MISCELLANEOUS AORTIC DISEASE



Large peripheral arterial emboli may obstruct the abdominal aortic bifurcation, resulting in so-called saddle emboli. These usually originate from the left heart but rarely may originate from the aorta itself in the area of an atherosclerotic lesion. Other rarer causes are “paradoxical em­boli” (from the right heart or venous.vsystem in patients with right-to-left shunts), atrial myxo­mas, or infective endocarditis (very large emboli can occur in acute endocarditis and fungal en­docarditis). Obstruction at the aortic bifurcation is characterized by the sudden onset of severe pain in both legs, peripheral neurological abnor­malities, and evidence of decreased perfusion bi­laterally. It must be differentiated from acute ath­erosclerotic aortic thrombosis and dissecting aneurysm. The diagnosis is confirmed by angiog­raphy. Surgical removal of the clot with subse­quent anticoagulation and/or treatment of the un­derlying etiology is necessary.

Infected aortic aneurysms are rare. The most common congenital aortic anomaly is coarctation of the aorta (see Chapter 4). Congenital aortic aneurysms of the sinus of Valsalva may rupture into the right atrium or ventricle, producing a con­tinuous murmur. Sinus of Valsalva aneurysms can occasionally produce coronary occlusion, con­duction disturbances, or valvular malfunction.