Objective: Minimally invasive epicardial atrial ablation to cure atrial fibrillation through the use of a percutaneous subxiphoid approach currently has a lack of dedicated technology for intrapericardial navigation around the beating heart. We have developed a novel articulated robotic medical probe and performed preliminary experiments in a porcine preparation.
Methods: In five large, healthy pigs, the teleoperated robotic system was introduced inside the pericardial space through a percutaneous subxiphoid approach. Secondary visualization of the left atrium and left atrial appendage was achieved with the use of a 5-mm scope inserted through a left thoracic port. The operator actively controlled the path of the robot by using a master manipulator. The catheter, with an irrigated radiofrequency tip, was guided through the working port of the robot to achieve epicardial ablation of the left atrium.
Results: Access to the pericardial space and progression around the left atrium was successful in all cases, with no interference with the beating heart such as a fatal arrhythmia, unexpected bleeding, and hypotension. Epicardial ablation was successfully performed in all five cases. No adverse hemodynamic or electrophysiological events were noted during the trials. When the animals were killed, there was no visually detected injury on the surrounding mediastinal structures caused by ablation. Transmural ablation was confirmed by histopathology of the left atrium.
Conclusions: We have developed a dedicated articulated robotic medical probe and successfully performed epicardial left atrial radiofrequency ablation. Based on the feedback from these preliminary experiments, the radius of curvature and proper visualization of the device are being improved in the next generation prototype.
From the *Division of Cardiac Surgery, The Heart, Lung, and Esophageal Surgery Institute, University of Pittsburgh, Pittsburgh, Pennsylvania; †Bio Robotics Lab, Carnegie Mellon University, Pittsburgh, Pennsylvania; and ‡Atrial Arrhythmia Center, University of Pittsburgh, Pittsburgh, Pennsylvania.
Address correspondence and reprint requests to Marco A. Zenati, MD, Division of Cardiac Surgery, The Heart, Lung, and Esophageal Surgery Institute, University of Pittsburgh, C700 PUH, 200 Lothrop Street, Pittsburgh, PA 15213. E-mail: firstname.lastname@example.org.
Presented at the annual meeting of the International Society for Minimally Invasive Cardiothoracic Surgery, San Francisco, CA, June 2006.