Percutaneous nephrostomy performed on kidneys with a thin renal cortex: a retrospective study of daily urine output in 46 nephrostomy procedures.

PURPOSE: This study investigated whether a thin renal cortex or any morphological kidney measurements can be predictors of post percutaneous nephrostomy (PCN) renal function, thereby lessening the need for the procedure.
MATERIALS AND METHODS: All patients underwent unilateral PCN that were performed under sonographic and fluoroscopic guidance. Kidney morphological measurements were subsequently taken to measure residual renal function; a thin renal cortex was defined from a computed tomography (CT) showing a cortical thickness <10 mm. Urine output was recorded daily, with patients divided into anuric and nonanuric groups.
RESULTS: Morphological measurements of residual renal function, such as renal length (p=0.004), renal width (p=0.004), renal thickness (p=0.008), and renal size (p=0.004) were significantly higher in nonanuric than anuric patients. Urine output increased by 85.47 ml/day for every millimetre increase in renal width (p=0.026) and 65.31 ml/day for every millimetre increase in renal thickness (p=0.024). Simple linear regression analyses showed that cancer patients had a significantly lower urine output (358.73 ml/day; p=0.046) than those without cancer.
CONCLUSIONS: This study showed that urine output and other clinical data can provide an index to evaluate residual renal function before deciding to perform PCN procedures.