Palmar Arch Insufficiency as a Risk Factor for Radial Artery Occlusion After Transradial Catheterization (PAIRAO)

Transradial access (TRA) is commonly used in different medical fields due to the superficial position of the radial artery and related advantages. Despite its popularity, the incidence and importance of related complications, in particular, radial artery occlusion (RAO) remains unclear. Further, the only known independent predictors of the radial artery occlusion are the periprocedural anticoagulation as well as the catheter size. The effect of a variable arterial anatomy has so far not been evaluated.

In this context, most institutions prefer to evaluate the collateral circulation of the hand, i.e., the arterial palmar arch and forearm circulation before TRA. The most commonly employed tests are the modified Allen test (MAT) or the combination of pulse oximetry and plethysmography according to Barbeau.In addition, there are more precise, but still semi-quantitative non-invasive methods for palmar arterial collateral function testing.

Despite the wealth of these variably accurate and practical tests, invasive and direct hemodynamic measurement of the arterial forearm circulation and its components is lacking. Thus, the human physiologic circulatory reference at this site has been unknown so far. Further, the need of pre-procedural testing itself can be questioned in light of the reported, widely varying prevalence of RAO (1-38%) or critical ischemia (0-0.09%) after TRA.

The present study investigated in a first step the invasively obtained, pressure-derived hemodynamic function, i.e., the physiology of the human arterial palmar arch and forearm collateral circulation and in a second step the clinical consequences of the variable palmar arterial anatomy.