Mechanical cardiac valve thrombosis. Is thrombectomy justified?

To determine the incidence and results of the treatment offered to acute thrombotic obstructions of mechanical valvular prostheses, we have reviewed a series of 3,637 consecutive hospital survivors who, between January 1970 and September 1990, underwent single mitral or aortic and double mitroaortic valve replacements (MVR, AVR, and DVR, respectively). The cumulative follow-up in these patients was 22,783 years (mean, 7.2 years; range, 0.6-19 years). Sixty-five patients (24 MVR, 13 AVR, and 28 DVR) experienced 72 thrombotic prosthetic obstructions (42 mitral and 41 aortic prostheses) at a mean interval of 3.4 years (range, 0.6-14 years) after the operation. The actuarial prosthetic thrombosis free estimates were 96 +/- 0.9% for MVR, 97 +/- 0.9% for AVR, and 96 +/- 0.8% for DVR (all NS). Mortality associated with prosthetic thrombosis was 25% (four in the MVR group, five in the AVR group, and seven in the DVR group). Fifty-seven patients (22 MVR, 12 AVR, and 23 DVR) underwent a total of 62 reoperations, with a hospital mortality of 17% (two MVR, four AVR, and four DVR). In 37 of the latter patients (20 MVR, three AVR, and 14 DVR), we performed valve replacement (31 mitral prostheses and 14 aortic prostheses), with a hospital mortality of 16% (six of 37) and only one case of subsequent rethrombosis (actuarial rethrombosis free estimate, 96 +/- 3.6%). Conversely, five of the 27 patients (actuarial rethrombosis free estimate, 41 +/- 20%) (two MVR, 11 AVR, and 14 DVR) (seven mitral prostheses and 21 aortic prostheses) whose prosthetic valves were debrided developed rethrombosis during follow-up (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)