Healing after Arterial Dilatation with Radiofrequency Thermal and Nonthermal Balloon Angioplasty Systems

Abstract

Thermal balloon angioplasty has been proposed as a means of reducing acute and delayed reclosure of arteries after percutaneous transluminal balloon angioplasty. A radiofrequency (rf) balloon catheter was used to perform thermal balloon angioplasty on canine arteries in vivo. The histologic appearance of rf-treated sites was compared with that of control sites treated by conventional percutaneous transluminal angioplasty. Acutely, rf-treated sites showed a reduced medial cellularity with preservation of internal elastic lamina except at the transitional zone between thermal injury and normal artery, where localized internal elastic lamina disruption was found. Nonthermal sites showed generalized disruption of internal elastic lamina and normal medial cellularity. Both thermal and nonthermal sites displayed a return of intimal cover commencing at 1 to 2 weeks and completed by 4 weeks. Diffuse myointimal hyperplasia appeared by 2 weeks after injury at breaks in the internal elastic lamina along the nonthermal vessels but was localized to the transitional zone in thermal injury sites. In rf-treated vessels, repopulation of the acellular thermally modified media had commenced by 4 weeks, and by 8 weeks the media was diffusely repopulated by spindle-shaped cells resembling smooth muscle cells lying between and aligned with preserved connective tissue laminae. Overall, the distribution and extent of the proliferative response after rf thermal balloon angioplasty were less than those seen after nonthermal balloon angioplasty. Thermal sites, which underwent reintimalization before medial cells returned, were considerably less prone to the development of myointimal hyperplasia. These results suggest that this modality may have beneficial effects on arterial healing after angioplasty.

Impact of monopolar radiofrequency energy on subchondral bone viability

“…The time course of bone regeneration in our study was markedly slowed in comparison with previous studies, supporting recent findings that heat-injured bone maintains only an inferior capacity to regenerate [16,28]. Recent studies have shown that revascularization begins one to 2 weeks after radiofrequency thermal balloon angioplasty, but is not complete until 4 weeks following treatment [29]. Thus, the delayed progress of bone regeneration in our study may result from thermal injury not only to bone but also to vascular structures, depriving subchondral tissue of the blood supply required for rapid growth.…”

“…Recent studies have shown that revascularization begins one to 2 weeks after radiofrequency thermal balloon angioplasty, but is not complete until 4 weeks following treatment [29]. Thus, the delayed progress of bone regeneration in our study may result from thermal injury not only to bone but also to vascular structures, depriving subchondral tissue of the blood supply required for rapid growth.…”

A New Endovascular Radiofrequency Device for Dilatation of Vascular Stenosis in a Rabbit Model

“…Moreover, the distribution and extent of the proliferative response after RF thermal balloon angioplasty have been shown to be less than those seen after nonthermal balloon angioplasty. Thermal sites are considerably less prone to the development of myointimal hyperplasia, which may have beneficial effects on arterial healing after angioplasty [18].…”

Restenosis after balloon angioplasty and/or stent insertion - origin and prevention. A review of the literature

“…Suppression of IH can be achieved by reduction of the number of proliferating SMCs in the vessel wall. Thermal methods, photodynamic therapy, external irradiation and brachytherapy have been used (55, 62, 96, 103, 114–116, 143, 178, 186, 202, 215). Radioactive stents were also constructed (179, 217).…”