Some doctors have the right idea. They’re making use of 3-D printers to produce extremely expensive ($250,000-plus) replicas of human organs. The Wall Street Journal explains:

Surgeons at a hospital in Japan recently faced a dilemma before transplanting a parent’s liver into a child: How exactly to trim the organ to fit the space in the child’s smaller cavity while preserving its functions.

So they took a knife to a three-dimensional replica of the donor’s liver built by a machine that resembles an office printer. The model helped the doctors figure out where to carve it, leading to a successful transplant last month…

…Using medical images such as CT scans, these printers can construct translucent models made with variations of acrylic resin, enabling surgeons to understand the internal structure of the livers and kidneys, such as the direction of blood vessels or the exact location of a tumor.

A more realistic-looking model, made partly of polyvinyl alcohol, assimilates the wetness and texture of a real human liver, making it more suitable to cut with a surgical knife.