Occlusion of Aorta by Living Tissue. 113 



removed and only a film of thyroid transplanted with one para- 

 thyroid gland, this film hypertrophies enormously and on micro- 

 scopical examination displays the typical picture of hyperplasia. 

 In one instance the graft was examined 15 months after operation. 1 

 It would be interesting to determine the amount of deficiency 

 which it is necessary to create for the successful transplantation 

 of the thyroid gland ; also whether hyperplasia necessarily ensues 

 when the transplant lives. In other words will a thyroid graft 

 always fail to take unless the deficiency created is so great that 

 hyperplasia must develop? 



Should it become a definitely established fact that hyperplasia 

 may be produced by infection, not only are a number of things 

 explained which otherwise seemed inexplicable, but new lines of 

 investigation suggested. 



75 (77i) 



Partial occlusion of the thoracic and abdominal aortas by bands 

 of fresh aorta and of fascia lata 



By W. S. Halsted, M.D. 



Ligation of the human abdominal aorta has been made 19 or 

 20 times and always with fatal result. 



Dubois, Assalini, Bujalsky, Pirigoff, Cooper, Keen and perhaps 

 others attempted to occlude the abdominal aorta gradually by 

 means of cleverly devised instruments which, carrying snares of 

 silk, metal or catgut might be tightened or loosened at will. 

 The instruments traversed the abdominal wall and hence infection 

 was a complication common to all of the methods and defeated 

 the plans of the operators. 



In 1904 assisted by Dr. W. F. M. Sowers, I began a series of 

 experiments on dogs in the hope of finding a safe method of oc- 

 cluding the aorta and curing aortic aneurysm. Bands of silver 

 and aluminum curled about the aorta by an instrument con- 

 structed for this purpose were rolled tighter by the fingers until 

 the desired degree of occlusion of this vessel was obtained. The 

 abdominal wounds were closed with the expectation that they 

 would have to be reopened one or more times for the purpose of 



1 Journal of Experimental Medicine, 1912, Vol. XV, Plate 30, Fig. 2. 



