Percutaneous transluminal renal artery stenting using digital subtraction angiography with diluted contrast medium in a patient with severe chronic kidney disease

Abstract

Atherosclerotic renal artery stenosis (ARAS) is associated with ischemic nephropathy, kidney failure, and secondary hypertension. Percutaneous transluminal renal artery stenting (PTRAS) is required for patients with hemodynamically significant ARAS. However, PTRAS can be problematic in patients with chronic kidney disease (CKD) because the use of a large amount of iodinated contrast medium is associated with an increased risk of contrast-induced nephropathy. We describe a case of PTRAS with successful revascularization by using digital subtraction angiography (DSA) with diluted contrast medium (1:10 dilution). An 89-year-old man with resistant hypertension and CKD was hospitalized in our institution for acute coronary syndrome. During hospitalization, the patient's blood pressure was extremely high (180–200/70–90 mmHg), despite the use of four antihypertensive agents. We examined the cause of hypertension and detected significant right renal artery stenosis and left kidney atrophy with renal artery obstruction. We performed PTRAS on the right renal artery by using DSA with a diluted contrast medium. Revascularization was successful using only 3 mL of the contrast medium. PTRAS using DSA with diluted contrast medium can be an effective technique for treating ARAS in patients with CKD to preserve renal function.

Learning objectives

Atherosclerotic renal artery stenosis (ARAS) is associated with ischemic nephropathy, kidney failure, and secondary hypertension. Percutaneous transluminal renal artery stenting (PTRAS) is required for patients with hemodynamically significant ARAS. However, PTRAS can be problematic in patients with chronic kidney disease because of the increased risk of contrast-induced nephropathy. We describe a technique of PTRAS using digital subtraction angiography with a diluted contrast medium to achieve a successful revascularization.

Introduction

Atherosclerotic renal artery stenosis (ARAS) is associated with ischemic nephropathy, kidney failure, and secondary hypertension. Percutaneous transluminal renal artery stenting (PTRAS) is required for patients with hemodynamically significant ARAS presenting with resistant hypertension, progressive chronic kidney disease (CKD), and cardiac disturbance syndromes. However, PTRAS can be problematic in patients with CKD because the use of large amount of iodinated contrast medium is associated with an increased risk of contrast-induced nephropathy (CIN).

We developed a method of PTRAS by using digital subtraction angiography (DSA) with a diluted contrast medium. We herein describe a case of PTRAS with successful revascularization by using DSA with diluted contrast medium.

Case report

An 89-year-old man with resistant hypertension and CKD was hospitalized in our institution for unstable angina. We performed coronary angiography, it showed stenosis of peripheral lesion of left anterior coronary artery not suitable for intervention.

During hospitalization, the patient's blood pressure was extremely high (180–200/70–90 mmHg), despite the use of four antihypertensive agents. On physical examination, the patient had abdominal bruit. Abdominal ultrasound revealed significant right renal artery stenosis and left kidney atrophy with renal artery obstruction. Significant findings of the right renal artery were a peak systolic velocity of 3.2 m/s; renal-aortic ratio, 6.53; resistive index, 0.78; and size, 108 mm (Fig. 1). Noncontrast computed tomography angiography (CTA) and magnetic resonance angiography (MRA) showed severe stenosis at the ostium site of the right renal artery (Fig. 2). The initial serum urea nitrogen was 67 mg/dL and creatinine was 2.51 mg/dL. The patient's estimated glomerular filtration rate (eGFR) was only 20 mL/min/1.73 m². We concluded that the cause of resistant hypertension was ARAS, and necessary to treat.

Fig. 1.

Color Doppler ultrasound imaging of the renal artery and peak systolic velocity in the main renal artery.

Fig. 2.

Imaging findings of severe stenosis at the ostium site of the right renal artery (circle). (A) Noncontrast computed tomography angiography image. (B) Magnetic resonance angiography image.

We attempted to treat the right renal artery stenosis. A 6Fr JR 40 guide catheter (EXTRACK; Medikit, Tokyo, Japan) was engaged to the right renal artery from the left radial artery using the nontouch technique, and a guidewire (Jupiter FC; Boston Scientific, Marlborough, MA, USA) was passed. We attempted renal artery angiography using DSA with a diluted contrast medium (1:10 dilution). Angiography was performed with the Azurion machine (Philips, Amsterdam, the Netherlands). We used a diluted contrast solution containing an iopamidol 370 mg/mL contrast medium (Fuji Pharma Co., Tokyo, Japan) and a normal saline solution. The DSA parameters and contrast medium were the same as that used in standard endovascular treatment. We were able to obtain acceptable images of the renal artery for intervention. Intravascular ultrasound (IVUS) (AltaView; Terumo, Tokyo, Japan) revealed an atherosclerotic plaque at the ostium of the renal artery. We marked the renal artery ostium and distal end by using IVUS. We used calcification of the aortic artery and the edge of vertebral body as the landmarks of the lesion. We attempted predilation with a semi-compliant balloon (Stering 5.0/15 mm; Boston Scientific) by using an embolic protection device (Filtrap, 6.5 mm; Nipro, Tokyo, Japan). We deployed an Express SD stent (6.0/18 mm; Boston Scientific) from the ostium of the renal artery by using an IVUS-guided approach. The final angiography showed good expansion of the lesion and no complications such as dissection of the stent distal (Fig. 3).

Fig. 3.

Angiography findings. (A) Present angiography using digital subtraction angiography (DSA) with diluted contrast medium. (B) Intravascular ultrasound is used to mark the renal artery ostium and distal end. (C) The stent is deployed. (D) The final angiography using DSA with diluted contrast medium.

The total volume of contrast medium used was 3 mL, which is substantially less than that used in the conventional procedure, which usually requires approximately 100 mL or more of contrast medium. The dose area product was 75.4 Gy cm². The total procedure time was 80 min, and the fluoroscopic time was 22 min, which is approximately the same time as that of the conventional procedure.

The patient's postoperative course was uneventful. The patient's eGFR improved from the preprocedure eGFR of 20 mL/min/1.73 m² to 31 mL/min/1.73 m². The patient's blood pressure decreased to 110–140/50–70 mmHg and the number of antihypertensive agents were decreased from four medications to two medications.

Discussion

ARAS contributes to the development and progression of systemic atherosclerotic disease. It stems from having a hemodynamically significant renal artery atherosclerotic lesion that causes upregulation of the renin-angiotensin-aldosterone system (RAAS), thereby resulting in accelerated hypertension that then adversely impacts pre-existing cardiovascular disease and ischemic nephropathy. PTRAS can relieve renal artery stenosis, restore the renal blood flow, block the activation of RAAS, treat the renal artery stenosis hypertension, and retard the progression of nephropathy and renal insufficiency. However, several randomized trials such as CORAL study showed that medical therapy plus PTRAS in patients with ARAS were not effective for preventing clinical events [1]. These results might be influenced by selection bias that included many patients with moderate renal artery stenosis. In our case, the patient's renal function improved and blood pressure control became controllable after PTRAS. PTRAS might be effective, if we select hemodynamically significant renal artery atherosclerotic lesions.

However, periprocedural complications such as CIN are often problematic in patients with CKD because of the use of large amount of iodinated contrast medium. If CIN occurred, it might have led to irreversible renal dysfunction and resulted in a poor prognosis [2]. Previous studies [3], [4] have shown a correlation between CIN and multiple risk factors such as diabetes mellitus, a history of chronic kidney disease, and the amount of contrast used during the procedure.

To prevent CIN, the amount of contrast medium used should be reduced as much as possible. Two important points to reduce the amount of contrast medium in patients with CKD are (1) using DSA with diluted contrast medium and (2) performing noncontrast CTA and MRA.

DSA with diluted contrast medium is an established effective method of endovascular therapy [5]. However, PTRAS using DSA with diluted contrast medium has not been reported. We attempted renal artery angiography using DSA with diluted contrast medium (1:10 dilution) and obtained acceptable images of the renal artery for intervention.

Carbon dioxide angioplasty is also a useful technique to perform PTRAS in patients with CKD. However, this method is associated with severe complications and poor image quality [6]. DSA with diluted contrast medium can resolve the problems associated with carbon dioxide angioplasty without using a large amount of contrast medium.

Noncontrast CTA and MRA are also effective methods to reduce the amount of contrast medium. A previous study [7] has demonstrated the usefulness of contrast-enhanced CTA and MRA to detect ARAS. In an era of technological progress, clear images without using contrast medium can be obtained. Compared to duplex ultrasonography, CTA and MRA can reveal the anatomical relationship of the renal artery position and reveal the accessory renal arteries. If the bifurcation angle of the renal artery and the position of stenosis are known at preprocedure, clinicians can image the shape of guiding catheter and make a strategy. This procedure can reduce the amount of contrast medium.

This technique has some limitations, such as holding breath and avoiding the movement of intestinal gas. It is difficult to use this technique on patients who cannot hold their breath and have a lot of gas in their intestines. We should perform standard methods for these patients.

In our institution, 10 patients have received PTRAS in the past 5 years. The average eGFR was 28.6 mL/min/1.73 m², creatinine was 2.26 mg/dL, and the amount of contrast medium used was 101 mL. However, we successfully performed PTRAS using only 3 mL of contrast medium and preserved the patient's renal function.

Conclusion

PTRAS using DSA with diluted contrast medium can be an effective technique to treat ARAS in patients with CKD.

Declaration of competing interest

The authors declare that there is no conflict of interest.