Development of vascular protheses for a child-expansion after long term implantation

植入生长中的儿童的血管假体可能会导致严重的血流动力学紊乱，当它们的直径变得太小，与生长的天然动脉相比。我们已经开发了血管假体，可以通过经皮腔内血管成形术（PTA）在给定的时间扩张，以补偿这种直径差异。假体由编织的聚酯纤维织物制成，其圆周纱线由两种不同类型的聚酯纤维束组成。我们已经报道了在体外和短期动物实验中使用PTA球囊成功地扩张了假体。在本研究中，将初始直径为6 mm的假体植入杂种犬的降胸椎（直径8- 10 mm）18个月作为长期评价。植入18个月后，使用15 ATM的PTA球囊扩张，植入的移植物扩张至直径9mm，并在30天后保持。未观察到出血、血肿或假性囊肿形成。总之，新开发的移植物在体内植入后可以安全地扩张。

Vascular prostheses implanted in growing children may cause serious hemodynamic disturbance, when they become too small in diameter comparing to the grown native arteries. We have developed vascular prostheses which can be dilated by a percutaneous transluminal angioplasty (PTA) at a given time to compensate such discrepancy in diameter. The prosthesis was made of woven polyester fiber fabrics, the circumferential yarns of which consist of two different types of polyester fiber bundles. We have reported that the prostheses were successfully dilated with the use of PTA balloon in vitro and in the short term animal experiment as well. In this study, the prostheses with the initial diameter of 6mm were implanted to descending thoracic aortae (8-10mm in diameter) of mongrel dogs for 18 months as a longer term evaluation. After 18 month-implantation, with the use of PTA ballooning of 15 ATM, implanted grafts were dilated to 9mm in diameter which was maintained after 30 days. No bleeding, hematoma or pseudo-aneurysmal formation were observed. In conclusion, the newly developed grafts could be safely dilated after implantation in vivo.