532 



DISEASES OF THE KIDNEYS. 



Causation Anything which obstructs the discharge of urine through 

 the ureters may cause hydro-nephrosis. Thus, vesical tumours pressing 

 on the orifices of the ureters, calculi which have become fixed in them, 

 torsion or "kinking" of the ureters, may bring about hydro-nephrosis. 

 The urine secreted by the kidney being unable to escaj)e, accumulates 

 in the pelvis of the kidney, in the ureter, and uriniferous tubules, 

 producing dull colic, which escapes observation, or the exact cause of 

 which is not discovered, because the second kidney vicariously acts for 

 the one affected, and urination continues regularly. Secretion continu- 

 ing in spite of the ob- 

 struction, that portion of 

 the ureter above the ob- 

 structed point, together 

 with the pelvis and 

 the uriniferous tubules, 

 gradually becomes di- 

 lated, until the whole 

 mass of the kidney is 

 hypertrophied. 



The ureter some- 

 times becomes enlarged 

 to the size of a man's 

 arm, the kidney double, 

 treble, or quadruple its 

 normal side : the inter- 

 lobular divisions are 

 lost, and each circum- 

 scribed lobule soon 

 forms a cystic cavity 

 varying in size. The 

 pressure due to the accumulated urine causes the renal tissue, first the 

 medullary substance and afterwards the peripheral zone, to undergo 

 atro])hj. 



The kidney is represented by a vast cystic cavity, and the lobules 

 by culs-de-sac ; the cortical layer may become atrophied to such a 

 degree as to form merely a fibrous sheath, the primary constituent 

 elements of which are difficult to discover. From 20 to 40 pints of 

 liquid may sometimes be found in the cystic kidney. 



Diagnosis. The condition is rarely diagnosed, because, as one of the 



kidneys continues to act, no acute disturbance follows. Only in cases 



where the cystic kidney projects into the flank are suspicions aroused. 



Examination per rectum will then permit of the diagnosis being made. 



Prognosis. Hydro-nephrosis being, as a rule, unilateral, the 



Fig. 228. — Hydro-nephrosis of the kidney. 



