不同血流状况下异种脱细胞血管移植物的超声研究

Small-caliber Decellularized Xenografts after Implantation into A Different Blood Flow Model: A Duplex Doppler Ultrasound Research

目的:探讨在不同血液流速中,肝素包被对异种脱细胞血管移植物在移植术后的影响。方法:犬颈动脉经脱细胞处理后,分为A组(未结合肝素)(n=9)和B组(结合肝素)(n=9),分别双侧移植到18只兔体内。移植后结扎左侧两吻合口间的颈动脉(结扎侧),而右侧不结扎(未结扎侧);术后1周、3周和12周对所有兔做超声检测,测量血管内径,计算血流动力学参数。结果:(1)A组的移植物血管内径无论在结扎侧或未结扎侧均较术前明显缩小(P<0.05),且未结扎侧的管腔内径较结扎侧明显缩小(P<0.01);B组中仅有未结扎侧第3、12周的内径较术前比较差异具有统计学意义(P<0.05)。(2)A组中的PSV随时间延长呈上升趋势,而B组中的PSV变化并不明显;术后第3周时,两组阻力指数(RI)比较差异有统计学意义(P<0.05)。结论:低流速对移植物血管的内膜增生具有促进作用;肝素包被可以有效地抑制内膜增生的发生;彩色多普勒超声检查为实验研究脱细胞血管移植物异体移植后的血流动力学变化提供了一种直观、无创、重复性好的方法。

Objective： Using duplex Doppler utrasound method to explore the effect of heparin coating on intimal hyperplasia in small-caliber decellularized xenografts after implantation into a different blood flow model. Method： Canine carotid arteries were decellularized by detergent and enzyme （A part of decellularized vascular grafts were covalently linked with heparin）. Then bilateral carotid implantation were performed respectively in 18 rabbits. To establish a different blood flow model, left carotid between the anastomotic stoma was ligated while right carotid was not after implantation. All the rabbits were randomly divided into two groups： A group（non-heparin-linked）（n=9） and B group（heparin-linked）（n=9）. Each animal was examined by ultrasound to evaluate the diameter of the implanted xenografts and calculate the parameter of the hemodynamics, such as PSV RI and PI, in postoperation 1, 3 and 12 weeks respectively. Result： （1）Compared with preoperation, the luminal diameter was obviously narrowing in both ligated side and non-ligated side of A group （P0.05）. The luminal diameter of non-ligated side was narrowing than that of ligated side. While only the luminal diameter of non-ligated side in B group at 3 and 12 weeks was narrowing than the initials （P0.05）. （2）With time increased, the PSV in A group also increased while there was no obvious change in B group. The RI in 3 weeks was obviously different between the two groups（P0.05）. Conclusion： Lower blood flow can promote the intimal hyperplasia occur. Heparin coating can reduce it happen efficiently. The high resolution ultrasound provide a direct and nontraumatic method in researching the hemodynamic change in small-caliber decellularized xenograft.