Radial Recurrent Artery: Anatomy, Course, Function, Imaging

Topic

Radial recurrent artery

The radial recurrent artery (RRA) is the first and one of the most important branches of the radial artery, arising just distal to the bifurcation of the brachial artery in the cubital fossa. It ascends proximally toward the lateral aspect of the elbow, where it participates in the arterial anastomosis around the elbow joint.

This artery plays a vital role in supplying the brachioradialis, brachialis, and supinator muscles, and forms a key collateral network with the radial collateral artery (a branch of the deep brachial artery). It ensures continuous perfusion of the elbow and forearm, especially during elbow flexion or brachial artery occlusion.

Synonyms

Recurrent radial artery
Superior radial collateral branch (older term)

Origin, Course, and Termination

Origin: Arises from the radial artery, typically within 1–3 cm distal to its origin from the brachial artery in the cubital fossa.
Course:
- Ascends proximally and laterally, passing deep to the brachioradialis and anterior to the supinator.
- Lies between the brachioradialis and brachialis muscles in the proximal forearm.
- Approaches the lateral epicondyle of the humerus.
Termination:
- Ends by anastomosing with the radial collateral artery (from the deep brachial artery) and small articular branches supplying the lateral elbow capsule.

Relations

Anteriorly: Brachioradialis and lateral cutaneous structures of the forearm
Posteriorly: Supinator and brachialis muscles
Medially: Brachialis muscle and radial nerve branches (superficial and deep divisions nearby)
Laterally: Brachioradialis muscle belly
Superiorly: Lateral epicondyle of the humerus and elbow joint capsule

Branches

Muscular branches: To the brachioradialis, supinator, and brachialis
Articular branches: To the lateral elbow joint and radiohumeral articulation
Anastomotic branches: With the radial collateral artery and sometimes the interosseous recurrent artery

Function

Arterial supply: Provides blood to the lateral aspect of the forearm and elbow flexor–extensor muscles.
Collateral circulation: Contributes significantly to the periarticular arterial anastomosis around the lateral aspect of the elbow.
Clinical role: Serves as a collateral route in brachial artery occlusion, trauma, or ligation, ensuring distal radial perfusion.

Clinical Significance

Collateral importance: A crucial artery in maintaining perfusion to the forearm during elbow motion or brachial artery blockage.
Surgical relevance: Important in radial artery harvesting for grafts and flap surgeries; must be preserved to maintain elbow collateral flow.
Vascular trauma: May be injured in elbow dislocation, radial head fracture, or penetrating wounds.
Embolism or thrombosis: Can compromise radial forearm circulation.
Aneurysm formation: Rare; may appear as a small pulsatile swelling near the lateral elbow.

MRI Appearance

T1-weighted images:
- Flowing blood: dark signal (flow void) due to rapid flow.
- Arterial wall: thin, low-signal rim.
- Perivascular fat: bright, helping delineate artery course.
- Thrombus or slow flow: intermediate signal may partially fill lumen.
T2-weighted images:
- Normal artery: dark signal (flow void).
- Thrombosed or stenotic segment: intermediate-to-bright signal depending on clot age.
- Perivascular edema or inflammation: bright hyperintense surrounding signal.
STIR:
- Artery: dark signal (flow void).
- Pathologic: bright hyperintensity in surrounding tissues in trauma, vasculitis, or hematoma.
Proton Density Fat-Saturated (PD FS):
- Flowing artery: dark linear structure with surrounding bright muscle fat interface.
- Vessel wall pathology or thrombus: bright signal replacing the flow void.
T1 Fat-Sat Post-Contrast:
- Normal: rapid homogeneous enhancement of the lumen.
- Occlusion: lack of enhancement with visible collaterals.
- Vasculitis: concentric wall enhancement.
- Aneurysm: focal saccular enhancement with mural contrast pooling.

MRA (Magnetic Resonance Angiography) Appearance

Normal:
- The radial recurrent artery is visualized as a small enhancing vessel branching from the radial artery near its origin and ascending obliquely toward the lateral epicondyle.
- Best seen on 3D contrast-enhanced MRA or time-of-flight (TOF) sequences.
Pathology:
- Occlusion: Segmental signal loss or abrupt cutoff.
- Stenosis: Focal narrowing or irregular lumen contour.
- Collateral flow: Multiple fine serpentine enhancing channels around lateral elbow in chronic obstruction.
- Aneurysm: Localized round or fusiform enhancement with preserved continuity.

CT Appearance

Non-Contrast CT:

Artery itself is not directly visualized unless calcified.
Adjacent bony landmarks (lateral epicondyle, supinator crest) help localize expected course.
Arterial wall calcification appears as fine linear or curvilinear high-density lines.

Post-Contrast CT (standard):

Artery appears as a contrast-enhancing tubular structure in the proximal forearm, lateral to the brachialis.
Enhancement pattern differentiates artery from adjacent veins and tendons.
Pathologies such as aneurysm, mural thickening, or perivascular hematoma may be delineated.

CTA (CT Angiography) Appearance

Normal:
- Clearly visualized as a small, contrast-filled branch arising from the radial artery and ascending toward the lateral epicondyle.
- Best displayed on arterial-phase CTA with thin-slice (0.5–1 mm) reconstruction and 3D volume rendering.
Pathology:
- Occlusion: Abrupt cutoff or non-opacification of the vessel.
- Stenosis: Focal narrowing with distal reconstitution.
- Aneurysm: Focal saccular or fusiform dilation with contrast pooling.
- Collateral circulation: Fine enhancing loops around the radial head and lateral elbow, especially in chronic brachial occlusion.
- Arteriovenous malformation (rare): Early venous filling adjacent to radial recurrent artery.

MRI image

Topics