Robotic-assisted closure of atrial septal defect under real-time three-dimensional echo guide: in vitro study

Several advances in robotic technology and imaging systems have enabled the broad application of minimally invasive techniques in cardiac surgery. We have previously demonstrated that real-time three-dimensional echocardiography (RT3DE) provided adequate imaging and anatomic detail to act as a sole guide for surgical task performance. In this study, we examined the feasibility of robotic-assisted RT3DE-guided repair of atrial septal defect (ASD) in an in vitro study.

Exp. I: An RT3DE system with x4 matrix transducer (Sonos 7500, Philips Medical Systems, Andover, MA) was compared to two-dimensional echo (2DE) in the performance of common surgical tasks with the da Vinci Robotic Surgical System (Intuitive Surgical, Sunnyvale, CA). Completion times and deviation of suture from an echogenic target (mm) were measured. Exp. II: Porcine ASDs (n=10) were created and closed with robotic-assisted direct suturing in a water bath. During all experiments the operator was blinded to the target and operated only under ultrasonic guidance.

Compared to 2DE guidance, completion times improved by 70% (p<0.0001) and deviation of suture by the robotic system was significantly smaller (2DE: 4+/-2mm, 3DE: 0.2+/-0.3mm, p=0.0002) in RT3DE-guided tasks. RT3DE provided satisfactory images and sufficient anatomical detail for suturing. All surgical tasks were successfully performed with accuracy.

These initial experiments demonstrate the feasibility of robotic-assisted direct closure of ASD under RT3DE guidance. An endoscopic port access approach may be possible with refinements in telemanipulator technology and further development of the transesophageal echo transducer.