Acute thrombosis of abdominal aortic aneurysm. An uncommon entity.

Acute thrombosis of an abdominal aneurysm is a catastrophic complication which is little known. It presents as a sudden event, characteristically with lower abdominal pain, signs of profound lower extremity ischemia and pronounced bilateral lower extremity neuromuscular dysfunction. While the mechanism of thrombosis is not understood and is unpredictable, it is certain that the condition is rapidly fatal if uncorrected. The mortality of acute thrombosis is very high, similar to rupture, which is the most common complication of an abdominal aortic aneurysm. Diagnosis is not difficult, and must be followed by prompt surgical restoration of circulation of the lower half of the body, if death is to be prevented. This can be accomplished by aneurysm resection and graft replacement. Retrograde transfemoral thromboembolectomy should not be done. This report describes two successfully operated cases which dramatize the symptomatology of the condition and show the gratifying results of immediate surgical intervention. Only 30 cases (15 fatal) have been reported in the literature.