RESULTS OF REPRESERVATION OF THE CHORDAE TENDINEAE DURING REDO MITRAL-VALVE REPLACEMENT

Background. Previous studies have shown that preservation of the chord ae tendineae improves early and late postoperative left ventricular fu nction after mitral valve replacement. This report describes the resul ts of represervation of the chordae tendineae during redo mitral valve replacement in patients who had their chordae tendineae preserved dur ing their initial operation. Methods. Fifty-four patients undergoing r eoperative mitral valve replacement with preservation of their chordal annular attachments (chordae group) were compared with 187 patients w ho had redo mitral valve replacement without preservation of the chord ae (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 rep lacement compared with 168 patients who had mitral valve replacement a lone. There were 15 patients who had their chordal attachments represe rved during redo double-valve replacement. Results. In the chordae gro up, intraoperative assessment revealed excellent chordal connections b etween the preserved papillary muscles and the mitral annulus in all p atients. One patient had adhesions between the preserved chordae and t he stent of the tissue valve. The chordal attachments were preserved d uring insertion of the second valve in all patients. The incidence of low output syndrome and operative mortality in the chordae group was 1 6.7% and 7.4%, respectively. In the nonchordae group, the incidence of low output syndrome was 27.3% (p = 0.112 compared with the chordae gr oup) and the operative mortality was 13.4% (p = 0.236 compared with th e chordae group). In patients with double-valve replacement, represerv ation of the chordae was associated with a reduction in low output syn drome (0% versus 24%; p = 0.034) and mortality (6.7% versus 15.5%; p = 0.374). Conclusions. Preservation of the chordal attachments between the papillary muscles and the mitral annulus can be accomplished durin g 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.