Introduction Currently, whole blood clots used for medical device testing are created by drawing blood directly from a subject (typically swine or bovine), then conducting a rigorous centrifuge process and/or introducing chemical additives. In recent years, synthetic blood clots have been developed that can complement whole blood thrombi. The present study involves the creation of synthetic hard and soft clots mechanically matched to human and animal thrombus samples.

Materials and Methods Polyacrylamide and alginate polymers (PAAM – ALG) were mixed at varying concentrations to achieve desired clot stiffness. After developing a manufacturing procedure for soft and hard clots, contrast agents were added during the polymer gelation process for radiopacity. The mechanical properties (compression and shear moduli) of all synthetic clots were assessed using a DMA-Rheometer (TA Instruments) at 40% compression, across a physiologically-relevant frequency range of 1-10 rad/s. Whole swine blood thrombi were also created and tested using the same mechanical testing methods. All clots were statistically compared to published human clot data.

Results Whole swine blood thrombi represented soft clots, as the mechanical properties corresponded to an organized viscous fluid with minimal compressive and shear resistance. Mechanical testing data demonstrated that high alginate concentrations (83% PAAM - ALG) corresponded to soft clots, whereas high acrylamide concentrations (90% PAAM - ALG) represented hard clots. Imaging via fluoroscopy verified clot radiopacity using 20 vol% Conray® added during polymer gelation.

Conclusion Polymer clots are ideal for benchtop testing, with increased shelf-life and minimal biohazard handling requirements when compared to animal blood clots. The polymer clots can be delivered to benchtop vessel models and used for surgical training and device testing. Synthetic clots show substantial promise for thrombectomy device testing as their mechanical properties can be tuned to replicate various whole blood clot types, and can be altered to include fibrous and calcified clot components.

Disclosures J. Vigil: None. H. Berns: None. S. Robertson: None. H. Gaines: None. C. West: None. D. Roser: None. W. Merritt: 4; C; Aneuvas Technologies, Inc.. 5; C; Aneuvas Technologies Inc. T. Becker: 4; C; Aneuvas Technologies, Inc.. 5; C; Aneuvas Technologies Inc. A. Ducruet: 2; C; Medtronic, Penumbra, Oculus, Stryker, Balt, Koswire. 4; C; Aneuvas Technologies, Inc.