Segmental Arterial Mediolysis

ABSTRACT

Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory arteriopathy, which is characterized by dissecting aneurysms resulting from lysis of the outer media of the arterial wall. The most common presentation is abdominal pain and hemorrhage in the elderly. Computed tomography (CT) and angiography imaging findings overlap with various vasculitides and include segmental changes of aneurysm and stenosis. A key distinguishing feature is the presence of dissections, the principle morphologic expression of SAM. Differentiation and exclusion of an inflammatory arteritis is crucial in appropriate management, as immunosuppressants generally used for treatment of vasculitis may be ineffective or even worsen the vasculopathy. Although the disease can be self-limiting without treatment or with conservative medical therapy, the acute process carries a 50% mortality rate and may necessitate urgent surgical and/or endovascular therapy. Prompt recognition and diagnosis are therefore of utmost importance in appropriate management of this rare entity.

KEYWORDS

Segmental arterial mediolysis - imaging findings

REFERENCES

• 1 Slavin R E, Gonzalez-Vitale J C. Segmental mediolytic arteritis: a clinical pathologic study.  Lab Invest. 1976;  35 23-29
• 2 Gruenwald P. Necrosis in the coronary arteries of newborn infants.  Am Heart J. 1949;  38(6) 889-897
• 3 Slavin R E, Cafferty L, Cartwright Jr J. Segmental mediolytic arteritis. A clinicopathologic and ultrastructural study of two cases.  Am J Surg Pathol. 1989;  13(7) 558-568
• 4 Slavin R E, Saeki K, Bhagavan B, Maas A E. Segmental arterial mediolysis: a precursor to fibromuscular dysplasia?.  Mod Pathol. 1995;  8(3) 287-294
• 5 Armas O A, Donovan D C. Segmental mediolytic arteritis involving hepatic arteries.  Arch Pathol Lab Med. 1992;  116(5) 531-534
• 6 Inayama Y, Kitamura H, Kitamura H, Tobe M, Kanisawa M. Segmental mediolytic arteritis. Clinicopathologic study and three-dimensional analysis.  Acta Pathol Jpn. 1992;  42(3) 201-209
• 7 Leu H J. Cerebrovascular accidents resulting from segmental mediolytic arteriopathy of the cerebral arteries in young adults.  Cardiovasc Surg. 1994;  2(3) 350-353
• 8 Hashimoto T, Deguchi J, Endo H, Miyata T. Successful treatment tailored to each splanchnic arterial lesion due to segmental arterial mediolysis (SAM): report of a case.  J Vasc Surg. 2008;  48(5) 1338-1341
• 9 Lie J T. Segmental mediolytic arteritis. Not an arteritis but a variant of arterial fibromuscular dysplasia.  Arch Pathol Lab Med. 1992;  116(3) 238-241
• 10 Shimohira M, Ogino H, Sasaki S et al.. Transcatheter arterial embolization for segmental arterial mediolysis.  J Endovasc Ther. 2008;  15(4) 493-497
• 11 Inada K, Maeda M, Ikeda T. Segmental arterial mediolysis: unrecognized cases culled from cases of ruptured aneurysm of abdominal visceral arteries reported in the Japanese literature.  Pathol Res Pract. 2007;  203(11) 771-778
• 12 Slavin R E, Inada K. Segmental arterial mediolysis with accompanying venous angiopathy: a clinical pathologic review, report of 3 new cases, and comments on the role of endothelin-1 in its pathogenesis.  Int J Surg Pathol. 2007;  15(2) 121-134
• 13 Heritz D M, Butany J, Johnston K W, Sniderman K W. Intraabdominal hemorrhage as a result of segmental mediolytic arteritis of an omental artery: case report.  J Vasc Surg. 1990;  12 561-565
• 14 Michael M, Widmer U, Wildermuth S, Barghorn A, Duewell S, Pfammatter T. Segmental arterial mediolysis: CTA findings at presentation and follow-up.  AJR Am J Roentgenol. 2006;  187(6) 1463-1469
• 15 Soulen M C, Cohen D L, Itkin M, Townsend R R, Roberts D A. Segmental arterial mediolysis: angioplasty of bilateral renal artery stenoses with 2-year imaging follow-up.  J Vasc Interv Radiol. 2004;  15(7) 763-767
• 16 Ryan J M, Suhocki P V, Smith T P. Coil embolization of segmental arterial mediolysis of the hepatic artery.  J Vasc Interv Radiol. 2000;  11(7) 865-868
• 17 Obara H, Matsumoto K, Narimatsu Y, Sugiura H, Kitajima M, Kakefuda T. Reconstructive surgery for segmental arterial mediolysis involving both the internal carotid artery and visceral arteries.  J Vasc Surg. 2006;  43(3) 623-626
• 18 LaBerge J, Kerlan R L. SCVIR Annual Meeting film panel sessions: case 3. Segmental arterial mediolysis (SAM) resulting in spontaneous dissections of the middle colic and left renal arteries and occlusion of SMA. Society of the Cardiovascular & Interventional Radiology.  J Vasc Interv Radiol. 1999;  10 509-513
• 19 Molloy E S, Langford C A. Vasculitis mimics.  Curr Opin Rheumatol. 2008;  20(1) 29-34
• 20 Rengstorff D S, Baker E L, Wack J, Yee L F. Intra-abdominal hemorrhage caused by segmental arterial mediolysis of the inferior mesenteric artery: report of a case.  Dis Colon Rectum. 2004;  47 769-772
• 21 Sakano T, Morita K, Imaki M, Ueno H. Segmental arterial mediolysis studied by repeated angiography.  Br J Radiol. 1997;  70(834) 656-658
• 22 Wang J JL, Huang T W. Ischemic colitis caused by an isolated dissecting aneurysm of the left colic artery: a presumed case of segmental mediolytic arteriopathy.  J Formos Med Assoc. 1994;  93(8) 715-720
• 23 Phillips C K, Lepor H. Spontaneous retroperitoneal hemorrhage caused by segmental arterial mediolysis.  Rev Urol. 2006;  8(1) 36-40
• 24 Frauenfelder T, Wildermuth S, Marincek B, Boehm T. Nontraumatic emergent abdominal vascular conditions: advantages of multi-detector row CT and three-dimensional imaging.  Radiographics. 2004;  24(2) 481-496
• 25 Ha H K, Lee S H, Rha S E et al.. Radiologic features of vasculitis involving the gastrointestinal tract.  Radiographics. 2000;  20 779-794
• 26 Abdelrazeq A S, Saleem T B, Nejim A, Leveson S H. Massive hemoperitoneum caused by rupture of an aneurysm of the marginal artery of Drummond.  Cardiovasc Intervent Radiol. 2008;  31(Suppl 2) S108-S110
• 27 Lie J T. Systemic, cerebral and pulmonary segmental mediolytic arteriopathy: villainous masqueraders of vasculitis.  Cardiovasc Pathol. 1996;  5 305-314