Percutaneous Thrombin Injection Based on Computational Fluid Dynamics of Femoral Artery Pseudoaneurysms

Optimal thrombin injection method for the treatment of femoral artery pseudoaneurysm

BACKGROUND

Iatrogenic femoral artery pseudoaneurysm (IFP) incidence is increasing with increase in diagnostic and therapeutic angiography, and so, the less invasive percutaneous thrombin injection (PTI) is the most widely used treatment. Moreover, studies that minimize PTI complications and highlight therapeutic effects are lacking.

OBJECTIVES

This study performed in vitro thrombosis modeling of pseudoaneurysms and analyzed thrombosis within and thromboembolism outside the sac during thrombin injection.

METHODS

We evaluated PTI in terms of thrombin injection location (at the junction of the IFP sac and neck, the center, and the dome, located farthest from the neck of the sac), thrombin injection time (5 and 8 seconds), and blood flow rate (ranging from 210 mL/min to 300 mL/min). Porcine blood was used as the working fluid in this study.

RESULTS

Thrombin injection at the junction of the IFP sac and the pseudoaneurysm neck led to less thrombosis within the sac but substantial thrombi consistently outside the sac, whereas thrombin injected at the sac center mostly led to complete thrombosis within the sac, preventing further blood flow into the sac and reducing likelihood of thrombi outside the sac. A longer thrombin injection time enhanced the therapeutic effect and decreased the possibility of thromboembolism. Thromboembolism occurred more frequently at flow rates of >240 mL/min.

CONCLUSION

The thrombin injection site in a pseudoaneurysm significantly influences thrombogenesis within and thromboembolism outside the sac. Thus, slow and deliberate injection of thrombin into the center of the sac could potentially reduce complications and enhance treatment efficacy.

Thrombin and Thrombin-Incorporated Biomaterials for Disease Treatments

Thrombin, a coagulation-inducing protease, has long been used in the hemostatic field. During the past decades, many other therapeutic uses of thrombin have been developed. For instance, burn treatment, pseudoaneurysm therapy, wound management, and tumor vascular infarction (or tumor vasculature blockade therapy) can all utilize the unique and powerful function of thrombin. Based on their therapeutic effects, many thrombin-associated products have been certificated by the Food and Drug Administration, including bovine thrombin, human thrombin, recombinant thrombin, fibrin glue, etc. Besides, several thrombin-based drugs are currently undergoing clinical trials. In this article, the therapeutic uses of thrombin (from the initial hemostasis to the latest cancer therapy), the commercially available drugs associated with thrombin, and the pros and cons of thrombin-based therapeutics (e.g., adverse immune responses related to bovine thrombin, thromboinflammation, and vasculogenic "rebounds") are summarized. Further, the current challenges and possible future research directions of thrombin-incorporated biomaterials and therapies are discussed. It is hoped that this review may provide a valuable reference for researchers in this field and help them to design safer and more effective thrombin-based drugs for fighting against various intractable diseases.

Strategies to Minimize Access Site-related Complications in Patients Undergoing Transfemoral Artery Procedures with Large-bore Devices

Large bore accesses refer to accesses with a diameter of 10 French or greater and are necessary for various medical devices, including those used in transcatheter aortic valve replacement, endovascular aneurysm repair stent-grafts, and percutaneous mechanical support devices. Notably, the utilization of these devices via femoral access is steadily increasing due to advancements in technology and implantation techniques, which are expanding the pool of patients suitable for percutaneous procedures. However, procedures involving large bore devices carry a high risk of bleeding and vascular complications (VCs), impacting both morbidity and long-term mortality. In this review article, we will first discuss the incidence, determinants, and prognostic impact of VCs in patients undergoing large bore access procedures. Subsequently, we will explore the strategies developed in recent years to minimize VCs, including techniques for optimizing vascular puncture through femoral cannulation, such as the use of echo-guided access cannulation and fluoroscopic guidance. Additionally, we will evaluate existing vascular closure devices designed for large bore devices. Finally, we will consider new pharmacological strategies aimed at reducing the risk of periprocedural access-related bleeding.