BACKGROUND AND AIMS Percutaneous renal biopsy is a fundamental technique for the diagnosis of numerous renal pathologies. However, it is an invasive technique that requires operator experience and is associated with adverse outcomes. Bleeding complications such as haematuria or perirenal hematoma are frequent, but generally self-limiting, and may rarely be severe to the point of culminating in hypovolemic shock or death. The objectives of this study are to identify the rate of adverse outcomes and potential predictors of adverse outcomes related to the procedure. METHOD A retrospective analysis of patients undergoing native kidney biopsy at a tertiary centre, between 2015 and 2019 was carried out, based on the demographic and clinical characteristics of the population, analyses (creatinine at admission, pre-procedure and post-procedure blood counts) and control at 24 h after biopsy) and imaging methods (renal ultrasound 24 h after biopsy). RESULTS A total of 176 patients were selected, with a mean age of 48.1 ± 17.6 years. They were mostly caucasian (80.1%) and there was a predominance of females (55.7%). Approximately 46.6% had arterial hypertension, although all had their blood pressure controlled at the time of the biopsy. Mean pre-biopsy creatinine value was 2.0 ± 1.7 mg/dL. Mean pre-biopsy haemoglobin value was 12.1 ± 2.0 g/dL and 24 h post-biopsy 11.8 ± 2 .0 g/dL. There was an overall complication rate of 30.1%, corresponding to 5 cases of haematuria, 36 minor hematomas and 8 major hematomas. There were no deaths and there was no need for surgical intervention to control the bleeding. The only predictor of post-biopsy complications was age, with younger patients having fewer complications (43.9 ± 16.2 versus 50.0 ± 17.9, P = .036). There was no correlation between pre-biopsy creatinine or haemoglobin values and the occurrence of complications, nor was there a greater number of complications in hypertensive patients. CONCLUSION Although bleeding complications were relatively frequent in this sample, serious events were rare, as this reinforces the safety of this procedure (which provides valuable information about the prognosis and decision of the therapy to be instituted). The presence of arterial hypertension and the pre-biopsy creatininemia value did not increase the risk of complications related to the procedure.

Background: Planning for vascular access (VA) creation is essential in pre-dialysis patients although optimal timing for VA referral and placement is debatable. Guidelines suggest referral when eGFR is 15–20 mL/min/1.73 m2. This study aimed to validate the use of kidney failure risk equation (KFRE) in VA planning. Methods: Retrospective analysis of all adult patients with CKD who were referred for first VA placement, namely AVF or AVG, at a tertiary center, between January 2018 and December 2019. The four-variable KFRE was calculated. Start of KRT, mortality, and VA placement were assessed in a 2-year follow-up. We used Cox regression to predict KRT start and calculated the ROC curve. Results: 256 patients were included and 64.5% were male, mean age was 70.4 ± 12.9 years and mean eGFR was 16.09 ± 10.43 mL/min/1.73 m2. One hundred fifty-nine patients required KRT (62.1%) and 72 (28.1%) died in the 2-year follow-up. The KFRE accurately predicted KRT start within 2-years (38.3 ± 23.8% vs 17.6 ± 20.9%, p < 0.001; HR 1.05 95% CI (1.06–1.12), p < 0.001), with an auROC of 0.788 ( p < 0.001, 95% CI (0.733–0.837)). The optimal KFRE cut-off was >20%, with a HR of 9.2 (95% CI (5.06–16.60), p < 0.001). Patients with KFRE ⩾ 20% had a significant lower mean time from VA consult to KRT initiation (10.8 ± 9.4 vs 15.6 ± 10.3 months, p < 0.001). On a sub-analysis of patients with an eGFR < 20 mL/min/1.73 m2, a KFRE ⩾ 20% was also a significant predictor of 2-year start of KRT, with an HR of 6.61 (95% CI (3.49–12.52), p < 0.001). Conclusion: KFRE accurately predicted 2-year KRT start in this cohort of patients. A KFRE ⩾ 20% can help to establish higher priority patients for VA placement. The authors suggest referral for VA creation when eGFR < 20 mL/min/1.73 m2 and KFRE ⩾ 20%.