肛门外括约肌压力偏位产生的解剖学基础及其特征

Anatomic basis of the pressure asymmetry of the external anal sphincter and its characters

目的:探讨肛门括约肌压力偏位产生的解剖学基础及其临床意义。方法:2004-07/09在解放军总医院病理解剖学实验室对19具非直肠肛门疾患的尸体标本进行了盆底肌和肛门外括约肌的局部解剖,分别从直肠肛门前后左右4个方向对肛门外括约肌及耻骨直肠肌至肛门缘的距离进行测定。其中3具引产胎儿因做病理切片而未进行上述测量,故实际测量例数为16具。结果:实际测量16具尸体,外括约肌复合体前部肌腹厚度为(9.56±5.33)mm,后部肌腹厚度为(12.12±6.42)mm,左侧肌腹厚度为(11.69±6.53)mm,右侧肌腹厚度为(11.16±5.70)mm。上述4个部位的肌腹宽度之间差异无显著性意义(P>0.05)。而耻骨直肠肌后上缘至肛门缘的距离为(16.17±7.59)mm,与外括约肌复合体前后部肌腹宽度之间差异有显著性意义(P<0.05)。结论:直肠肛门测压中呈现压力偏位的现象是由外括约肌复合体解剖学基础决定的,这种压力偏位的形成有助于形成外括约肌对直肠肛门产生的压力绞锁机制,从而获得最大限度的肛门节制。

AIM:To investigate the anatomic basis of the pressure asymmetry of anal sphin cter and the clinical significance. METHODS:Pelvic muscles and external anal sphincters of 19 human cadavers with out rectal- anal diseases were dissected locally in the Laboratory for Patholog ical Anatomy,General Hospital of Chinese PLA from July to September 2004.The dis tances from external sphincter muscle complex to the anal verge in anterior,post erior,left and right directions were measured.The distances from puborectalis to upper and lower anal verge were also measured.Three induced labor fetuses were not measured as above due to taking pathological sections,so 16 cases were measu red actually. RESULTS:In the measured 16 cadavers,the thickness of anterior,posterior,left and right muscle belly of the external sphincter muscle complex was(9.56± 5.33) ,(12.12± 6.42),(11.69± 6.53) and(11.16± 5.70) mm respectively,with insignific ant difference among them(P >0.05).However the distance between the posterior up per puborectalis and the anal verge was(16.17± 7.59) mm,significantly different from that between anterior and posterior muscle belly of external sphincter mus cle complex(P CONCLUSION:Pressure asymmetry during pressure measurement of rectal anus lies on the anatomic basis of external sphincter muscle complex.Such pressure asymme try benefits pressure noose of external sphincter muscle into rectal anus so as to obtain continence of anus furthest.