Evolution of the in situ bypass.

The origins of the in situ vein bypass in Montreal, Canada and in London, England, are described. The subsequent evolution of the original techniques in Europe and the United States are followed. The condemnation of the procedure in the United States in 1969 is noted. The persistence of Cartier in Montreal and Hall in Norway and the revival of interest in the procedure by Leather and Karmody in Albany, New York, is recounted. The pathophysiologic basis for the complications of the method are analyzed and the measures by which they are currently remedied are shown. The method's present superiority is reported. The initial rejection and slow acceptance of this method is explained in terms of the special conditions attendant on its introduction and the attitudes of surgeons to new procedures.