Safety of Percutaneous Ultrasound-Guided Kidney Biopsy in Patients with AA Amyloidosis

Abstract

Background: Bleeding is the most frequent complication of kidney biopsy. Although bleeding risk in patients with AA amyloidosis after kidney biopsy has not been studied in a large population, AA amyloidosis has long been perceived as a risk factor for bleeding. The aim of the present study was to evaluate post-biopsy bleeding risk in patients with AA amyloidosis. Methods: We retrospectively analyzed bleeding complications in 88 patients with AA amyloidosis and 202 controls after percutaneous kidney biopsy. All the kidney biopsies were performed under the guidance of real-time ultrasound with the use of an automated core biopsy system after a standard pre-biopsy screening protocol. Bleeding events were classified as major when transfusion of blood products or surgical or radiological intervention was required, or if the bleeding caused hypovolemic shock or death. Bleeding events that did not meet these criteria were accepted as minor. Results: The incidence of post-biopsy bleeding was comparable between AA amyloidosis and control groups (5.7 vs. 5.0%, p = 0.796). Major bleeding events were observed in 3 patients from each group (p = 0.372). Selective renal angiography and embolization were applied to 2 patients from the AA amyloidosis group. One of these patients underwent colectomy and died because of infectious complications. Bleeding events were minor in 2.3% of the patients with AA amyloidosis and 3.5% of the controls (p = 0.728). Conclusions: AA amyloidosis was not associated with increased post-biopsy bleeding risk. Kidney biopsy is safe in AA amyloidosis when standard pre-biopsy screening is applied. Further data are needed to confirm these findings.