852 



ARTERIA INNOMINATA. 



of sight, &c. Where the tumor extends to- 

 wards the right side it presses upon the right 

 brachio-cephalic vein, preventing the return of 

 blood from the right arm and side of the head 

 and neck ; if upwards in that direction the 

 carotid and subclavian arteries become im- 

 plicated, and consequent interruption to the 

 circulation ensues; if forwards, the passage 

 of blood is stopped through the left brachio- 

 cephalic vein and the interior thyroid venous 

 plexus; if to the left, it encroaches upon the 

 left carotid artery and trachea, whilst by en- 

 larging backwards it acts immediately upon the 

 trachea and mediately upon the oesophagus. 



Although the above facts are interesting, as 

 serving to elucidate the various phenomena 

 occurring in this malady, I fear that we must 

 not attach too much importance to them as 

 means of diagnosis, inasmuch as many, if not 

 all, of llie above symptoms may result from 

 enlargement of other vessels and other causes, 

 indeed we have only to turn to the admirable 

 work of Mr. Allan Burns on the Surgical Ana- 

 tomy of the Head and Neck, to be at once aware 

 of the probability of deception in this respect. 



Anomalies, There are perhaps few arteries 

 in the body which present so many varieties 

 and anomalies as the innominata, whether stu- 

 died with respect to its extent, course, situ- 

 ation, or the number of branches which it gives 

 oft'. In the lirst place, it is frequently met 

 with extending up into the neck as high as 

 the thyroid cartilage before it divides into its 

 ultimate branches, and sometimes lying in 

 front of the trachea. It is scarcely necessary 

 to remark in how great a degree this anomaly 

 increases the difficulties and dangers attending 

 the operation of tracheotomy. Secondly, the 

 most remarkable variety occurring in the course 

 of this artery is described by M. Velpeau, who, 

 in his Elmens de Medecine Operatoire, men- 

 tions three instances in which it passed to the 

 left side in front of the trachea, and subse- 

 quently wound from before backwards over 

 this organ, returning between the oesophagus 

 and vertebral column, to its usual points of 

 division opposite the right sterno-clavicular 

 articulation. Thirdly, the innominata is also 

 occasionally irregular as to situation. It has 

 been found arising from the centre of the trans- 

 verse portion of the arch of the aorta instead 

 of its commencement, and dividing into right 

 and left carotid arteries, the right subclavian 

 taking its origin from the spot usually occupied 

 by the innominata. Again, instead of being 

 placed on the right it has been met with given 

 off from the left or posterior part of the arch 

 dividing into the right and left carotids and left 

 snbclavian, in other instances into left sub- 

 clavian and left carotid. Cases are also on 

 record in which the innominata was altogether 

 absent, the right carotid and subclavian arte- 

 ries arising directly from the arch of the aorta. 

 Fourthly, it is frequently anomalous in the 

 number of branches it gives off. Occasionally 

 the lelt carotid arises from it in addition to its 

 usual branches, sometimes it divides into the 

 two carotids instead of the subclavian and 

 carotid; and Tiedeimmu mentions an instance 



where it gave off the right internal mam- 

 mary. 



The considerations of the functions, size, and 

 situation of the innominata, as well as its relations 

 not only to the heart and aorta but also to the 

 surrounding parts, at all times rendered the study 

 of this vessel a subject of interest and impor- 

 tance in the eyes of the operative surgeon; but 

 it is comparatively of later years since Mr. 

 Allan Burns tirst directed the attention of the 

 profession to the fact that circulation through 

 this vessel might be suddenly arrested without 

 the functions of the brain, and power of the 

 superior extremity being of necessity de- 

 stroyed, that surgeons have been found bold 

 enough to attempt placing a ligature upon it. 



There are three cases upon record in which a 

 ligature has been placed upon the trunk of the 

 innominata itself. The first operation was per- 

 formed by Professor Mott, of New York, on 

 the llth of May, 1818. The patient died on 

 the 26th day after the operation from repeated 

 hemorrhage resulting from ukeration and yield- 

 ing of the vessel. 



The second was by Professor Graeff on the 

 5th of March, 1829. The patient died on the 

 sixty-seventh day after the operation from re- 

 peated hemorrhage. 



The third was by Mr. Lizars at the Edin- 

 burgh Hoyal Infirmary, on the 31st of May, 

 1837. The patient died on the twenty-first day 

 after the operation, likewise from hemorrhage. 



This artery was likewise tied by Mr. Bland on 

 the 25th March. 1 832. The patient died on the 

 13th of April, three weeks after the operation. 



The following are the steps of the operation. 

 The patient being placed in the horizontal po- 

 sition with the shoulders raised and the head 

 thrown back, make an incision of about two 

 inches upwards along the anterior margin of 

 the sterno-cleido-mastoid muscle of the right 

 side, commencing at the upper edge of the 

 sternum : from the inferior extremity of this 

 carry another of similar extent outwards upon 

 the right clavicle; these should divide the skin 

 and subcutaneous tissue : next dissect this flap 

 from below upwards and reflect it, exposing the 

 platisma muscle ; cut through this muscle and 

 the superficial fascia beneath it, and then care- 

 fully detach the sternal insertion of the sterno- 

 mastoid musc'e and anterior layer of deep 

 fascia, and should there not be sufficient space 

 a portion of the clavicular fibres of the muscle. 

 Having proceeded thus far, cut through the 

 second layer of deep fascia, avoiding the vein 

 already described as crossing this spare, and 

 subsequently divide the sterno-hyoid and thy- 

 roid muscles upon a director; this will expose 

 the third layer of deep fascia covering the 

 vessel; a portion of this should be- pinched up 

 by forceps and an opening veiy cautiously 

 made in it, after which, with the handle of a 

 scalpel, clear the artery of its surrounding cel- 

 lular tissue, draw the thyroid veins to the left 

 side, the right pneumo-gastric nerve and in- 

 ternal jugular vein to the right, and pressing 

 the left brachio-cephalic vein downwards, carry 

 the ligature obliquely upwards and inwards, 

 or from the right to the left side, keeping it 



