The drive toward minimally invasive surgery has yielded multiple benefits for patients but has also increased the incidence of pseudoaneurysms (PSA). The current standard of care is ultrasound-guided thrombin injection to coagulate blood in the PSA sac and seal the ruptured vessel. There is, however, a risk of downstream thrombosis if thrombin escapes into the communicating vessel and this limits patient eligibility for thrombin injection. In this study, the feasibility of using magnetic targeting to reduce the risk of distal thrombosis is investigated. Thrombin-loaded magnetic microbubbles are formulated and injected into tissue-mimicking phantoms of PSAs with different geometries using either saline or whole (equine) blood. Ultrasound imaging is used to quantify the concentration of bubbles remaining in the sac with and without application of a custom-built magnetic array. An absorbance-based assay is also used to quantify the concentration of thrombin escaping from the sac. Magnetic targeting enables a significant increase in thrombin retention in all femoral artery PSA models except one, with up to 97% ± 2.5% of the injected thrombin being retained. It is also confirmed that the enzymatic activity of thrombin is maintained, and that clot formation can be successfully achieved in whole blood.

中文翻译：

---

载有凝血酶的磁性微泡用于治疗假性动脉瘤

微创手术的发展为患者带来了多重好处，但也增加了假性动脉瘤 (PSA) 的发生率。目前的护理标准是超声引导凝血酶注射，以凝固 PSA 囊中的血液并封闭破裂的血管。然而，如果凝血酶逃逸到交通血管中，则存在下游血栓形成的风险，这限制了患者接受凝血酶注射的资格。在这项研究中，调查了使用磁性靶向来降低远端血栓形成风险的可行性。使用生理盐水或全血（马）血配制载有凝血酶的磁性微泡，并将其注射到具有不同几何形状的 PSA 模拟组织模型中。超声成像用于量化囊中残留的气泡浓度，无论是否应用定制的磁阵列。基于吸光度的测定法也用于量化从囊中逸出的凝血酶的浓度。磁性靶向能够显着增加所有股动脉 PSA 模型中的凝血酶保留，除了一个，高达 97% ± 2.5% 的注射凝血酶被保留。还证实凝血酶的酶活性得以维持，并且可以在全血中成功地形成凝块。保留了 5% 的注射凝血酶。还证实凝血酶的酶活性得以维持，并且可以在全血中成功地形成凝块。保留了 5% 的注射凝血酶。还证实凝血酶的酶活性得以维持，并且可以在全血中成功地形成凝块。