276 CLINICAL APPLIED ANATOMY. 



usually found near its bifurcation. Pressure symptoms will be 

 in evidence, such as dyspnoea, dysphagia, alteration in voice, 

 and cough, owing to the sac pressing upon the trachea, oesophagus 

 and larynx. Interference with the proper circulation of blood 

 through the brain on the affected side will cause giddiness and 

 some tendency to syncope. Embolism of one or other of the 

 cerebral vessels not infrequently occurs, and hemiplegia may 

 result. 



A subclavian aneurysm is most usually met with in the third 

 part of the vessel, and more frequently on the right than on the 

 left side. The tumour develops above the clavicle external to 

 the sterno-mastoid, forming one of the swellings met with in the 

 lower part of the posterior triangle of the neck. In connection 

 with its diagnosis it is well to remember the possible occurrence 

 of a cervical rib, which may raise the artery in such a way as 

 to give a very close resemblance to an aneurysmal sac. The 

 most marked evidences of pressure are found in the oedema of 

 the upper limb, from interference with the return of blood 

 through the subclavian vein, which lies anterior to the artery ; 

 and in the radiating pain over the area of distribution of the 

 cords of the brachial plexus, which lie posterior and external to 

 the sac. 



The axillary artery may be the site of an aneurysm, which is 

 most usually of traumatic origin. It frequently assumes large 

 proportions, on account of the looseness of the surrounding 

 tissues, which give the vessel but little support. Again, pressure 

 upon the accompanying vein leads to considerable oedema of the 

 limb on the distal side, and likewise pressure upon the surround- 

 ing nerves occasions pain, or marked interference with their 

 function. 



An aneurysm upon the brachial artery is usually seen at the 

 bend of the elbow, and is dependent as a rule upon traumatism. 

 Not infrequently it is of the nature of an arterio-venous aneurysm, 

 the outcome of a wound of the median basilic vein and of the 

 brachial artery, over which it lies. 



An aneurysm of the abdominal aorta does not as a rule give 



