Operation of Ligature of the FemoralScarpa's Space.The patient being placed on his back, and being brought very thoroughly under chloroform, the knee of the affected limb should be bent at an angle of about 120°, and supported on a pillow. Having previously ascertained the angle of junction of the sartorius and adductor, the surgeon should make an incision (Plate I. fig. 5) just over the pulsations of the vessel, in the middle line of the space, having its lower end quite over the sartorius muscle, and its upper one, at a distance from two and a half to three and a half inches, varying according to the amount of fat and muscle. The saphena vein can generally be recognised, and is almost always safe out of the way of this incision at its inner side.
The first incision should divide the skin, superficial fascia, and fat, quite down to the fascia lata. The edges of the wound being held apart, the fascia should be carefully divided, and the sartorius exposed; its fibres can generally be easily enough recognised by their oblique direction; once recognised, the fascia should be dissected from it till its inner edge be gained, the corner of which should then be turned so that it may be held outwards by an assistant with a blunt hook. The sheath of the vessels is now exposed, and after having thoroughly satisfied himself of the position of the artery by the pulsation, the surgeon should carefully raise a portion of the sheath with the dissecting forceps, and open it freely enough to allow the coats of the artery to be distinctly seen. If the parts are deep, as in a fat or muscular patient, great advantage will be gained by seizing one edge of the sheath by a pair of spring forceps, and committing it to the care of an assistant, while the operator holds the other in his dissecting forceps; there is thus no fear of losing the orifice of the sheath, which without this precaution may easily happen, from the parts being confused with blood, or the position altered by movements of the patient. Now comes the stage of the operation on which, more than on anything else, success or failure depends. A small portion of the vessel must be cleaned for the reception of the ligature, and it must be thoroughly cleaned, so that the needle may be passed round it without bruising of the coats, or rupture of an unnecessary number of the vasa vasorum by rough attempts to force a passage for it. Hence all compromises, such as blunted instruments, silver knives, and the like, are dangerous, for in trying to avoid the Scylla of wounding the artery, they fall into the Charybdis, on the one hand, of isolating too much of the vessel and causing gangrene from want of vascular supply, or, on the other, expose the vein to the danger of injury by the aneurism-needle in their attempts to force it round an uncleaned vessel.
The needle should in most cases be passed from the inner side, care being taken to avoid including the vein which is on the inner side and behind the vessel; the internal saphenous nerve, if seen, should be avoided. The needle must not be passed quite round the vessel raising it up, still less must the vessel be held up on the needle, as used to be done, as if the surgeon was surprised at his own success, but the needle should be passed just far enough to expose the end of the ligature, which must be seized by forceps and cautiously drawn through. It must then be tied very firmly and secured with a reef knot.
The edges of the wound must be brought into accurate apposition, and secured by one or two stitches. If antiseptics are used, drainage should be provided for.
From the very fact that ligature of the superficial femoral is a remarkably successful operation in causing consolidation of the aneurism and a rapid cure, there is also a corresponding danger that the limb be not sufficiently supplied with blood at first. The limb may very possibly become cold, and remain so for some hours at least after the operation. To avoid this as far as possible, it should be wrapped in cotton wadding, and very great care should be taken that it be not over-stimulated by hot applications, friction, or the like, any of which measures might very likely excite reaction, which would result in gangrene.
Complete rest of the limb and of the whole body must be enjoined; the food must be nourishing and in moderate quantity. The chief danger is from gangrene of the limb, which is especially apt to result when the vein is wounded, or even too much handled during the operation.
When properly performed, and in suitable cases, the operation is very successful. Mr. Syme tied this artery for aneurism thirty-seven times, and of these every one recovered. The statistics of Norris and Porta, who collected all the cases in which ligature of the femoral had been employed for any cause, show a mortality of somewhat less than one in four. Rabe's table up to 1869 with the additional cases collected by Mr. Barwell to 1880 gives 297 cases with 53 deaths.9 Mr. Hutchinson's table, again, of fifty cases collected from the records of Metropolitan Hospitals, shows the very startling result of sixteen deaths out of the fifty cases, or a mortality, in round numbers, of one-third.
Certain anomalies have been observed in the distribution of the femoral vessels, of some importance as affecting the possibility of applying, and the result of, ligature; such as1. A high division of the branches which afterwards become posterior tibial and peroneal. 2. A double superficial femoral, both branches of which may unite and form the popliteal, as in Sir Charles Bell's well-known case. 3. Absence of the artery altogether, as in Manec's case, where the popliteal was a continuation of an immensely enlarged sciatic.
In such a case the absence of pulsation in front, and the presence of increased pulsation behind the limb, ought to prevent any fruitless attempt at search.
Ligature of the Superficial Femoral below the Sartorius Muscle.This operation, though once common in France, and though the one recommended by Hunter himself, is now comparatively little used in this country; and rightly so; for while it has no advantage over the upper position, it is at once nearer the seat of disease, and the vessel is more deeply buried under muscles, and has a more distinct fibrous sheath, which requires division.
It is, however, by no means a difficult operation, and is thus performed:
The limb being laid as before on the outside, and slightly bent, the skin shaved and the pulsation of the artery detected, an incision (Plate I. fig. 6) must be made from the lower edge of the sartorius muscle just as it crosses the vessel, along the course of the vessel, avoiding if possible the internal saphena vein.
The sartorius when exposed must be drawn inwards. The fibrous canal filling the interspace between the abductor magnus and vastus internus is then recognised, and must be fairly opened; the artery is now seen lying in it, and over the vein which is posterior to it, but projects slightly on its outer side; the internal saphenous nerve is lying on the artery. The needle is best passed from without inwards so as to avoid the vein. The anastomotica magna is sometimes a large trunk, and has been mistaken for the femoral in this situation, and tied instead of it.
Ligature of the Popliteal.This operation is now hardly ever performed for aneurism, ligature of the superficial femoral having quite superseded it, and it is very rarely required for wounds, from the manner in which the vessel is protected by its position.
Before the invention of the Hunterian principle of ligature at a distance, the old operation for popliteal aneurism consisted in cutting into the space, clearing out the contents of the aneurismal sac, and tying both ends of the vessel; from the depth of parts and the close connection of the popliteal vein, this operation was very rarely successful, and is now quite given up. If the vessel is wounded the bleeding point is the object to be aimed at, and is generally sufficient guide.