Researches on phthisis: anatomical, pathological and therapeutical / by P. C. A. Louis.

  • Pierre Charles Alexandre Louis
Date:
1844
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Licence: Public Domain Mark

Credit: Researches on phthisis: anatomical, pathological and therapeutical / by P. C. A. Louis. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    It is, in truth, now established by the inquiries of M. Schroeder van der Kolk, and more especially those of M. Natalis Guillot/ that the branches of the pulmonary artery stop short at a cer- tain distance, one and a half, two, or two and a half lines [3, 4, or 5 millimeters], from tubercles or gray granulations; and the more these adventitious productions increase in size, the further from their perimeter do the divisions of the artery cease to be discoverable. To such a degree is this true, that when tuber- cles are of large size, or have given place to cavities, they may be surrounded by a sort of involucrum, upwards of nine lines [2 centimeters] broad, into which no ramification of the pul- monary artery makes its way. M. N. Guillot^s injections ap- pear to me to render doubt upon this point inadmissible. The injections, dissections, and microscopical examinations of this obsen'^er likewise show that, during a space of time which is always very limited, the sort of involucrum in question ex- hibits no trace of vascularity; at the end of that period a few red streaks with tapering extremities are perceived,—the largest of them measuring as much as half a line [1 millimeter] in dia- meter. These vessels, which are for a certain time perfectly unconnected with the rest of the vascular system, and conse- quently not the seat of apparent circulation, soon enter into com- munication with the bronchial arteries or with those supplying the thoracic parietes. The connexion with these latter vessels is effected by means of the pseudo-membranes, so common on the pleural surfaces,—pseudo-membranes, themselves the seat of de- velopment of vessels, isolated at first, like those of the involucrum surrounding the tubercles, but eventually inosculating with the neighbouring arteries and the vessels of new formation. The seat of these vessels is at first, as has been stated, the interspace between the ultimate ramifications of the pulmonary artery and the periphery of the tubercles; but, in proportion as the latter multiply, enlarge, and soften, the vascular rete spreads in every spot where it has appeared, and ere long an entire lobe, oftentimes a large portion even of the lung, is the seat of this adventitious vascular system, replacing the pulmonary ar-' tery, the existence of which vessel ceases to be a demon- strable fact. Thus is accomplished, to use the expression of M, Guillot, the great transformation of the circulation, one of ' L'Experience. t. i, p. 545.