[Primary failure of pericardial valvular heterografts]. / Défaillance primitive des hétérogreffes valvulaires péricardiques.

From July 1981 to October 1984, 79 Hancock pericardial valves were implanted in 74 patients surviving the hospital period and with a mean age of 64.2 years. Fifty-two patients underwent aortic valve replacement, 16 had mitral valve replacement, 5 bad a double replacement and 19 associated procedures were performed. The mean survival is 48 months. Until 1st June 1987, 11 primary failures have required reoperation (14.9%), 4 in the mitral position (4.6% patient-years), 7 in the aortic position (3.01% patient-years). The time to reoperation was 48.4 months for the aortic orifice and 36.5 months for the mitral orifice. The lesions most frequently encountered were tears (7 cases), calcifications (5 cases) and stretching of valvular tissue (2 cases); two patients died during the postoperative phase of this operation. Despite the small number of patients followed, this series demonstrates of high incidence of dysfunction due to primary tissue degeneration as, after the 5th year, the actuarial rate of absence of primary lesion is 85.3 +/- 8% with no significant difference between the aortic and the mitral orifices, although dysfunction appears to occur more rapidly in mitral prostheses. These results are much less favourable than those obtained with Ionescu bioprostheses in the aortic position of those obtained with porcine bioprostheses in either position. This justifies very regular clinical and echocardiographic follow-up of patients with Hancock pericardial valvular heterografts.

Changes in plasma fibronectin levels after cardiac and pulmonary surgery: role of cardiopulmonary bypass.

The changes in immunoassayable plasma fibronectin were studied during seven days after cardiac surgery with cardiopulmonary bypass (group A, 19 patients) or lung surgery without bypass (group B, 11 patients). In group A the fibronectin showed a series of rapid changes during the 24 perioperative hours. Simultaneous assessment of other plasma proteins (albumin, fibrinogen and immunoglobulin G) suggested that these changes mainly reflected hemodilution and hemoconcentration processes following the cardiopulmonary bypass, being influenced by the necessarily large transfusions of plasma. The fibronectin level decreased after day 1, with maximum depletion (averaging -32% of preoperative value) on day 3. Despite subsequent progressive rise, full restoration had not been reached by day 7. Group B did not show the initial rapid changes, but progressive fall in fibronectin level to a nadir on day 2 (-20% of preoperative) was followed by gradual return to outset value on days 4-5. The study demonstrated 1) that cardiac or lung surgery induces transient fibronectin depletion on days 2 to 3 postoperatively, and 2) that in surgery with cardiopulmonary bypass the decrease is significantly greater and more prolonged. It is proposed that this supplementary decrease is due to the large amounts of particulates of various origin entering the blood during the bypass.

[Circulating immune complexes and bronchopulmonary cancers]. / Complexes immuns circulants et cancers broncho-pulmonaires.

This study of circulating immune complexes was carried out using a C1q radio-labelled complement fixation test in 162 patients suffering from broncho-pulmonary disease. There were a similar number of positive results in primary cancer (44%) or secondary (53%) in tuberculosis (37%) or other pathologies (64%). With primary causes neither the histological type nor the stage of extension were associated with any particular frequency of positive tests. The diagnostic interest of research into circulating immune complexes thus appears limited. This study shows however, the activation of humoral systems of immunity during the course of broncho-pulmonary diseases, and raises the prospect of qualitative studies into the nature of the antigen implicated and their role in the mechanism of defence of the organism.