Safety of Outpatient Kidney Biopsies.

BACKGROUND: Kidney biopsy is frequently performed in our centre as an outpatient procedure. The aim of this study was to evaluate the safety of biopsy in the outpatient setting.

METHODS: We analysed kidney biopsies performed from March 2013 to February 2017. Seven hundred twenty-five biopsies performed in the outpatient setting were identified: There were 592 transplant and 133 native biopsies including 3 solitary kidney biopsies. All were performed under ultrasound guidance using a 16G or 18G needle, with freehand technique. In all patients with estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2 desmopressin was administered. Patients were observed for 6h before discharge, with a complete blood count and urine test after 4 h. Major complications were haemorrhage requiring therapeutic intervention or transfusion. Minor complications were significant reduction in haemoglobin (Hb) levels (>10%), without need for transfusion or intervention and macrohaematuria.

RESULTS: There were 506 (69.8%) male patients. Average age was 50.3 ± 12.7 years. Indications for native kidney biopsy included nephrotic syndrome (39.8%), nephritic syndrome (42.9%), follow-up biopsy (15.8%), and other (1.5%). There were no major complications. A decline in Hb was observed in 72% of patients. Average Hb decline was 4.2 ± 6.3 g/L. In 10.1% patients there was >10% reduction in Hb level, with no evident bleeding, including by ultrasonography. In 2.5% of patients, macrohaematuria was present. In a multivariate analysis, male gender, lower eGFR, higher pre-biopsy Hb and native kidney biopsy were predictive for Hb decline. No therapeutic interventions were required.

CONCLUSION: We found that kidney biopsy performed in an outpatient setting in select patients is only rarely associated with adverse events and is a safe procedure.