Besides working on breast cancer, Halsted also contributed to the surgical treatment for other diseases including vascular aneurysm, inguinal hernia, and a certain kind of primary carcinoma of the ampulla of Vater. In addition, he helped develop anesthesia, an integral part of modern surgery. As one of the first proponents of hemostasis and investigators of wound healing, Halsted pioneered Halsted's principles, modern surgical principles of control of bleeding, accurate anatomical dissection, complete sterility, exact approximation of tissue in wound closures without excessive tightness, and gentle handling of tissues.