ARTERY, PATHOLOGICAL CONDITIONS OF. 



229 



rhage than the small one. The next step is 

 the entanglement of blood in the cellular coat 

 of the vessel and its consequent coagulation 

 when it comes to press in the most advantageous 

 direction on its open mouth, and the haemor- 

 rhage is stopped. 



Thus the immediate agent of nature, in the 

 suppression of haemorrhage, is pressure effected 

 by the clot of blood, whilst the vessel is placed 

 by its own properties in the condition most fa- 

 vorable to the operation ; and it is curious to ob- 

 serve how universally the principle has been 

 acted on, though probably first suggested by 

 accident er empiricism. The burning iron of 

 the older surgeons produced the pressure of an 

 eschar; agaric and sponge entangled the blood 

 and retained a coagulum on the spot ; even the 

 more modern invention of the ligature is in the 

 first instance only pressure, but with the mani- 

 fest advantages of being applied directly and 

 immediately, of being firm and not likely to slip, 

 and independent of rest, position, and bandage, 

 which are indispensable when other modes of 

 compression are had recourse to. 



But the permanent suppression of arterial 

 haemorrhage can only be effected by the actual 

 obliteration of the vessel at the spot where it 

 had been opened or divided, a process that is 

 the result of inflammation of the lining mem- 

 brane, and of the coagulating lymph thereby 

 poured out, or of the artery ceasing to transmit 

 blood through it, and thus becoming as it were 

 useless in the economy. Both these influences 

 are exemplified in the permanent cure of a 

 wounded artery, for in an incredibly short space 

 of time after the external coagulum has been 

 formed, lymph is effused from the wound in 

 the vessel : and internally, between this lymph 

 and the nearest collateral branch, another coa- 

 gulum of blood is formed, to which a consi- 

 derable degree of importance has been attached, 

 though probably without sufficient reason. It 

 cannot be very instrumental in controlling hae- 

 morrhage, because it does not occupy the entire 

 capacity of the artery : its shape is conical, the 

 base lying on the lymph poured out from the 

 wound, from which it gradually tapers to the 

 next branch, and it seems to be formed of a small 

 quantity of the blood, which, being pushed into 

 that branch, remains there, is placed out of the 

 current of the circulation, and must coagulate. 

 The transmission of blood to the limb below 

 is now to be effected through the medium of the 

 anastomosing vessels, which for this purpose 

 become proportionally enlarged. This quality 

 possessed by arteries of increasing their own 

 diameters, or in other words of accommodating 

 themselves to their contents, is curious and 

 interesting, and although not admitting of ex- 

 planation, cannot for a moment be doubted. 

 No fact has been more satisfactorily proved by 

 dissection, and like the contractility of the artery 

 already noticed, the effects of this power exhibit 

 themselves gradually and slowly. The circu- 

 lation of the limb seems scarcely to be inter- 

 rupted, for in a few minutes the arteries below 

 appear, as has been observed by Dupuytren, 

 like soft cords under the finger, evidently filled 

 with blood, but totally devoid of pulsation. It 



is a long time before this latter proof of a re- 

 stored activity in the circulation comes to be 

 perceptible, and perhaps is never again equal 

 to what it had been before the occurrence of 

 the accident. The external wound, of course, 

 heals like any other of a similar nature, and it 

 is rare that the limb experiences any incon- 

 venience subsequently. The internal coagulum 

 is soon absorbed, and in process of time the 

 vessel, from the point of division to the next 

 branch above and below, degenerates into an 

 impervious ligamentous cord. 



Such is the progress of events when the 

 efforts of Nature are sufficient to arrest the 

 bleeding; but after all it is a fortunate case 

 that ends thus, and experience teaches that 

 there is little wisdom in leaving a moderately 

 sized artery to her resources alone. What more 

 frequently happens is this : the artery retracts 

 and contracts it is true, and a coagulum forms, 

 which, as the patient becomes faint or weak, is 

 allowed to become consolidated, and for that 

 time is sufficient to save him. But he recovers, 

 or perhaps he uses some stimulus or some ex- 

 citement, and the renewed circulation gradually 

 loosens the clot, and a fresh gush of blood takes 

 place. This recurs frequently, and an hremor- 

 rhagic disposition is formed ; the patient be- 

 comes pale and exsanguineous, anxious, and in 

 continual agitation, and without the interven- 

 tion of art has but a slender chance of sur- 

 viving. In these cases, art adopts the principle 

 of the natural cure, only regulating its force, 

 and ensuring its continued operation for the 

 requisite period. The first object to be at- 

 tained is the application of a sufficient degree 

 of pressure to control the bleeding : the second 

 to maintain that pressure for a length of time 

 to ensure the obliteration of the vessel. This 

 is not the place to discuss the various methods 

 that have been adopted for the accomplishment 

 of these ends ; suffice it that the superiority of 

 the ligature has been so far proved by expe- 

 rience, that few surgeons of the present day 

 would feel satisfied in entrusting a large or im- 

 portant vessel to a less powerful or enduring 

 compression. But the ligature is in itself not 

 unfrequently a cause of great and frightful mis- 

 chief, and, therefore, it will be necessary to 

 examine into all the circumstances connected 

 with this part of the subject. 



In practice, a ligature is applied around an 

 artery under two different circumstances ; one, 

 in the case of the wounded and bleeding artery, 

 it is placed on the open orifice of the vessel ; 

 the other, in the treatment of aneurism, the 

 artery is taken up and tied at a part where it 

 is supposed to be sound and uninjured. When, 

 in either of these cases, an artery is tied, the 

 first effect is obviously to bring its opposite 

 sides into apposition, and to arrest the flow of 

 blood through it. At the same time that the 

 internal and fibrous coats being shorter and less 

 tough yield under its pressure and are divided 

 completely, leaving the cellular coat entire, 

 still sustaining the ligature in its place. The 

 consequences of this division of the internal 

 coats are very similar to those already explained 

 as following the complete section of the artery ; 



