Celiomesenteric trunk: New classification based on multidetector computed tomography angiographic findings and probable embryological mechanisms

Figure 3 Schematic diagram of embryologic development for normal anatomy and celiomesenteric trunk variants of the celiac trunk and the superior mesenteric artery. The primitive dorsal abdominal aorta is an origin for four ventral mesenteric roots-;the left gastric artery (LGA), common hepatic artery (CHA), splenic artery (SA), and superior mesenteric artery (SMA). These are joined by a longitudinal anastomosis (arrowheads). A: When the longitudinal anastomosis is interrupted between roots 3 and 4 (dashed line), the normal configuration of the celiac trunk and SMA can be generated; B: Persistence of the longitudinal anastomosis among all four roots may generate a type Ia celiomesenteric trunk (CMT); C: An incomplete interruption between roots 1 and 2 (dashed line) could result in a type Ib CMT, and both types should also be long type CMT; D: An incomplete interruption between roots 3 and 4 (dashed line) could result in a short type CMT; E: Dislocation interruption between roots 1 and 2 (dashed line) may generate a type II CMT. Since the origins of CHA, SA and LGA approximate at the same level, the up and down position among the three arteries may not be invariant; F: If the root 1 is the CHA and a dislocation interruption occurs between roots 1 and 2 (dashed line), a type III CMT would form; G: If the root 1 is the SA, the dislocation interruption (dashed line) would result in a type IV CMT; H: Type V may be due to complete regression or absence of the root 1 (dashed line), a replaced LGA arising from other arteries. CMT: Celiomesenteric trunk; SMA: Superior mesenteric artery; LGA: Left gastric artery; CHA: Common hepatic artery; SA: Splenic artery.