Successful percutaneous transluminal renal angioplasty with multimodality imaging guidance for a juvenile patient with renovascular hypertension due to fibromuscular dysplasia

Abstract

Percutaneous transluminal renal angioplasty (PTRA) is an effective treatment for renovascular hypertension due to fibromuscular dysplasia (FMD). PTRA for renovascular FMD is performed with only balloons based on the consensus that stent kinking and fracture have been reported in cases of PTRA using stents for FMD. Therefore, it is important to avoid procedural complications, such as flow-limiting dissection or arterial rupture, in PTRA for renovascular FMD.We present a case of a juvenile patient who presented with renovascular hypertension due to FMD. Angiography revealed focal stenosis of the right renal artery, and the pressure wire showed a resting distal coronary to aortic pressure ratio (Pd/Pa) of 0.83. Intravascular ultrasound (IVUS) showed an intima-media complex that could not be qualitatively assessed. Optical coherence tomography (OCT) showed intimal fibroplasia and medial hyperplasia with areas of low intensity. Based on the OCT images, balloon angioplasty was performed using a semi-compliant balloon. After balloon angioplasty, IVUS and OCT revealed luminal expansion with mild residual stenosis, and the Pd/Pa ratio was 0.99. We decided not to increase the balloon size to avoid vascular injuries. In conclusion, PTRA with only balloon can be safely performed for FMD under the guidance of multimodal imaging, using IVUS, OCT, and a pressure wire.

Learning objectives: This report describes successful percutaneous transluminal renal angioplasty (PTRA) for a juvenile patient with renovascular hypertension due to fibromuscular dysplasia (FMD) under the guidance of multimodal imaging, using intravascular ultrasound (IVUS), optical coherence tomography (OCT), and a pressure wire. When IVUS for FMD cannot assess the culprit lesion qualitatively, OCT could be effective in performing angioplasty with only balloon, without significant vascular injuries. A pressure wire can show the endpoint of PTRA and help avoid increasing the balloon size to prevent significant vascular injuries.

Keywords: Intravascular ultrasonography; Optical coherence tomography; Percutaneous transluminal renal angioplasty; Pressure wire.

Fig. 1

Renal ultrasound imaging and contrast-enhanced computed tomography used in diagnosing renal artery stenosis in fibromuscular dysplasia (FMD). (A) Renal ultrasound imaging showed turbulent flow in the middle region of the right renal artery and the peak systolic velocity was 4.1 m/s. (B) Contrast-enhanced computed tomography showed severe focal stenosis in the middle of the right renal artery and a smaller size of the right kidney compared with the left kidney. The FMD did not involve other vessels.

Fig. 2

Various imaging modalities pre-angioplasty. (A, arrow) Angiography revealed 90% focal stenosis in the mid-segment of the right renal artery. (B) Intravascular ultrasound showed hyperplasia of intima-media complex with focal hyperechoic area in culprit lesion although it could not assess the lesion quality. (C) Optical coherence tomography showed intimal fibroplasia and medial hyperplasia with areas of low intensity (asterisks). (D) A 0.014-inch pressure monitoring guide wire was then advanced through the guiding catheter across the stenosis and phasic and mean pressure showed the resting distal coronary to aortic pressure ratio (Pd/Pa) was 0.83.

Fig. 3

Various imaging modalities post-angioplasty. (A, arrow) Angiography postangioplasty showed good flow across the renal artery with mild residual stenosis. (B) A repeat intravascular ultrasound showed luminal expansion. (C) Optical coherence tomography imaging revealed only minor dissection and mild residual stenosis. (D) The resting distal coronary to aortic pressure ratio (Pd/Pa) post dilatation was 0.99.