先天性小肠I型闭锁胚胎期再贯通残留液泡的组织学形态观察

Histological observations of septum from type I intestinal atresia and residual vacuoles during recanalization in fetal period

目的探索Ⅰ型肠闭锁隔膜的组织学形态和其内残留的胚胎液泡结构,为再通障碍学说提供理论依据。方法对15例Ⅰ型肠闭锁隔膜组织进行连续切片和常规HE、Masson染色,观察隔膜的组织学形态,并寻找其内残留的胚胎液泡结构。结果15例隔膜组织标本中,大体观察隔膜中央有孔洞者3例,12例为完整隔膜组织。HE染色镜下可见隔膜组织断面上、下缘各有黏膜层覆盖。对于中央有孔洞的隔膜在孔洞处黏膜互相延续。隔膜中央断面可见疏松的黏膜下层和纵行平滑肌,无典型环形平滑肌和肠壁浆膜层。2例隔膜组织内发现胚胎期液泡,位于隔膜中央散在纵行平滑肌之间。液泡可见囊壁和囊壁裂隙,外被大量成纤维细胞和纤维条索所包裹。Masson染色显示部分囊壁组织呈现红色坏死团块。结论Ⅰ型肠闭锁隔膜上、下缘有完整黏膜层覆盖并在孔洞处延续,提示肠管再通过程发生在肠管不同部位,黏膜相互融合,而非单一方向融合。胚胎发育期黏膜、黏膜下层和肌层可能参与此过程。在隔膜中央所见残留的原始胚胎液泡是肠管再通学说的形态学结构依据。

Objective To explore the morphology of septum in type I intestinal atresia and examine residual vacuoles during recanalization in fetal period. Methods A total of 15 septum collected from departments of pediatric surgery at three hospitals.After serial tissue sectioning, hematoxylin-eosin (HE) and Masson stains were performed for histological observations of residual vacuoles during recanalization in fetal period. Results Macroscopic observations indicated that septum with central hole was noted in 3 samples and the remainders belonged to complete septum.Mucous layers covered both sides of all septums and continued at central septum.Submucosal and longitudinal smooth muscles could be seen between both sides of mucous layer.However, circular smooth muscle and serosa were absent.Among all samples, residual vacuoles during recanalization in fetal period could be occasionally seen in 2 septum tissue samples among longitudinal smooth muscle.Residual vacuoles had complete cystic wall and was encircled by fibrosis.And red necrotic tissue was found in outer surface of residual vacuoles. Conclusions Mucous layers cover both sides of septums and continue at central septum in type I intestinal atresia.It suggests that recanalization in fetal period occurs in differential parts of fetal intestine and this biological process compromises proximal and distal continuity of mucous layer, submucosa and muscular layers.There is never one-way direction.Microscopic residual vacuoles further provide biological evidence for recanalization theory in fetal period.