In 3231 prosthetic valves implanted between January 1975 and November 1990, we observed 61 cases of prosthetic obstruction of biological origin with clinical and laboratory findings of severe functional impairment which required surgery as emergency treatment. The hospital mortality was 19.67% (12/61). The obstruction was due to a primary thrombosis in all 5 bioprostheses which were not anticoagulated and in 11/56 (19.64%) mechanical prostheses of which 3 were not anticoagulated and 4 were not properly anticoagulated. The obstruction was due to fibrous tissue overgrowth in the other 45 mechanical prostheses (80.35%) with secondary thrombosis in 34 cases (60.71%) and no thrombosis in 11 (19.64%); 71.11% of these prostheses were adequately anticoagulated. Of the 61 obstructed prostheses, 53 were mitral and 8 were aortic. No tricuspid obstruction was observed. A statistical assessment by multiple correspondence, cluster and chi square analysis was performed in two groups of patients with different models of mechanical mitral prostheses. The 5-year actuarial incidence of obstruction was 6.08%. Significant risk factors were: tilting disc prostheses, prostheses without pyrocarbon coating, large prostheses, tilting disc prostheses with a small orifice posteriorly oriented, atrial fibrillation, enlarged left atrium, time from implant >4 years, age between 40 and 50 years. In our opinion, prosthetic obstruction may be referred to a primary thrombosis only in cases where it may be prevented by adequate anticoagulation. In most cases, the obstruction is produced by periprosthetic fibroblastic proliferation which may develop in spite of adequate anticoagulation in both groups. Important risk factors are the prosthetic design, pyrocarbon coating and orientation, time from the implant, pregnancy, endocarditis, bioprosthetic degeneration, composite conduits, local haemodynamic conditions, age and individual factors. Present knowledge of this complication is still inadequate and therefore we must find a solution to a problem that still causes high mortality.
ACUTE THROMBOSIS OF PROSTHETIC VALVES - A MULTIVARIATE-ANALYSIS OF THE RISK-FACTORS FOR A LIFE-THREATENING EVENT
DE LUCA TUPPUTI SCHINOSA, Luigi;
1992-01-01
Abstract
In 3231 prosthetic valves implanted between January 1975 and November 1990, we observed 61 cases of prosthetic obstruction of biological origin with clinical and laboratory findings of severe functional impairment which required surgery as emergency treatment. The hospital mortality was 19.67% (12/61). The obstruction was due to a primary thrombosis in all 5 bioprostheses which were not anticoagulated and in 11/56 (19.64%) mechanical prostheses of which 3 were not anticoagulated and 4 were not properly anticoagulated. The obstruction was due to fibrous tissue overgrowth in the other 45 mechanical prostheses (80.35%) with secondary thrombosis in 34 cases (60.71%) and no thrombosis in 11 (19.64%); 71.11% of these prostheses were adequately anticoagulated. Of the 61 obstructed prostheses, 53 were mitral and 8 were aortic. No tricuspid obstruction was observed. A statistical assessment by multiple correspondence, cluster and chi square analysis was performed in two groups of patients with different models of mechanical mitral prostheses. The 5-year actuarial incidence of obstruction was 6.08%. Significant risk factors were: tilting disc prostheses, prostheses without pyrocarbon coating, large prostheses, tilting disc prostheses with a small orifice posteriorly oriented, atrial fibrillation, enlarged left atrium, time from implant >4 years, age between 40 and 50 years. In our opinion, prosthetic obstruction may be referred to a primary thrombosis only in cases where it may be prevented by adequate anticoagulation. In most cases, the obstruction is produced by periprosthetic fibroblastic proliferation which may develop in spite of adequate anticoagulation in both groups. Important risk factors are the prosthetic design, pyrocarbon coating and orientation, time from the implant, pregnancy, endocarditis, bioprosthetic degeneration, composite conduits, local haemodynamic conditions, age and individual factors. Present knowledge of this complication is still inadequate and therefore we must find a solution to a problem that still causes high mortality.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
