Splenic branches of splenic artery

The splenic branches of the splenic artery are the terminal arterial divisions that arise from the main trunk of the splenic artery to supply the splenic parenchyma. These branches represent a hierarchical vascular system organized into successive levels of division that define the lobar and segmental architecture of the spleen.

Anatomical Organization

The splenic artery, the largest and most tortuous branch of the celiac trunk, terminates by dividing into primary (lobar), secondary (segmental), and tertiary (subsegmental) branches:

• Lobar (primary) arteries: The splenic artery most commonly bifurcates into two lobar arteries a superior and an inferior in approximately 84-86% of cases. Trifurcation into three lobar arteries occurs in about 11-16% of cases, while quadrifurcation and other patterns are rare. Each lobar artery supplies a corresponding lobe of the spleen.

• Segmental (secondary) arteries: Each lobar artery further subdivides into two to four segmental arteries. The total number of segmental arteries entering the spleen ranges from three to eight, with four being the most common (approximately 53% of specimens). Each segmental artery supplies an independent vascular territory (segment) separated from adjacent segments by relatively avascular planes.

• Subsegmental (tertiary) arteries: These are further subdivisions of the segmental arteries that supply smaller areas within each splenic segment.

• Polar arteries: In addition to the main terminal branches, the splenic artery gives off superior and inferior polar arteries in a significant proportion of cases (approximately 42% and 48%, respectively). The superior polar artery usually arises from the main splenic trunk or the superior lobar artery, while the inferior polar artery most commonly originates from the left gastroepiploic artery or the splenic artery itself. These polar arteries supply the upper and lower poles of the spleen and define additional polar segments.

Intrasplenic distribution

Once inside the splenic parenchyma, the segmental arteries continue as central arteries (also called trabecular arteries), which course centripetally and give off side branches termed penicillar arteries. The penicillar arteries leave the white pulp and enter the red pulp, where they capillarize to supply the splenic sinusoids and cords.

Other distal splenic branches that don't supply the spleen (Terminologia Anatomica 2):

• Left gastroomental artery

• Short gastric arteries