Abstract 3062: Minimally Invasive Epicardial Injection Using a Miniature Crawling Robotic Device Through a Subxiphoid Approach
Itroduction: We have developed a miniature crawling robot (HeartLander) that navigates on the surface of a heart to dedicate minimally invasive intrapericardial interventions. We performed a series of epicardial injections with the HeartLander using a beating porcine heart through a closed chest subxiphoid approach.
Hypothesis: The HeartLander can provide precise and safe epicardial injections under the minimally invasive approach.
Methods: HeartLander consists of two articulated modules that adhere to the epicardium using suction. The modules are each 6.5 mm tall and 8 mm wide, and include two working channels for instrumentation. Vacuum pressure and wire actuation for inchworm-like locomotion are provided through the tether of the robot. The device uses 3-D magnetic tracking for navigation, and a joystick for control input. The control software also enables semi-automated navigation to a selected target location, as well as pre-planning of injection locations after the target is reached. In 8 porcine preparations, the device was inserted into the pericardial space through a subxiphoid approach. Epicardial injection on the ventricular wall was performed with a dedicated injection needle device through the working port.
Results: The HeartLander could precisely be maneuvered to designated targets. Injections into left ventricles (i.e. anterior, lateral, posterior walls) were successfully accomplished in all cases. Mean depth of injection was 3.1 ± 0.34 mm. Mean path length was 48 ± 10 mm. Mean speed was 22 ± 7 mm/min. Mean suction pressure and force on wires during trials was 562 ± 26 mmHg and 4.1 ± 0.9 Newton, respectively. The magnetic tracking system provided adequate visualization. Mean deviation from the target path was 0.2 ± 1.0 mm. Target acquisition was within 2.1 ± 1.4 mm. No fatal arrhythmia and bleeding were noted during the trials. There were no injuries to the heart and surrounding structures due to the robot locomotion. A histological study verified no epicardial damage.
Conclusions: The HeartLander demonstrated successful epicardial injection on a beating porcine heart through a closed chest subxiphoid approach. This approach may facilitate the cardiac cell transplantation therapy in the field of minimally invasive surgery.