Arteriovenous fistulas complicating biopsy of renal allografts: treatment of bleeding with superselective embolization.

The use of superselective embolization was assessed as a treatment for bleeding from postbiopsy arteriovenous fistulas (AVFs) in renal transplants. AVFs commonly occur after biopsy procedures in renal transplants, but severe bleeding is rare. Transcatheter embolization can be used to control bleeding, but unless it is sufficiently selective, the procedure results in loss of significant amounts of renal parenchyma. During a 4-year period, embolization procedures were attempted in seven patients 30-65 years old. All had AVFs shown on arteriography. Five patients underwent embolization; occlusion occurred only in the branch supplying the AVF. In one patient with three large AVFs, two were found to have occluded the day after embolization was attempted. In another, an AVF occluded when superselective catheter position was achieved but before embolization. Catheter manipulation in these cases may have precipitated occlusion. In five cases, coaxial embolization techniques were used. Embolization materials consisted of coils in three cases: 0.038 in. (0.97 mm) in one case, 0.025 in. (0.64 mm) in one case, 0.018 in. (0.46 mm) in one case; 0.038 in. (0.97 mm) coils and gelatin foam particles in one case; and localized contrast extravasation in one case. Serum creatinine level was measured before and after embolization in all patients, and radionuclide studies were undertaken in three cases. In all patients, bleeding was effectively controlled. None of the patients showed an increase in serum creatinine level after embolization, and in four, significant improvement was seen. Nuclear medicine studies showed no loss of renal function and a dramatic improvement in one patient. No complications due to the procedure were seen. Our experience suggests that superselective embolization with coaxial catheter techniques is an effective method of treating bleeding from postbiopsy AVFs in renal transplants with minimal loss of renal parenchyma.