Variations of Urinary Bladder and the Urogenital Fatty Fascial Compartment with Different Filling of the Bladder are Notable Factors Relevant to Hernia Repair-Related Bladder Injury

The present study investigated bladder and urogenital fatty fascial compartment (UFFC) variations during bladder filling in an attempt to identify other possible causes of hernia repair-related bladder injury besides mesh migration. The study included 30 patients scheduled for abdominal computed tomography (CT) scan for nonhernia diseases. Sixty-four-slice CT scan was performed immediately after urination and no more than 30 minutes later. Three-dimensional images were constructed by two independent experienced readers. The empty bladder was triangular in shape, narrow in the front and broad in the rear. Its vertex deviated from midline of the abdominal wall in 11 cases (36.7%). With normal filling, it appeared as an irregular oval shape. Only two cases (6.7%) of empty bladder extended inside Hesselbach's triangle. However, this area was occupied to some extent in all cases during bladder filling (P = 0.003). The UFFC formed a molar-like structure in cross-section. In three dimensions, it appeared as an inverted V-shaped structure from the front. In the lateral view it appeared as a spoon that contained the bladder. UFFC volume increased from 61.85 ± 6.23 to 139.23 ± 5.29 cm³ with bladder filling (P < 0.0001). The UFFC can be clearly identified by CT scanning or three-dimensional reconstruction. The considerable spatial variation of the UFFC and movement and deformation of the mesh within this area may be related to bladder injury.