What's the ancient technique used to preserve bodies in Egypt that involved the removal of internal organs?

Mummification.

The mummification process took seventy days.

The first step in the process was the removal of all internal parts that might decay rapidly. The brain was removed by carefully inserting special hooked instruments up through the nostrils in order to pull out bits of brain tissue. It was a delicate operation, one which could easily disfigure the face. The embalmers then removed the organs of the abdomen and chest through a cut usually made on the left side of the abdomen. They left only the heart in place, believing it to be the center of a person’s being and intelligence. The other organs were preserved separately, with the stomach, liver, lungs, and intestines placed in special boxes or jars today called canopic jars. These were buried with the mummy.

The embalmers next removed all moisture from the body. This they did by covering the body with natron, a type of salt which has great drying properties, and by placing additional natron packets inside the body. When the body had dried out completely, embalmers removed the internal packets and lightly washed the natron off the body. The result was a very dried-out but recognizable human form. To make the mummy seem even more life-like, sunken areas of the body were filled out with linen and other materials and false eyes were added.

Next the wrapping began. Each mummy needed hundreds of yards of linen. The priests carefully wound the long strips of linen around the body, sometimes even wrapping each finger and toe separately before wrapping the entire hand or foot. In order to protect the dead from mishap, amulets were placed among the wrappings and prayers and magical words written on some of the linen strips. Often the priests placed a mask of the person’s face between the layers of head bandages. At several stages the form was coated with warm resin and the wrapping resumed once again. At last, the priests wrapped the final cloth or shroud in place and secured it with linen strips. The mummy was complete.