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

Abstract

Background: In previous studies, celiomesenteric trunk (CMT) was narrowly defined as a hepato-gastro-spleno-mesenteric (HGSM) trunk, but other possible types were ignored. With the widespread use of multidetector computed tomography (MDCT) angiography, it is easy to collect a large sampling of data on arterial anatomy of the abdomen in daily radiological practice. A new classification system for CMT may be created based on its MDCT angiographic findings and variation patterns.

Aim: To identify the spectrum and prevalence of CMT according to a new classification based on MDCT angiographic findings, and discuss the probable embryological mechanisms to explain the CMT variants.

Methods: A retrospective study was carried out on 5580 abdominal MDCT angiography images. CMT was defined as a single common trunk arising from the aorta and its branches including the superior mesenteric artery and at least two major branches of the celiac trunk. Various types of CMT were investigated.

Results: Of the 5580 patients, 171 (3.06%) were identified as having CMT. According to the new definitions and classification, the CMT variants included five types: I, II, III, IV and V, which were found in 96 (56.14%), 57 (33.33%), 4 (2.34%), 3 (1.75%) and 8 (4.68%) patients, respectively. The CMT variants also were classified as long type (106 patients, 61.99%) and short type (65 patients, 38.01%) based on the length of single common trunk. Further CMT classification was based on the origin of the left gastric artery: Type a (92 patients, 53.80%), type b (57 patients, 33.33%), type c (11 patients, 6.43%) and type d (8 patients, 4.68%).

Conclusion: We systematically classified CMT variants according to our new classification system based on MDCT angiographic findings. Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could all be embryological mechanisms of various types of CMT variants.

Keywords: Anatomic variation; Celiac artery; Classification; Computed tomography angiography; Mesenteric artery; superior.

Figure 1

Long and short types of celiomesenteric trunk. A: A long type celiomesenteric trunk (CMT). The celiac trunk (CT) and the superior mesenteric artery (SMA) branch from the single common trunk (CMT) after originating from the aorta and continuing about 28 mm in length in this patient; B: A short type CMT. The CT and the SMA branch from the single common trunk (CMT), which continues for about 9 mm in this patient. CMT: Celiomesenteric trunk; CT: Celiac trunk; SMA: Superior mesenteric artery; LGA: Left gastric artery; CHA: Common hepatic artery; SA: Splenic artery; GDA: Gastroduodenal artery.

Figure 2

Five types of celiomesenteric trunk. A: Type I, a hepato-gastro-spleno-mesenteric trunk, can be further divided into type Ia-;the left gastric artery (LGA) originating from the celiac trunk; B: Type Ib-;the LGA originating from the single common trunk; C: Type II, a hepato-spleno-mesenteric trunk with LGA arising from the aorta; D: Type III, a gastro-spleno-mesenteric trunk with the common hepatic artery (CHA) arising from the aorta; E: Type IV, a hepato-gastro-mesenteric trunk with the splenic artery (SA) arising from the aorta; F-H: Type V, any other variation that meets the above definition of the celiomesenteric trunk (CMT), for example, a CMT with the LGA originating from the CHA (F) or the SA (G), or a CMT with the CHA arising from the superior mesenteric artery (H). CMT: Celiomesenteric trunk; CT: Celiac trunk; SMA: Superior mesenteric artery; LGA: Left gastric artery; CHA: Common hepatic artery; SA: Splenic artery; GDA: Gastroduodenal artery.

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.