5475 SAFETY OF NATIVE AND TRANSPLANT KIDNEY BIOPSY IN A NATIONAL COHORT

Abstract Background and Aims Safety of kidney biopsy is variably reported in different published series. Since 2014, all native kidney biopsies undertaken in the 9 adult renal units in Scotland have been recorded by the Scottish Renal Registry (SRR) and since 2015 all transplant kidney biopsies were included. In this complete national dataset, we report data on safety of kidney biopsy in a current real world setting. Method Major complications of kidney biopsy are recorded using pre-defined terms and include: arteriography and embolisation, arteriography no embolisation, clot retention, blood transfusion only, death within 28 days directly attributable to biopsy, nephrectomy and other. Biopsies are undertaken under ultrasound guidance using 16G or 18G spring loaded biopsy guns. All centres discontinue clopidogrel, DOACs and warfarin. Some centres continue aspirin. In some centres biopsy is performed by nephrologists and in others by radiologists Results In total, 6979 biopsies in 5755 patients were recorded between 2014 and 2021 (5095 native biopsies and 1884 transplant biopsies), with an adequacy for diagnosis of 98.1%. Table 1 describes the demographics, indications, operator and diagnoses made by biopsy type. Overall, in patients undergoing native kidney biopsy 2.4% suffered a major complication and 1.4% of patients undergoing transplant biopsy. The commonest complication was the requirement for arteriography, with or without embolisation. We included CT angiography in this group. There were 8 deaths within 28 days attributable to renal biopsy. Table 1: Baseline demographics and complications recorded in native and transplant biopsies. Biopsy Type Native Transplant Total biopsies (n) 5095 1884 % Male 54.7% 59.4% Mean age (years) 57.2 48 % Adequate 98.2% 95.1% Commonest Indication (% of biopsy type) AKI query cause (30%)Chronically reduced eGFR (28.1%)Nephrotic syndrome (19.7%) AKI query cause (37.7%)Chronically deteriorating transplant function (25.4%)Achieved transplant function lower than expected (9.1%) Commonest Diagnosis (% of biopsy type) 1. IgA nephropathy (13.1%)2. Tubulointerstitial nephritis (8.5%)3. Membranous nephropathy (7.2%) 1. Acute Rejection (34.3%)2. Other (23.9%)3. Acute tubulodegenerative Change (15.8%) Biopsies performed by radiology (%) 31.3% 38.3% Biopsies performed by nephrology (%) 61.9% 57.6% Median serum creatinine (mg/mmol) 163 (96-271) 212 (156-357) Mean number of glomeruli 14.6 15.2 Total Complications (% of biopsy type) 12