dr. mike levy children's hospital, san diego. >> i like it here. >> reporter: why pediatric neurosurgery?> it's the way to make the biggest impact. giving a child in a country with less resources their full f facul faculties. >> reporter: the poorest 30% of the population receives only 3.5% of all surgeries. >> this is all for you guys. this is for the hospital. >> reporter: those hand me down tools bring smiles here nothing is taken for granted. >> it's a huge help for a struggling hospital. >> reporter: for the next four days, the doctors will work with this team of peruvian neurosurgeons. their first patient is frederick. on the outside, he's a picture of a healthy toddler. but inside there's a ticking timebomb, a brain hemorrhage. is it challenging to work with a team that you've never worked with before? >> we have an international language for neurosurgery. so having to yield old fashioned tricks like how high is it above the ear, counting centimeters, how far forward it is from the middle of your head. that's the way to triangulate this artery that exploded. >> reporter: frederick'