While Salgado said he had never operated on a patient with an injury exactly like Canelos', there were two main risks associated with the procedure.
"There's a risk that he'll develop a clot in his artery or vein, and we'll have to go back to the operating room," said Salgado. "If we can't save the tissue, we have to go to his other forearm and do it all over again."
Another risk, Salgado said, was that when he connected Canelos' existing urethra to his new urethra, there's a chance that the area between the two may break down, causing Salgado to urinate out of the side of his penis.
Canelos told ABCNews.com that he was very nervous about his upcoming surgery but was hoping for a positive outcome.
"I want to have a family, yes. I want to have a family by my side," he said. "I am so happy. I thank God for allowing me to come here with the nonprofit. I thank them for giving me this opportunity."
When he returns to Peru after his recovery, Canelos said he wanted to continue his schooling, and hopes one day to have a career as an agricultural engineer.
Roger Canelos, Luis' father, told ABCNews.com he was so grateful to the nonprofit and the doctors who are helping his son.
"I want to thank God for us being here, the nonproft for having us brought here for my son's surgery. I hope God touches the heart of this community. I want to thank everyone profoundly.
"For the future, I want my son to be just as any kid his age, for him to have a family, with his kids," Roger Canelos said.