Definition:—An accumulation of urine in the pelvis of the kidney from obstruction usually in the ureter, but which may be at the cystic sphincter or in the urethra, causing distention and ultimate suspension of the functional action of the organ.

Etiology:—The conditions named in nephrolithiasis are common causes, but there are many others. These may be disease of the walls of the ureter, flexion or torsion of the ureter, external pressure upon the ureter, with perhaps ultimate adhesion, various uterine conditions, such as misplacements, the development of fibroid tumors, tubercular or malignant growths, and obstruction during confinement. Ulceration and cicatricial formations may also cause it, or it may result from chronic cystitis or other disease of the urethra. There may be a partial obstruction only, or the obstruction may be complete, resulting in the formation of a tumor sufficiently large to fill the abdomen and justify a diagnosis of ascites. The condition may be congenital.

Symptomatology:—When the condition involves both kidneys or is congenital, uremic symptoms quickly appear and death results. There are no regular symptoms that may be named, the diagnosis being often uncertain. There may be but slow increase in the size of the tumor, and if small it may be present a long time before it is discovered. When there is plainly a tumor present, which has at times some fluctuation, with at other times considerable resistance, the presence of this condition may be suspected. There is a sensation of dragging and heaviness in the loins, with a considerable decrease in the urine in those cases where the development is slow, but seldom is there severe pain. Where the obstruction is immediate, as from calculus, or sudden closure of the ureter, the pain will be at first severe and agonizing, as described in nephrolithiasis.

Diagnosis:—In the diagnosis the possible presence of ascites, ovarian cyst, renal cyst, distention of the gall bladder or tumors must be excluded. In acute cases the partial suppression of urine, the extreme pain, which may have disappeared spontaneously, and the rather sudden appearance of the tumor will suggest the cause. Where the occlusion and resulting distention are gradual, the diagnosis is exceedingly difficult and sometimes impossible. When the distention of the abdomen suggests aspiration, the character of the liquid will usually prove its origin. If it is serous in character, hydronephrosis would be excluded; if it has the characteristics of urine, and especially the odor, that fact would be confirmatory. The presence of pus is sometimes confusing in an examination of the aspirated fluid. The condition can readily be distinguished from pyonephrosis by the absence of symptoms of infection.

Prognosis:—In congenital cases the prognosis is invariably fatal. In induced cases the prognosis depends upon the cause.

Treatment:—In the female immediate relief may sometimes be obtained by catheterization of the ureter. This is no longer a difficult procedure, and its results will be twofold; they will evacuate the fluid, and may remove the occluding cause. If stricture is present, it will dilate the stricture and sometimes result in permanent relief. Aspiration is resorted to in extreme cases or in cases where the fluctuation is superficial. Medicinal treatment is of no service except in the relief of pain or in supporting the strength of the patient. Where the condition is recurrent or intermittent, medicinal measures will be available, if specifically administered, in relieving the existing conditions which act as causative factors.

Surgical measures, such as the evacuation of the sac or the removal of the kidney, have not produced results which are encouraging. But where there is no other recourse, extirpation may be resorted to.

The Eclectic Practice of Medicine with especial reference to the Treatment of Disease, 1910, was written by Finley Ellingwood, M.D.