A Case of Syphilitic Aortic Aneurysm

Abstract

Syphilis is a known cause of aortic aneurysm. We report a case in which we were unable to diagnose syphilitic aortic aneurysm before surgery in a 71-year-old male. Computed tomography identified a large ascending aneurysm with a maximum diameter of 60 mm. The serum rapid plasma reagin (RPR) test was positive at 2.6 R.U. and the fixed Treponema pallidum Latex Agglutination (TPLA) test was positive at 2,387 U/ml. However, the fusiform aneurysm was diagnosed as an atherosclerotic aneurysm before surgery. We performed aortic hemi-arch replacement and right brachiocephalic artery/left common carotid artery reconstructive surgery. However, the aortic aneurysm was strongly adherent to the surrounding tissues, and thickening of the aortic arch wall was observed. Pathological findings showed infiltration of plasma cells around the feeding artery in the media of the aortic aneurysm wall, and we postoperatively diagnosed a syphilitic aortic aneurysm. On postoperative day 8, we started oral administeration of amoxicillin 1,000 mg per day for 2 weeks.
The patient did well after surgery, and was discharged on postoperative day 13. The RPR became negative and the TPLA was 1,542 U/ml at postoperative month 18. Today, a syphilitic aortic aneurysm is extremely rare, and may be incorrectly diagnosed before surgery unless consciously considered.