This work is based on dissection and the analysis of the arteriographies of two mesenteric arteries and it analyses the type of intermesenteric anastomoses and their importance in surgical practice. The morphological varieties of Riolan's arcade depends on its pillars, as well as on the eventual presence, especially in the middle part of the transversal mesocolon, of the secondary arcades; it seems that the colic wall necrosis depends less upon the location of the lesion or the level of the suture of the arcade, but more so on the stretch of the destruction of the mesocolon. The intermesenteric trunk, a second way of intermesenteric anastomoses is a embryological remaining, non-functional in normal conditions, but capable to partially or completely replace the Riolan's arcade when the later is sutured or interrupted.