Cath Lab Digest - October 2007 - (Page 9)

9 (Meyers, personal observations). There are, however, pediatric case reports and results of treatment of renovascular hypertension in children.17,18 O’Neill described 45 children with renovascular FMD, 17 with aortic involvement. The average age at diagnosis was 9 years. Three children had renal failure. Twentythree of the 45 (51%) had bilateral vessel involvement. A variety of surgical approaches were used, depending on the pathology encountered. Thirty-eight patients underwent revascularization, seven underwent primary nephrectomy, five underwent primary partial nephrectomy and 12 had aortoaortic bypass performed. Seventy percent were cured, 26% improved and 4% did not respond to treatment, with up to 16 years of follow-up. There was no mortality.17 In adults, Goncharenko et al reported on forty-two hypertensive patients with various forms of FMD who had progression of the disease over an eleven-year observation period.19 Schreiber et al observed progression of medial hyperplasia in 22/66 patients (33%) with renal artery involvement.20 Asymptomatic adults with incidental findings of renal artery FMD determined upon evaluation for LRD kidney donation develop hypertension at a rate greater than that of agematched control subjects with normal blood pressure.21 Of note, FMD is unlikely to progress to renal failure in adults.22 In children, renovascular causes of hypertension, including FMD, are not listed as a separate cause for ESRD.23 In addition, progression to renal artery stenosis has been seen after successful allografting in kidneys taken from donors with FMD.24,25 While no prospective studies have evaluated the surgical treatment of renovascular FMD in children and young adults, it is reassuring to know that in selected patients less than 25 years of age, blood pressure is well-controlled and the majority of patients do not require anti-hypertensive medication post vascular repair.26 The causes, natural history, management and long-term outcomes of FMD in children requires further research and evaluation. ■ The authors can be contacted at: Kevin Meyers, MD Pediatric Nephrologist Assistant Professor of Pediatrics Second Floor Main Building The Children’s Hospital of Philadelphia Cnr 34th Street and Civic Center Boulevard Philadelphia, PA 19104 Telephone: (215) 590-4155 Fax: (215) 590-3705 Email: meyersk@email.chop.edu Note: This article underwent double-blind peer review by members of the Cath Lab Digest Editorial Board. References 1. Olin JW. Recognizing and managing Fibromuscular dysplasia. Cleveland Clinic Journal of Medicine 2007;74(4): 277–282. 2. Cluzel P, Raynaud A, Beyssen B, et al. Stenoses of renal branch arteries in fibromuscular dysplasia: results of percutaneous transluminal angioplasty. Radiology 1994; 193(1): 227–232. 3. Bofinger A, Hawley C, Fisher P, et al. Alpha-1antitrypsin phenotypes in patients with renal arterial fibromuscular dysplasia. Journal of Human Hypertension 2000; 14(2): 91–94. 4. Rushton AR. The genetics of fibromuscular dysplasia. Arch Internal Medicine 1980;140(2): 233–236. 5. Safian RD, Textor SC. Renal-artery Stenosis. N Engl J Med 2001;344(6):431–442. 6. Bofinger A, Hawley C, Fisher P, et al. Increased severity of multifocal renal arterial fibromuscular dysplasia in smokers. Journal of Human Hypertension 1999; 13(8):517–520. 7. McDonnell NB, Yang J, Chen W, et al. A cohort of patients with generalized Fibromuscular Dysplasia and features of Ehlers-Danlos Syndrome: A new phenotype. Abstract. Presented at the American Society of Human Genetics Annual Meeting. October 2006. 8. Feig D, Croix B. Symptoms in hypertensive children before and after antihypertensive treatment. Abstract. Presented at the American Society of Nephrology annual meeting in Philadelphia, 2005. 9. Slovut DP, Olin JW. Fibromuscular dysplasia. N Engl J Med 2004;350(18): 1862–1871. 10. Plouin PF, Perdu J, La Batide-Alanore A, et al. Fibromuscular dysplasia. Orphanet Journal of Rare Diseases 2007;2(1):1–28. 11. Sabharwal R, Vladica P, Coleman P. Multidetector spiral CT renal angiography in the diagnosis of renal artery fibromuscular dysplasia. Eur J Radiol 2007;61(3):520–527. 12. National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics 2004;114(2): 555–576. 13. McLaren CA, Roebuck DJ. Interventional radiology for renovascular hypertension in children. Technical Vascular Interventional Radiology 2003; 6(4):150–157. 14. Towbin RB, Pelchovitz DJ, Baskin KM, et al. Cutting balloon angioplasty in children with resistant renal artery stenosis. J Vasc Interv Radiol 2007;18(5):663–669. 15. Klow NE, Paulsen D, Vatne K, et al. Percutaneous transluminal renal artery angioplasty using the coaxial technique. Ten years of experience from 591 procedures in 419 patients. Acta Radiology 1998;39(6):594–603. 16. Hansen KJ, Starr SM, Sands RE, et al. Contemporary surgical management of renovascular disease. J Vasc Surg 1992; 16(3): 319–331. 17. O’Neill JA Jr. Long-term outcome with surgical treatment of renovascular hypertension. J Pediatr Surg 1998;33(1): 106–111. 18. Robitaille P, Lord H, Dubois J, et al. A large unilateral renal artery aneurysm in a young child. Pediatric Radiology 2004;34(3): 253–255. 19. GoncharenkoV, Gerlock AJ Jr., Shaff MI, et al. Progression of renal artery fibromuscular dysplasia in 42 patients as seen on angiography. Radiology 1981;139(1):45–51. 20. Schreiber MJ, Pohl MA, Novick AC. The natural history of atherosclerotic and fibrous renal artery disease. Urol Clin North Am 1984;11(3):383–392. 21. Cragg AH, Smith TP, Thompson BH, et al. Incidental fibromuscular dysplasia in potential renal donors: long-term clinical follow-up. Radiology 1989;172(1):145-147. 22. Davidson RA, Barri Y, Wilcox CS. Predictors of cure of hypertension in fibromuscular renovascular disease. American Journal of Kidney Disease 1996;28(3): 334–338. 23. Smith JM, Stablein DM, Munoz R, et al. Contributions of the Transplant Registry: The 2006 Annual Report of the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS). Pediatric Transplantation 2007;11(4):366–373. 24. Benavides CA, Csapo Z, Timmins K, et al. Fibromuscular dysplasia recurrence after kidney transplantation: case report. Clinical Nephrology 2006;66(1):67–70. 25. Sevastos J, Lonergan M. Fibromuscular hyperplasia as a cause of transplant renal artery stenosis. Nephrology (Carlton) 2003;8(2): 98–100. 26. Chalmers RT, Dhadwal A, Deal JE, et al. The surgical management of renovascular hypertension in children and young adults. Eur J Vasc Endovasc Surg 2000;19(4): 400–405. Figure 3. 3D CT angiography. Panel A. Left renal artery shows beading typical of FMD (arrow). Panel B. Renal artery with a long segment of narrowing with aneurysmal dilatation at the major bifurcation (arrow). Figure 4. Conventional angiography. Tight stenosis of the right renal artery with marked post stenotic dilatation. Right nephrectomy was required after failed backbench repair to the thin-walled aneurysm. difficulty in controlling high blood pressure despite the use of a comprehensive antihypertensive regimen, intolerance to anti-hypertensive medications, patient non-adherence issues, and loss of renal volume due to ischemia.1 In addition, this procedure is often an appropriate alternative to lifelong dependency on a medication in a relatively young individual.13 Effective PTRAs result in cured or controlled blood pressure, which is often signified by reductions in plasma rennin activity and angiotensin II levels.9 When compared with surgery, percutaneous balloon angioplasty is less costly, able to be performed on an outpatient basis, results in lower morbidity, and the use of stenting is not primarily necessary.9 Follow up with duplex ultrasonography is recommended to monitor blood flow in the previously narrowed arterial segment and to ensure the effectiveness of the treatment.1 There is a subset of children with FMD, however, that appear to be resistant to PTRA. Associated adverse events may include recurrent stenosis, arterial occlusion with renal loss, and arterial rupture with extravasations and pseudo aneurysm formation. These patients are often treated surgically. Furthermore, the development of the Cutting Balloon (Boston Scientific, Natick, MA) may provide a minimally invasive alternative to surgery in these individuals.14 Careful selection of patients for PTRA is important for increasing the success rate, and follow-up to detect restenosis is required.15 Due to the advent of various medical therapies and percutaneous balloon angioplasty, surgical revascularization is only required in specific instances. Surgical reconstruction is reserved for patients with complex FMD that penetrates into the segmental arteries or those that present with macroaneurysms.10 Various surgical approaches exist, including aortorenal bypass, extracorporeal revascularization and autotransplantation, spleno- or hepato-renal bypass (Figure 4). Their specific utilization is based on the type of FMD lesion and its position.16 Success rates range from 89–97%. Approximately half the patients are cured of their hypertension, one-third experience an improvement in their hypertension and the remainder fails to improve after surgery.9 Factors that may decrease this success rate include longer duration of hypertension, associated atherosclerotic disease (adults), and complex branch-vessel repair (not infrequent in children).9 Prognosis There are presently no specific studies or reports on the long-term prognosis and outcome of FMD in children

Table of Contents Feed for the Digital Edition of Cath Lab Digest - October 2007

Saints Medical Center Fibromuscular Dysplasia in Children and Adolescents Cerebral Vascular Accident Following a Pulmonary Embolism: Search for the Hidden Patent Foramen Ovale Contents Clinical Editor’s Corner Meetings Calendar CEU Education Center Radiation Tracking in the Cardiac Catheterization Lab Letter to the Editor Carotid Stenting: An update Release from Stent-jail: Beneficial Snow-Plowing? Patient Management Guidelines Searching for a Cardiovascular Position? Tips for Creating a ‘Stand-Out’ Resume Long-Term Implications of Short-Term Closure Decisions – The Evolution to Vascular Access Management and the Boomerang Catalyst System The Ten-Minute Interview with… Angie Bowles, RN, CCRN CMS Issues Final FY 2008 IPPS Rule ACVP• Membership Page Experience with a New Workhorse Guidewire Ask the Clinical Instructor: Q&A for Those New to Cath Lab A Glimpse of the Future of Clinical Education: Boston Scientific’s SimSuite Bus Visits Carnegie Institute 2007 Educational Fair Held at the Washington Hospital Center Research Update: Original Contribution Abstracts from The Journal of Invasive Cardiology What Do You Think? A Virtual Cath Lab Viewer (VCL): The Development of an Online 3D C-arm Simulator and Coronary Anatomy Viewer Clinical & Industry News Cost-Effectiveness of the Radial versus Femoral Artery Approach to Diagnostic Cardiac Catheterization

Cath Lab Digest - October 2007

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