1396 



VEIN. 



wound. If the wound be linear, and made 

 in the axis of the vessel or somewhat ob- 

 liquely, and there be not much bleeding, its 

 lips will come together, adhere, and rapidly 

 form a linear cicatrix. If, however, it be 

 transverse, or if much bleeding occur from 

 it, a coagtilum will form in and over the 

 aperture. " An oval naked coagulum forms 

 the plug of the orifice, and a flattened co- 

 vered clot, which is an extravasation into 

 the cellular sheath, extends to some distance 

 around it."* In twenty-four hours the lips 

 of the wound are found separated, the edges 

 are everted and adhere to the clot. At the 

 expiration of three days the internal margin 

 of the wound is elevated and rounded, and a 

 thin, narrow, membranous expansion, parti- 

 ally extending over the inner surface of the 

 clot, is seen to be continuous with the everted 

 edge of the internal tunic. The clot is more 

 compact and lamellated. At the fifth clay the 

 membranous appearance extends over the 

 whole inner surface of the clot. Subsequently 

 the clot becomes more and more absorbed, 

 and the new membrane, extending from the 

 lips of the wound, becomes more organ- 

 ised. Vasa vasorum can be seen on it by 

 means of a lens from the twelfth to the six- 

 teenth day. " On the twentieth day it is only 

 possible to distinguish the recent from former 

 wounds, by the tenuity, smoothness, and 

 transparency of the new membrane compared 

 witli the old, which is dense, tough, and 

 wrinkled." These dates, &c. refer to the 

 wounds made in ordinary bleeding operations j 

 in larger wounds the process is proportion- 

 ately longer. The wound is ever after indi- 

 cated by the peculiar thin, transparent, exten- 

 sile membrane with which it was repaired. 

 If a vein, having one of these cicatrices in it, 

 be injected with water, the new membrane 

 bulges out, on account of its elasticity, into 

 a pouch or bag.f Mr. Travers is quite con- 

 vinced that this new membrane is continuous 

 with the internal membrane of the vein. 



Effects of Ligatures on Veins. The effects 

 of ligatures on veins are different from those - 

 on arteries. The coats of the vein are, by the 

 ligature, thrown into longitudinal folds, which 

 are indicated when the vessel is slit up, and its 

 interior examined. The effect on the ele- 

 mentary coats of the veins is different from 

 that produced by ligature on the arteries : 

 instead of the deep cut through the inner 

 and middle coat, which occurs in the latter, 

 there is but a slight indentation, correspond- 

 ing to the ligature on the vein. This is 

 produced by the lesion of the thin internal 

 tunic, and that alone. As regards the rest 

 of the thickness of the vein's walls, it ap- 

 pears that the outer or cellular tunic is di- 

 vided, leaving the middle condensed portion 

 of the venous wall uninjured. Upon a close 

 examination, however, it is found that one 

 element namely, the yellow elastic tissue 

 is divided throughout the entire thick- 



* Travers, loc. cit. p. 246. 



f See the beautiful plates accompanying Mr. Tra- 



Vtfvs's essays before referred to. 



ness of the outer and middle coats, leaving 

 the continuity of tube to be maintained by 

 the white fibrous element, which does not 

 suffer division ; and therefore that part of the 

 wall where the white fibrous element is most 

 condensed and abundant is that where least 

 impression is made by the ligature. A thin, 

 tightly tied, string produces the deepest im- 

 pression. 



Accordingto Mr Travers, when a ligature lias 

 been applied for a period of from twenty-four 

 hours to five days, it has produced the follow- 

 ing changes : " The vein above and below 

 is thrown into longitudinal folds on either side 

 of the ligature. The portion next the heart is 

 perfectly empty and collapsed ; that next the 

 extremity is filled to distens'on by a long, and, 

 generally, firm, coagulum of blood, which is a 

 mould of the vessel, and bears the impression 

 of its semilunar valves. The coagulum ex- 

 tends for several inches ; it is not always com- 

 pact and lamtllated, and adhering to the in- 

 ternal tunic, being sometimes less consistent 

 and broken ; but it always fills the calibre of 

 the vein. There is no blush upon the in- 

 ternal tunic, much less any sign of adhesive 

 inflammation, or thickening of the proper coats 

 of the vein, or agglutination of its contiguous 

 folds ; these folds being effaced on the re- 

 moval of the ligature ; but the cellular sheath 

 is thickened by a deposit of lymph in the vi- 

 cinity of the ligature." * If two ligatures be 

 applied, and the vessel divided between them, 

 the ends retract about an inch. At the se- 

 venth day the interstitial deposit of Ijmph 

 among the areolar tissue around the vein is 

 very dense, and forms a hard fibrinous mass, 

 through which the ligature runs in a sort of 

 canal. According to Mr. Travers, ulceration 

 commences on the ninth day, and lasts from 

 fifteen to twenty-five days. " The ulcerated 

 ends of the vein formed a crescentic sweep, and 

 were separated to the extent of an inch, and 

 fastened by adhesion to the cellular sheath, 

 which was much extended and thickened by 

 a subjacent deposition of lymph, so as to 

 form a smooth solid bed between the divided 

 ends of the vein. The internal membrane of 

 the superior portion of the vein had a thin 

 ragged edge, where it had been severed by 

 ulceration. The lower edge was smooth and 

 blended in with the bed of the wound. The 

 extremities had undergone no contraction but 

 that produced by the adhesion of the severed 

 extremity to the sheath. The portion of the 

 vein next the heart was empty. The upper f 

 was filled by a dark lamellated coagnlum of 

 blood, adhering very strictly to the internal 

 tunic, which was discoloured by it. On care- 

 fully separating the outer lamella? which 

 coated the interior of the vein, I could not 

 discover any thickening of the proper coats of 

 the vein, nor any appearance of inflammatory 

 action within its canal, nor was any such ap- 

 pearance indicated in the lower portion of 

 the vein.J 



* Travers, loc. cit. p. 252. 



f The jugular vein is referred to. 



J Travers, loc. cit. p. 253. 



