The Isolated Bowel Segment : Iowa Models

Abstract

The isolated bowel segment (IBS) is a loop of bowel which is totally free of its mesenteric attachment, but with its viability preserved. The IBS is created by two staged procedures ; initial coaption of the IBS to certain host organs, and secondary IBS mesenteric division several weeks later. During the interval between these procedures, vascular collaterals are formed between the IBS and host organs, which preserves viability of the IBS. The IBSs can be attached to host organs such as abdoninal wall muscle, liver and adjacent bowel, which we have termed Iowa Models I, II and III, respectively. In previous studies, motility and absorption in the IBS were observed in experimental animals. We conclude from these studies that a loop of bowel can maintain its normal physiologic functions without extrinsic innervation. This paper describes the techniques used to create the IBS, and a newly designed bowel elongation procedure which incorporates the principle of the IBS.