What size needle should be used in kidney biopsies?
There remains controversy regarding the ideal needle size to use in kidney biopsies.
Most operators prefer the use of automated needles; however, there is no difference in the complication rates between an automatic needle and a manual needle of the same size.
Several studies have shown no difference in the number of glomeruli obtained between automated needles of 14 gauge compared to 16 gauge. However, a recent meta-analysis found the rate of blood transfusion was significantly greater in patients biopsied using a 14-gauge needle as compared to a 16-gauge needle.
There are also less asymptomatic perinephric hematomas demonstrated by routine screening ultrasound at 1 hour post-percutaneous kidney biopsy using 16-gauge needles compared to 14-gauge needles, suggesting a lower complication rate.
In a prospective study undertaken in Norway, which included 9288 biopsies, there was a higher rate of complications with the use of 18-gauge needles as compared to 14-gauge or 16-gauge needles.
Furthermore, the median number of glomeruli was significantly higher in both the 14-gauge and the 16-gauge needles compared to the 18-gauge needles.
Based on these data, we recommend the use of the 16-gauge automated needle with real-time ultrasound sound guidance as our standard approach.
