Doctors at UC San Diego's Thorton Hospital conducted a rare surgery Sunday to implant a second heart into a 36-year-old patient with a failing heart.

During the surgery—called heterotopic heart transplantation—doctors positioned the new heart on the right side of patient Tyson Smith's own heart that was failing, creating two beating hearts. Smith is a San Diego resident. In a news release, Dr. Jack Copeland, professor of surgery and director of cardiac transplantation and mechanical circulatory support at UC San Diego Health System, said Smith is a pioneer among heart transplant patients. Copeland said that while the procedure is very rare, it is one "worth having in the tool kit of options in cardiac replacement."