Six-hour procedure is a world first for the length of vertebral bodies replaced by a 3-D printed implant

Doctors in Beijing have used 3-D printing to create a new spine for a local man after five cancer-riddled vertebrae were removed from his body. The procedure is a world first in terms of the length of vertebrae replaced this way, the doctors say.

On June 12 the man, surnamed Yuan, 40, of Beijing, underwent a surgery over six hours to have a 3-D printed implant of multiple thoracic and lumbar vertebral bodies, measuring 19 centimeters, inserted into his spine.

In an earlier operation lasting eight hours, doctors had removed five vertebral posterior structures of the cancer-riddled vertebrae.

The vertebrae were affected by chordoma, a cancer that can occur anywhere in the spine and skull. The surgery's success means he is able to live a normal life after he recovers. With traditional treatment, doctors say, even in the best of circumstances he may have been left paralyzed.

Treatment for chordoma, a slow-growing cancer, usually involves surgery to remove the tumor first, before using chemotherapy or radiotherapy if necessary.

"Chordoma is not that rare for us," said Liu Zhongjun, director of the orthopedics department at Peking University Third Hospital, where the surgery was performed.

"What is rare in this case is that the cancer had affected so many vertebrae. Without 3-D printing technology it would have been impossible to treat him."

In the first operation in mid May, back sections of Yuan's cancer-riddled vertebrae were removed, and the surgeons attached titanium rods to what was left of the back part of the spine using titanium screws. These rods were screwed in at the other end, on the front of the spine, still bearing cancerous vertebrae, to make everything stable.

It was deemed too dangerous to remove sections of vertebrae on both sides in the one operation.

In the second operation the front parts of the vertebrae were finally removed and the 3D-printed implant was then put in place.

There had been no reports about the removal of such a large section of spine in one patient anywhere in the world, and the medical team needed to be highly skilled and experienced to deal with any emergency during the two operations, Liu said.

The void left in the spine after the front part of the five vertebrae was removed would have been too large for any existing titanium mesh cage, which is traditionally used in such surgeries. Even if it had existed, it would have been straight and ill-suited to Yuan's spine.

Also, with normal titanium mesh cage, doctors usually put crushed bone in the mesh cage, so that when that bone fuses with the neighboring bones the implant becomes stronger and firm enough to support the spine.

In Yuan's case this method was judged to be too risky because of the size of the implant needed. Any movement of the implant would damage the spinal cord and nerve roots in the spinal channel.