Tunable Polymer Embolic Implant for Vascular Occlusion.

In this study, we have developed a tunable polymer vascular embolic implant (TPVEI) with adjustable precipitation rates allowing for personalized, controlled vascular occlusion depths. We hypothesized that reducing the water miscibility of the solvent would result in slower TPVEI precipitation, leading to distal vascular occlusion. To investigate homogeneous vascular distribution and occlusion control, the TPVEI was directly injected into the portal vein of a rat and imaged with microCT. Changing the solvent ratio of NMP/BB from 100/0 to 50/50 showed a significant (p < 0.05) decrease in vessel size occluded from 675 ± 20 to 170 ± 25 µm, respectively. The 60/40 (NMP/BB) formulation was able to occlude several branches throughout the whole liver, displaying a homogeneous vasculature distribution. Broadband Doppler ultrasound validated that there was complete portal vein occlusion after embolization with all materials. These findings suggest that adjusting the solvent polarity allows embolization control and with appropriate optimization, phase-inverting embolics could be used better to control depth of occlusion for endovascular therapies.