3:00 PM Abstract No. 91 Population-based analysis of percutaneous renal biopsies: complications, utilization, and predictors of outcomes

Abstract

Percutaneous renal biopsies are commonly performed minimally invasive interventions to determine etiologies of renal failure and characterize focal renal lesions. Data regarding utilization and outcomes for these procedures are generally limited to retrospective series from high volume centers. The purpose of this study was to establish population-based measurements for percutaneous renal biopsy procedure complications and their risk factors. Using administrative data from all inpatient and outpatient hospital encounters in California (2009-2011), patients undergoing percutaneous renal biopsies were identified. The demographic characteristics of this patient cohort as well as risk factors for complications were analyzed. 14,973 percutaneous renal biopsies were performed in 13,372 patients during the study period. Comorbidities included renal failure (35.1%), hypertension (58.8%), atherosclerosis (8.7%), diabetes (20.5%), obesity (10.0%), congestive heart failure (9.6%), coagulopathy (6.9%), and malignancy (11.7%). Biopsies were performed across 282 hospitals, with yearly procedural volumes ranging from 1 to 312.6. Of the 4, 796 patients who underwent biopsies as outpatients, 183 patients (3.8%) had unscheduled hospital visits within 7 days of the procedure with a median length of stay of 3 days (range, 0 - 68 days). Post-biopsy hemorrhage was identified in 6.1% of patients undergoing biopsy, and 1.8% of patients required blood transfusions within 30 days of the biopsy. The all cause 30-day inpatient mortality rate was 2.8%. History of renal failure (OR 1.03 [1.01 – 1.05]) and hypertension (OR 1.02 [1.00 -1.04]) were significantly associated with post-biopsy hemorrhage, and history of renal failure (OR 1.03 [1.01 – 1.04]), hypertension (OR 1.03 [1.02 – 1.05]), and diabetes (OR 1.02 [1.00 – 1.03]) were significantly associated with - day unscheduled hospitalization. Percutaneous renal biopsies are a commonly performed procedure with low complication risks. These population-level estimates should help establish patient and physician expectations as well as societal guidelines for complication rate thresholds.