The emergency department now treats 28,065 persons each year, while the hospital also houses the major transplantation service for Ontario, performing heart, lung, kidney, liver, pancreas, and small intestine, amongst others, for patients referred from all over Canada. The hospital is the largest organ transplant center in North America, performing 639 transplants in 2017. The hospital is also renowned for cardiac and thoracic surgery. The world's first single and double lung transplants were performed at TGH in 1983 and 1986 and the world's first valve-sparing aortic root replacement was done by Tirone David at Toronto General Hospital in 1992. The Lung Transplant program is currently the largest in the world, performing 167 lung transplants in 2017. In 2015, surgeons performed the world's first triple organ transplant (lung, liver and pancreas) in 19 year old Reid Wylie at Toronto General Hospital. TGH teaches resident physicians, nurses, and technicians; it also conducts research through the Toronto General Research Institute.