zvei dinim -“Toi there is documentation of the Chazon Ish’s instructions for brain surgery (Shu”t Ugnazim Chazon Ish vol. 1), which subsequently saved the patients life.”
I knew the guy. He had the surgery as a baby. I knew him as an adult. He had quite a few kids. He was left with a skin disease and subsequently lost an ear. They say this happenned because the Docs didn’t do exactly as the Chazon Ish said. His tumor eventually came back and he died about twenty years ago.