Why perirenal disease does not extend into the pelvis: the importance of closure of the cone of the renal fasciae.

Abstract

There is an anatomic barrier between the inferior perirenal space and the extraperitoneal pelvis formed by the fusion of the leaves of the renal fasciae into a single multilaminar fascia that acts as a barrier of disease extension. The multilaminar nature of this fascia, however, may also act as a filter, allowing some permeability between its layers. This potential interlaminar pathway is rare and is manifested as fascial thickening on CT scans. This laminar filter-barrier observation explains the lack of extension of perirenal diseases into the pelvis.