Comparison of the effect of monopolar and bipolar cauterization on skeletonized, dissected internal thoracic arteries

Abstract

The internal thoracic artery is preferable to the saphenous vein for use as a conduit for coronary artery bypass. More extensive use is possible if this artery is mobilized in a skeletonized form to provide greater length. Internal thoracic arteries are usually mobilized with cauterization. This study compared the effectiveness and effects on neighboring areas of division of the branches of the canine internal thoracic artery with bipolar cauterization and monopolar cauterization. Branch closure was significantly more secure in the bipolar cauterization group, with bleeding in 25 (9%) of 279 branches of 15 internal thoracic arteries treated with monopolar cauterization, in contrast to bleeding in 4 (1.3%) of 306 branches in the 15 internal thoracic arteries treated with bipolar cauterization, which were paired with the group treated with monopolar cauterization. The group of internal thoracic arteries treated with monopolar cauterization had a significantly higher prevalence of leakage when luminal pressure was increased from 120 to 160 mm Hg. Scanning electron microscopy demonstrated partial loss of endothelial cells on the flow surface of internal thoracic arteries treated with bipolar cauterization, compared with almost complete loss of endothelial cells around the orificial areas after monopolar cauterization. Secondary bipolar cauterization treatment caused only slightly more damage than primary treatment, but secondary monopolar cauterization was much more severe and extensive than primary treatment. These data suggest that bipolar cauterization is preferable to monopolar cauterization for skeletonized dissection of the internal thoracic artery.

Effect of Electrocautery on Endothelial Integrity of the Internal Thoracic Artery: Ultrastructural Analysis with Transmission Electron Microscopy

“…However, the heat that is transmitted to the artery can occasionally injure the endothelium. [5][6][7] This iatrogenic sequela presents with regional vascular spasm and associated decreased ITA flow. Adventitial hematoma or intimal dissection might also develop.…”

“…Electron-microscopic studies about the effect of cautery on endothelial layers are sparse. 5,6 The few available studies reported features of the luminal surface of ITA endothelium after electrocautery harvesting. Yoshida and associates 6 observed accumulations of red blood cells and platelets, with almost a complete loss of ECs, in skeletonized ITAs harvested by means of monopolar electrocautery.…”

“…[1][2][3][4] The ITA graft can be harvested by means of mechanical dissection with a scalpel and clips, or through the use of electrocautery, ultrasonic energy, or radiofrequency energy. [5][6][7][8][9] When electrocautery is used to harvest the ITA from the chest wall, heat and electric current can be conducted through the surrounding tissues or clips and cause thermal injury or vasospasm. Suboptimal flow due to vasospasm increases the risk of early postoperative sequelae in patients who have poor left ventricular function and a recent myocardial infarction.…”

“…[5][6][7] In those investigations, scanning electron microscopy was used to reveal histologic features on the flow surface of the ITA after mobilization. 5,6 The aim of this study was to evaluate ultrastructural changes at the cellular level when the ITA is mobilized from the chest wall by means of electrocautery. We used transmission electron microscopy to evaluate the effect of electrocautery on EC integrity and vessel-wall morphology.…”

Endoscopic vein harvesting in coronary artery bypass surgery

“…Cable et al [21] reported no significant endothelium disruption using EVH. Yoshida et al [22] propose that bipolar cauterization, as used in EVH, has been shown to produce less scattering of thermal injuries in vascular grafts compared with unipolar cautery. Acute perioperative events that might be associated with severe graft trauma have been observed for both endoscopic and open harvest techniques with similar frequencies [8].…”