1. MYCOTIC ANEURYSM OF INFRARENAL AORTA(MAIA) ABSTRACT ID NUMBER- 209

2. Clinical history 28 years female with history of chronic kidney disease on hemodialysis Presented with abdominal pain, giddiness, generalized weakness since 2 months USG showed dilated infra renal aorta with ill defined walls and was subject to CT aortogram

3. Protocol for CT Aortogram Non-gated CT aortogram was done using 80ml of non-ionic iodinated contrast media with 18G cannula @ 4.5ml/ sec with 120 Kv and 300-550 auto mA through bolus track method and images acquired at 0.625 mm thickness from the aortic root to the common femoral arteries

4. Case findings There is evidence of large saccular aneurysm in the infrarenal aorta just above bifurcation. Anterior wall is not clearly defined and appear irregular

6. Multiple enlarged lymph nodes seen, around celiac axis in the retroperitoneum, in the preaortic, paraaortic, aortocaval & retrocaval regions

8. Case discussion

9. An aneurysm is a pathologic dilatation of a segment of a blood vessel TRUE ANEURYSM Involves all the three layers of vessel wall intima, media and adventitia PSEUDO ANEURYSM There is disruption of intimal and medial layers and the dilated segment of aorta is lined by adventitia only

10. Classification of aneurysms by their gross appearance FUSIFORM ANEURYSM Affects the entire circumference of a segment of a segment the vessel, resulting in a diffusely dilated artery SACCULAR ANEURYSM Involves only a portion of the circumference, resulting in an outpouching of the vessel wall

11. Classification based on pathology Atherosclerotic aortic aneurysms(mc) Aortic sinus aneurysms Inflammatory abdominal aortic aneurysms Mycotic aneurysms

12. Classification of mycotic aneurysms A) true mycotic aneurysms B) secondary mycotic aneurysms due to bacterial arteritis C) infected preexisting abdominal aortic aneurysms D) post traumatic infected false aneurysms

13. Lymph node biopsy from left paraaortic nodes Showed macrophages, Langerhans giant cells, suggestive of granulomatous inflammation consistent with tuberculosis

14. Conclusion So the above case discussed is a secondary mycotic aneurysm due to tuberculosis

15. Epidemiology Secondary mycotic aneurysms due to tuberculosis is very rare. To define the epidemiology, pathogenesis, pathology, presentation, and management of tuberculous mycotic aneurysm of the aorta (TBAA) in the therapeutic era, we reviewed all of the cases reported in the English language literature from 1945 to the present. To the 43 cases in the published literature. Although it is exceedingly rare, the prevalence of this lesion has remained relatively constant. In 75% of the cases, TBAA appeared to result from erosion of the aortic wall by a contiguous focus; 25% from direct seeding of the aortic intima or of the adventitia or media (via the vasa vasorum). Most of the aneurysms were saccular (90%)

16. References 1. Long R. Tuberculous Mycotic Aneurysm of the Aorta *. Chest. 1999;115(2):522. 2. Papadimitriou D, Tachtsi M, Koutsias S, Pitoulias G, Mpompoti T. Mycotic aneurysm of the infrarenal aorta. VASA. 2003;32(4):218-220. 3. Driscoll P. Gray's Anatomy, 39th Edition. Emergency Medicine Journal. 2006;23(6):492-492. 4. Ashton HA et al: The Multicenter Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: A randomized controlled trial. The Multicenter Aneurysm Screening Study Group. Lancet 360:1531, 2002 [PMID: 12443589