ABSTRACT
<p><b>OBJECTIVE</b>To provide anatomic evidence for identification of "holy plane" between fascia propria and its adjacent fascia in total mesorectal excision.</p><p><b>METHODS</b>A total of 26 pelvic specimens of adult male preserved in 10% formalin solution were used in this study. Twenty pelvis were employed for topographic anatomy, six for sectional anatomy.</p><p><b>RESULTS</b>Rectovesical septum was formed by the ventral part of the fascia propria and Denonvilliers' fascia, with no blood vessel and nerve coursed between two layers. Dorsal part of the fascia propria parallelled with the presacral fascia, with no blood vessel and nerve coursed between two layers in 80% of the pelvis. However, anatomic variations was encountered occasionally--with muscle-like tissue or fusion of presacral fascia interposed between them for 20%. The lateral space of rectum was between lateral part of the fascia propria and parietal fascia which witnessed pelvic nerve plexus and lateral ligament of the rectum traveling. Pelvic nerve plexus was categorized as two types according the relation between fascia propria and nerve plexus: fusion type accounting for 85% and rarefaction type for 15%.</p><p><b>CONCLUSION</b>'holy plane' is sandwiched between the fascia propria and its adjacent fascia--ventrally Denonvilliers fascia, dorsally presacral fascia and laterally parietal fascia.</p>