BACKGROUND: Needle guides have recently come into use for ultrasound-guided percutaneous renal biopsies; however, it is not yet clear if the use of needle guides leads to decreased post-biopsy complication rates and improved tissue yields. Thus, we conducted a retrospective single center study comparing biopsy yield, adequacy, and rates of complications before and after utilization of a needle guide device. METHODS: A retrospective analysis was performed on all native kidney biopsies performed before and after June 2015 corresponding to the start of needle guide use. All biopsies in the latter period of the study were performed by a single operator. We compared clinical characteristics, indications, type of investigation, tissue yield, adequacy of procedure, and rates of major and minor complications. RESULTS: A total of 343 biopsies were analyzed, 140 in the pre-needle guide use period (Period I) and 203 in the needle guide use period (Period II). Biopsy yields were similar, irrespective of the use of needle guides. Tissue adequacy was better in Period II (93.7% vs. 84%, P < 0.001, with respect to pathologist-reported inconclusive biopsies. There were no differences in terms of major complications (1.7%) for the two periods; however, the rate of minor complications (8.4%) was significantly reduced in Period II (P = 0.006). According to multiple logistic regression analysis, not using a needle guide (odds ratio, 3.70; P < 0.001) along with low hemoglobin level, higher pre-dialysis serum creatinine level, and high urinary red blood cell count were significant predictors of biopsy complications. CONCLUSION: Use of a needle guide improves biopsy adequacy and is associated with reduced rates of minor complications in native renal biopsies. Therefore, needle guides may be recommended in percutaneous renal biopsies, especially when transitioning to single-operator performed procedures.
Biopsy* ; Biopsy, Needle ; Creatinine ; Erythrocyte Count ; Image-Guided Biopsy ; Kidney ; Logistic Models ; Needles* ; Renal Insufficiency ; Retrospective Studies ; Ultrasonography, Interventional

Objectives: Patients with chronic kidney disease (CKD) are known to develop sarcopenia, an agingrelated disorder, with low muscle mass, strength and physical performance. Ultrasound-derived thigh muscle and rectus femoris thickness (TMT and RFT) can be measured easily in clinical practice, but need validation for use in predialysis CKD (stages III through V) for muscle mass estimation. The study aims to compare ultrasound-derived TMT and RFT with bioelectrical impedance analysis (BIA)-derived muscle mass estimation in the diagnosis of sarcopenia in predialysis CKD. Methods: Patients with stable CKD stage III, IV, V and not yet on dialysis were recruited, and underwent anthropometric assessment, BIA and ultrasound examination of midthigh region. Appendicular skeletal muscle index (ASMI)/height2 derived from BIA was taken as a standard for the diagnosis of low muscle mass. Gait speed and handgrip were also measured. The Asian Working Group criteria were applied. Cutoff values for low muscle mass by TMT and RFT were obtained using receiver operator curve (ROC) analysis. Results: Of the total of 117 enrolled study participants, 52 (45%) had low muscle mass, 34 (29%) had sarcopenia, of whom 79% were male, majority (38%) were CKD stage IV and had a mean age of 58 years. Using ROC analysis, TMT cutoffs of 19 mm in males and 17 mm in females were computed. Comparison of TMT cutoffs and ASMI/h2 showed good agreement between the 2 methods using Bland-Altman plots. Conclusions Ultrasound-derived TMT and RFT can be used for muscle mass estimation in the diagnosis of sarcopenia.