Working heart off-pump cardiac repair (OPCARE)--the next step in robotic surgery?

The objective of the present study was to assess the feasibility of working heart off-pump cardiac repair (OPCARE), for example, for simple congenital defects or valves, with the help of a commercially available surgical robot in order to identify problem areas and to explore potential solutions. OPCARE was studied in four bovine experiments using the Zeus (Computermotion, Santa Barbara, CA, USA) surgical robot providing 3D viewing of the extra cardiac instruments in combination with two intra-cardiac ultrasound visualisation systems (Clearview Ultra, Boston Scientific, La Garenne, France) and Accunav (Accuson, Mountain View, CA, USA) allowing for two different viewing planes of the heart and identification of both, intra-cardiac structures and intra-cardiac robotic instruments. For the given experimental set-up, introduction of robotic instruments into the right atrium (typical for instrumentation during OPCARE), grabbing of the second instrument (typical for removal of intra-cardiac foreign bodies), and grabbing of relatively still atrial structures, which can be visualised by intra-cardiac ultrasound (typical for resection of specific cardiac tissue, clipping of a specific cardiac structure, steered access to other cardiac cavities) have been realised with relative ease. In contrast, grabbing of moving cardiac structures like a-v valve leaflets (typical for valve testing and absolutely necessary for valve repair) required, in general, numerous attempts, but was finally successful in the majority of test animals. Finally, introduction of self-attaching suture material (U-clips, Coalescent Surgical, Sunnyvale, CA, USA) typical for edge-to-edge valve repair could not be performed in reproducible fashion with the equipment used. We conclude that OPCARE is feasible for simple intra-cardiac lesions using current robotic instrumentation and state of the art intra-cardiac ultrasound. However, more complex procedures require further development of both robotic instrumentation and intra-cardiac visualisation.