Arteriovenous fistula in a renal allograft with gross hematuria and subsequent acute kidney injury due to urinary tract obstruction: a case report.

BACKGROUND: Arteriovenous fistula (AVF) due to renal allograft biopsy is mechanical trauma resulting from the penetration of small arteries and veins by a core needle. Most AVFs are reported to resolve asymptomatically and spontaneously. This report presents a patient with acute kidney injury (AKI) due to urinary tract obstruction caused by a bleeding AVF in a renal allograft. CASE PRESENTATION: A 22-year-old Japanese woman who underwent living-donor kidney transplantation (KT) at 3 years due to end-stage renal disease caused by focal segmental glomerulosclerosis (FSGS) presented with a renal transplant AVF (gourd-shaped; 42 × 19 × 20 mm). The AVF was unexpectedly discovered by ultrasound before a surveillance biopsy at 10 years after KT. The patient had a history of recurrent FSGS, had undergone several renal allograft biopsies after KT, and did not experience symptoms or growth of the AVF for years. Nineteen years after KT, the patient developed AKI with sudden, asymptomatic, gross hematuria and anuria. Plain computed tomography revealed a hematoma in the pelvis of the renal allograft and bladder tamponade. The AVF was successfully treated by coil embolization. Hemodialysis was performed for AKI, and graft function was gradually recovered. CONCLUSIONS: Unexpected bleeding from a renal transplant AVF may lead to transplant dysfunction. Angiographic embolization against the ruptured renal transplant AVF may prevent rebleeding and rescue the renal allograft.

Novel technique for repair of arteriovenous fistula with aneurysm.

Aneurysm of autogenous arteriovenous fistula is a common complication in patients receiving hemodialysis. We present a novel method for repair of a case of aneurysm of arteriovenous fistula resulting from stenosis. A 52-year-old woman presented with aneurysm formation of the left upper arm arteriovenous fistula, with related numbness in the left hand. Clinical examination revealed a tense, pulsatile aneurysm above the brachiocephalic anastomosis. Ultrasound examination revealed an aneurysm (50 mm × 25 mm) with proximal stenosis and an arteriovenous fistula flow rate above 1200 mL/min. An incision was made lateral to the aneurysm from the brachiocephalic anastomosis to the proximal stenosis through the antecubital fossa. After exposure of the entire aneurysmal arteriovenous fistula, the narrowed segment, and the proximal cephalic vein, the aneurysm outflow was ligated and the narrowed segment was removed. A U-shaped incision was made on the aneurysm to create an aneurysmal flap (75 mm × 20 mm). The flap was tubularized after calibration of the lumen with a 14-Fr cannula. End-to-end anastomosis was performed between the distal tubularized flap and the proximal cephalic vein. Intra- and postoperative arteriovenous fistula flow rates were below 900 mL/min. After surgery, the remodeled arteriovenous fistula was immediately usable for hemodialysis with normal arteriovenous fistula flow in the upper arm. The repair technique achieved not only aneurysmorrhaphy but also created an autologous vascular graft as the bypass after removal of the narrowed segment. Moreover, this technique achieved reduced arterial inflow and is suitable for patients with conditions similar to those of this case.