Dr. William Middlesworth joined the medical staff of Morgan Stanley Children's Hospital of NewYork-Presbyterian/Columbia (MSCHONY), Division of Pediatric Surgery in 1997. He currently serves as director of the Pediatric ECMO Program, and Residency Program Director of the Pediatric Surgical Fellowship. Dr. Middlesworth has founded and leads the Pediatric Thyroid Center and the REACH (Researching Esophageal Atresia for Children's Health) Clinic.

A graduate of Dartmouth College, Dr. Middlesworth spent two years in the Genetics Department at the Boston Children's Hospital on work leading to the identification and characterization of the dystrophin gene, important in the pathophysiology of muscular dystrophy. He went on to medical school at Rutgers University, and completed his general surgery training at the University of Maryland Medical System. During residency he spent a year as a surgical research fellow at the Royal Children's Hospital in Melbourne, Australia. His pediatric surgery fellowship was completed at MSCHONY.

In addition to the responsibilities listed above, Dr. Middlesworth serves on numerous hospital and university committees focused on Quality and Patient Safety, and is the Quality Chair for Columbia Department of Surgery. He is the Surgeon Champion at the Columbia campus for the National Surgical Quality Improvement Project (NSQIP) of the American College of Surgeons. He chairs a multi-institution collaborative to reduce harm and enhance safety in the peri-operative setting that is sponsored by MCIC Vermont, the member-owned malpractice insurance carrier for Columbia, Cornell, New York Presbyterian Hospital, Johns Hopkins Medicine, University of Rochester Medicine and Yale.

Dr. Middlesworth is a fellow of the American College of Surgeons, and the American Academy of Pediatrics. He is a member of numerous professional organizations dedicated to advancing the surgical care of infants and children, including the American Pediatric Surgical Association (APSA), the Eastern Association for the Surgery of Trauma(EAST) and the Extra-corporeal Life Support Organization(ELSO), among others.

Dr. Middlesworth has been selected as a Best Doctor in New York Magazine, and a Castle Connolly Top Doctor. He has received recognition for excellence in teaching, and authored numerous papers in important journals including the Journal of Pediatric Surgery, the Journal of Pediatric Hematology and Oncology and Pediatric Critical Care Medicine.