Table 6

The trans-radial angiography “TRA” grading scale*

VariablePointsClinical correlate
Tortuosity level (0–6 points)
Presence of a double subclavian innominate curve†3Loss of distal control to reform Simmons shape, additional fluoroscopy time
Presence of a left proximal carotid loop†3Inability to maintain a stable configuration of Simmons while accessing target vessel
Radial anatomy (0–2 points)
Presence of a proximal radial loop†2Additional catheters, wires, and fluoroscopy time required to gain distal access
Aortic arch anatomy (0–5 points)
Type 2 aortic arch1Harder to access vessels of interest due to curve of the aortic arch
Type 3 aortic arch2Harder to access vessels of interest due to curve of the aortic arch
Large diameter aortic arch at apex (>28 mm)†2Harder to form Simmons catheter
Additional factors (−2 to +17 points)
Acute right subclavian vertebral angle†2Harder to access vertebral artery on right
Acute left subclavian vertebral angle†4Harder to access vertebral artery on left with lack of support
Presence of bovine arch†-2Easier to select vessels without having to form Simmons catheter shape
Presence of aberrant right subclavian artery11Very difficult to form Simmons and select vessels of interest, alternative access recommended
  • *Grades determined by the following breakdown of points: grade I: <5 points, easy; grade II: 5–9 points, moderate; grade III: ≥10 points, difficult.

  • †Denotes factors found to be significantly correlated with the operator rating scale of difficulty.