Ligature is a thread that is used in surgery to tie a bleeding blood vessel. Surgeons did not use ligatures extensively until germfree surgery developed during the mid-1800’s. Before that time, ligatures almost always caused infection. The British surgeon Joseph Lister devised a sterile ligature, called catgut, from a sheep’s bowel. The body absorbs this material without harm. Surgeons also use silk, cotton, linen, and nylon ligatures. These are not absorbed, but are not harmful.
