Reducing Neointimal Hyperplasia in Post-Vessel Anastomosis Surgery: A Study on Bivalirudin-Loaded Carbopol 940 Gel.

Background: After vascular anastomosis, stenosis at the site of anastomosis is a significant concern as it can lead to severe illness and even death. The primary cause of stenosis in graft anastomoses is the excessive growth of vascular neointima.Methods: We used a bivalirudin-loaded carbopol 940 gel, which can effectively inhibit platelet aggregation. Bivalirudin possesses thrombin-inhibitory properties and can suppress platelet activation and aggregation. Bivalirudin was mixed with carbopol 940 gel to achieve slow release. In vivo experiments were conducted on Wistar rats, and longitudinal incisions were made on the abdominal aorta of the rats. Subsequently, the gel was applied around the vascular incision site. The incision was then sutured with polypropylene suture lines.Results: The drug-releasing profile showed that approximately 60% of bivalirudin was released in 24 hours, and the remainder was slowly released after 50 hours. WST-1 assay and live/dead staining results obtained from A7r5, L929, and HUVEC revealed that the gel is not cytotoxic. In the in vivo study, the vessel walls in the group untreated with the gel increased by 233.3% in four weeks, whereas it increased by 2.8% in the group treated with the gel (p = 0.039).Conclusions: Bivalirudin-loaded carbopol 940 gel can inhibit postoperative neointimal hyperplasia and improve the outcomes of vascular repair surgery.