Researchers reported that sheathless transradial PCI using standard large-bore guiding catheters can successfully and safely treat complex lesions, according to the study published in the December edition of Catheterization and Cardiovascular Interventions (CCI).
“A major limitation of transradial percutaneous coronary intervention (PCI) is the inability to use large guides because of the relatively small size of the radial artery,” the authors wrote.
To better understand the ability to perform the sheathless technique with standard large-bore nonhydrophilic guiding catheters, Aaron M. From, MD, the study's principle investigator, and colleagues from the Mayo Clinic in Rochester, Minn., enrolled 10 patients who underwent transradial PCI between September 2009 and March 2010 using a sheathless technique with either 7F — used in 60 percent of patients — or 8F large-bore guides.
Ninety percent of the patients enrolled in the trial were male and had an average age of 68.8 years. The researchers attempted treatment on 15 vessels; bifurcation lesions were present in six patients.
The researchers reported no complications of the radial artery access site and there were no cases that required cross-over to a femoral artery access site. Only one coronary complication occurred during the study. After a mean follow-up of 26.5 days, the authors reported that no incidences of death, post-procedural radial occlusion or radial artery spasm had occurred.
“Overall, using standard nonhydrophilic sheathless guiding catheters was met with a greater than 90 percent procedural success rate and minimal, nonclinically relevant coronary complications without radial complications,” the authors wrote.
In addition, the authors noted that limited operator experience and the small size of the radial arteries make the procedure difficult in patients. Using a sheathless guiding catheter allows a larger internal lumen without increasing the outer diameter size.
"The numbers are still too small to make a judgment, but in general women have smaller radial arteries than men," Charanjit S. Rihal, MD, an investigator of the trial, told Cardiovascular Business News in an interview. "Our approach will allow transradial interventions in many people, but particularly women, whose radial arteries would otherwise be too small."
Because the standard sheath does not have a pre-made internal dilator to provide a smooth tapered tip, the researchers integrated a method that can help insert the sheath directly into the radial artery with use of a long diagnostic catheter that is inserted into and through the guiding sheath. The new technique does not require a hydrophilic-coated sheathless guiding catheter and central dilators, the authors noted.
“Furthermore, the technique for insertion of nonhydrophilic-coated guiding catheters may reduce the potential complications associated with long hydrophilic coatings such as granulomatous inflammation of the skin at the insertion site or unwanted catheter motion leading to coronary artery dissection,” the authors stated.
"The study results will facilitate broader adoption of transradial technique and its proven advantages, to a much broader range of patients," Rihal said.
The devices evaluated during the trial are not yet available for use in the U.S.