Assessment of splenic artery variations with CT angiography and IPALGE classification

SA (splenic artery) is an anatomical structure with high variability in the population, particularly in terms of its terminal branching pattern, and lacks of standardization. Our study aimed to contribute to the literature by evaluating SA variations with Computed Tomography Angiography (CTA) findings and assisting in stomach, pancreas, spleen surgery, and endovascular interventions, while also improving standardization between studies using the newly created IPALGE classification system. Retrospective analysis of the CTAs of 274 patients who met our criteria was performed. The CT (Coeliac Trunc) bifurcation distance and CT-SMA distance were measured higher in males than in females. No relationship was found between these distances and SA origin or SA course. SA originated most commonly from the CT (93.8%). No significant relationship was found between SA origin and SA course or polar artery frequency. In 81% of cases, the SA showed a superior course over the body-tail section of the pancreas, and when it showed a superior course, the probability of an IPA (inferior pancreatic artery) being present was higher. The second most common course was retropancreatic (16.8%). SA showed a Y-type terminal branching pattern most frequently (65%). In the population, terminal branching was found to be bifurcation in 84.7% and trifurcation in 11.3%. The mean hilum distance was found to be 1.95±1.25 cm (minimum=0 cm, maximum=6.2 cm). The probability of an IPA being present was higher in patients with a shorter hilum distance (p=0.034). Furthermore, the hilum distance was measured shorter when an IPA originated from SA compared to when there was no IPA or when it originated from the LGE (left gastroepiploic artery). The probability of an IPA being present was also higher when LGE (left gastroepiploic artery) originated from SA. However, differences were found in the data between studies, and an IPALGE classification system was created to establish a common language and help standardize data. We believe that this classification system, focusing on LGE origin and its relationship with IPA, can assist in standardizing parameters such as terminal branching point, hilar distance, lobar branch count, polar artery frequency, and polar artery origin detection.