慢传输型便秘结肠肌间神经丛超微结构改变

目的　慢传输型便秘（ＳＴＣ） 病因不清、症状顽固、临床处理较困难． 进一步探讨其发生和发展的病理学基础．方法　应用电镜技术对１４ 例ＳＴＣ 患者和１１ 例非梗阻性直肠癌患者经手术切除的乙状结肠标本进行了对照研究．结果　与对照组相比，ＳＴＣ 患者结肠肌间神经丛的超微病理改变表现为：神经元及其突起有十分明显的退行性变，轴突及树突空化呈网格状结构，胞质内出现空泡及脂褐素等；轴突末端膨体及突触前区内突触小泡含量明显减少，大部分突触小泡出现空化．结论　ＳＴＣ 患者结肠肌间神经丛有明显的神经病理学改变，存在递质耗竭或递质合成、传输障碍等现象，它是ＳＴＣ 患者肠道传输减慢的超微病理基础． 这种改变可能与ＳＴＣ 患者长期滥用接触性泻剂有关．

Ultrastructural abnormalities of colonic myenteric plexus in patients with slow transit constipation

AIM The etiology of slow transit constipation (STC) is yet poorly understood and the symptoms are intractable. This study aims to investigate the ultrastructural features of the colonic myenteric plexus in patients with STC. METHODS By using electron microscopic technique, resected sigmoid colon specimens from 14 patients with STC and 11 nonobstructed rectal adenocarcinoma controls were studied, the ultrastructural neuropathology of myenteric plexus was examined. RESULTS In patients with STC, significant retrograde degeneration, vacuolization and lipofusion were demonstrated in the neurons. Nerve endings and vavicosities showed a significant decrease in neurosecretory granules. Vacuolar degeneration was showed in the synaptic vesicles. CONCLUSION There is a distinct ultrastructural abnormality of colonic myenteric plexus in patients with STC. The reduction of functioning nerve elements is probably of morphological correlation to clinically evident disturbances of bowel motility. It is probably associated with contact laxatives abused by the patient.