ARTERY, PATHOLOGICAL CONDITIONS OF. 



231 





the neighbour! lood are neither distended nor 

 ruptured, and the blood within it passes through 

 the general circulation, and of course does not 

 coagulate. It is difficult to class this disease 

 with aneurism in any form, yet is it termed the 

 aneurism t>i/ OtUUtomotU. 



No part of the natural history of any disease 

 can be more interesting than that which has 

 reference to its causes, whether predisposing 

 and remote, or immediately exciting. Cer- 

 tainly, when an aneurism has been formed, a 

 knowledge of the circumstances that occa- 

 sioned it will not be very useful in contributing 

 to its removal, although it may often assist in 

 forming a prognosis as to the result of an 

 operation : yet if it can be made available in 

 tin; prevention of the disease, it must prove of 

 no inconsiderable value. It is admitted that 

 aneurism frequently appears suddenly as the 

 result of a blow, a strain, or some violent exer- 

 tion, the patient being conscious of something 

 having torn or given way within him. With 

 still greater frequency it occurs without any 

 such consciousness on the part of the sufferer, 

 and persons have borne this formidable disease 

 about them for months, and even for years, 

 not only without being themselves aware of its 

 existence, but, if situated internally, without 

 its being recognized by their professional at- 

 tendants ;* and it often happens that a patient 

 complains of the crookening of the fingers or 

 the numbness of the foot, unmindful of the 

 tumour under the clavicle or in the popliteal 

 space. Without denying that an artery, in a 

 perfectly healthy condition, can become the 

 seat of aneurism, because there are too many 

 facts apparently in support of such an opinion, 

 it may be remarked that if such was generally 

 or even frequently the case, the disease ought to 

 be much more common amongst the labouring 

 poor, and also that it should prevail amongst 

 some particular trades. These considerations 

 lead to a belief, that previous to the occurrence 

 of spontaneous aneurism, the artery has under- 

 gone some change predisposing to it, although 

 it may not be so easy to point out the nature 

 of that change, or the causes that lead to its 

 production. 



It is observed that aneurism is of far less 

 frequent occurrence in woman than in man ; 

 a comparison between the numbers of internal 

 cases proving this fact in a remarkable manner, 

 and in cases of external aneurism still more so. 

 It is very rare to meet w r ith a popliteal aneu- 

 rism in a female. Certainly, the more labo- 

 rious habits and constant exposure to accident 

 in the one sex may in some respects serve to 

 account for this circumstance, but to those 

 who know that in many places women are 

 obliged to undergo at least as much hardship 

 and fatigue, the explanation will be far from 

 satisfactory. Again, it has been stated that 

 certain pursuits of life predispose to aneurism, 

 inasmuch as it prevails amongst coachmen and 

 postilions, but there never has been even a 

 plausible reason offered to explain this greater 



* A very curious case of this description is related 

 in the Dublin Hospital Reports, vol. v. p. 167. 



liability of particular callings. It cannot be 

 the bent positions of the limbs of such per- 

 sons, because many other classes, studious 

 persons for instance, maintain similar postures 

 for a longer time and with greater frequency, 

 yet is not aneurism common amongst them. 

 Neither will the sudden stretching of the limb 

 by pressing the foot against the stirrup or foot- 

 board in managing the horses throw any light 

 upon the subject, for it is found by experiment 

 that no force will rupture a healthy artery short 

 of what would also tear asunder the ligaments 

 of the adjacent joints. Allowing, therefore, 

 the accuracy and truth of these observations, 

 their explanation is still to be sought for. 



Some have supposed that old age, and the 

 deposit of earthy material which is formed in 

 the arteries at that period, are predisposing 

 causes of aneurism ; yet, if this was the case, 

 the disease should be very prevalent indeed 

 among those advanced in life, whereas it is 

 in reality almost as rare as in infancy or early 

 youth. Of fifteen cases of large aneurism 

 operated on, only two had exceeded the age 

 of forty years, the average of all being but 

 thirty-one and a half ; and if a larger number 

 of cases (inclusive of the internal forms of the 

 disease) were collected and compared, it would 

 probably be shewn to be considerably less. 

 With respect to the earthy deposit alluded 1o, 

 it is found between the fibrous and internal 

 coats closely adhering to the latter, from which 

 it can scarcely be separated : it is disposed in 

 thin laminae or plates of different sizes, the 

 largest being seldom greater than a spangle, 

 and these earthy spots are distinct and separate, 

 not running into or connected with each other, 

 and never encircling the vessel with an un- 

 interrupted bony ring. They are supposed to 

 render an artery friable and brittle, and there- 

 fore to predispose to aneurism, and have been 

 considered by some to be the products of 

 arterial inflammation. Unfortunately the origin 

 and progress of this earthy degeneration have 

 not yet been satisfactorily traced. Scarpa* 

 seems to regard it as arising from the same 

 cause that produces the steatomatous deposit, 

 and states that it cannot be said to be proper 

 to old age, as it is sometimes met with in 

 patients who are not much advanced in life. I 

 have seen these earthy depositions in the aorta 

 of a female not twenty -five years of age, which 

 was also highly inflamed and covered with 

 spots of soft steatomatous deposit, but still 

 that is far from proof of its being the product 

 of active inflammation, or of its rendering the 

 artery weak or disposed to aneurism. 



Of any number of subjects above the age 

 of sixty brought into a dissecting-room, three- 

 fourths will be found with this earthy dege- 

 neration in some of the arteries, yet the in- 

 frequency of aneurism amongst old patients 

 has been already remarked. Again, this de- 

 posit has been seen in the sac of a true aneu- 

 rism, a circumstance that would shew it did 

 not greatly interfere with the distensibility of 

 the arterial tunics or render them more friable, 



* On Aneurism, page 90. 



