seton
/ˈsiːt(ə)n
/noun Medicine, historical
A skein of cotton or other absorbent material passed below the skin and left with the ends protruding, to promote drainage of fluid or to act as a counterirritant.In addition to simple fistulotomy, treatments include cutting or draining setons, endo-anal mucosal advancement flaps, sliding cutaneous advancement flaps, fistulectomy with muscle repair and fibrin glue injection.
Origin
Late Middle English: from medieval Latin seto(n-), apparently from Latin seta 'bristle'.