Annular abscesses in surgical endocarditis: anatomic, clinical, and operative features.

ABSTRACT

BACKGROUND: The aim of this study was to determine patterns of anatomic, clinical, and operative features in surgical endocarditis (SE) with annular abscess (AA). METHODS: The study consisted of a retrospective analysis of SE cases with AA between 1981 and 1997. RESULTS: A total of 41 cases with AA were found in 106 consecutive SE cases. There was a higher incidence of AA in aortic (37 of 71 [52%]) (p<0.01) compared to mitral (6 of 42 [14.3%]) or tricuspid (0 of 12) infections. However, the mitral abscesses had a greater tendency toward fistula or pseudoaneurysm formation (4 of 6 [67%]) than other valve abscess cavities (7 of 46 [15%]) (p<0.01). Severe heart failure (p<0.01), heart block (p<0.05), and fistula/pseudoaneurysm (p<0.001), were more often found in SE with AA than without. There were 46 separate aortic AA in 37 instances of aortic valve SE. Of these, 31 of 46 (67%) were less than 1 cm (group 1), 10 of 46 (22%) were large but confined to a given cusp annulus (group 2), 4 of 46 (8.6%) were large between multiple cusps (group 3), and 1 of 46 (2.2%) was circumferential (group 4). There were four instances of aortoventricular discontinuity. Group 1 abscesses were repaired by local closure without a patch significantly more often than the other groups. The mortality of SE with AA was significantly greater for larger AA (groups 3 and 4, 3 of 5 [60%]) than for smaller AA (groups 1 and 2, 0 of 36) (p<0.001). There were six separate mitral AA in six instances of mitral SE, five requiring patch repair. The 30-day operative mortality for AA cases was 3 of 41 (7.3%) compared to 2 of 65 (3.1%) without AA. All AA mortalities involved large AA in the aortic valve position. Of 35 mechanical valves placed for AA, only one required subsequent removal for prosthetic endocarditis. CONCLUSIONS: Annular abscesses are most frequent in aortic AA, but fistulas/pseudoaneurysms are more frequent in mitral AA. Small to moderate aortic AA can be managed by local closure without an increased mortality compared to SE without AA. Patients with large aortic AA have a higher operative mortality. Mechanical prostheses are safe and effective for the majority of patients with AA.