Phenox (Germany)

Bare metal endovascular implants pose a significant risk of causing thrombogenic complications. Antithrombogenic surface modifications, such as phenox’s “Hydrophilic Polymer Coating” (pHPC), which was originally developed for NiTi implants, decrease the thrombogenicity of metal surfaces. In this study, the transferability of pHPC onto biomedical CoCr-based alloys is examined. Coated surfaces were characterized via contact-angle measurement and atomic force microscopy. The equivalence of the antithrombogenic effect in contact with whole human blood was demonstrated in vitro for CoCr plates compared to NiTi plates on a platform shaker and for braided devices in a Chandler loop. Platelet adhesion was assessed via scanning electron microscopy and fluorescence microscopy. The coating efficiency of pHPC on CoCr plates was confirmed by a reduction of the contact angle from 84.4° ± 5.1° to 36.2° ± 5.2°. The surface roughness was not affected by the application of pHPC. Platelet adhesion was significantly reduced on pHPC-coated specimens. The platelet covered area was reduced by 85% for coated CoCr plates compared to uncoated samples. Uncoated braided devices were completely covered by platelets, while on the pHPC-coated samples, very few platelets were visible. In conclusion, the antithrombogenic effect of pHPC coating can be successfully applied on CoCr plates as well as stent-like CoCr braids.

Objectivep64MW HPC is a new low-profile flow diverter with reduced thrombogenicity due to hydrophilic coating. The purpose of this study was to evaluate its safety and efficacy in Mongolian patients under dual antiplatelet therapy.MethodsConsecutive patients with unruptured anterior circulation aneurysms were prospectively enrolled. All patients received aspirin and clopidogrel before and six months after the procedure, followed by lifelong aspirin medication. High platelet reactivity (VerifyNow) did not trigger further action. The safety and efficacy endpoints were clinical outcome and aneurysm occlusion.ResultsIn 29 patients (26 female, median age 57 years), 46 aneurysms (neck width 3.3 mm, fundus diameter 3.7 mm, median) were treated. Dual platelet function inhibition was confirmed in eight patients (28%). The response to Clopidogrel was between 100 and 239 P2Y12 reaction units (VerifyNow) in 13 patients (45%). Non-response to at least one drug was found in 8 of 29 patients (28%). One collapsed p64MW HPC required balloon angioplasty. No other periprocedural thrombus formation occurred. Postprocedural MRI revealed lesions with diffusion restriction in 3 of 29 patients. Digital subtraction angiography after three months for 42 of 46 (91%) aneurysms showed an adequate aneurysm occlusion in 25 (60%). Distal p64MW HPC migration of 3 implants was retreated with another p64MW HPC. Follow-up digital subtraction angiography of 26 of 46 (57%) aneurysms after six months showed adequate aneurysm occlusion in 22 (85%). Significant in-stent stenosis or thrombosis, morbidity or mortality was not encountered.Conclusionp64MW HPC implantation in patients under dual antiplatelet therapy with or without dual platelet function inhibition has a low procedural complication rate. The early aneurysm occlusion rate is high.

A blood clot needs to have the right degree of mechanical, chemical and biological properties to stem the flow of blood and yet to be suitable for lytic enzymes or mechanical thrombectomy so as not to form a thrombotic event. The origin and understanding of these mechanical properties are still unknown. Clots are made of a threedimensional network of fibrin fibers stabilized through ligation with a transglutaminase, factor XIIIa. New methods to achieve information about the in-situ mechanical properties were established. We performed compressive strength experiments of aged human blood clots. After the set up of a new test environment, we were able to perform in-situ tensile strength measurements of aged animal and human blood clots. Stress strain curves of aged clots were measured and discussed. The viscoelastic properties of the clot material were quantitatively described. This work should finally give a better understanding of the behaviour of aged blood thrombus bulk material and induced mechanical stress.