Fibromuscular Dysplasia (FMD) of the renal arteries Angiographic features and therapeutic options Poster No.: C-0630 Congress: ECR 2012 Type: Educational Exhibit Authors: K. I. Ringe, B. Meyer, F. Wacker, H. Rosenthal ; Hannover/DE, 1 2 2 1 1 1 Hannover /DE Keywords: Cardiovascular system, Interventional vascular, Kidney, Catheter arteriography, Angioplasty, Hypertension, Dysplasias DOI: 10.1594/ecr2012/C-0630 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 14
Learning objectives The aim of this tutorial is to make especially young and more advanced radiologists not so familiar with Fibromuscular Dysplasia (FMD) more acquainted with the disease, and to learn about typical imaging features and therapeutic options. Page 2 of 14
Background FMD is a non-inflammatory, non-atherosclerotic disease of the vessel wall of unknown 1 cause, characterized by muscular hyperplasia in one or more layers. FMD accounts for less than 10% of renal artery stenoses and most often affects the middle and distal portion of the main renal artery or its segment branches in contrast to atherosclerotic disease, which tends to be located at the origin or proximal portion of the renal artery 2. Depending on the predominantly affected layer varying histologic types can be differentiated. Whereas medial fibroplasia is the most common cause (75-80%), intimal and adventitial fibroplasia is less often (less than 10% and less than 1%, respectively). Although any artery can be affected, FMD most often occurs in the renal (60-75%; 35% 3 bilateral) and carotid arteries. FMD typically occurs in young women (less than 35 years). Symptoms may include arterial hypertension with a sudden onset of high blood pressure or an epigastric bruit, transient ischemic attack (TIA) and stroke. Renal failure appears less often. FMD may be diagnosed incidentally or in the course of evaluation 4 for hypertension. Treatment is indicated in patients with renal artery stenosis and hypertension or impairment of renal function. In asymptomatic patients watch and wait strategy is implemented. Page 3 of 14
Imaging findings OR Procedure details Imaging Findings: Diagnosis of FMD can be made by duplex ultrasound, CT (Figure 1-3) or MRAngiography. However, catheter angiography by means of DSA (Figure 4) still is the gold standard with characteristic findings such as unifocal or tubular lesions ("non-media type") or a "string of beads" appearance indicating multiple stenoses and aneurysms ("media type") 2,5. Treatment: Treatment of choice in symptomatic patients is percutaneous transluminal angioplasty (PTA) (Figure 5-8). Cure or improvement of renal function can be achieved in a high percentage of these patients. After PTA often residual stenoses can be appreciated. Primary stent implantation is not recommended. Only in case of suboptimal PTA result or dissection, a secondary stent implantation can be considered. Surgery may be necessary 6,7 in patients presenting with macroaneurysms or complex arterial disease. It has been demonstrated that even delayed revascularization of renal artery occlusion can be successful and is recommended for treatment of renovascular hypertension and acute renal failure 8,9,10. Page 4 of 14
Images for this section: Fig. 1: Figure 1: Media type FMD in a 25 year old male symptomatic patient. CTAngiography (left 3D VR image, right coronary MIP) shows multiple stenoses (arrows) in the middle portion of the right renal artery ("string of beads appearance). Page 5 of 14
Fig. 2: Figure 2: Media type FMD in a 28 year old female patient with arterial hypertension. CT-Angiography (left 3D VR image, right coronary MIP) depicts characteristic "string of beads" appearance in the lower left renal artery. In addition, an aneurysm in a smaller lower segment branch is seen. Page 6 of 14
Fig. 3: Figure 3: Non-media type FMD in a 35 year old female patient. CT-Angiography (coronary MIP) shows a focal dissection (arrow) in the middle portion of the lower left renal artery. Fig. 4: Figure 4: 51 year old female patient with new onset arterial hypertension. Digital subtraction angiography (DSA): Pigtail catheter placed in the aorta at the level of the renal arteries (A). Selective probing of the right (B) and left (C) renal arteries using a Cobra catheter depicts multiple stenoses in the middle and distal portion of both renal arteries. Page 7 of 14
Fig. 5: Figure 5: Digital subtraction angiography (DSA) in a patient with media type FMD. A: Selective probing of the right renal artery using a Terumo stiff wire (Terumo, Leuven, Belgium) and a sidewinder II catheter, depicting multiple stenoses and aneurysms in the medial portion of the right renal artery. B: Control angiography after dilatation up to 4.7mm using a Wanda balloon catheter shows minor residual stenosis in the proximal segment of the artery. Page 8 of 14
Fig. 6: Figure 6: 43 year old female patient with arterial hypertension and status post nephrectomy on the left side due to reflux nephropathy. A: Pigtail catheter placed in the aorta at level of the right renal artery. B: Selective probing of the right renal artery using a Cobra II catheter. Typical "string of beads" appearance can be appreciated. C: Dilatation of the main renal artery using a 6mm Wanda balloon catheter. D: Control series depicts no residual stenosis. Page 9 of 14
Fig. 7: Figure 7: 37 year old male patient with arterial hypertension and renal failure (hemodialysis since three weeks). A: Pigtail catheter placed in the aorta at level of the right renal artery. In addition to a high grade stenosis in the middle portion of the left renal artery total occlusion of the right renal artery can be appreciated. B: After dilatation of the left renal artery using a 6mm Wanda balloon catheter residual stenosis in the proximal portion of the left renal artery is noticed. C: After implantation of a 7mm Herkulink stent no residual stenosis is seen. Page 10 of 14
Fig. 8: Figure 8: 44 year old female patient with arterial hypertension and suspicion of FMD on prior ultrasound examination (not shown). A: Pigtail catheter placed in the aorta at level of the renal arteries. Thr right kidney is distinctly smaller than the left kidney. B: Selective probing of the left renal artery using a Cobra catheter shows no significant stenosis. C, D: Selective probing of the right renal artery using a Sidewinder I catheter depcits multiple high grade stenoses in the distal portion of the artery. E: Dilatation of the distal portion of the right renal artery using a 7mm balloon. F: Control series depicts discrete residual stenosis. Page 11 of 14
Conclusion FMD typically affects younger patients and usually has a good prognosis, compared for example with atherosclerotic stenosis. Knowledge and identification of this condition is indispensible in the work-up of patients with renal artery stenosis. Treatment of choice in patients with FMD is PTA, which is only indicated in symptomatic patients. Page 12 of 14
Personal Information Page 13 of 14
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