后矢状位肛门直肠成形术后便秘原因初探

Preliminary study of constipation after posterior sagittal anorectoplasty

目的 研究无肛畸形胎鼠直肠盲端神经元细胞分布情况 ,探讨后矢状位肛门直肠成形术 (PSARP)后便秘发生原因。方法 选用 2～ 3个月龄 ,体重 2 5 0～ 30 0g健康Wistar大白鼠 12只 ,其中雌鼠 8只 ,雄鼠 4只。实验组雌鼠为 5只 ,对照组为 3只。雌雄交配后第 11d对实验组 5只雌鼠使用乙烯硫脲 (ethylenethiourea ,ETU)灌胃 (1%乙烯硫脲溶液 ,12 5mg/kg) ,对照组孕鼠在同一天使用等量蒸馏水灌胃。第 2 2d对两组孕鼠剖宫取胎 ,形态学研究取实验组及对照组各一只孕鼠 ,获实验组无肛胎鼠 6只 ,正常 5只 ,对照组胎鼠 10只。对胎鼠盆腔进行正中矢状切片 ,HE染色后在光镜下观察其形态。免疫组化研究将两组剩余孕鼠 (实验组 4只 ,对照组 2只 ) ,获胎鼠实验组无肛、正常和对照组各 2 7只、16只和 2 1只 ,取胎鼠直肠盲端 ,利用神经元特异性烯醇化酶 (neuronspecificenolaseNSE)和S 10 0蛋白标记肠壁内源性神经元细胞及胶质细胞 (SP)法 ,分别对肌间神经元、粘膜下神经元及胶质细胞进行计数并与对照组对比 ,进行统计学分析。结果 实验组无肛胎鼠盆腔正中矢状切面可显示直肠盲端的形态。直肠盲端与对照组直肠肌间神经元细胞数分别为 2 .0 9± 0 .5 0 ,2 .74±0 .5 1;直肠盲端与对照组直肠粘膜下神经元细胞数分别为 0 .

Objective Constipation is a major complication after posterior sagittal anorectoplasty(PSARP) for imperforate anus. Although anomalous innervation patterns of the rectal pouch in clinical studies, the innervation patterns of the rectal pouch in rats have not been reported. The aim was to study the innervation patterns of the rectal pouch in rats and correlate this to the cause of constipation after PSARP. Methods 12 mature Wistar-Imamichi rats, aged from 2 to 3 months, weighing 250 to 300?g, were used in this experiment. The rats were mated. The presence of sperm in the vaginal smear signifies gestation day one. Eight pregnant rats were divided into experiment (5) and control (3) groups. Gavage with ethylenethiourea (ETU, 1% 125?mg/kg) and distilled water were carried out on gestation day 11 for experiment and control groups respectively. 33 fetuses with imperforate anus and 31 in control were harvested by Cesarean section on gestation day 22.Serial sagittal sections were performed on fetuses and were HE stained. The slides were labelled with specific antibodies (Neuron Specific Enolase, S-100), intestinal internal neurons and glial cells were counted and compared with those of the controls. Results Photomicrograph of the midsagittal section in fetuses with imperforate anus showed rectal pouch. The amounts of myenteric neurons in rectal pouch and normal rectum were 2.09± 0.50 and 2.74± 0.51 respectively. The amounts of submucous neurons in rectal pouch and normal rectum are 0.72± 0.37 and 1.34± 0.37 respectively. The amounts of neurons in rectal pouchs were less than control (P< 0.01). The glial cells in rectal pouches showed no difference to that of control.Conclusions The decrease of neurons in rectal pouchs may be the cause of dysfunction of rectum and the cause of constipation after PSARP.