vincent was 12 years old when dr. saw him. he was flown to st. louis to one of wpp's 17 partner hospitals to have open heart surgery that will let him lead a full life. >> you said the biggest challenge is to build trust in these countries. why is that such a challenge? >> because i think there's been a lot of distrust earned with group two upon in and a net state. >> chris: wpp started in 2001 and the numbers are impressive. 55 medical teams travel to the region each year, treat some 2500 children and fly 100 more back to the u.s. over the last 18 years, they've cared for 13,000 kids. the funding comes entirely from private donations, but that doesn't tell the full story. >> you raised $5 million last year be provided $25 million in services, how does that work? >> because of our doctors in our nurses donating and giving of their time. we have medical supply companies for giving us hundreds of thousands of dollars of supplies for us to take down without surgical team. >> chris: susan rickman has been part of wpp since the start. she says there's