Small kidney and hypertension: selection of patients for surgery.

We studied 37 patients with various degrees of hypertension and a small unilateral kidney. Renal vein renin studies were shown to be positive on 19 occasions and negative on 18. Of those positive, 10 had severe and 1 moderate hypertension. Surgery cured 63.3%. In 27% blood pressure improved and 1 patient failed to respond. Eight patients had mild hypertension with a positive renal vein renin ratio (RVRR), but on observation their home blood pressures were normal without medication and they were not considered for surgery. Eighteen patients with mild hypertension and negative RVRR were also not operated. We believe that RVRR is important for a surgical decision, but only in severe and moderate hypertensives. In mild hypertension, measurement of blood pressure at home is normal on most occasions. These are hyperreactive patients and should not have surgery, regardless of the results of their RVRRs.