Intracoronary irradiation markedly reduces restenosis after balloon angioplasty in a porcine model

Abstract

Intracoronary irradiation (2,000 cGy) delivered to a target porcine coronary segment before balloon overdilation markedly reduces neointima formation at 30 days and thus significantly impairs the restenosis process.

Radiation therapy to prevent coronary artery restenosis

“…Wiedermann and coworkers found suppression of neointima 4 weeks after angioplasty when 20 Gy was delivered at a radial depth of 1.5 mm just before arterial injury. 24 These same researchers demonstrated a persistence of this effect in arteries harvested at 6 months. 25 Similarly, our group at Emory demonstrated profound suppression of neointima using 192 Ir with a dose-response effect in vessels treated with 3.5, 7, and 14 Gy at a radial depth of 2 mm, and continued benefit at 6 months in arteries treated with 7 and 14 Gy.…”

<b>Irradiation and Postangioplasty Restenosis</b>

“…6,7,70,71,75) Wiedermann and co-workers found suppression of neointima 4 weeks after angioplasty when 20 Gy was delivered at a radial depth of 1.5 mm just before arterial injury and demonstrated that this effect persisted at 6 months. Similarly, Waksman and co-workers demonstrated profound suppression of neointima using 192 Ir with a doseresponse effect in vessels treated with 3.5, 7, and 14 Gy at a radial depth of 2 mm.…”

“…To evaluate the proper method to apply this new modality of treatment, several investigators have used both externally delivered X ray-irradiation as well as various catheter-based and radioactive stent endovascular approaches with various isotopes in experimental studies primarily using pigs and rabbits. 6,7,70,71) …”

“…Since the discovery of X-rays by Roentgen in 1895 and of radium by Madame Curie in 1898, ionizing radiation is well known as a potent antiproliferative agent for both malignant and benign disorders and the use of radiation to modify the wound healing response has also been well-documented. 6,7) Low dose external radiation is currently used for a number of different problems including the prevention of keloid formation after surgery and recurrence of pterygium after surgical removal. [8][9][10][11] Restenosis may be considered as a type of exuberant wound healing.…”

Increased Expression of Macrophage Colony–Stimulating Factor After Coronary Artery Balloon Injury Is Inhibited by Intracoronary Brachytherapy

“…6 ICBT delivers radiation locally to the arterial wall at the time of angioplasty or stenting by means of catheter-based delivery systems using ␥ or ␤ irradiation sources, with demonstrated efficacy in reducing the incidence of restenosis. [7][8][9][10][11][12][13][14] The mechanism by which ICBT inhibits restenosis is not fully understood, but it appears to involve reduced smooth muscle cell (SMC) proliferation and delayed healing responses to vascular injury. 14,15 Macrophage colony-stimulating factor (M-CSF) is a multifunctional proinflammatory protein that regulates the differentiation, proliferation, and survival of mononuclear phagocytic lineage cells such as macrophages and SMCs.…”