Fiberoptic-guided CO₂ laser for harvesting of the internal mammary artery

Objective: The internal mammary artery is the preferred conduit in coronary artery bypass grafting. Although most centers use electrocautery to dissect the internal mammary artery, it has several disadvantages. The purpose of this study in a canine model was to evaluate and compare a fiberoptic CO₂ laser device versus electrocautery for harvesting the internal mammary artery. Material and methods: In ten mongrel dogs, both internal mammary arteries with their surrounding pedicles, were dissected from the thoracic wall, using a low-current electrocautery for one artery and a continuous wave, fiberoptic-guided CO₂ laser (13 watts) for the contralateral vessel. Blood flow through the vessels was measured immediately after dissection. Results: Mean flow through the laser dissected arteries was 71.3 ± 23.7 ml/min versus 52.9 ± 16.5 ml/min in those dissected using electrocautery. Histological examination of the chest wall specimens dissected with electrocautery showed the presence of necrosis, edema and hemorrhage surrounding the muscle, while the specimens dissected with the laser revealed only a narrow area of burn on the surgical margins of the muscle. The laser-assisted dissection was more accurate, as easy, and almost as fast as with the use of electrocautery. Conclusions: Stripping of the internal mammary artery with the fiberoptic CO₂ laser offers a promising alternative to electrocautery. Owing to its greater accuracy, the laser technique may reduce the likelihood of damaging the endothelial lining of the dissected vessel. By reducing the degree of soft tissue damage, the CO₂ laser may also lower the incidence of sternal wound infection and reduce postoperative chest wall pain and dysesthesia.