[Ultrasound controlled puncture of renal cysts: biochemical and radiological findings (author's transl)].

Ultrasonographically-guided renal cyst puncture was done in 128 patients on outpatient basis. Cortical renal cysts were seen in both male and female patients in an equal ratio. Mean age was 59.6 years. Complication rate of percutaneous puncture was low. Only twice transient haematuria was observed, needing no treatment. Aspirated fluids were examined cytologically and biochemically. None of the aspirated specimens showed malignant cells. Biochemically lactate dehydrogenase activity and concentrations of total protein, cholesterol, triglycerides, potassium and creatinine were determined. Potassium and creatinine determination were found to be valuable in distinguishing between cystic-like lesions containing secondary urine (like caliceal cysts, hydronephrosis, urinoma) and those containing primary urine (like cortical renal cysts). Thus measurement of potassium and creatinine in aspirated fluids may be helpful in determining the need for open exploratory surgery. In cases where cystic lesions produce urographically visible defects of the pelvic system, a dilatation of this area after evacuation of the cyst can be demonstrated via intravenous urography.