Elements of Surgery. Robert Liston

time, as when it is left undisturbed and ultimately separated by nature. Such a theory, however, has proved to be incorrect in most of the instances in which it has been reduced to practice on the human subject; and the operation is at best very uncertain, and not to be relied on. Others have employed a double ligature, and some of the Continental surgeons have applied a great many; some were tightened, others left loose, and looked upon as ligatures of reserve to be tightened, should hemorrhage take place, an occurrence likely enough to follow their clumsy and unsurgical proceedings. A thick broad ligature like tape has also been used, from an ill-grounded apprehension that all the coats of the artery would be cut completely through by the tight application of a thin and firm one. With the same view, a roll of linen or plaster has been interposed betwixt the noose and the vessel, and this practice has been advocated even by good surgeons—as Scarpa. Such complications can do no good, and may do much mischief. The artery must be greatly detached from its surrounding connections before the numerous and flat ligatures can be applied, in consequence of which its coats will be apt to slough or ulcerate, and hemorrhage occur. When, from any cause, the vessel has been detached to a greater extent than is sufficient for the passing of one ligature, two ought undoubtedly to be used, and one applied close to each extremity where it is attached to the surrounding parts.

      Again, it has been proposed, after the application of a double ligature, that the vessel should be cut through betwixt the two deligated points; it being supposed that in this way the closure of each extremity will be more rapid, the cut ends retracting, and being, in fact, in the same circumstances as the extremities of arteries which have been tied on the face of a stump. Mechanical contrivances have also been invented for the compression of the artery,—such as the serrenœud and presse artere; these, however, are clumsy, insufficient, and often injurious.

      The single ligature, when properly applied, is the most safe, and preferable to any other, for arresting permanently the flow of blood in a vessel. In its application, the artery must not be separated from its connexions farther than is barely sufficient for the passage of the armed needle beneath it; but the external incision ought to be free, in order that this may be readily effected, and that the operation may be easily and speedily performed. By the firm application of a single ligature, the vessel is rendered impervious; the internal and middle coats are divided, so that the ligature only encircles the outer or cellular one, which resists the influence of any moderate degree of force by which it may be tightened. The blood coagulates above the deligated point,—the coagulum is of greater or less extent, in proportion to the vicinity of a collateral branch, and is of a conical form, the apex of the cone pointing to the free portion of vessel. Incited action in the vessel takes place at the deligated point; the divided margins of the internal and middle coats secrete lymph, by which they adhere, and so obliterate the canal of the artery. Lymph is also effused on the external surface, and in this deposit the ligature becomes imbedded. The direct influx of blood into the aneurismal sac is thus intercepted, and time is allowed for coagulation of the blood which it contains; the artery for a considerable distance below the ligature becomes ultimately converted into a firm and impervious chord. The coats of the vessel above the ligature are much thickened, and the internal membrane is occupied with the transverse rugæ occasioned by projecting fasciculi of the fibres, which are always apparent after obstruction of an artery. If this operation be properly conducted, success must almost uniformly follow. Before determining on its performance, however, the state of the arterial system ought to be examined as carefully as possible; for not unfrequently the degeneration of the coats is almost universal, and therefore an artery, or even arteries, may be diseased at more points than one; and if this aneurismal diathesis exist, the patient may be found to labour under an internal aneurism of the aorta. In such a case, an operation could not with propriety be undertaken for the cure of the external aneurism; there might be no inconsiderable danger of the patient’s death being suddenly accelerated by the operation, the sac of the internal aneurism giving way perhaps during its performance: such a circumstance has actually occurred.

      Ligatures composed of animal substance, such as catgut, have been proposed as preferable to all others, on the supposition that they would be absorbed, and occasion less irritation; the fallacy of any such theory has already been adverted to. After the ligature has been applied for some time, it induces ulceration of the external coat which it envelopes, by which means it becomes detached from the vessel; acting as a foreign body, and causing a slight degree of suppuration, it makes its way by nature to the surface and is discharged. The period at which it separates may be said to be from the tenth to the twentieth day; sometimes sooner, seldom later. If, however, much of the surrounding parts have been extensively included along with the vessel, a longer period will probably elapse before the separation of the ligature. One end only of the ligature should be cut away close to the artery, the other being left hanging from the external wound; perhaps it is even safer to leave both, unless a third knot is made upon it; thus the extraneous body, when detached, can be gently pulled at so as to hasten the separation: this must be done with very great caution. When both ends are cut short, and the knot closed in, there is a risk of secondary hemorrhage, from the ligature causing formation of matter round it, perhaps detaching the vessel from its connections, and causing ulceration of its coats.

      The operation ought to be performed at as early a period of the disease as possible. Some recommend that it should be delayed in recent cases, with the view of allowing sufficient time for the anastomosing vessels to enlarge, in order that the circulation may be more vigorous in the smaller branches after obstruction of the principal vessel. Such delay prolongs the patient’s sufferings, which are in many cases extremely acute, and the precaution is altogether unnecessary, as has been amply proved by experience. On the same principle, the previous application of pressure to the vessel has been recommended; but few surgeons, if any, are now afraid of trusting to the resources of Nature when the principal vessel of a limb is obliterated, and that suddenly, without previous dilatation of the anastomoses. Cases are on record, in which the abdominal aorta has been completely obstructed by a natural process, without much impeding the inferior circulation; and in one remarkable instance of this description, the inconvenience was so slight that the disease was not suspected during the life of the patient, the lower limbs retaining their usual size and activity. In plethoric habits it may sometimes be prudent to abstract blood, even more than once, previously to the operation.

      When the ligature is placed immediately below a collateral branch of considerable size, a bloody coagulum is not formed, though adhesion may occur; but if the excited action should extend to the collateral branch, and its canal become thereby obliterated, a coagulum is speedily deposited. In consequence of the enlargement of the anastomosing branches, and the increasing circulation in them, pulsation generally returns in the tumour, to a slight degree, some days after the operation. This, however, is by no means a sign that the operation has been ineffectual; for the renewed pulsation almost always disappears in the course of a very short time. In one instance only have I found it assume a more permanent and troublesome aspect; in that case, it recurred about ten months after the performance of the operation, but speedily disappeared under the careful use of a compress and bandage.

      On account of the aneurismal diathesis, it occasionally happens, that after the cure of one aneurism, another appears in a different situation; in two instances, I operated on both thighs, at a considerable interval, successively and successfully, for popliteal aneurism, in the same patients.17

      

      When the tumour is so situated as not to admit of the application of a ligature between it and the heart, it has been proposed to place the ligature on the distal side of the aneurism, upon the supposition that coagulation will occur within the sac in this case as after the common operation.18 The practice has been made trial of, but its expediency appears very doubtful; neither has the success attendant upon it been such as is generally supposed: the post mortem examinations have been very unsatisfactory in some of the cases. The application, indeed, of a ligature in that situation can seldom be of any advantage, the artery being already obliterated, in aneurisms of some standing, a long way beneath the tumour; and it is, perhaps, from this circumstance that, in such operations, great difficulty has been experienced in securing the vessel, and that it has been thought necessary even to pass a needle under a thick mass,