External heating of stents by radio waves: pilot studies in rabbit aorta.
OBJECTIVE
This experiment was designed to assess the feasibility of radio frequency energy delivered by a prototype radio frequency generator inductive heating device (REVAX) positioned external to the body, for transient heating of stents after arterial implant.


METHODS
Twenty-one New Zealand White rabbits underwent stenting of their infrarenal aorta. Nine rabbits were stented and immediately placed in the REVAX for external stent heating with internal temperature probes in place. Twelve rabbits were stented and 3 days later either heated or placed in the generator as a sham for 20 min. The animals were terminated 28 days later.


RESULTS
The REVAX was able to heat the aortic stents in a controlled fashion; in Phase II experiments, the stent temperature was raised to 42 degrees C for 20 min. In Phase I mild necrosis was noted at the stent struts. In Phase II, necrosis and mineralization of the media was seen at the stent struts, and evidence of neointimal suppression was observed.


CONCLUSIONS
This study demonstrated that external heating of stents in a blood vessel in a live animal via radio frequency energy is feasible. Further studies will be needed to assess whether any specific heating regimen might inhibit fibrocellular neointimal hyperplasia.
American Cardiovascular Research Institute, 3155 Northwood's Place, Norcoss, GA 30071, USA. adam.levitt@comcast.net
Adam B
AB
Levitt
Keith
K
Robinson
Nicolas A F
NA
Chronos
Wolfgang
W
Daum
D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation; D003106:Colon / Q000098:blood supply / Q000000981:diagnostic imaging; D005240:Feasibility Studies; D006361:Heating; D006965:Hyperplasia / Q000209:etiology; D007416:Intestinal Perforation / Q000209:etiology; D023421:Models, Animal; D008955:Models, Cardiovascular; D010865:Pilot Projects; D011183:Postoperative Complications / Q000209:etiology; D011817:Rabbits; D011846:Radio Waves; D011859:Radiography; D015607:Stents; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology