This volume contains the revised texts of the presentations at the 29th International Congress of the European Society of Cardiovascular Surgery, held from July 2-5, 1980, in Dusseldorf under the presidency of Jan Nielobowicz (Warsaw). We express our gratitude to all the authors who have been partici- pating in the Congress, in particular to the invited speakers A. R. Castaneda (Boston), D. B. Effler (Syracuse), F. Fontan (Bordeaux), F. Robicsek (Charlotte), and D. N. Ross (London) for their cooperation. We are grateful to our colleagues of the Surgical Department B at the University of Dusseldorf, J. A. Herzer, G. Irlich, R. Karfer, and A. Krian, for their help during preparation and organisation of the Congress. Finally, we are indebted to Sanol Schwarz GmbH for its support of this publication. Dusseldorf, June 1981 Wolfgang Bircks Jarg Ostermeyer Hagen D. Schulte Contents The Contribution of European Surgeons to the Development of Modern Vascular Surgery. J. Nielubowicz. With 20 Figures *. ****** Session I Cardiac Surgery Valvular Surgery I Chairman: V. O. Bjork, Stockholm; Co-Chairman: A. Carpentier, Paris Special Morphological Structures Along the Closing Zone of the Mitral Valve. H. Heine and M. Laatz. With :5 Figures **. **. . *. *. . ** 25 Conservative Surgery of the Mitral Valve. Annuloplasty on a New Adjustable Ring. M. Puig Massana, J. M. Calbet, and E. Castells With :5 Figures ********. **. *****. **. ****. *****************...*.

Cette etude interroge la possibilite de modifier l'action publique locale par le recours a la participation citoyenne. L'auteur adopte pour ce faire une approche pragmatiste afin de determiner les conditions reelles de la mise en uvre des dispositifs participatifs et de leurs effets concrets en s'appuyant sur l'exemple de la ville de Nancy et du Conseil general de Meurthe-et-Moselle. Les conditions de l'emergence d'une norme participative guidant l'action publique paraissent indiquer une certaine retenue, caracterisee par la restriction du champ d'application des procedures participatives ou des savoirs citoyens mobilises. Les effets de l'application de la norme participative sur l'espace public local suscitent egalement des interrogations. Les dispositifs etudies semblent tres eloignes des cadres theoriques deliberatifs et participatifs. Le defaut d'inclusion, la persistance de logiques de politisation propres au systeme representatif interrogent en definitive sur la capacite de la democratie participative a relever les defis qu'elle se propose de surmonter.