“A cutting-edge operation has restored a man’s ability to make sperm by transplanting tissue samples that were removed from one of his testicles and frozen 16 years earlier, when he was still a boy. Scientists say that the remarkable achievement could mark the beginning of a new wave of fertility treatments…

In 2008, physicians at the University Hospital in Brussels removed a testicle from a ten-year-old boy and froze tissue samples that had been taken from it. The boy then received chemotherapy in preparation for a blood-stem-cell transplant to treat sickle-cell disease.

More than a decade later, he returned to the hospital as an adult with dreams of having children. Clinicians monitored him for two years and confirmed that he could not produce normal sperm on his own. They then grafted 11 of the tissue fragments — which by then had been frozen for 16 years — either into his remaining testicle or under the skin in his scrotum.

The grafts incubated there for a year, bathed in the hormones and other environmental cues found in an adult man. After that, the tissue fragments were removed and examined.

The team found sperm-producing stem cells and signs of active sperm production in several of the transplants. In a sample from one graft, they found a single mature sperm.

At that point, the researchers stopped their analysis and saved the rest of the graft in the hope that more sperm could be collected from it later and used for in vitro fertilization.”

From Nature.