We found that in one-third of patients a change in diverticular size was observed corresponding to the site of the de novo recurrent fistula. An increase in diverticular size could be explained by increased diverticular wall tension (law of LaPlace) and attenuation of the diverticular wall resulting in a higher likelihood of developing a CSF-venous fistula and a decrease in size could be explained by decompression of the diverticulum through the fistula. A change in size of meningeal diverticula may help guide the invasive myelographic studies necessary to locate CSF-venous fistulas.
Schievink et al. (Mon,) studied this question.