Electrosurgery is fundamental to the precise, fast and bloodless preparation of internal thoracic artery grafts in cardiac surgery. The PEAK PlasmaBlade is a monopolar electrosurgical device that uses pulsed radiofrequency energy to generate a plasma-mediated discharge along an insulated electrode, creating a cutting edge while the blade stays near body temperature. The aim of this study is to compare the histological samples, cardiac computed-tomography of graft patency, and clinical outcomes of patients after off-pump coronary artery bypass grafting with preparation of the internal thoracic arteries by a conventional electrosurgical device and the PlasmaBlade.
In twenty subjects one internal thoracic artery was prepared with PlasmaBlade and the other artery with a conventional electrosurgical device. Histological samples were evaluated for three factors for potential graft failure: endothelial damage, integrity of the vessel wall and adventitial hemorrhage. Five samples per artery were evaluated by a novel scoring method based on the exposed circumference of the histological sample ("0": 0%, "1": 1-25%, "2": 26-50%, "3": 51-75%, "4": ≥76% of the circumference). The Wilcoxon signed ranks test for mean scores within subjects was performed. Six-month-follow up by cardiac computed tomography for evaluation of graft patency was completed in 16 patients.
Histological results demonstrated significantly less endothelial damage after PlasmaBlade (83% vs 60%, absolute: 75/90 vs. 53/89 samples with score "0-1", p = 0.04). PlasmaBlade samples demonstrated a tendency to better wall integrity (72% vs. 54%, absolute: 64/89 vs. 47/87 samples with score "0-1", p = 0.32). There were no differences in endothelial bleeding (PlasmaBlade 46% vs. electrosurgery 53%, absolute: 41/88 vs. 48/90 samples with score "0-1", p = 0.63). Computed tomography confirmed non-inferiority of the PlasmaBlade to conventional electrosurgery with a patency rate of 94%.
Histologically, internal thoracic arteries harvested with PlasmaBlade demonstrate a more intact endothelial layer and a tendency to better wall integrity. Computed tomography of graft patency speaks for non-inferiority to conventional electrosurgery. PlasmaBlade may be preferable to conventional electrosurgery, if further follow-up confirms patency of internal thoracic arteries.
NCT03510026 , registered 4th April 2018 (retrospectively registered).