超低位直肠前切除术中会阴前平面的应用解剖研究

目的 对超低位直肠前切除术涉及的会阴前平面及相邻组织结构进行局部解剖研究.方法 对16具带下肢的男性半骨盆矢状位标本进行解剖,测量并记录直肠前壁与尿道膜部距离、会阴体头侧宽度、会阴体尾侧宽度、会阴体厚度、耻骨直肠肌厚度、直肠前壁处及后壁处耻骨直肠肌上缘与齿状线距离以及盆膈裂孔宽度等8项指标.结果 在16具标本中均可清晰找到会阴前平面.直肠前壁与尿道膜部距离(rectum-urethra,R-U)的中位数为14(10～17)mm.会阴体轮廓呈梯形,头侧窄,尾侧宽,头侧宽度(width of cranial perineal body)的中位数为8(6～9)mm,尾侧宽度(width of caudal perineal body)的中位数为21(18～23)mm.会阴体厚度(thickness of perineal body)的中位数为20.5(17～23)mm.耻骨直肠肌厚度(thickness of puborectalis)的中位数为12(10～16)mm.直肠前壁处耻骨直肠肌上缘与齿状线距离[puborectalis-dental line(anterior wall of rectum)]的中位数为25(21～27)mm,直肠后壁处耻骨直肠肌上缘与齿状线距离[puborectalis-dental line(posterior wall of rectum)]的中位数为20(16～23)mm.盆膈裂孔的宽度(width of pelvic diaphragm)的中位数为8(6～10)mm.结论 会阴前平面清晰存在,经此平面可以利用长约20 mm的最远端直肠,提高低位直肠癌手术的保肛率.

A topoanatomical study of the anterior perineal plane for the application of ultra-low anterior resection of the rectum

Objective To study the topoanatomy of anterior perineal plane and adjoining tissue structure in the preparation of ultra-low anterior resection of the rectum. Methods Dissection was performed on 16 male cadavers of semi-pelvis sectioned in the saggital plane. Eight indexes were measured and recorded. Results Anterior perineal plane was clearly found in all 16 cadavers. The median distance of rectum-urethra (R-U) was 14 mm (ranging 10 -17 mm). The contour of perineal body was trapezoid,which was narrow cranially and broad caudally. The median width of cranial perineal body was 8 mm (ranging 6 -9 mm), while the median width of caudal perineal body was 21 mm (ranging 18 -23 mm).The median numerus of thickness of perineal body (TPB), thickness of puborectalis (TPR), arrterior wall of rectum (aPR) -D, pPR-D and width of pelvic diaphragm (WPD) were 20. 5 mm ( ranging 17 - 23 mm),12 mm(ranging 10 -16 mm), 25 mm(ranging 21 -27 mm), 20 mm(ranging 16 -23 mm) and 8 mm (ranging 6 - 10 mm) respectively. Conclusions Anterior perineal plane clearly exists, through which about 20 mm more length of the distal rectum is available which could increase the sphincter-saving rate in cases of low rectal carcinoma.