Impact of hybrid thoracoabdominal aortic repair on visceral and spinal cord perfusion: The new and improved SPIDER-graft

Abstract

Objectives: SPIDER-graft for thoracoabdominal aortic aneurysm repair avoiding thoracotomy and extracorporeal circulation was modified, enabling reimplantation of lumbar arteries to prevent spinal cord ischemia and compared with open aortic repair (control) in a pig model.

Methods: Graft implantation was performed in 7 pigs per group (75-85 kg). For SPIDER-graft (groups I and II), the infra-diaphragmatic aorta was exposed through retroperitoneal access. The right iliac branch was first temporarily anastomosed end-to-side to the distal aorta maintaining periprocedural retrograde visceral perfusion. SPIDER-graft was deployed in the descending thoracic aorta via the celiac artery ostium. The celiac, superior mesenteric, and renal arteries were successively connected to the corresponding side branches of the graft. In group II, the lumbar arteries were reimplanted into the former access branch. For control, complete thoracoabdominal exposure of the aorta was required. After crossclamping, proximal anastomosis was performed, and the celiac artery, superior mesenteric artery, renal arteries, and iliac arteries were reattached. Technical feasibility, ischemic times, blood flow, and visceral and spinal cord perfusion in the related organs were evaluated before implantation and 3 and 6 hours after implantation using transit-time flow measurement and fluorescent microspheres.

Results: Technical success was achieved in all animals in all groups. Total aortic clamping time and selective ischemic times of related organs were significantly longer during open aortic repair compared with groups I and II (P < .0001). Fluorescent microspheres confirmed best spinal cord perfusion in group II.

Conclusions: SPIDER-graft reduced ischemic time, avoided extracorporeal circulation and thoracotomy, and improved spinal cord perfusion during thoracoabdominal aortic aneurysm repair in a pig model.

Keywords: TAAA; experimental study; hybrid repair; stentgraft; thoracoabdominal aorta.