After several weeks of
fever and
chills, a 31-year-old logger developed
pain in his right thigh. Upon examination a tender, pulsating upper thigh mass was found with a long loud bruit arising from it. Severe aortic insufficiency was present; however, blood cultures were negative. An angiogram, captured blood with contrast spewing from the profunda femoral artery to fill a 5 x 10 cm sac. A
false aneurysm was diagnosed and resected; numerous gram positive cocci were present in cut sections, but cultures from the cavity grew the gram negative bacteria Salmonella and Alcaligenes. After one month of intravenous
ampicillin the aortic valve was replaced after being destroyed by
endocarditis.
Ampicillin was continued and recovery was uneventful.
Mycotic aneurysms are commonly caused by Salmonella (10%), which was second only to Staphylococcus (30%). The femoral artery accounts for 38% of all
mycotic aneurysms. They typically present with a pulsatile mass (52%), bruit (50%), and
fever (48%). This diagnosis can be supported by
leukocytosis (64-71%), positive blood cultures (50-85%), and a history of arterial
trauma (51%) (injection
drug use,
intravascular procedure, or
trauma) or
endocarditis (10%).