Radiological aspects of Zenker's diverticulum.

In a retrospective study of 143 patients with Zenker's diverticulum followed for a period of 20 years, we classified the diverticula into 4 categories (A, B, C and D) using Brombart's scheme as a basis; the difference between the first two categories, however, was made on the basis of a morphological-dynamic criterion rather than a purely morphological one. Furthermore, a quantitative index was introduced to define the size of the diverticulum. In two cases we noted a substantial increase in volume with the transition from category C to D after more than 3 years, but we were unable to demonstrate an evolution from category A to B, nor from B to C. Our study confirms, on a large scale, the presence of three possible pathogenetic mechanisms, as proposed earlier in the literature: decreased relaxation of the upper esophageal sphincter as the most frequent factor in all categories except category A, and delayed opening or early closing of this sphincter as less frequent factors. The good relaxation of the upper esophageal sphincter in our category A, the different sex ratio and the absence of evolution in this category suggest that category A does not necessarily evolve further.