Transatrial Access to the Normal Pericardial Space

BACKGROUND: A nonsurgical means to access the normal pericardial space could provide opportunities for diagnostic sampling and therapeutic interventions. Because there are currently no approved nonsurgical methods to accomplish this, we tested a new approach in large animals. METHODS AND RESULTS: A catheter system was employed in a percutaneous approach from a femoral vein to pierce the right atrial appendage. Pericardial access was confirmed by placement of a radiopaque guidewire visible under fluoroscopy (6 dogs, 13 pigs). In 7 of the pigs, pericardial tamponade, produced by injection of saline or heparinized blood into the pericardial space through this route, was confirmed by fluoroscopy and hemodynamic evidence. The feasibility and safety of this access route were tested with multiple repetitions in all 19 animals. At the end of each of the 17 acute experiments, direct inspection after thoracotomy revealed no hemopericardium, laceration, or bleeding on catheter withdrawal. In 24-hour survival studies performed in 2 of the 6 dogs, the animals exhibited no behavioral signs of discomfort or untoward consequences on recovery from anesthesia. Histology revealed only a small (approximately 1-mm) fibrinous plug at the site of puncture. CONCLUSIONS: The percutaneous approach via the right atrial appendage provides a rapid, safe route to access the normal pericardial space for diagnostic sampling and to alleviate high-volume and low-volume (<200 mL) pericardial effusions. The access route is potentially useful for selective administration of therapeutic agents, growth factors, gene vectors, and cardioactive and vasoactive agents to the heart.