Results of represervation of the chordae tendineae during redo mitral valve replacement

Previous studies have shown that preservation of the chordae tendineae improves early and late postoperative left ventricular function after mitral valve replacement. This report describes the results of represervation of the chordae tendineae during redo mitral valve replacement in patients who had their chordae tendineae preserved during their initial operation.

Fifty-four patients undergoing reoperative mitral valve replacement with preservation of their chordal annular attachments (chordae group) were compared with 187 patients who had redo mitral valve replacement without preservation of the chordae (nonchordae group). The interval between the initial operation and the reoperation was 8.7 +/- 4.4 years in the chordae group and 8.6 +/- 4.9 years in the nonchordae group (p = 0.315). Seventy-three patients underwent aortic valve replacement during their redo mitral valve replacement compared with 168 patients who had mitral valve replacement alone. There were 15 patients who had their chordal attachments represerved during redo double-valve replacement.

In the chordae group, intraoperative assessment revealed excellent chordal connection between the preserved papillary muscles and the mitral annulus in all patients. One patient had adhesions between the preserved chordae and the stent of the tissue valve. The chordal attachments were preserved during insertion of the second valve in all patients. The incidence of low output syndrome and operative mortality in the chordae group was 16.7% and 7.4%, respectively. In the nonchordae group, the incidence of low output syndrome was 27.3% (p = 0.112 compared with the chordae group) and the operative mortality was 13.4% (p = 0.236 compared with the chordae group). In patients with double-valve replacement, represervation of the chordae was associated with a reduction in low output syndrome (0% versus 24%; p = 0.034) and mortality (6.7% versus 15.5%; p = 0.374).

Preservation of the chordal attachments between the papillary muscles and the mitral annulus can be accomplished during reoperative mitral valve replacement. Represervation of the chordae tendineae may reduce postoperative low output syndrome, especially in high-risk patients undergoing redo double-valve replacement.