Kasai and a colleague, Sozo Suzuki, worked together in the 1950s to devise a surgery to treat babies born with biliary atresia, a typically fatal condition of the gastrointestinal tract. While American surgeon William E. Ladd had first described surgery for the condition in the 1920s, the widely held belief was that only a small percentage of cases could be corrected with surgery. Most affected children died before reaching one year of age.
