A Rare Case of Periadventitial Fibromuscular Dysplasia in External Iliac Artery: A Short Report
Article Outline
Fibromuscular dysplasia (FMD) is a non-atherosclerotic, non-inflammatory vascular pathology that affects medium to small sized arteries and has 3 different histological entities.1,4 It rarely affects iliac arteries. We report a histologically proven case of periadventitial FMD of the iliac artery in a young cyclist, which was treated successfully with surgery.
Keywords: Fibromuscular dysplasia, Iliac artery, Competitive cyclist
Introduction
FMD is a non-atherosclerotic, non-inflammatory vascular pathology that affects medium to small sized arteries. It commonly affects females,1, 2 83% in fourth decade, with a female to male ratio of 8:1–2.2, 3 Renal vessels are the commonest involved (60–75%),1, 3, 4 followed by carotids (25–30%)1, 3, 4 and iliacs.5 Histologically, it has 3 different entities. We report a case of periadventitial FMD which is the rarest form and has not yet been reported in literature.
Case Report
A 27 years old male professional cyclist presented with worsening symptoms of right leg weakness and numbness, exaggerated by sprinting for a few minutes on bicycle. He denied having any rest or night pains and had no other risk factors. Examination revealed bilateral palpable pulses.
Bilateral arterial duplex scans and angiograms in flexed and extended hips revealed a kink in the right external iliac artery with a stenosis just below its origin.
The diseased segment was resected and end to end anastomosis was performed. Histology revealed irregular and concentric thickening of intima (Fig. 1) and prominent adventitial reaction with bundles of muscle in and amongst the connective tissue (Fig. 2). The media and elastic lamellae were unremarkable. These are diagnostic of periadventitial FMD with intimal changes secondary to the adventitial reaction.
Fig. 1
Low-power picture to show the irregular but concentric intimal thickening.
Fig. 2
Note the bundles of smooth muscle in the thickened adventitia.
Discussion
In comparison to the relatively more common condition of Endofibrosis in endurance athletes,6, 7 FMD of the iliac arteries is rare.5 Endofibrosis most commonly affects the first few centimetres of the external iliac arteries and histologically shows fibrotic thickening of the intima with no signs of inflammation.
FMD was initially described by Leadbetter and Burkland in 19381, 2, 4, 5 and was later classified histologically according to the involvement of vessel wall by Harrison and McCormack in 1971.4
Intimal FMD (1%–5%) is characterized by circumferential or eccentric accumulation of fibrous tissue in the intima. A long tubular stenosis or a focal smooth stenosis is seen.4 Medial FMD (75%–90%) can be medial fibroplasia with the classical “string of beads” sign on angiogram, the beads being larger in diameter than the proximal unaffected artery. In contrast, the “beads” are typically smaller in diameter than the proximal unaffected artery in perimedial fibroplasias. Medial hyperplasia typically has excessive smooth muscle proliferation.4 Periadventitial FMD (1%–2%) involves the adventitia extending into surrounding tissues.4
Humoral, mechanical, genetic, ischemic factors,1, 4, 5 and smoking4 are hypothesized to cause FMD. Oestrogen increases secretory activity of smooth muscle and fibroblasts. Mechanical and ischemic factors cause increase in proliferation of connective tissue.4 A high incidence is seen in Caucasians and with HLA-DRW6 antigen. Smoking is related but exact pathogenesis remains uncertain.4
Clinical manifestations depend upon the site of involvement and associated complications. It may manifest as loin pain or hypertension (renal arteries),4 TIA, amaurosis fugax, stroke or Horner's syndrome (carotid arteries)4 or lower abdominal pain,2 intermittent claudication2, 3, 5 or acute lower extremity ischemia (iliac arteries).1, 5
Angiography remains the gold standard tool of investigation, whereas, ultrasound and CT scans have been used in clinical emergencies.
Management of FMD varies from conservative control, endovascular correction to surgical resection, depending upon clinical picture. Antiplatelets and antihypertensives have been used to prevent worsening of dissection3 and hypertension, respectively. Graduated dilatation5 and angioplasty3 have been used as minimal invasive approaches to correct stenosis. Surgically, diseased segments are resected.1, 2, 5
Conclusion
To our knowledge, there has not been a reported case in the literature of periadventitial fibroplasia concomitantly associated with kinked iliac arteries that is treated successfully by excision of the kink and end to end anastomosis. The decision for surgical intervention was dictated by the presence of the kink, otherwise angioplasty would have been our first treatment option.
Acknowledgement
The authors like to thank Dr PJ Gallagher, Southampton General Hospital, for his kind help with the histology.
References
- . Treatment of fibromuscular hyperplasia of the external iliac artery by percutaneous transluminal angioplasty. Australas Radiol. 1993 May;37(2):223–225
- Recurrent aneurysms of the upper arteries of the lower limb: an atypical manifestation of fibromuscular dysplasia – a case report. Angiology. 1987 May;38(5):411–416
- . External iliac artery fibrodysplasia. J Belge Radiol. 1995 Jun;78(3):180–181
- . Arterial fibromuscular dysplasia. Mayo Clin Proc. 1987 Oct;62(10):931–952
- . Clinical spectrum of symptomatic external iliac fibromuscular dysplasia. J Vasc Surg. 1990 Oct;12(4):488–495[discussion 495–496]
- . Past, present and future of arterial endofibrosis in athletes: a point of view. Sports Med. 2004;34(7):419–425
- Clinical case of the month. Iliac artery endofibrosis in a soccer player. Rev Med Liege. 2002 Mar;57(3):135–137
PII: S1533-3167(07)00038-6
doi:10.1016/j.ejvsextra.2007.10.001
© 2007 European Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Refers to article:
- A Rare Case of Periadventitial Fibromuscular Dysplasia in External Iliac Artery: A Short Report , 21 January 2008
