The availability of a non-surgical treatment for renal artery stenosis, percutaneous transluminal renal angioplasty (PTRA), makes it possible to cure the decreased renal function and exacerbated hypertension resulting from renal artery disease. However, bilateral renal artery occlusion (BRAO) that brings about anuria and azotaemia is rare. In the case we report here, a patient with BRAO recovered completely from anuria and azotaemia following the successful implantation of stents into both renal arteries. We are unaware of prior reports documenting the benefits of a distal embolism protection device in the clinical setting as described here.
Case. A 70-year-old man with a right-side weakness due to a cerebrovascular attack 15 years earlier was brought to the emergency department because of melena. Following admission, he developed acute renal failure (ARF). At admission, his blood pressure was 170/90 mmHg, haemoglobin concentration 8.0 g/dl and platelet count 320 x 109/l. Blood chemistry revealed: total serum protein of 5.4 g/dl, albumin 2.7 g/dl, blood urea nitrogen (BUN) 44 mg/dl and creatinine 1.6 mg/dl. His urinary output was too little for urinalysis. Oesophago-gastro-duodenoscopy revealed a peptic ulcer without active bleeding. Even though an abdominal ultrasonogram showed both kidneys to be of normal appearance and size, his renal function declined further, oliguria persisted, and BUN and creatinine levels increased to 117 and 12.0 mg/dl, respectively. A chest roentgenogram showed pulmonary oedema. Therefore, we decided to begin emergent haemodialysis. Other laboratory findings were unrevealing. Renal biopsy was performed to clarify the cause of the renal failure. Surprisingly, the biopsy specimen was histologicaly unremarkable. There were no retracted glomeruli consistent with ischaemia, no evidence of crescent formation and no evidence of vasculitis. The intrarenal resistive index was 0.83. A renal arteriogram demonstrated BRAO at the ostial levels. The patient underwent PTRA and stent implantation in the proximal reaches of both renal arteries with the PercuSurge GuardWire (PSGW) system (Medtronic, Minneapolis, MN) (Figure 1). During the 18 post-intervention days, his serum creatinine gradually fell from a range of between 9 and 12 mg/dl to 1 mg/dl. No subsequent haemodialysis was required.
|
In our case, we think that the collateral blood flow to the kidney demonstrated on aortography was sufficient to maintain normal renal architecture without any histological evidence of ischaemia, and to allow recovery of renal function [5]. During the intervention, a measure was needed to prevent atherosclerotic microemboli from passing distally into the renal capillary beds [6]. The GuardWire arm, a device for transient distal balloon occlusion during angioplasty or stent placement, allows recovery of liberated plaques by aspiration before restoration of antegrade flow, and it thereby performs a double service. Henry et al. announced that this new approach may end up being the standard of care in the near future [7].
An application of the PSGW system aimed at minimizing the effects of distal embolization is worthy of consideration in BRAO in ARF patients.
We would like to strongly recommend combining stent implantation with adjunctive distal protection, something essential for obtaining a complete restoration of distal blood flow in elderly patients with BRAO and azotaemia, even if there is sufficient collateral blood flow.
Conflict of interest statement. None declared.
Department of Nephrology and Cardiology Yonsei University Wonju College of Medicine 162 Ilsandong, Wonju Kangwon Korea 220-701 E-mail: kidney77{at}wonju.yonsei.ac.kr
References