Adequacy and complication rates of percutaneous renal biopsy with 18- vs. 16-gauge needles in native kidneys in Chinese individuals

BACKGROUND: Percutaneous renal biopsy (PRB) is the primary biopsy technique and it was used by 16G needles or 18G needles in China, but there is controversy about the effect and safety of the two different diameters. The study aims to compare the adequacy, complication rate and pathological classification when using 18G vs. 16G needles to perform renal biopsy with ultrasound-guidedance on native kidneys in Chinese individuals. METHODS: We retrospectively analyzed the number of glomeruli, adequate sample rates, complication rates and pathological classification in 270 patients with the use of 18G or 16G needles from January 2011 to May 2017 and verified whether the needle gauge affected the disease diagnosis. RESULTS: A total of 270 kidney biopsies were performed. Among them,72 were performed with 18G needles, and 198 were performed with 16G needles. There was no difference in the number of glomeruli under light microscope using 18G relative to 16G needles (24 ± 11 vs. 25 ± 11, p = 0.265), whereas more glomeruli were found in the 16G group than in the 16G group using immunofluorescence microscopy (3 ± 2 vs. 5 ± 3, p < 0.05). There was no significant difference in the adequate sample rates between the 18G group and the 16G group (90.28% vs. 93.94%, p = 0.298). Minor complications including the incidence of lumbar or abdominal pain (4.17% vs. 7.07%, p = 0.57), gross hematuria (4.17% vs. 3.54%, p = 0.729), and perinephric hematoma without symptoms (4.17% vs. 1.52%, p = 0.195), were not significantly different between the 18G and 16G groups. In the 16G group, 2 cases of serious complications occurred: severe gross hematuria requiring blood transfusion and retroperitoneal hematoma requiring surgery. No serious complications were observed in the 18G group, although there was no significant difference in serious complications rates between the 18G and 16G groups (0% vs. 1.02%, p = 1). CONCLUSION: There was no significant difference in the number of glomeruli, adequate sample rates, or complication rates when using 18G or 16G needles to perform renal biopsy, and the use of an 18G needle with a smaller diameter did not affect the pathological diagnosis or classification of IgA nephropathy and lupus nephritis.