236 



ARTERY, PATHOLOGICAL CONDITIONS OF. 



rism by dilatation, was obliged to support his 

 opinions more by argument than by facts de- 

 monstrable by dissection ; and although later in- 

 vestigations, particularly those of Mr. Hodgson 

 and Mr. Guthrie, have satisfactorily proved the 

 occasional existence of both true and false 

 aneurism, yet it must be a favourable case and 

 patient examination that will enable the morbid 

 anatomist to exhibit its nature and structure 

 without possibility of error. When cases of 

 inflamed or diseased artery are seen, compli- 

 cated with aneurism, and the same depositions 

 are observed in the artery and in the sac, it 

 proves beyond doubt the identity of structure 

 in both. Thus, if an aorta be found studded 

 over with specks of a soft steatomatous deposit 

 situated between its internal and middle coats, 

 and if on one side of it an aneurism is placed, 

 in the sac of which, throughout its entire ex- 

 tent, the same appearances and the same de- 

 posit are observed, it follows that the same 

 structures must exist in both, and that one is 

 a prolongation of the other. One of the cases 

 already noticed as being a true aneurism, that 

 destroyed the patient by pressure on the trachea, 

 exhibited such evidence of its nature : and a 

 similar one, but still more satisfactory, occurred 

 in the person of a gentleman, who died some 

 years since. This patient had laboured under 

 some anomalous cerebral symptoms, and on 

 inspecting the brain a small aneurismal tumour 

 was seen at the bifurcation of the basilar artery, 

 in the sac of which were found the same kind 

 of earthy depositions that pervaded all the 

 arteries of the body the same so generally 

 observed in the arteries of aged persons. These 

 examples are sufficient to prove that aneurism 

 by dilatation may exist, and perhaps its occur- 

 rence in the aorta and larger vessels is more 

 frequent than has been supposed. 



During the past spring two opportunities 

 occurred of examining into the nature and 

 condition of aneurism, both in its early stage 

 and long after it had been apparently cured by 

 operation. They were, probably, both ex- 

 amples of what has been termed true aneu- 

 rism, although unquestionably all the coats of 

 the artery were not engaged : and as the mor- 

 bid appearances have not been hitherto de- 

 scribed, it may be useful to take notice of 

 them here. 



A man was admitted into the Meath Hos- 

 pital, with popliteal aneurism in each ham : 

 one of these had existed for several weeks ; 

 the other was of very recent occurrence. The 

 limb in which the older and larger one was 

 situated was first made the subject of opera- 

 tion, the femoral artery was tied, but the 

 patient died on the sixteenth day afterwards, 

 of venous inflammation, the ligature on the 

 vessel still remaining firm and undetached. 

 On examining the aneurismal tumour exter- 

 nally it appeared of an oval shape, and to have 

 been formed by the gradual expansion of all 

 the coats of the vessel. On being cut into, 

 however, it was found that the lining mem- 

 brane was wanting throughout the entire extent 

 of the sac, the edge of it terminating sharply 

 and abruptly, above and below, at the junc- 



tions of the tumour with the more healthy 

 parts of the vessel, and being as accurately 

 defined as if made by a careful dissection. 

 The fibrous coat was. evidently continued into 

 the tumour, which seemed to be formed of an 

 expansion of it and the cellular. It was, 

 moreover, otherwise diseased, being thickened, 

 greatly softened and thrown into irregalar rugae 

 or folds, the interstices between which were 

 filled with coagula of lymph or fibrine. As 

 the sac of this aneurism was in a state of sup- 

 puration, the deficiency of the lining mem- 

 brane was attributed to that circumstance until 

 the other aneurism came to be examined when 

 the same appearances were observed. The 

 second tumour was not so large as a walnut 

 and evidently formed by the gradual expan- 

 sion of the fibrous coat, for the abrupt ter- 

 minations of the lining membrane at the 

 healthy extremities of the artery were still more 

 exactly defined. 



The other case is even more interesting, be- 

 cause it exhibits a cure of aneurism after 

 operation in a manner that has not been de- 

 scribed, the principle of which it is not easy 

 to understand. A man was operated on by 

 Mr. Collis, in the Meath Hospital for popliteal 

 aneurism on the 22d of January, 1831. The 

 ligature came away on the seventeenth day, the 

 tumour diminished ; in short, every thing went 

 on well and the patient left the hospital per- 

 fectly cured. So far as the aneurism was con- 

 cerned, he remained healthy and free from 

 inconvenience until his death, which hap- 

 pened in March 1835, from fever, and such an 

 opportunity for pathological inquiry was not 

 neglected. The tumour which had been origi- 

 nally of the size of a turkey's egg, was found 

 to have diminished to little more than that of a 

 walnut : externally it felt hard and as if com- 

 pletely solidified : on being cut into, however, 

 neither artery nor sac was obliterated, the latter 

 being occupied by a coagulum of a deep red 

 colour, through the centre of which was a canal 

 of a sufficient size to allow the blood from the 

 portion of the artery above the tumour to flow 

 freely into that below it. It seemed as if the 

 current of blood through the sac had never 

 been interrupted, the only effect of the former 

 ligature having been the removal of the im- 

 pulse of the heart from it. This aneurism 

 appeared to have been a true one, so far as the 

 fibrous and cellular coats were concerned, but 

 the fact could not be so satisfactorily demon- 

 strated as to admit of no dispute ; however, 

 the absence of the lining membrane and its 

 sharp and abrupt terminations at the healthy 

 portions of the vessel were sufficiently ob- 

 vious. 



If it be difficult to demonstrate the nature 

 and constitution of the small and recent aneu- 

 rism, it becomes impossible when the tumour 

 has attained to a considerable size. It seems 

 probable, however, that the arterial structures 

 will not long endure this state of unnatural 

 distension, and they either ulcerate or tear in 

 their internal and middle coats. A mixed 

 aneurism will thus be formed, having its sac at 

 first composed of all the structures of the artery, 



