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Appendicular artery

The appendicular artery is the principal artery supplying the vermiform appendix. It typically arises from the ileocolic artery, a branch of the superior mesenteric artery (SMA), via its terminal branch known as the appendicular branch. The artery runs within the mesoappendix, a peritoneal fold that connects the appendix to the ileum, where it courses toward the tip of the appendix.

The appendicular artery is an end artery, meaning it provides the sole arterial supply to the appendix without significant collateral circulation. This anatomical fact is clinically crucial, as obstruction of the appendicular artery results in ischemia and necrosis of the appendix, contributing to the pathogenesis of acute appendicitis. Variations may exist, with occasional accessory appendicular arteries arising from the posterior cecal artery.

The artery forms small branches along its course to supply the appendiceal wall, mesoappendix, and terminal lymphoid tissue.

Synonyms

  • Artery of the appendix

  • Appendiceal artery

  • Branch of ileocolic artery

Function

  • Sole arterial supply to the vermiform appendix

  • Provides blood to the appendiceal wall, serosa, and mesoappendix

  • End-artery nature explains high susceptibility of appendix to ischemic necrosis in obstruction

  • Serves as a key surgical landmark in appendectomy and right hemicolectomy

MRI Appearance

T1-weighted images:

  • Appears as a linear flow void (black lumen) within the mesoappendix

  • Difficult to identify without high-resolution sequences

T2-weighted images:

  • Artery remains a dark signal void against surrounding mesoappendix fat

  • Appendiceal wall edema in appendicitis may highlight the artery’s location

STIR:

  • Fat suppression helps outline artery within mesoappendix fat

  • Perivascular inflammatory changes appear hyperintense in acute appendicitis

T1 Fat-Saturated Post-Contrast:

  • Appendicular artery enhances brightly and homogeneously following gadolinium

  • Useful in demonstrating vascularity of mesoappendix and detecting complications (abscess or ischemia)

T1 Fat-Saturated (non-contrast):

  • Lumen shows intermediate signal intensity, standing out against the suppressed fat of the mesoappendix

  • Allows clearer differentiation from surrounding tissues

MRA (Magnetic Resonance Angiography):

  • Contrast-enhanced MRA shows appendicular artery branching from ileocolic artery and coursing in the mesoappendix

  • Useful in vascular mapping and detecting appendiceal ischemia, anomalies, or surgical planning

CT Appearance

CT Pre-Contrast:

  • Appendicular artery appears as a small soft-tissue linear density in the mesoappendix

  • Rarely visualized clearly without contrast

CT Post-Contrast:

  • Enhances brightly as it courses within the mesoappendix toward the appendix tip

  • Demonstrates active bleeding as contrast extravasation in appendiceal rupture or complicated appendicitis

CT Angiography (CTA):

  • Best non-invasive modality for detailed visualization

  • Shows appendicular artery origin from ileocolic artery, its mesoappendiceal course, and terminal branches

  • 3D reconstructions highlight its end-artery nature

  • Essential in acute appendicitis with bleeding, ischemia, or pre-surgical mapping

CT images

Appendicular artery CT axial anatomy image 1

CT images

Appendicular artery CT axial anatomy image 2

CT images

Appendicular artery CT axial anatomy image