Elements of Surgery. Robert Liston

extremely apt to extend along the coats of the vessel; which latter circumstance has been ascribed to the great proportion of cellular tissue in their coats. When punctured longitudinally, the lips of the wound remain in contact, and cicatrisation, by means of effused lymph, is soon effected; in fact, the wound heals by the first intention. But if opened obliquely or transversely, not to a great extent, the immediate result is discharge of blood, and, when this has ceased, a coagulum forms in the wound, the margins of which remain separate; and this coagulum generally communicates with blood effused into the sheath of the vessel. After some time, the lips of the wound, encircling the coagulum which occupies the aperture, and which has temporarily averted the hemorrhage, become somewhat turgid, and increased in vascularity; they then appear to assume a secreting action, by which a membranous substance, of extreme delicacy, is produced; and the extent of this membrane is increased until it form an expansion, investing the outer surface of the clot; it then becomes thickened, by addition of matter, similar to itself, from the recent vessels which ramify in it. At the same time it forms adhesions to the surrounding cellular tissue, and resembles the original tunics of the vein. After being consolidated, so as to prevent the flow of blood through that part, the coagulum, formed to arrest the hemorrhage until a more complete barrier should be furnished, is gradually absorbed. But the membrane long remains smooth, thin, and diaphanous, and can be thereby readily distinguished from the original coats. This reparative process is much longer in being finished than the corresponding one in arteries; and, from what has been stated, it is evident that the two actions differ in other respects than the time requisite to complete them. When a vein has been completely divided, the extremities are closed by means similar to those which have been already detailed in regard to arteries.

      In many, nay in most, instances of hemorrhage from a wounded artery, the surgeon cannot wait for the natural processes by which the flow of blood is arrested, but must have recourse to immediate and certain means. In division of the smaller arteries, or in minute wounds of the larger, pressure, well applied, will often be sufficient. In both cases it immediately stops the flow: in the former, it prevents the blood from penetrating into that portion of the sheath which has been vacated by the retracted artery; and it being thereby confined, and kept in a state of rest, coagulation soon takes place. At the same time, the compression brings the divided margins of the vessel into close apposition, and thereby permanent closure, by adhesion, is quickly accomplished. In the latter, the mere circumstance of the escape of blood being prevented, naturally hastens the closure of the minute aperture by the natural process; and, if the compression be accurate and very firm, the opposite surfaces of the vessel, being brought in contact, may adhere, and the canal be obliterated at the wounded point. It is obvious that, in this latter class, pressure can only be of advantage immediately after the infliction of the wound, and not when blood is extravasated to a great extent.

      Pressure may be used along with styptics, or along with escharotics, actual or potential. They may be often employed when pressure ought not; styptics promote the contraction and retraction of the divided extremities, and thereby expedite the formation of a coagulum. Escharotics form a slough, which, adhering to the extremity of the vessel, stops the flow of blood, and the cut margins of the vessel, being stimulated by the application, soon cohere. Active stimulating applications merely cause effusion quickly of coagulated lymph, and thus often arrest hemorrhage from very vascular surfaces better than the so-called styptics. Not unfrequently, after the separation of the slough, it is found that union has not taken place, and hemorrhage is renewed; from this circumstance, the remedy cannot be trusted to, except when the divided vessels or vessel are of small size. It may be stated, generally, that these means are of little avail without methodical pressure. In oozing from small vessels, pressure may be applied by means of agaric, sponge, or lint. In bleeding from small vessels, where there is general oozing from the surface, and pressure cannot readily be made, applications tending to produce effusion of lymph—stimulants, such as turpentine or creosote, are often remarkably efficacious, and very speedily so; but in wounds of the larger vessels, the most efficient mean is a graduated compress of lint placed immediately on the external wound, and supported by a firmly-applied bandage. The bandage ought to encircle not only the wounded part, but every part of the limb with a uniform tightness, not so great as to arrest the general circulation; the parts are thereby supported, and engorgement prevented. This method, when employed previously to the effusion of much blood into the cellular tissue, has proved effectual in wounds even of the brachial, femoral, and carotid arteries. When blood has been extensively injected into the limb, when the aperture in the vessel has remained pervious, and when a large diffused aneurism exists, bandaging is worse than useless. By its application in such a case the limb becomes discoloured and swells extensively; there is a risk of mortification from impeded circulation. If a small quantity only of blood has escaped, its diffusion and increase may be prevented by the bandage: but a cyst will nevertheless be formed in the cellular tissue; its parietes will communicate with the margins of the aperture in the artery, its cavity with the canal of the vessel; an aneurism of the false kind will be established, and will run the course of one arising spontaneously.

      A ligature, well applied, is the only means that can be relied on. The immediate effect of a tightly-drawn ligature is to avert the flow of blood, to divide the internal and middle coats at the deligated point, the cellular coat remaining entire, and to narrow the canal for some extent above the point at which it is applied. Coagulation then occurs within the vessel above the ligature, provided there is no collateral branch in the immediate vicinity. The ruptured margins of the internal coat effuse lymph and cohere; lymph is effused also in the cellular tissue, exterior to the artery and to the ligature; by the compression of the ligature, ulceration occurs in those parts which it envelopes, and the foreign body is discharged; but before this occurs the canal of the vessel has been obliterated by an internal coagulum, and by the effused lymph. Afterwards, the same absorption and consolidation occur as in a divided artery, the orifice of which has closed permanently and spontaneously.

      When from a punctured wound profuse hemorrhage ensues, there is reason to suspect that an important vessel has been hurt, and the bleeding point must be sought for. After the artery giving out the blood has been discovered, the external wound must be enlarged, so as to expose the vessel, and admit of the convenient application of a ligature. It will not be sufficient to include the vessel above the wounded point, for the lower part will, after some time, be supplied with blood by the collateral branches almost as freely as by the large trunk, and, consequently, bleeding will be renewed. Two ligatures are to be employed, one above, the other below, the wound. The wounded vessel must be exposed, as already stated, but not detached more than is sufficient for the application of the ligature; and at the same time the ligatures ought to enclose nothing but the vessel. Neither ought the ligatures to be placed at any considerable distance, but as close to the wounded point as possible; otherwise circulation in the included part may be restored. The ligature, round, narrow, and firm, ought to be tightly applied. Cases of hemorrhage have occurred in which the tying of the vessel immediately above the wound has been successful; but these are few, and by no means afford any authority for the general adoption of such a measure. If the vessel is merely punctured, it is necessary to apply the ligature by means of a blunt pointed needle, and the parts are to be disturbed as little as possible. If, however, the artery is completely divided, its cut extremities are to be drawn out of their sheath by a hook or forceps, and the ligatures applied close to the connections of the vessel; the vasa vasorum, in the immediate vicinity of the deligated point, being left to carry on those processes by which obliteration is accomplished. In punctured or partial wounds of arteries, it deserves consideration whether the hemorrhage may not be restrained by the application of slight pressure, so regulated as to prevent the flow of blood laterally through the wound, but not so forcibly applied as to stop the onward current of the blood along the vessel, from the part of the tube above to that below the puncture. Some experiments made by Dr. Davy seem favourable to this view; as bleeding from the carotid arteries, partially divided transversely, in dogs was easily arrested by the means above-mentioned, the wound of the vessel readily healing, so as to preserve its tube entire; whereas, when the pressure was increased, the hemorrhage became violent. The subject is mentioned as one worthy of a further experimental investigation. The instrument which will generally be found most useful for laying hold of the vessel is the common dissecting forceps, but a tenaculum will, in certain circumstances, be more convenient. By far the most convenient machine is that here represented.