HYDRONEPHROSIS.
This term refers to a more or less permanent distention of the kidney cavity by retention of urine, due to partial or intermittent obstruction to its escape. An intermittent form is common, which, however, at almost any time may lead to some degree of enlargement, while when the obstruction is permanent the resulting tumor becomes practically a thin-walled cyst, which may contain an enormous amount of fluid, more or less altered urine, which will contain, in addition to the ordinary urinary elements, cholesterin crystals and other adventitious products. Hydronephrosis, then, may be congenital or acquired in origin, intermittent or permanent in character, and unilateral or bilateral in location. Among the acquired causes are strictures of any portion of the urinary tract below, either in the ureter, the prostate, or the urethra; tumors of any kind making pressure; movable kidney which permits of kinking; tuberculous diseases which lead to chemosis of the mucosa and consequent obstruction; renal calculi which plug the ureter; foreign bodies, blood clot, and the like ([Figs. 640] and [641]).
Fig. 640
Hydronephrosis from obliteration of ureter by tuberculous disease. (Tuffier.)
Fig. 641
Hydronephrosis in first stage of development. (Rayer.)
Fig. 642
