In-vitro thrombogenicity assessment of polymer filament modified and native platinum embolic coils.

BACKGROUND: Embolic coils have been used to treat intracranial aneurysms using an endovascular approach for more than two decades. However, significant aneurysm recanalization rates have been reported specifically in large and giant aneurysms. Adding filaments to bare Platinum coils is considered a modification and has been proposed to achieve higher aneurysm occlusion rates as compared to bare Platinum coils. Quantitative information - in terms of thrombin generation potential of these modifications - is however lacking. OBJECTIVE: We report here in vitro thrombogenicity of Platinum coils containing Nylon (Axium™ MicroFx™ Nylon coil) and PGLA (Axium™ MicroFx™ PGLA coil) filaments and compare them with equivalent bare Platinum Axium™ coils. METHOD: We utilize a quantitative method that tracks the formation of thrombin upon exposure of the test samples to human platelet rich plasma using a slow binding fluorogenic substrate. RESULTS: We report a significant increase in the total thrombin turnover, the peak thrombin amount and the rate of thrombin generation for the Axium™ MicroFx™ coils and filaments compared to the Axium™ coils and Platinum wire. CONCLUSION: Nylon and PGLA filaments added to bare Platinum coils increase thrombogenicity of coils. This study offers a robust quantitative method to compare thrombus formation efficacy of embolic coils under static conditions.

Genetic risk factors in recurrent venous thromboembolism: A multilocus, population-based, prospective approach.

BACKGROUND: Recurrent venous thromboembolism (VTE) is a common, complex disorder; however, genetic factors have been suggested to play a role in the disease development. We therefore conducted a multi-locus genetic study examining the potential associations of candidate gene variants in inflammation, thrombosis, coagulation, and lipid metabolism pathways, individually or interactively, with risk of recurrent VTE. METHODS: Using DNA samples collected at baseline in the Prevention of Recurrent Venous Thromboembolism trial (PREVENT), we genotyped 86 candidate genes polymorphisms among 43 individuals who subsequently developed recurrent VTE and among 396 individuals who remained free of recurrent event over a mean follow-up period of 2.1 years to prospectively determine whether these gene polymorphisms contribute to the risk of recurrent VTE. RESULTS: Using a single-marker 'uncorrected' analysis, CCR5 A(-2459)G [rs1799864], MMP3 5A(-1171)6A [rs3025058] and PON1 gln192arg [rs662] gene variants were associated with increased risk, and CETP C(-629)A [rs1800775] gene variant with reduced risk of recurrent VTE, respectively. Furthermore, potentially important gene-gene-interactions were detected by the Monte Carlo Markov chain Logic Regression method. CONCLUSIONS: Although the present findings are hypothesis-generating and require confirmation in an independent investigation, our study provides a practical example of detecting epistasis in common, complex diseases.