Grant-funded Project Nr. 103/2004/C/3.LF Final Report
Project title:
Architecture and blood supply of ileoceacal area
Research leader:
Prof.MUDr. Josef Stingl, CSc.
Co-researcher:
MUDr. David Kachlík;
MUDr. Václav Báèa
Period of project:
2004-2006
Overall grant:
821 000 CZK
Project Results
The ileocaecal junction is one of the most peculiar parts of the digestive tube. Its anatomical arrangement, as well as its blood supply, have been studied by methodical approaches comprising the macropreparations of cadaverous and section material, histological techniques and injection techniques using India ink and methylmetacrylate resin. The macropreparation and histological sections revealed two types of the ileocaecal junction arrangement: papillary and labial. The tunica muscularis is composed of three different layers, two circular and one longitudinal lying in between the former ones. They are not independent, exchanging fibres between each other. All layers are continuous from the terminal ileum into the caecum and none of them reaches as far as the aboral third of the papilla ilealis (to its tip protruding into the colon lumen). They cooperate in closure mechanism of the ileocaecal junction, but no large thickening of the circular layer resembling a real sphincter has been observed. In brief, it works as a functional sphincter. The arterial blood supply is fed mainly by the arteria ileocolica anastomosing with the last (most aboral) arteria ilealis, a continuation of the arteria mesenterica superior trunk. The arteria ileocolica itself or its branches send ileal branches to the area of the terminal ileum. This segment, considered as “avascular area” by Treves, should not be regarded as unblooded anymore. An ileocolic arcade, serving as a huge supplying vessel and present between the ramus colicus and ilealis arteriae ileocolicae in 74% of cases, has been described. Scanning electron microscopy showed an area of a lesser vascular supply, formely qualified as a so-called critical point. In about 16% of cases the continuation of parallel Dwight’s artery was interrupted and the terminal ileum can thus suffer in the case of possible disease, e.g. morbus Crohn, whose blood supply arrangement changes were studied, too. In comparison, the arterial blood supply of the appendix vermiformis is richer. No regional differences were detected between the colon and appendix blood supply arrangement on either India-ink-injected samples or corrosion casts. A detailed branching of the arteria appendicularis is described concerning branches for the base of the caecum and terminal ileum as well as the branch from the ceacal arteries supplying the root of the appendix vermiformis. Their precise terminology is discussed and new exact terms are suggested. The arterial blood supply of the caecum corresponds to the general arrangement of the colon vascular bed with Lieberkühn’s gland orifices 60 to 90 µm wide, the depth of the glands ranges from 250 to 300 µm. The arteriae caecales are considered as the principal terminal branches of the arteria ileocolica (this arrangement is present in 71% of cases) and feature the arcus ileocolicus and the arcus caecocolicus (present in 97% of cases) connecting them with neighbouring source arteries. The data obtained serve as an anatomical basis for the orthotopic and heterotopic neobladders surgery and for functional studies on the physiology of the ileocaecal junction and the mechanism of ileum emptying, as well as for studies concerning diseases afflicting the terminal ileum, especially Crohn’s disease. The results will be published in the monography “The Blood Supply of the Large Intestine” and, later, in an international anatomical journal and in a national surgical review.