Although the rapidly advancing field of 3D printing has moved beyond the creation of prosthetics, use of 3D printing to create artificial tissues or drug delivery systems is years away from any practical application in the hospital or clinic. But surgeons are taking advantage of the technology now to do something simple but important: improve their success rates.

Before a liver transplant surgery begins, for example, a team of pediatric surgeons in Japan have used a 3D replica of a child’s liver to determine where and how to best trim an adult-sized liver so that it would fit into the smaller space while preserving the organ’s key functions.

They used digital medical images, such as CT scans, to program a printer to create clear models made from acrylic resins that allowed them to visualize and understand the liver’s complex internal structures, such as blood vessels. Then, they printed liver models in part from polyvinyl alcohol to mimic the wetness and texture of a human liver, and to make the model a realistic stand-in for surgical practice. They practiced on the model and successfully transplanted the liver.

Maki Sugimoto, the surgeon at Japan’s Kobe University Hospital where the transplant was done, has used 3D personalized models of patients’ organs for surgical navigation purposes since 2011. He uses 3D models produced by the Japanese company Fasotec. According to the Wall Street Journal, two of the world’s largest industrial 3-D printer makers, Stratasys and 3D Systems, both U.S. companies, offer machines that can replicate human organs.

In 2012, 3D printing has been used to create experimental artificial ears, and earlier in 2013, a group even used stem cells as the ink to create a matrix of healthy stem cell cultures. Clinicians hope that 3D printers using living cell mixtures as the ink to form human tissue will ultimately allow them to make personalized organs for their patients to improve outcomes and reduce the risk of tissue rejection.

“The potential impact is no smaller than the shift from fixed-line phones to mobile phones,” says Sugimoto.