Comparison of outcomes of an 18-gauge vs 16-gauge ultrasound-guided percutaneous renal biopsy: a systematic review and meta-analysis

Background: The needle size used in ultrasound-guided percutaneous renal biopsy significantly influences the efficacy and safety of the procedure. The aim of this study is to perform a comparative analysis of 16-gauge and 18-gauge needles for ultrasound-guided percutaneous renal biopsy. Methods: This systematic review and meta-analysis included randomized controlled trials and observational studies that compared the outcomes of using 18-gauge and 16-gauge needles for ultrasound-guided percutaneous renal biopsy. The efficacy parameters included a mean number of glomeruli obtained and the number of passes, while the safety parameters focused on the rate of complications. We searched multiple databases, assessed the risk of bias, and conducted statistical analyses using appropriate models. Results: Fifteen studies were included. Compared to the 18-gauge needle, the use of 16-gauge needle for the biopsy was associated with the significantly higher mean number of glomeruli obtained (pooled SMD 0.61, 95%CI: 0.32 to 0.89; p < 0.001) and fewer required passes (pooled SMD −0.57, 95%CI: −0.97 to −0.18; p = 0.004). No significant difference was observed in the individual safety parameters, including pain, hematuria, need for blood transfusion, major, and minor complications. However, the use of 16-gauge needle was associated with higher odds of total complications (pooled OR 1.57, 95%CI: 1.16 to 2.13; p = 0.004). Conclusion: While the 16-gauge needle for ultrasound-guided percutaneous renal biopsy offers improved efficacy in terms of a higher mean number of glomeruli and fewer required passes, it is associated with higher total complications. A judicious needle size selection that would consider patient-specific factors and risk-benefit ratio, is crucial for optimizing patient outcomes.