Kikuchi Yuta, Wakabayashi Naohiro, Braghirolli Daikelly I, Pranke Patricia, Kamiya Hiroyuki, Oyama Kyohei
Department of Cardiac Surgery, Asahikawa Medical University, Asahikawa, Japan.
Sapporo Cardiovascular Clinic, Department of Cardiovascular Surgery, Sapporo, Japan.
Front Surg. 2024 Nov 21;11:1464155. doi: 10.3389/fsurg.2024.1464155. eCollection 2024.
The global increase in cardiovascular diseases has resulted in an augmented development of artificial small-caliber vascular grafts used in bypass graft surgeries, such as coronary and distal artery bypass graft surgeries. However, no consensus exists regarding the best method for creating vascular grafts. Poly-ε-caprolactone (PCL) is a biocompatible and biodegradable material that has been widely studied as a scaffold for tissue regeneration, inclusive of vascular grafts. In this study, a vascular graft was created from a PCL nanofiber sheet (PCL graft), and the performance thereof was examined using a rat abdominal aortic implantation model.
The PCL nanofiber sheets were created using an electrospinning machine. These nanofiber sheets were rolled up. Glue was applied between layers using a PCL solution to create a PCL nanofiber vascular graft, with an inner diameter of 1 mm. PCL grafts with 7 mm length were implanted into the abdominal aorta of rats. Thereafter, the patency was determined by pulsating blood flow from the hemiresection site of the distal aorta of the graft anastomosis, and endothelialization was examined using hematoxylin and eosin and immunofluorescent staining methods.
The patency rate of the PCL graft at 2 weeks was 57.1% (12 of 21 cases), which is not satisfactory as a small-caliber vascular graft. Patent cases, however, revealed a CD31-positive endothelial cell layer in the inner lumen and autologous cell infiltration into the scaffold, indicating autologous vessel-like regeneration. By contrast, the occluded cases showed disassembly of the nanofiber layers; and the inner layers folded into the middle of the lumen. This observation suggested that the disassembled inner layer of the PCL graft disturbed the blood flow and triggered occlusion.
PCL grafts can exhibit autologous vessel-like regeneration; nonetheless, regarding patency, grafts made from rolled-up PCL nanofiber sheets have structural weaknesses. Further improvements are required to achieve a long-term and high patency rate for PCL grafts.
全球心血管疾病的增加导致了用于旁路移植手术（如冠状动脉和远端动脉旁路移植手术）的人工小口径血管移植物的开发增加。然而，关于创建血管移植物的最佳方法尚无共识。聚ε-己内酯（PCL）是一种生物相容性和可生物降解的材料，已被广泛研究作为组织再生的支架，包括血管移植物。在本研究中，用PCL纳米纤维片（PCL移植物）制作了血管移植物，并使用大鼠腹主动脉植入模型检查了其性能。
使用静电纺丝机制作PCL纳米纤维片。将这些纳米纤维片卷起。使用PCL溶液在层间涂抹胶水，制作内径为1毫米的PCL纳米纤维血管移植物。将长度为7毫米的PCL移植物植入大鼠腹主动脉。此后，通过从移植物吻合口远端主动脉的半切除部位的脉动血流来确定通畅情况，并使用苏木精和伊红以及免疫荧光染色方法检查内皮化情况。
PCL移植物在2周时的通畅率为57.1%（21例中的12例），作为小口径血管移植物并不理想。然而，通畅的病例在内腔中显示出CD31阳性内皮细胞层以及自体细胞浸润到支架中，表明有自体血管样再生。相比之下，闭塞的病例显示纳米纤维层解体；内层折叠到管腔中间。这一观察结果表明，PCL移植物解体的内层扰乱了血流并引发闭塞。
PCL移植物可以表现出自体血管样再生；尽管如此，关于通畅性，由卷起的PCL纳米纤维片制成的移植物存在结构弱点。需要进一步改进以实现PCL移植物的长期高通畅率。
