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

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.