Reconstructive procedures and organ transplants demand nimble fingers that may restore blood circulate by stitching collectively millimeter-scale arteries. It is a robust ask and time-consuming job for even essentially the most expert surgeon.
However a stent filled with sugar could assist the surgical procedures go down — in a 3D-printed approach.
Designed by Nebraska engineer Ali Tamayol and nationwide colleagues, the small sugar-based tube matches contained in the adjoining ends of a clipped artery. By sticking to the interiors, the stent holds these ends in place and supplies structural assist through the precarious stitching course of.
“One of many plastic surgeons informed us in regards to the challenges of this sort of microsurgery — how time-consuming it’s, how skill-dependent it’s,” stated Tamayol, assistant professor of mechanical and supplies engineering.
The stent-assisted suturing took simply 5 minutes when examined on pig arteries, the workforce reported, in contrast with the roughly 15 minutes required of a standard clamp-based approach. Tamayol stated the stent additionally reduces the danger of a surgeon mistakenly threading by means of each the highest and backside partitions of an artery, which blocks subsequent blood circulate.
Then, the end: Minutes after the arteries are sutured, the resuming blood circulate dissolves the stent and harmlessly sweeps it away.
In designing the stent, the researchers got here up with a guidelines of important properties. It wanted some flexibility — too brittle, and it may break throughout suturing — so the workforce added a glucose spinoff known as dextran. It wanted sufficient stickiness to bind with the arteries, which glucose itself supplied, plus a big dose of sucrose to assist fight blood clotting. And it wanted a pinch of sodium citrate to additional diminish any probability of clotting when the stent dissolved.
The recipe was easy sufficient. However arteries, just like the individuals who comprise them, are available in a number of sizes. So the workforce turned to 3D printing as a method of customizing the stent’s diameter to people and areas of the physique. By dissolving their sugar-based concoction in water and baking the answer till many of the water evaporated, the researchers produced a molten ink that is fluid sufficient to print however viscous sufficient to solidify in minutes.
Experiments with clear tubing and pig arteries confirmed that the stent erodes shortly however steadily when subjected to the circulate charge, temperature and salinity of human arteries. The suturing held up, too, with no indicators of leakage instantly following the process.
The researchers finally plan to check the stent’s use in reside animal arteries, Tamayol stated. They usually envision a future through which such stents are printed at hospitals to fulfill the wants of particular person sufferers.
“One factor that I actually like about this idea: We’re all the time making an attempt to keep away from sugar,” Tamayol stated. “Everybody is aware of that sugar is (typically) dangerous. However right here we discovered an utility through which it is good.”