Robotic-Assisted Endoscopic Thoracic Aortic Anastomosis in Juvenile Lambs

Abstract

Background: 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.

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

Methods: 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.

Results: 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. Conclusions: 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.