Vascular 3D Printing with a Novel Biological Tissue Mimicking Resin for Patient-Specific Procedure Simulations in Interventional Radiology: a Feasibility Study.

Three-dimensional (3D) printing of vascular structures is of special interest for procedure simulations in Interventional Radiology, but remains due to the complexity of the vascular system and the lack of biological tissue mimicking 3D printing materials a technical challenge. In this study, the technical feasibility, accuracy, and usability of a recently introduced silicone-like resin were evaluated for endovascular procedure simulations and technically compared to a commonly used standard clear resin. Fifty-four vascular models based on twenty-seven consecutive embolization cases were fabricated from preinterventional CT scans and each model was checked for printing success and accuracy by CT-scanning and digital comparison to its original CT data. Median deltas (Δ) of luminal diameters were 0.35 mm for clear and 0.32 mm for flexible resin (216 measurements in total) with no significant differences (p > 0.05). Printing success was 85.2% for standard clear and 81.5% for the novel flexible resin. In conclusion, vascular 3D printing with silicone-like flexible resin was technically feasible and highly accurate. This is the first and largest consecutive case series of 3D-printed embolizations with a novel biological tissue mimicking material and is a promising next step in patient-specific procedure simulations in Interventional Radiology.

Aspects of the mechanism of action of local anesthetics on the sarcoplasmic reticulum of skeletal muscle.

1. The effect was studied of local anesthetics (tetracaine, dibucaine, procaine and xylocaine) on the forward and the backward reactions of the calcium pump of skeletal muscle sarcoplasmic reticulum. 2. The inhibition of the rate of calcium uptake, the rate of calcium-dependent ATP splitting and the rate of calcium-dependent ATP-ADP phosphate exchange by sarcoplasmic reticulum in the presence of the above drugs is at least partially due to the inhibition of the phosphoprotein formation from ATP. 3. The rate of the ADP-induced calcium release from sarcoplasmic reticulum and the rate of ATP synthesis driven by the calcium efflux are inhibited on account of a reduction of the phosphoprotein formation by orthophosphate. 4. The phosphorylation of calcium transport ATPase by either ATP or orthophosphate is diminished by the local anesthetics owing to a reduction in the apparent calcium affinity of sarcoplasmic reticulum emmbranes on the outside and on the inside, respectively. 5. The drug-induced calcium efflux from calcium-preloaded sarcoplasmic reticulum vesicles, a reaction not requiring ADP, is probably not mediated by calcium transport ATPase.