Robotic-assisted endoscopic thoracic aortic anastomosis in juvenile lambs

Advances in robotic technology have enabled a wider range of applications for minimally invasive techniques in cardiac surgery, including mitral valve repair and coronary artery bypass grafting. With increased technical sophistication, robotic-assisted techniques can be developed for the endoscopic repair of certain congenital cardiac lesions.

The purpose of this study was to assess the feasibility of closed chest thoracic aortic anastomosis in a juvenile ovine model.

Lambs, aged 45 to 55 days, underwent surgery that was performed using the da Vinci robotic surgical system. Using 3 ports, the surgeon dissected the descending thoracic aorta and mobilized it free from attachments, using single-lung ventilation and CO2 insufflation. Snares were introduced through 2 stab wounds for aortic occlusion proximally and distally. In 4 lambs, the aorta was completely transected and reanastomosed using interrupted nitinol sutures. One lamb underwent longitudinal aortotomy, and patch aortoplasty was performed with the placement of a Gore-Tex patch. Snares were released and the animals were recovered once hemodynamically stable. Animals were sacrificed at 6 to 12 hours after surgery and the descending aorta was harvested. Burst-pressure testing was performed on the anastomoses.

All 5 lambs survived the procedure with stabilization of hemodynamic parameters following surgery. The mean aortic clamp time was 47 +/- 17 minutes, and the anastomosis was completed in 26 +/- 5 minutes. The mean burst pressure was 163 +/- 9 mm Hg.

Endoscopic thoracic aortic anastomosis can be performed safely and with adequate exposure in a juvenile large-animal model using computer-assisted surgical techniques. With further refinements, these approaches could be applied to the repair of congenital anomalies of the aorta, including interrupted aortic arch and aortic coarctation.