直肠周围筋膜和间隙环形分布模式的解剖学观察

目的阐明与全直肠系膜切除术密切相关的直肠周围筋膜和间隙的解剖结构。方法利用21具固定尸体（男15、女6）制作30个半盆腔和6个3／4盆腔．解剖和观察直肠周围筋膜和间隙。结果直肠后方由前至后存在3层筋膜：包绕直肠系膜的直肠固有筋膜、骶前筋膜和与骶骨骨膜相愈着的梨状肌筋膜。直肠系膜包含两个部分：经典的由直肠固有筋膜所包绕的后外侧脂肪为其后部．由Denonvilliers筋膜后叶包绕的直肠前脂肪为其前部。骶前筋膜向前延续于Denonvilliers筋膜前叶．将直肠系膜和梨状肌筋膜之间的间隙分为前方的直肠后间隙和后方的骶前间隙。直肠后间隙向头侧与左结肠后间隙交通,向前与Denonvilliers筋膜两叶之间的间隙（直肠前间隙）交通。结论以直肠系膜为中心,直肠固有筋膜、骶前筋膜和盆壁肌肌膜自内向外呈环形分布。骶前筋膜将直肠周围的间隙分为中心的直肠后间隙和外周的骶前间隙两个环形间隙。直肠后间隙是全直肠系膜切除术的理想外科平面。

Anatomic observation of annular distribution of perirectal fascia and space around the mesorectum

Objective To explore the regional anatomy of the rectum including the perirectal fasciae and spaces.Methods Twenty-one cadavers (15 males and 6 females) were embalmed and their vessels were visualized by injection with color dye.From the cadavers,30 hemipelvis and 6 three-quarter pelvis were harvested.The perirectal fasciae and spaces and the pelvic autonomic nerves were dissected and examined.Results Three tissue layers were dissected from the inside to the periphery including the proper rectal fascia enveloping the mesorectum,the presacral fascia,and the piriformis fascia fused with the sacral periosteum.The mesorectum comprised 2 parts with the classical posterolateral fat covered by the proper rectal fascia posterialy and the anterior fat covered by the posterior layer of Denonvilliers fascia anteriorly.Extending anteriorly to the anterior layer of Denonvilliers fascia,the presacral fascia bisected the space between the mesorectum and the piriformis fascia into the retrorectal space and the presacral space.The retrorectal space extended cranially to the left retrocolic space,anterior to the space between the 2 layers of Denonvilliers fascia(prerectal space).Conclusions From the inside to the periphery,the proper rectal fascia,the presacral fascia,and the muscular fascia are distributed in an annular pattern around the mesorectum.The presacral fascia divides the perirectal space into 2 annular parts,the central retrorectal space and the peripheral presacral space.The retrorectal space is the ideal surgical plane for total mesorectal excision.