Dynamic observation of degradation property of novel magnesium alloy stents in Bama mini-pig models of carotid artery stenosis by high-resolution C-arm CT: a feasibility study / 中华神经医学杂志

ABSTRACT

Objective:To explore the degradation property of novel magnesium alloy stents in Bama mini-pig models of carotid artery stenosis, and evaluate the feasibility of observing their dynamic and continuous process by high-resolution C-arm CT.Methods:Twelve Bama mini-pigs were selected; carotid artery stenosis models were established by large balloon over-dilation and high-fat and high-salt diet in Bama pigs; 24 weeks after that, self-made braided degradable magnesium alloy stents were inserted into the carotid artery stenosis models (confirmed by DSA) by balloon dilation. Degrees of stent patency and in-stent restenosis were examined by DSA immediately after procedure and on the 30 th, 60 th and 90 th d of procedure. Four experimental pigs were sacrificed on the 30 th, 60 th and 90 th d of procedure, respectively; the degradation property of the novel magnesium alloy stents was observed according to results of high-resolution C-arm CT in the inserted-stent areas and staining results of specimens in the stenosis areas, and stent imaging features during degradation were summarized. Results:Twelve Bama mini-pig models of carotid artery stenosis were established and 12 magnesium alloy stents were successfully inserted with a technical success rate of 100%. Both immediate postoperative and follow-up angiography showed patency of the vascular lumens without obvious in-stent restenosis. High-resolution C-arm CT and pathological examination showed homogeneous stent lumens and clear delineation of the stent meshes, with slightly degraded stent on the 30 th d of procedure; the stent lumen was blurred and some magnesium alloy wires were fractured with developed degradation of the stent on the 60 th d of procedure; and the stent meshes and stent strut could not be visualized due to severe degradation of the stent on the 90 th d of procedure. Conclusion:Magnesium alloy degradable stent is almost completely degraded within 90 th d of procedure in Bama mini-pig models of carotid artery stenosis, and high-resolution C-arm CT can be used to dynamically monitor the degradation of the stent in vivo.