Robinson Karyn G, Scott Rebecca A, Hesek Anne M, Woodford Edward J, Amir Wafa, Planchon Thomas A, Kiick Kristi L, Akins Robert E
Nemours - Alfred I. duPont Hospital for Children Wilmington DE1 9803.
Dept. of Materials Science & Engineering University of Delaware Newark DE 19716.
Bioeng Transl Med. 2017 May 30;2(2):222-232. doi: 10.1002/btm2.10060. eCollection 2017 Jun.
Arteries for bypass grafting are harvested either with neighboring tissue attached or as skeletonized vessels that are free of surrounding tissue. There are significant benefits to skeletonization, but reports suggest that skeletonized vessels may develop structural defects and are at risk for atherosclerosis. We investigated the specific short-term effects of skeletonization on carotid artery biomechanics and microanatomy in a rabbit model. Six carotid arteries were surgically skeletonized. To support healing, three of these received polyethylene glycol hydrogel injected along their exterior surfaces. M-mode ultrasonography was used to track circumferential cyclic strain in the skeletonized, hydrogel-treated, and contralateral vessels. On day 21, the arteries were harvested, and vessel structure was assessed by histology, immunofluorescence microscopy, two-photon elastin autofluorescence, and second harmonic generation (SHG) microscopy. Intimal-medial thickness appeared unaffected by skeletonization, but the SHG signals indicated significant changes in collagen turnover in the adventitia. Skeletonized arteries also exhibited significantly decreased radial compliance (circumferential cyclic strain dropped ∼30%) and decreased numbers of elastic laminae (9.1 ± 2.0 to 2.3 ± 1.4). Hydrogel treatment protected against these effects with treated vessels maintaining normal mechanical properties. These results indicate that arterial skeletonization triggers immediate effects on vessel remodeling and reduced vessel compliance resulting in specific tissue alterations within 21 days, but that these effects can be attenuated by the placement of hydrogel on the exterior surface of the skeletonized vessel.
用于搭桥移植的动脉可以在附着相邻组织的情况下获取，也可以作为无周围组织的骨骼化血管获取。骨骼化有显著益处，但报告表明骨骼化血管可能会出现结构缺陷并存在动脉粥样硬化风险。我们在兔模型中研究了骨骼化对颈动脉生物力学和微观解剖结构的特定短期影响。通过手术将六条颈动脉骨骼化。为了促进愈合，其中三条在其外表面注射了聚乙二醇水凝胶。使用M型超声跟踪骨骼化、水凝胶处理和对侧血管的周向循环应变。在第21天，采集动脉，通过组织学、免疫荧光显微镜、双光子弹性蛋白自发荧光和二次谐波产生（SHG）显微镜评估血管结构。内膜中层厚度似乎不受骨骼化影响，但SHG信号表明外膜中胶原周转有显著变化。骨骼化动脉的径向顺应性也显著降低（周向循环应变下降约30%），弹性层数量减少（从9.1±2.0降至2.3±1.4）。水凝胶处理可防止这些影响，处理后的血管保持正常力学性能。这些结果表明，动脉骨骼化会立即引发对血管重塑的影响并降低血管顺应性，导致21天内出现特定的组织改变，但通过在骨骼化血管外表面放置水凝胶可减弱这些影响。
