1394 



VEIN. 



cause. In the latter case the inflammation of 

 the vein is excited by contact of a coagu- 

 lum of vitiated blood with the lining of the 

 vessel. But the veins may, as well as other 

 tissues and organs, be the seat of spontaneous 

 inflammation. This is frequent in some forms 

 of varix ; especially in haemorrhoids, and usu- 

 ally, though not always, leads to the coagu- 

 lation of the contained blood. 1 have seen 

 acute inflammation of a varicose saphena 

 causing much interstitial plastic deposit, in 

 which no coagulum formed in the interior of 

 the vessel, whose canal was quite pervious. 



Suppiirative Phlebitis. When phlebitis leads 

 to suppuration, it is generally, I believe always, 

 accompanied by plastic effusion also. 



The question of pus formation within veins 

 is one of great importance and interest, and 

 difficult of solution. In a great proportion 

 of examples, purulent phlebitis is originally 

 lighted up by the mechanical introduction 

 of pus into the veins. In some few cases the 

 pus would seem to originate within the vein, 

 either from an ulceration of the inner surface, 

 or perhaps it is secreted free on the unbroken 

 lining membrane. One very remarkable point 

 is the enormous multiplication of the pus 

 within the vein. No absorption, or me- 

 chanical introduction, can at all explain the 

 immense increase ; and it is obvious that there 

 exists within the vessel some source of this 

 pus generation. It was imagined by Gendrin 

 and Donne that the blood itself was the source 

 of the pus, and that it was developed by the 

 metamorphosis of blood globules into pus 

 cells ; and they imagined that the change of 

 form to a sphere, which the blood discs un- 

 dergo, when submitted to the action of certain 

 fluids, was an indication of the change. This 

 doctrine has, however, been long since ex- 

 ploded. 



A more reasonable explanation, and one 

 founded upon analogy, is that, the pus is se- 

 creted by the inner surface of the vein, by a 

 metamorphosis of epithelium. Vogel has long 

 since demonstrated, on the mucous mem- 

 branes, that pus is producible by a change of 

 epithelial cells, and this suggests an explana- 

 tion, why, in an unbroken vessel, pus may 

 be produced in great abundance. Wherever 

 epithelium exists, it appears that pus cells may 

 be generated without lesion of surface; espe- 

 cially where the action is started by contact of 

 pus from some other source. This certainly 

 happens in serous cavities, pleura, pericar- 

 dium, &c.; and we may, from analogy, judge 

 that the same occurs in veins. This doctrine 

 is entertained by the high authority of Hasse : 

 he. observes, "In accordance with these 

 views, the puriform masses, generated within 

 the veins, would be developed as follows : 

 First of all the cells of epithelium-lining dis- 

 covered by Henle, separate from the internal 

 membrane' of the vein, so as to give the inner 

 surface of the vessel the dull appearance al- 

 ready described, and to render it more sus- 

 ceptible of a morbid tinge from imbibition. The 

 next change affects the passing blood cor- 

 puscles, which assume a spheroid or else a 



gibbous appearance, advance with a slow re- 

 volving movement, or cling to one another, 

 parting with their serum and with their pig- 

 ment. The internal membrane of the vessel 

 generates new imperfect epithelium cells, 

 which mingle with the altered blood, and 

 finally actual pus-globules, which, when con- 

 gregated in sufficient number, completely ar- 

 rest the current of the blood, and affect the 

 blood-corpuscles in the manner already pointed 

 out. The simultaneous effusion of both fibrin 

 and albumen now serves to complete the 

 formation of a plug, which differs in external 

 characters according to its more or less rapid 

 development, and to the varying proportions of 

 its constituent parts. The plug, thus originat- 

 ing, afterwards undergoes further changes."* 

 The actual changes that occur, and are ob- 

 vious to the naked eye, affect the plastic plug, 

 the fluid contents, and the parietes of the vein. 

 In suppurative as well as adhesive phlebitis, 

 plugs of lymph and coagula are formed, and 

 are partly the result of inflammatory action, 

 and partly they are the direct result of the 

 contact of fluid pus with the blood. f 



The plugs that form in suppuracive phle- 

 bitis are softer, more numerous, and vary in 

 form. They soon become broken down, and 

 exhibit disintegrated fibrin mixed with ge- 

 nuine pus. The coagula become softened, 

 first in the centre ; they loose their laminated 

 structure, and ultimately break up. These 

 coagula, in phlebitis the result of infected 

 blood, must not be considered as any indica- 

 tion of the locality in which the disease has 

 originated. In such cases the whole circu- 

 lating mass is infected : little portions of coagu- 

 lating fibrin, entangling pus-cells, are con- 

 tinually passing through the vessels, and here 

 and there attaching themselves to the lining 

 of the vessel, light up circumscribed regions 

 of inflammation. This coagulation is a re- 

 medial effort : by its means the materies morbi 

 is shut up and circumscribed by a harmless 

 coagulum : circulation in the affected vessel is 

 suspended and the poison cannot again mix 

 with the blood. Perhaps these coagula some- 

 times become absorbed, or organised and ob- 

 literate the vessel ; at other times they sup- 

 purate, and the walls of the vessel become 

 implicated and ultimately give way. " The 

 formation of matter being brought about with- 

 in the inflamed vein, its membranes have like- 

 wise to undergo a further change. Their 

 colour now inclines to a greyish white; they 

 become softened and thickened, are no longer 

 to be distinguished from one another, and 

 form, in conjunction with the surrounding tex- 

 tures, a nearly uniform membranous layer of 



* Hasse's Pathological Anatomy, p. 16. 



f The influeiiee of pus in causing coagulation of 

 the blood may be seeu in the following experiment : 

 "An abscess was opened in the groin, and a 

 quantity of pus received into a gallipot ; some blood 

 from the divided vessels was also received into the 

 same vessel ; they were then stirred together, and 

 in two minutes the mass coagulated. Some blood 

 taken from the same patient in the same manner, 

 but not mixed with pus, coagulated in eleven and a 

 half minutes.'" Lee on J'hleLitis, &c. p. 27. 



