Color-coded duplex sonography study of arteriovenous fistulae and pseudoaneurysms complicating percutaneous renal allograft biopsy

BACKGROUND: The exact incidence and clinical impact of arteriovenous fistulae (AVF) and pseudoaneurysms as complications emerging from renal allograft biopsy are not well established. We therefore conducted a prospective study using color-coded duplex sonography (CCDS) to determine the frequency, clinical presentation and spontaneous occlusion rate of biopsy-related AVF and pseudoaneurysms in kidney transplant recipients. METHODS: We investigated 72 consecutive patients undergoing renal allograft biopsy using an automated biopsy technique. CCDS was performed before, immediately after and up to more than 6 months after biopsy. The diagnosis of AVF was based on the presence of perivascular vibration artifacts and detection of typical Doppler curves. Pseudoaneurysms were diagnosed based on the presence of"to-and-fro" signals. RESULTS: In 5 patients (6.9%), an AVF was detectable before biopsy. Post-biopsy AVF were found in 12 additional patients (16.7%) with a spontaneous occlusion rate of 50% within 48 hours and 75% after 4 weeks. Three (25%) AVF persisted longer than 1 year. Four patients (5.6%) were found to have pseudoaneurysms. All pseudoaneurysms were located closely to AVF and closed spontaneously. None of the post-biopsy AVF and pseudoaneurysms required specific therapy. In 2 patients (2.8%), allograft biopsy lead to significant hemorrhage independent of AVF or pseudoaneurysms. CONCLUSION: These results indicate that post-biopsy AVF and pseudoaneurysms are a frequent finding after automated renal allograft biopsy. The natural history of these lesions shows a high rate of early occlusion. The present data fail to demonstrate significant clinical impact of AVF and pseudoaneurysms after renal allograft biopsy.