Collection of facts illustrative of the morbid conditions of the pulmonary artery / by Norman Chevers.

  • Norman Chevers
Date:
1851
Catalogue details

Licence: Public Domain Mark

Credit: Collection of facts illustrative of the morbid conditions of the pulmonary artery / by Norman Chevers. Source: Wellcome Collection.

    7/138 page 7
    tion M. Basse has met with earlier in males than in females, (in the former from the 50th year upwards, in the latter not till after the 60th). In a still later period of life it no longer applies*. I have found that, in persons above the age of 60 years, there is always considerable dilatation of both arteries, but that their relative proportions vary in great measure according to the nature of the causes which have occasioned death. Tims, in an extremely enfeebled woman, who died of bronchitis at the age of 65, the circumference of the pulmonary outlet exceeded that of the aortic by three lines. On the contrary, in two men who died of malignant disease at the respective ages of 74 and 77, the circumference of the aortic ostium exceeded that of the pulmo¬ nary by one and a half, and two lines. But, in a man who died of gangrene in his 89th year, although (as in the other cases) the tissues of the pulmonary artery and ascend¬ ing aorta appeared almost entirely free from any other change than loss of elasticity, the lower portion of the orifice of the former measured 45 lines, while that of the latter was only 39 lines in circumference. I noted it as a remarkable fact, that, in this aged person, the narrowest por¬ tions (which were here the lower ostia) of the pulmonary artery and aorta had re¬ spectively become dilated very nearly to the utmost extent to which I have shewn that these parts of the vessel are naturally capable of being stretched. It will be found in the pulmonary artery, as in the aorta, that in an exact ratio to the degree in which any part of the vessel has become perma¬ nently dilated, is the loss of elasticity in that portion of the tube : thus we have seen that the natural measurement of the lower ostium of the pulmonary artery is 38£ lines, and that it admits of being stretched about eight lines : hence, in adult males, where this portion of the vessel is 41 lines in cir¬ cumference, it may be prem’sed that it will probably not admit of being dilated more than four or five lines ; and, in eases where it is 44 or 45 lines in circumference, it will be found to have nearly or entirely lost its elastic properties.f In cases where the upper or lower * Cyclopa:d. of Anat. and Physiol.; Art. Heart, t When any vessel is found dilated, if its stan¬ dard capacity be known, the loss of elasticity in its tissues may generally be taken as an indication of the degree in which its calibre has become increased. But this test does not, of course, hold good after the canal has become permanently widened beyond the extent to which it is natu¬ rally dilatable. Whatever slight amount of elas¬ ticity varicose and aneurismalvessels maypossess, is due to the increased development of their elastic tissues. It is scarcely necessary to add, that a test of this kind only avails to show that every vessel has a naturally fixed amount of elas¬ ticity, as well as an average capacity. portions only of the two great arteries are much dilated, life may be considerably prolonged; but it is probable that, when¬ ever both the upper and lower portions of their cardiac orifices become perma¬ nently dilated to the greatest extent which the natural yielding of their structures is capable of admitting—even independently of any very apparent change in their tissues beyond mere loss of elasticity—life begins to be held on an exceedingly frail tenure, ft is true that, in a few cases, the widest part of the pulmonary orifice has been found to exceed its natural measurement by an inch or more, but the subjects of this lesion have invariably died from failure of the heart’s action. And it can scarcely be doubted 4hat a considerably less degree of dilatation than this is sufficient to occasion sudden death in consequence of any cause which tends to produce over-distension of the ventricles. This question appears to be by no means undeserving of further investigation, espe¬ cially as illustrative of the immediate cause of death in extreme old age, and in cases of long-standing disease of the heart and lungs. The following are the principal subjects which will be considered in the succeeding observations :—Congenital Irregularities in the Mode of Origin and Distribution of the Pulmonary Artery; Unnatural Dilatation and Contraction of its Canal; Inflammation ; Pulmonary Apoplexy; The causes which determine the deposition of Clots in the Pulmonary Artery; The Diseases of its Valves ; Ulceration and Laceration of its cardiac and pulmonary divisions. The Pathological Condition of the Ventricles, especially of the Right, in cases of Disease of the Pulmonary Artery and Lungs ; Symp¬ toms and Diagnosis of the Diseases of this vessel; a Sketch of the General Principles of Treatment which it is necessary to pursue in these and other forms of Organic Obstruc¬ tive Disease in the Cardiac and Pulmonary Apparatus. CONGENITAL MALFORMATIONS OF THE PUL¬ MONARY ARTERY, AND IRREGULARITIES IN ITS FORM AND MODE OF ORIGIN. As it almost amounts to an invariable rule that each of the severer kinds of congenital malformation of the heart is characterised by more or less departure from the natural condition of the pulmonary artery, a com¬ plete description of all the cases where this vessel is found in an abnormal condition must involve an allusion to nearly every one of the congenital malformations to which the cardiac apparatus is liable. I shall there¬ fore endeavour to render this portion of the history as brief as possible consistently with my plan of furnishing reference to all the
    digitised image 1
    digitised image 2
    digitised image 3