366 SURGICAL APPLIED ANATOMY. [Chap. xvn. 



the promontory of the sacrum, or be discovered in 

 the iliac fossa or pelvis. The misplaced kidney 

 is often misshaped. The kidney may exhibit a more 

 or less extreme degree of tabulation. The ureter 

 may be double. 



The two kidneys may be fused. " The lowest 

 degree of fusion is seen in the horse-shoe kidney. 

 The two kidneys are united at their inferior portions 

 by a flat, riband-like, or rounded bridge of tissue, 

 which crosses the vertebral column. In the higher 

 degrees the two lateral portions approach one another 

 more and more until they reach the highest degree, 

 in which a single disc- like kidney, lying in the 

 median line, and provided with a double or single 

 calyx, represents complete fusion" (Rokitansky). 

 When the two kidneys are united by a web of 

 connective tissue, the condition is no bar to opera- 

 tion. There may be an entire absence of one 

 kidney. The single kidney may be lateral or median 

 in position. Henry Morris gives the following 

 estimate of the frequency of these abnormal con- 

 ditions. Congenital absence or extreme atrophy of one 

 kidney may be expected in about one in 4,000 cases, 

 the horse-shoe kidney in one in 1,600, and the single 

 fused kidney in one in 8,000 cases. 



Operations on the kidney. (1) Nephrotomy. 

 Incision into the kidney for exploration, or the 

 evacuation of pus. (2) Nephro-lithotomy. Incision 

 into the gland for the removal of a calculus. (3) 

 Nephrectomy. Removal of the entire organ. (4) 

 Nephroraphy. The operation of securing a movable 

 kidney in its normal position. In the first, second, 

 and fourth operations the kidney is reached through 

 the loin by an oblique incision, such as is used in 

 colotomy (page 349), the cut, however, being carried 

 a little farther backwards. In nephrectomy a like 

 incision may be used. The cut is carried backwards 



