Sir,
With an incidence of around 16%, arteriovenous fistula (AVF) is a frequent complication of percutaneous renal biopsy (PRB) after kidney transplantation [1]. In only 05% of cases, however, an AVF causes clinical signs, such as systolicdiastolic murmur in the area of the graft, haematuria or hypertension [13]. A more serious consequence of AVF is a decline in renal function caused by shunting of part of the blood flow directly through the AVF into the venous system, bypassing the glomerular vessels. This leads to a shortage in circulation at the glomerular level in the flow area behind the AVF. The perfusion outside the flow area of the AVF will also be reduced since a substantial part of the blood flow in this region will be shunted towards the affected flow area. Due to this diminished blood flow the affected flow area will activate the reninangiotensin system causing hypertension and sodium-retention [1,4,5].
Recently a 36-year-old male with end-stage renal failure due to type 1 diabetes received a simultaneous pancreaskidney transplant in our clinic. Due to limited improvement of renal function (Figure 1) in total three PRBs were performed during follow-up, all taken from the upper pole. The first two biopsies showed signs compatible with cyclosporine and tacrolimus toxicity, respectively, but cessation of these drugs did not improve renal function. After the second PRB a systolicdiastolic murmur was heard above the graft and presence of an AVF was suspected. Colour-coded Doppler sonography (CCDS), however, did not support this diagnosis. Forty-five days after transplantation the patient had to return to haemodialysis and a third PRB was performed, showing signs of focal tubular necrosis. Clinically there was now hypertension and mild urinary sodium retention, both suspected to have a renovascular cause, which strengthened earlier suspicions of the existence of an AVF despite the negative CCDS. Subsequent angiography revealed two large AVFs with rapid venous outflow in the upper pole of the graft (Figure 2). Both AVFs were coiled using superselective transcatheter embolization, which resulted in disappearance of the murmur, improvement of renal function, normalization of blood pressure and urinary sodium-excretion. Currently, more than 1.5 years after transplantation, the patient has an excellent renal function with a creatinine clearance of 54 ml/min.
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1 Department of Internal Medicine Division of Nephrology2 Department of Radiology3 Department of Surgery University Medical Center Groningen The Netherlands
Acknowledgments
No funding was received for the writing of this article.
Conflict of interest statement. None declared.
References
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