Renal growth and function in patients nephrectomized in childhood.

Eight patients nephrectomized in childhood were studied with regard to growth and function of the remaining kidney. The age of the patients ranged between 8 1/2 and 31 years and the follow-up period was from 1 to 20 years. In most of the patients, repeated renal size determinations were made on postoperative urograms. Normal values for kidney size in childhood are also presented. The structural hypertrophy continued for at least three years after nephrectomy and was most pronounced in patients nephrectomized before three years of age. When more than three years had passed after nephrectomy the remaining kidney was 35-65% larger than normal. Healthy young adults and children with a previous history of urinary tract infection served as controls for function studies. The balance between glomerular and tubular function was well preserved in nephrectomized patients. The renal surface area showed the same relation to GFR and to reabsorption of bicarbonate in nephrectomized patients as in controls. It is therefore concluded that the increase in kidney function following unilateral nephrectomy is, at least in early life, primarily due to structural enlargement.