Interactive blood-coil simulation in real-time during aneurysm embolization

Over the last decade, remarkable progress has been made in the field of endovascular treatment of aneurysms. Technological advances continue to make it possible for a growing number of patients with cerebral aneurysms to be treated with a variety of endovascular strategies, essentially using detachable platinum coils. Yet, coil embolization remains a very complex medical procedure for which careful planning must be combined with advanced technical skills in order to be successful. In this paper, we describe a complete process for patient-specific simulations of coil embolization, from mesh generation with medical datasets to computation of coil-flow bilateral influence. We propose a new method for simulating the complex blood flow patterns that take place within the aneurysm, and for simulating the interaction of coils with this flow. This interaction is twofold, first involving the impact of the flow on the coil during the initial stages of its deployment, and second concerning the decrease of blood velocity within the aneurysm, as a consequence of coil packing. We also propose an approach to achieve real-time computation of coil-flow bilateral influence, necessary for interactive simulation. This in turns allows to dynamically plan coil embolization for two key steps of the procedure: choice and placement of the first coils, and assessment of the number of coils necessary to reduce aneurysmal blood velocity and wall pressure. Finally, we provide the blood flow simulation results on several aneurysms with interesting clinical characteristics both in 2D and 3D, as well as comparisons with a commercial package for validation. The coil embolization procedure is simulated within an aneurysm, and pre- and post-operative status is reported.     

新型三联栓塞材料在肝血管瘤栓塞治疗中的应用

目的：探讨新型三联栓塞材料在肝血管瘤栓塞治疗中的应用价值。方法：对47例肝血管瘤病人通过超选择性肝动脉插管,应用平阳霉素、超液态碘油和生物微球embosphere组成的新型三联栓塞材料治疗肝血管瘤。观察治疗前和治疗后12月血管瘤的大小变化、临床症状及并发症的发生情况。结果47例病人中肿瘤缩小〉50%或消失者为28例,瘤体缩小30%50%者16例,肿体缩小〈30%者5例。结论新型三联栓塞材料治疗肝血管瘤安全有效,是理想的肝血管瘤介入于段。     

髂内动脉栓塞术治疗产后难治性大出血的护理体会

目的：探讨髂内动脉栓塞术治疗产后难治性大出血的护理方法。方法对53例行经皮双髂内动脉栓塞术（IIAE）治疗的产后大出血伴休克产妇的临床资料与护理资料进行回顾性分析。结果53例患者 IIAE 手术均一次性成功,手术耗时0．5～1 h;即刻停止出血者44例,8例出血明显减少,1例24 h 内仍有暗红色血液经阴道排出,至第4 d 完全停止。术后5例出现不同程度臀部或下腹部疼痛,1例患者出现恶心、呕吐症状,对症处理后症状缓解。随访18～37个月,无严重并发症发生。结论IIAE 治疗产后难治性大出血具有操作简单、损伤小、止血快、并发症少的特点;同时做好术前、术后护理及并发症对症处理是保证手术顺利进行及取得满意治疗效果的关键。     

Bioactive-Tissue-Derived Nanocomposite Hydrogel for Permanent Arterial Embolization and Enhanced Vascular Healing

Transcatheter embolization is a minimally invasive procedure that uses embolic agents to intentionally block diseased or injured blood vessels for therapeutic purposes. Embolic agents in clinical practice are limited by recanalization, risk of non-target embolization, failure in coagulopathic patients, high cost, and toxicity. Here, a decellularized cardiac extracellular matrix (ECM)-based nanocomposite hydrogel is developed to provide superior mechanical stability, catheter injectability, retrievability, antibacterial properties, and biological activity to prevent recanalization. The embolic efficacy of the shear-thinning ECM-based hydrogel is shown in a porcine survival model of embolization in the iliac artery and the renal artery. The ECM-based hydrogel promotes arterial vessel wall remodeling and a fibroinflammatory response while undergoing significant biodegradation such that only 25% of the embolic material remains at 14 days. With its unprecedented proregenerative, antibacterial properties coupled with favorable mechanical properties, and its superior performance in anticoagulated blood, the ECM-based hydrogel has the potential to be a next-generation biofunctional embolic agent that can successfully treat a wide range of vascular diseases.     

Blood-Derived Biomaterial for Catheter-Directed Arterial Embolization

Vascular embolization is a life-saving minimally invasive catheter-based procedure performed to treat bleeding vessels. Through these catheters, numerous metallic coils are often pushed into the bleeding artery to stop the blood flow. While there are numerous drawbacks to coil embolization, physician expertise, availability of these coils, and their costs further limit their use. Here, a novel blood-derived embolic material (BEM) with regenerative properties, that can achieve instant and durable intra-arterial hemostasis regardless of coagulopathy, is developed. In a large animal model of vascular embolization, it is shown that the BEM can be prepared at the point-of-care within 26 min using fresh blood, it can be easily delivered using clinical catheters to embolize renal and iliac arteries, and it can achieve rapid hemostasis in acutely injured vessels. In swine arteries, the BEM increases cellular proliferation, angiogenesis, and connective tissue deposition, suggesting vessel healing and durable vessel occlusion. The BEM has significant advantages over embolic materials used today, making it a promising new tool for embolization.     

Injectable and Radiopaque Liquid Metal/Calcium Alginate Hydrogels for Endovascular Embolization and Tumor Embolotherapy

Improved endovascular embolization can contribute to assistant treatment for patients. However, many traditional embolic materials, such as metal microcoils or liquid embolic agents, are associated with limitations of coil migration or recanalization. Herein, as the first trial, an injectable and radiopaque liquid metal/calcium alginate (LM/CA) hydrogel is introduced and fabricated as a candidate for endovascular embolization and tumor embolotherapy through developing LM droplets as radiopaque units into biocompatible calcium alginate cross‐linked network. The adoption of LM droplets makes hydrogels radiopaque under X‐ray and CT scan, which significantly facilitates the tracking of material location during surgical vascular operation. In addition, in vitro and in vivo experiments prove that such smart hydrogel could convert from liquid to solid rapidly via cross‐linking, showing pretty flexible and controllable functions. Benefiting from these properties, the hydrogel can be performed in blood vessels through injection via syringes and then served as an embolic material for endovascular embolization procedures. In vivo experiments demonstrate that such hydrogels can occlude arteries and block blood flow until they ultimately lead to ischemic necrosis of tumors and partial healthy tissues. Overall, the present LM/CA hydrogels are promising to be developed as new generation embolic materials for future tumor embolotherapy.     

Renal artery embolization in severe nephrotic syndrome

Introduction Severe nephrotic syndrome is associated with increased morbidity and mortality. Renal artery embolization (RAE) has been used in a number of renal diseases such as renal tumors, arteriovenous fistulas etc. However, data regarding benefits of RAE in patients with symptomatic severe proteinuria is limited. We decided to evaluate role of RAE in the setting of severe symptomatic nephrotic syndrome. Methods Eight patients who had undergone transcatheter renal artery embolization with polyvinyl alcohol (PVA) were included. Clinico‐demographic characteristics as well as baseline laboratory data including level of proteinuria, serum albumin, C‐reactive protein and LDL cholesterol levels were recorded for each patient. After RAE, outpatient clinic control laboratory values were also assessed. Findings All patients except one underwent bilateral RAE (four simultaneous or three sequential). Two patients experienced postembolization syndrome characterized by flank pain, fever, and leukocytosis, which was self‐limited and responded to analgesics in all patients. There was no technical complications associated with RAE procedure. All patients became anuric except one. Serum albumin levels increased and serum LDL‐cholesterol levels decreased considerably in treated patients. Discussion Renal artery embolization with the purpose of amelioration in nephrotic syndrome complications was effective and free of major technical complications in our patients.     

基于距离变换的肝脏栓塞治疗仿真

栓塞治疗是非手术肿瘤治疗方法的首选方案,血管栓塞后的肝癌大部分瘤体组织因缺血、缺氧而逐步坏死,而正常肝组织的供血受影响不大,且能形成侧支循环,不会导致明显的肝功能障碍。假定肝实质组织由距离其最近的血管供血,提出一种肝脏血管栓塞治疗的计算机仿真方法,选用一种精确的欧氏距离变换算法,在改进算法步骤之后,使得该算法支持多背景点。实验结果表明,该方法可以将血管栓塞的结果,映射到肝实质组织中,达到肝实质的栓塞显示效果,能够帮助医生直观地观察栓塞后肝脏组织的供血状况,评估栓塞效果。     

Biodistribution characteristics of ^188Re-TSC after TAE in rabbits bearing VX2 liver tumor

188Re-tin sulfur colloid (TSC) was prepared to compare its biodistribution characteristics with 188Re-macroaggregates album (MAA) after transhepatic arterial embolization (TAE) in rabbits bearing VX2 liver tumor. Labeling efficiencies of the 188Re-TSC and 188Re-MAA were 99.94%±0.04% and 99.95%±0.03%, respectively,and they were stable for 72 h in human serum. Sintigraphy and biodistribution in 31 rabbits bearing VX2 liver tumor after transcatherter hepatic arterial injection of the radiopharmaceuticals were performed, and relevant activity accumulated mostly in the tumor. The percentage of the injected dose per gram of wet tissue (%ID/g) of 188Re-TSC and 188Re-MAA were calculated. Tumor uptake of 188Re-TSC at 1 h and 24 h were 24.32%±11.93% and 21.88%±18.29%, and the radioactive ratios of tumor/liver were 70.89±19.58 and 17.42±13.96, respectively. Tumor uptake of 188Re-MAA at 1 h and 24 h were 38.78%±30.23% and 15.98%±96.64%, and the radioactive ratio of tumor/liver of 188Re-MAA were 39.71±95.06 and 8.13±4.61, respectively. 188Re-TSC is a potential radiopharmaceutical for the therapy of tumors.