LIGATURE (Lat. ligatura, from Uwe, to bind). A thread of silk. eatglit. or other material, tied around a blood-vessel to arrest hemorrhage or to diminish the (low of blood to an aneurism or tumor. The use of liga tures was known many centuries ago. the old Roman surgeons using them with considerable skill. During the Dark Ages they were forgotten, and it was not until Ambroise (q.v.) in troduced them (about 1530), while in ltaly with the army of Rem". de Mont-Jean. that their use was slowly revived. L'p to this time hemorrhage from wounds was stopped by searing them with red-hot irons, or plunging the part in hot pitch. John Ilunter, an English surgeon, first advocated the ligature in the treatment of aneurisms by tying off the artery at some distanee from the aneurism:11 sac. The materials from whieh liga tures have been made are very numerous. Those in most. common use, however. are silk. catgnt, and silkworm gut. Catgut. like most animal sub stances, is quickly absorbed by the tissues and is used for buried ligatures. Silk is not hut has Ow advantage of being much stronger than catgut (and therefore more suitable for (Hi eate work) and more easily sterilized. Silver wire is useful where considerable masses of tissue have to be included in the ligation.
Ligatures are employed for arresting hemor rhage in arteries or veins either at the time of an amputation or other operation in which a vessel is divided, or when an artery is wounded acci dentally: for removing tumors of various kinds such as hemorrhoids: for diminishing the sup ply of blood to a part. as ill the ease of inoper able malignant tumors. whose growth may be sometimes temporarily arrested by cutting off their circulation, and for bringing, about a cessa tion of blood-flo• through an aneurism.
The usefulness of the ligature depends upon the tact that when the internal coat of an artery is torn off or injured, the hlood clots, the fluidity of the blood depending upon the integrity of this coat. Ligatures are therefore applied with
sufficient force to rupture the internal and mid dle coats and constrict firmly the outer coat of the artery. Clotting takes place as far as the nearest branch, and this portion of the vessel is ultimately converted into a filmons cord. in jured arteries of any size are tied on both sides of the wound to prevent possible recurrent hem orrhage from connecting branches. When the injured point is not a•eessilde the ligature is sometimes placed at a distance from the NV1)111111.
In the treatment of aneurisms, the lig:1111re is placed upon the artery, when possible, between the heart and the sae, and at sonic distance from the aneurism, for the reason that the artery in the vicinity of the aneurism is too diseased to resist being cut through by a ligature. This operation was devised by Hunter. Brasdor aft erwards conceived the idea of tying on the distal side of the aneurism; a barrier to the blood current is just as effectively formed, collateral branches above the aneurism enlarge, the blood is diverted and a clot forms in the aneurism:II sae. Another device is that of Wardrop. which consists in tying one of the brandies of the artery below• the aneurism.
The important in arterial ligature are those involving the subelavhin, innominate, Parotid, and iliac arteries, and the abdominal aorta. The latter vessel has been tied on nine or ten occasions and the olieration has always re sulted' fatally. IL was first performed by Sir Astley Cooper in IS17, the patient surviving forty-eight hours; the latest ease, reported (1902) by Keen, an American surgeon, survived forty-eight days. These operations are done only in eases Id desperate need, either in the event of an aneurism about to rupture or alarming hemorrhage from penetrating wounds. See ANEURISM; CIRCULATION; 11RASDOR'S OPERATION.