He and another Penn doctor were scheduled to run a clinical trial of the plasma substitute in China. Five days before they were to leave, however, the Army told them it wanted military physicians to run the study. Dr. Koop and his colleague unpacked their bags. The airplane carrying the Army researchers disappeared over the Atlantic.
Early surgical achievements
After the war, the surgeon in chief at the Hospital of the University of Pennsylvania suggested that Dr. Koop take a job as the head of surgery at Children’s Hospital of Philadelphia (CHOP). When he assumed the position in January 1946, he was not yet 30.
At the time, general surgeons, or specialty surgeons such as urologists, operated on infants and children without specific training in how their anatomy and physiology differed from those of adults. The only pediatric surgery program in the country was in Boston. Operations on newborns were rare and mortality was high.
“I went to the Children’s Hospital to do pediatric surgery. I spent the first 18 months doing pediatric anesthesia — trying to get rid of the barriers that were making it impossible to get living babies out of the operating room,” Dr. Koop said in 2007.
Often there wasn’t even appropriate equipment. Before an operation on a newborn, he and the anesthesiologist would make a tube for the windpipe by cutting the smallest urine catheter down to size, filing the edges smooth with an emery board, and then inserting a wire and boiling it to get the desired curvature.
Dr. Koop insisted that his team provide all the postoperative care to surgical patients, much to the consternation of pediatricians at CHOP old enough to be his father. In 1956, he created what was reputedly the first neonatal surgical intensive care unit in the country.
Over four decades of practice, he improved the technique for hernia repairs (and did 17,000 of them). He developed a correction for a congenital defect known as esophageal atresia and a method for draining fluid from the brain into the abdomen for infants with hydrocephalus. He separated several sets of conjoined twins, including, in 1977, a pair joined at the heart in which only one baby could be saved. He trained dozens of pediatric surgeons who went on to head departments elsewhere.
After retiring as surgeon general in 1989, Dr. Koop lectured, wrote an autobiography and in the 1990s, with other investors, established a Web site, DrKoop.com, that provided medical information. The enterprise proved an embarrassment, however, when it turned out some of the information was paid advertising. It no longer exists.
President Bill Clinton awarded Dr. Koop the Presidential Medal of Freedom in 1995. In recent years, he was a scholar at an institute that bears his name at Dartmouth Medical School. Its purpose is “promoting the health and well-being of all people.”
Dr. Koop’s wife of 67 years, the former Elizabeth Flanagan, died in 2007. She had worked as a secretary to support the couple while her husband was in medical school.
Survivors include his wife, the former Cora Hogue, whom he married in 2010; three children from his first marriage, Allen Koop, the Rev. Norman Koop, a Presbyterian minister, and Elizabeth Thompson; and eight grandchildren.
A son from his first marriage, David Koop, was killed in a mountaineering accident in New Hampshire in 1968 when he was a 20-year-old student at Dartmouth. Dr. Koop and his first wife later wrote a book, “Sometimes Mountains Move,” about their experience of grieving in the hope it might help other parents who had lost children.
Brady Dennis contributed to this report.