Course and relevance of arteriovenous fistulas after renal transplant biopsies

Arteriovenous fistulas (AVFs) after renal transplant biopsy are considered harmless. However, verification of the clinical course has not been thoroughly documented. We evaluated the data of our outpatient renal transplant biopsy program regarding the clinical course of AVFs after 2824 biopsies since 2000. We also reviewed all selective renal transplant embolizations. AVFs were the most frequent biopsy complications (8.3%). Seventy-seven percent of AVFs disappeared spontaneously. Renal function in patients with AVFs was not different compared to those without during 2 years of observation. There were no differences in AVFs comparing protocol or indication biopsies, needle size, the time after transplantation, the use of acetylic salicylic acid or serum-creatinine at biopsy. Living or younger donors were less likely to get postbiopsy AVFs. Ten embolizations were performed. Only one patient was from our outpatient biopsy program. Nine others were biopsied as inpatients in the course of complications during 6 weeks after transplant. Six of nine successfully embolized patients profited with improvement of renal function. Large AVFs occur most commonly shortly after transplantation in patients with poor graft function. There is no established test predicting which patient will benefit from embolization; however, Doppler-determined resistive index may help in this regard.