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 as—1. 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.
In cases of hæmorrhage for suppuration of an aneurismal sac, it might possibly be advisable, and there are certain cases of rupture of the artery, without the existence of an external wound, in which attempts have been made to save the limb by tying the vessel.[10] From the complexity of the parts, the numerous tendons, veins, and nerves crowded together in a narrow hollow, and chiefly from the great depth at which the artery lies, any attempt at ligature is very difficult. It is least so at the lower angle of the space, where, between the heads of the gastrocnemius, the vessel comes more to the surface, but is still overlapped by muscle.