494 



CAROTID ARTERY. 



2. With the knowledge of this freedom of 

 communication between the carotids, no sur- 

 geon will look for uniform success after the 

 application of a ligature, in cases of wounds 

 of either carotid or of one of its branches, 

 if the ligature be applied only below the situ- 

 ation of the wound. Nevertheless, experience 

 tells us, that such a plan of treatment has been 

 successful in several instances ; and it is wor- 

 thy of notice that in almost all the successful 

 cases the primitive carotid was tied very shortly 

 after the infliction of the wound, at a time 

 when the collateral branches could not have 

 become sufficiently enlarged to admit of the 

 full circulation in them ; while, on the other 

 hand, in two unsuccessful cases, the primitive 

 carotid was not tied for some days after the 

 receipt of the wound, and secondary hemor- 

 rhage ensued in each case. 



3. The free anastomosis of the two internal 

 carotids with each other and with the sub- 

 clavians through the vertebrals within the cra- 

 nium, sufficiently evinces that the circulation 

 of the brain after the obliteration of either 

 carotid, by ligature or otherwise, may be easily 

 maintained ; and experience fully confirms this 

 inference from anatomy. That a disturbance 

 of the cerebral circulation does occur occa- 

 sionally after the operation of tying the carotid 

 is fully proved ; but it would appear that it is 

 an occurrence much more rare than might, 

 a priori, be expected. Of seventy cases, col- 

 lected by Berard,* in which this operation was 

 performed, symptoms arising from cerebral 

 affection appeared only in a very few, and in 

 two only of these instances the patients died 

 from the effect produced upon the cerebral cir- 

 culation. One of these cases occurred in the 

 practice of Mr. Aston Key ; the patient fell 

 into a deep sleep after a severe fit of coughing, 

 and died shortly afterwards without awaking. 

 On examination it was found that the carotid 

 of the opposite side was obliterated by a co- 

 agulum nearly as low as its origin from the 

 aorta, so that the cerebral circulation could 

 only have been maintained by the two vertebral 

 arteries, which in this case were smaller than 

 usual. In the second case, which was ope- 

 rated on by Langenbeck,f immediately after 

 the application of the ligature the patient be- 

 came motionless, with closed eyes, without 

 speaking, except when addressed several times 

 in succession; he sank gradually, and died in 

 thirty-four hours after the operation .J 



In three of the cases collected by Berard, 

 some disturbance or indistinctness of vision, 

 on the same side as that on which the artery 

 was tied, followed the operation; in one of 

 these the impairment of sight was accompanied 

 by syncope, and a sensation of cold affecting 



* Diet, de Medecine, art. Carottde. 



f Arch. Gen. de Med. t. xix. p. 118. 



t Dr. Mussey, of New Hampshire, in America, 

 has recorded a case in which he tied both primitive 

 carotids within twelve days of each other, and 

 without any untoward result. The reader will find 

 the case quoted at length in Mr. Guthrie's valuable 

 work on the Diseases and Injuries of Arteries, 

 p. 350. 



the whole of that side of the face ; in a second, 

 related by Mr. Mayo, the impaired vision was 

 only on the right side, the carotid of which 

 side had been tied, and the sense was perfectly 

 restored in a few hours. In the third case one 

 eye was completely deprived of sight, and the 

 sense of hearing greatly weakened in the ear 

 of the same side. Berard remarks that the loss 

 or impairment of vision on one side is un- 

 favourable to the opinion that such an occur- 

 rence is to be attributed to disturbed cerebral 

 circulation ; it is sufficiently accounted for by 

 the fact that there is a considerable diminution 

 in the quantity of blood sent to the eye ; for 

 that organ is supplied by a direct branch of the 

 internal carotid, viz. the ophthalmic, which 

 anastomoses at its termination with several of 

 the terminal branches of the arteries of the 

 face ; and it is not improbable that in the cases 

 above referred to, the branches which form this 

 anastomosis, as well as those forming the circle 

 of Willis at the base of the brain, were much 

 smaller than usual. 



In other cases hetniplegia, more or less ge- 

 neral and perfect, followed the operations after 

 a longer or shorter period. In a case related 

 by Magendie, that of a young girl, in whom 

 the left carotid was tied, there appeared on the 

 sixth day paralysis of the right arm, of the 

 pharynx and larynx, and numbness of the right 

 lower extremity. The paralysis gradually di- 

 minished, but the intellect was so far impaired 

 that the patient lost the power of reading.* 

 In Sir A. Cooper's first case, the right arm and 

 leg were deprived of sensation and in part of 

 motion on the seventh day after the operation ; 

 and a man, in whom Mr. Vincent tied the right 

 carotid for aneurism, was attacked with com- 

 plete hemiplegia of the left side in half an hour 

 after the operation, and continued in that state 

 till his death on the seventh day. It is re- 

 markable that, in all these cases, the paralysis 

 was situated on the side opposite to that on 

 which the artery was tied ; a fact which alone 

 would indicate that the cause of the paralysis 

 was seated in the brain. 



Aneurisms do not occur so frequently in the 

 carotid arteries as in the aorta or in the large 

 arteries of the extremities. They are most 

 frequently found situated at the bifurcation of 

 the common carotid, where also calcareous 

 and atheromatous deposits are very often met 

 with. In the lower part of the common ca- 

 rotid an aneurism is, of course, a more for- 

 midable disease than if it were situated high 

 up, in consequence of the impossibility of 

 applying a ligature between the artery and the 

 heart. Sometimes an aneurism of the aorta 

 projects upwards into the neck, compressing 

 and obliterating the carotid, and simulating all 

 the characters of aneurism of its lower portion. 

 I am not aware that there is on record any 

 instance of aneurism of the internal carotid 

 artery in its cervical portion, although our mu- 

 seums are not without specimens of aneurismal 

 dilatations of it after it has entered the cranium, 

 and as it lies by the side of the sella Turcica. 



* Journal de Physiol. April, 1827. 



