The transition from a default transfemoral access approach for coronary angioplasty to a default transradial approach increased fluoroscopy time, according to a study published in the September edition of American Journal of Cardiology. The transradial approach increased dose-area product for diagnostic procedures, but not interventional procedures.
Studies indicate that transradial coronary procedures have fewer access-site complications compared to the transfemoral approach; however, previous studies about the amount of radiation delivered to the patient and operator reached conflicting results, according to lead author Johanne Neill, MD of the cardiology center at Belfast City Hospital in Northern Ireland, and colleagues.
Neill and colleagues compared fluoroscopy time (FT), dose-area product (DAP) and contrast delivery between radial and femoral access for diagnostic procedures and percutaneous coronary intervention (PCI) during a transition from default transfemoral access to default transradial access. They also assessed the impact of operator experience with radial access on radiation dose.
The study covered three time periods: the default femoral access approach from January 2007 to April 2007; the transition phase with some operators using radial access and others using femoral access from January 2008 to July 2008; and the default radial approach from January 2009 to July 2009, and included 848 femoral access cases and 965 radial access cases.
In the diagnostic angiography subset of 412 femoral cases and 456 radial cases, radial access FT was longer than femoral access FT at 4.43 minutes versus 2.34 minutes, respectively, with a 14 percent increase in DAP for radial access, according to Neill and colleagues. The increase in DAP was significant, but the absolute different was small, they found. Contrast volumes were similar for the two approaches. The researchers attributed the longer FTs in the initial stages of radial experience to navigating the guidewire to the aortic root, overcoming anatomic variations and loops.
Researchers found that FT was longer in the radial access cases than femoral access cases at 12.02 minutes vs. 9.36 minutes, respectively, in the PCI group of 436 femoral cases and 506 radial cases. “[The longer FT] likely reflects similar technical obstacles as for diagnostic cases,” wrote Neill and colleagues. However, DAP and contrast volumes were similar.
The reseaerchers assessed the effect of operator experience by comparing radiation variables from radial access during the transition phases to the default radial phase and found that FT decreased from 5.12 minutes during the transition phase to 4.21 minutes during the default radial phase, which was not associated with decreased DAP. “[This provides] evidence of a learning curve with shortening of FT with accumulating experience,” wrote Neill and colleagues.
For interventional procedure, FT increased from 10.51 minutes in the transition phase to 12.14 minutes in the default radial phase, the authors reported, which was not linked with an increase in DAP.
The results are consistent with previously published data, which report an increases in radiation dose delivered to the patient and operator when the transradial route is used, concluded Neill and colleagues.