Swenson began his medical career as an intern at
Ohio State University. After a year, he returned to Boston to work at
Boston Children's Hospital and
Peter Bent Brigham Hospital. Initially a resident in
pathology, he took a residency in surgery from 1939 to 1945, When Swenson performed the procedure in 1948, it was the first successful surgical correction of megacolon. This operation, however, became the only procedure that treated Hirschsprung's disease and became known as the "
Swenson pull-through". He described the hallmark clinical and radiological markers of Hirschsprung's disease in newborns and showed that the only way to make a definitive diagnosis was to perform a full-thickness rectal
biopsy. Swenson subsequently followed his patients for a number of years. Over his career, he traveled to India, Australia, South America, Europe and Canada to demonstrate his procedure.
Other surgical work As well as Hirschsprung's disease, Swenson worked on the treatment of other birth defects. He performed
esophageal anastomoses for
esophageal atresia and
tracheoesophageal fistula, and resection and anastomosis in
intestinal atresia. He was among the first to advocate performing a pelvic
osteotomy when treating
bladder exstrophy and for partial
nephrectomy in bilateral
Wilms' tumors. ==Awards and honors==