained preoperatively and registered to the operative field. In five large (40-60 kg) healthy pigs, percutaneous subxiphoid access to the sac using both anterior and posterior approaches was performed. Spatial inaccuracy was measured as the distance between the pericardial puncture site and the anterior or posterior descending coronary artery, the pericardium contiguous to which had been targeted by the needle. In each animal, pericardial access was gained at 4 discrete sites (2 anterior, 2 posterior). Inaccuracy was 4.2 ± 2.2 millimeters (range 0-8 millimeters) and did not differ significantly between anterior and posterior approaches. No damage to the epicardium or coronary arteries was observed. CONCLUSIONS: Percutaneous subxiphoid access to the pericardial sac utilizing this toolkit was feasible, including safety and reasonable accuracy.

Computational fluid flow and mass transfer of a functionally integrated pediatric pump-oxygenator configuration.

Ension, Inc., under a contract with the National Heart, Lung, and Blood Institute (HHSN268200448189C), is currently developing a pediatric cardiopulmonary assist system (pCAS). This work reports on the utilization of computational fluid dynamics to predict the performance of the first of two device iterations before physical fabrication and in vitro testing. Fluent, Inc. was consulted to assist with key technical aspects of model development. Activities included porous model development and verification, generation of predictive fluid velocity fields, and incorporation of postprocessing subroutines for calculating oxygenation, decarbonation, and hemolytic blood damage. Experimental validation was conducted using bovine blood and good quantitative agreement with computational predictions was demonstrated. The success of this work suggests that the generated models and subroutines can be used as a practical tool for design and analysis of subsequent candidate pCAS design configurations.