Ienaga T, Kimura K, Hashimoto K, Lee S C, Brakstad M, Soper R T
Department of Surgery, University of Iowa College of Medicine, Iowa City 52242.
J Pediatr Surg. 1990 Aug;25(8):902-4. doi: 10.1016/0022-3468(90)90200-s.
An isolated bowel segment (IBS) is a viable loop of bowel that is completely free of its mesenteric attachments. We created an IBS by staged procedures: (1) myoenteropexy between the undersurface of the abdominal wall muscle and a jejunal loop that is exteriorized at both ends as mucous fistulae; and (2) division of the IBS mesentery several weeks later. Viability of the IBS is preserved by vascular collaterals that develop at the myoenteropexy during the interval between these two procedures. In this study, histological observation of the IBS was performed to retrospectively determine the optimal interval required for adequate collateral circulation to develop. Twenty-eight rats were subdivided into seven groups of four rats each; each group underwent mesenteric division of the IBS at successive 1-week intervals after myoenteropexy (1 to 7 weeks). The bowel wall structures were histologically examined under light microscopy for each group after mesenteric division. Ischemic changes were observed in the groups in which the intervals were shorter than 6 weeks. With the time interval longer than 6 weeks, no ischemic changes were observed in the intramural ganglia and muscle layers and minimal changes were noted in the mucosa. This study concluded that an IBS can be safely created in the rat that preserve normal bowel structures when its mesentery is divided 7 weeks after myoenteropexy.
孤立肠段（IBS）是一段完全脱离肠系膜附着的有活力的肠袢。我们通过分阶段手术创建了IBS：（1）在腹壁肌肉下表面与两端均作为黏液瘘外置的空肠袢之间进行肌肠固定术；（2）数周后切断IBS系膜。在这两个手术之间的间隔期，肌肠固定术处形成的血管侧支可维持IBS的活力。在本研究中，对IBS进行组织学观察以回顾性确定形成足够侧支循环所需的最佳间隔时间。28只大鼠被分为7组，每组4只；每组在肌肠固定术后每隔1周（1至7周）依次进行IBS系膜切断。系膜切断后，对每组肠壁结构进行光学显微镜下的组织学检查。在间隔时间短于6周的组中观察到缺血性改变。当时间间隔长于6周时，壁内神经节和肌层未观察到缺血性改变，黏膜层仅观察到轻微改变。本研究得出结论，在大鼠中，若在肌肠固定术后7周切断其系膜，可安全创建能保留正常肠结构的IBS。
