Animal experimental study of a new aortic arch fenestrated stent graft

Abstract

Objective To evaluate the safety and efficacy of a novel aortic arch fenestrated membrane-covered stent graft implanted in situ in large animals after long-term maintenance. Methods Three healthy male Large White pigs (named PD01, PD05, PZ02 respectively), weighing 86-150 kg and aged 12-14 months, were selected. Under general anesthesia and intubation, thoracotomy was performed through the fourth intercostal space on the left side of the pigs to establish extracorporeal circulation. The aortic arch fenestrated covered stent was implanted by incising the aorta. Postoperative follow-up was conducted for 6 months, with safety and efficacy analyzed through routine blood tests, biochemical indices, ultrasonography, angiography, dissection, and pathology. Results In all three animals, postoperative levels of red blood cells, plasma hemoglobin, hematocrit, and platelets remained stable. The ALT of three animals elevated immediately after operation, the AST only elevated in PZ02. The albumin of three animals decreased and the levels of serum creatinine and blood urea nitrogen increased immediately after operation. All the indexes returned to normal along with time. Cardiac ultrasound results after the implantation of the aortic arch fenestrated covered stent showed no significant clinical signs of aortic valve stenosis in terms of transvalvular pressure gradient and blood flow velocity until the endpoint. Digital subtraction angiography revealed that the positioning of the fenestrated covered stents was satisfactory, with no instances of displacement or other adverse phenomena. No obvious thrombosis, perforation, or infection occurred in the experimental animals. Conclusion The novel aortic arch fenestrated covered stent system meets the basic requirements for artificial vascular substitutes. It can simplify surgical procedures, shorten operation time, and reduce the incidence of postoperative complications. Additionally, this stent system exhibits good tissue compatibility and safety.

Keywords

• aortic dissection
• stent
• animal experiment
• aortic arch fenestrated membrane-covered stent