Bacteremia following laser and conventional surgery in hamsters

The CO₂ laser prevents bleeding by sealing blood and lymph vessels as it vaporizes tissue. Bacteremia following oral surgery might not occur under these conditions. To test this hypothesis, a 0.2-mm-deep incision 1 cm long was made in the right buccal cheek pouch of hamsters using either laser, electrosurgery, or a scalpel. Twenty minutes later, 1mL of blood was taken from each animal by cardiac puncture, inoculated on a blood agar medium, and incubated anaerobically for 4 days; then the colonies were counted. Using an operational definition of bacteremia as five colonies or more per plate, there were no positive results out of 18 trials ( 0 18) for laser surgery, 7 8 for electrosurgery, and 8 12 for scalpel surgery. Based on the Student t test using the binomial distribution, the laser produced statistically less bacteremia than the other two methods (P < .01). Because the five-colony cutoff was arbitrary, the nonparametric Wilcoxon Rank test was also used. Colony formation from blood from the laser group was significantly less than from the electrosurgery group (P < .01) and the scalpel group (P < .05). The laser surgery group was not statistically different from the control (nonsurgerized) group. These results suggest that there is a considerable bacteremia following scalpel and electrosurgery, but that laser surgery produces no bacteremia.