Question: Maryland Subscriber Answer: Abdominal aortic aneurysm (AAA) occurs in the abdominal region. Use 441.3 (Aortic aneurysm and dissection; abdominal aneurysm, ruptured) or 441.4 (... abdominal aneurysm without mention of rupture) to report the condition with or without rupture. Thoracic aortic aneurysm (TAA) occurs in the thoracic region. Report TAA as 441.1 (... thoracic aneurysm, ruptured) or 441.2 (... thoracic aneurysm without mention of rupture), depending on whether a rupture is present. For an aneurysm between the two regions, report 441.6 (... thoracoabdominal aneurysm, ruptured) or 441.7 (... thoracoabdominal aneurysm, without mention of rupture), depending on rupture status. For an unspecified site, use 441.5 (... aortic aneurysm of unspecified site, ruptured) or 441.9 (... aortic aneurysm of unspecified site without mention of rupture). Watch for: Aortic ectasia, which involves dilation of the aorta but to a lesser degree than an aneurysm, is getting its own set of codes effective Oct. 1, 2010 ICD-9 also distinguishes these codes by anatomic location: