Anatomic variations of the main branches of the abdominal aorta in patients undergoing abdominal CT angiography

Aim: It was aimed to detect variations in main branches of the abdominal aorta (AA) with computed tomography angiography (CTA). Material and Method: Totally 281 cases, of which 145 were male and 136 were female, who were examined with abdominal CTA due to various reasons between January 2012 and January 2015 were included in the study. Cases were scanned with 64 slice computed tomography device using a slice thickness of 0.625 mm and single phase contrast examination. Axial scans were processed to construct 2 dimensional multi-plane reformats and 3 dimensional images using MIP and volume tendering techniques. Anatomical variations in the main branches of abdominal aorta were determined. Results: Most frequent levels of origin for the visceral branches originating from AA were as follows: level of T12-L1 intervertebral disc space for celiac trunk (CT) (%26,4), level of upper 1/3 of L1 vertebra for superior mesenteric artery (SMA) (%27,1), level of lower 1/3 of L1 vertebra for right and left renal arteries (%26,3 and %28,1), level of upper 1/3 of L3 vertebra for inferior mesenteric artery (IMA) (%25,3). Of the visceral branches, frequency of variation in CT and SMA was 11%, and the most frequent variation was left gastric artery directly coming out of AA (3,9%). Frequency of variation in hepatic artery (HA), which is a branch of CT, was 40,9%. Most frequent variations in HA were Michels type III (13,2%) and Michels type V (12,4%). The most common variation were the accessory renal artery (%9,9) on the right renal artery, while the most common variations of the left renal artery were early division (%12,4) and aberrant renal artery (%12,4). No variation was observed in IMA. Statistically, there was no significant difference between the sexes for all variations detected in the examined visceral branches of AA. Conclusion: The frequent variation has been observed in CT, SMA, HA, RA in particular to HA, RA. Knowing these variations will enhance the success of the interventional radiological proceedings and transplant, cardiovasculer, hepatobiliary, gastrointestinal, pancreatic, renal surgical proceedings and decrease the complications. Key Words: Abdominal aorta, variation, CT angiography.