Such are the general relations of the pro funda artery; but it presents frequent varieties, which derive importance from the practical connections of the femoral vessels. The par ticulars, in which it is subject to diversity, are the precise situation and relation of its point of origin, and the relation of its course to that of the femoral artery.
The profunda arises generally, as has been stated, from the posterior and outer side of the femoral; but at times its origin is directly behind that vessel, at others directly from its outer side, and occasionally again from its inner side, as may be seen from fig. 3, tab. xxxiii. of Tiedemann. The situation of its origin also is variable, at times being close to Poupart's ligament, at others at some distance from it. According to Boyer* it corresponds to " the middle of the space comprised be tween the pubis and the little trochanter; sometimes higher, but rarely lower." Accord ing to the division of the femoral artery takes place " at the distance of one inch, or one and a half, very rarely two inches, below the crural arch in a well-formed adult, of the ordinary stature." According to liar rison,r the profunda arises " in general about two inches below Poupart's ligament, some times an inch or two lower down, and some times much nearer to this ligament." Of those three accounts that of Scarps appears pre ferable : the " distance between the pubis and the lesser trochanter" is variable, and affords no guide for the living subject, and the author has never witnessed the origin of the vessel by any means so far from Poupart's ligament as the statement of Harrison would imply : a distance of four inches, which may be un derstood from it sometimes to occur, would bring the origin down to the point at which the sartorius generally commences to overlap the femoral artery, and this is manifestly alto gether too low ; while on the other hand Searpa* states expressly that it is never below the maximum point which he has laid down, viz. two inches from the ligament, and I lodg sont asserts that " it very rarely arises so low as two inches." The maximum distance im plied in the description of Harrison is that which has been laid down by Bell as the me dium point of origin, on which Burns/ re marks, " I infer that Mr. Bell has described this artery from dried preparations, in which, from the retraction of Poupart's ligament, the origin of the profunda seems to take place lower than on the recent subject." The only objection which can be made to the view of Scarpa, is that the vessel not unfrequently arises nearer to the ligament than one inch from it, its origin being at times abso lutely at it, and having been in some few instances observed even above the ligament, before the femoral had escaped from the ab domen, or more properly from the external iliac artery : of this extraordinarily high origin four instances have been recorded by Burns,§ and Tiedemann II has met with it in a female, upon both sides. Tiedematinc has also in
ferred from his researches that the profunda arises nearer than usual to Poupart's ligament more frequently in females and in subjects of small stature than in others.
The relation of the course of the profunda to that of the femoral is the next point of variety.
The main course of the former is external to that of the latter; in arriving at its destination, however, it does not at all times pursue an uniform course, but presents diversities in this respect, which affect very much its relation to the femoral artery. Its general direction is downward, backward, and outward ; still more outward than the femoral : it is seldom how ever direct, but describes one or more inflec tions, by which its course is made at times to cross once or oftener that of the other vessel; and hence the diversities in its relation to the femoral which have been adverted to. When the course of the vessel is direct or little tor tuous, the profunda is situate throughout, external to the femoral, and this relation would appear to prevail at least as frequently as any other, or to be the most prevalent, for such is the view of the course of the artery given by Haller,* in two of three views in which the relative course of the two vessels is repre sented, and by Tiedemannt in two of four views. But at other times, when the artery is more tortuous, after descending for a little way external to the femoral, it makes a turn, and passes inward behind it, and thus fre quently gains the inner side of that vessel before it reaches the adductor longus, after which it again inclines outward toward its destination. Such is the view given of its course by Scarpa,I with which the description of Harrison coincides : it is similarly repre sented by Tiedemann in fig. 4, tab. xxxiii., and also by IIaller§ in one instance; but the author is disposed to regard this as a less common disposition, as well from the fre quency with which he has observed the former one to occur, as from the weight of the autho rities which have been adduced in favour of that opinion. In other but rare instances the profunda, arising from the inside of the femo ral, inclines at first inward and becomes in ternal to it, and then bending outward crosses behind the femoral to its outer side: of this arrangement an instance is furnished by Tiede mann in fig. 3, tab. xxxiii. And in others the artery does not in the first instance incline sensibly to either side; but arising from the back of the femoral it descends behind that vessel, and does not gain its outer side until it has reached the lower part of the inguinal region.