In Reply.—Dr Lanzafame raises questions about bias in our study and putative flaws in its design. This study was undertaken in response to a number of reports, many of them by Dr Lanzafame, claiming that the carbon dioxide laser was a better instrument for making incisions than the scalpel or electrocautery. We tried to address this question objectively by randomly allocating patients undergoing an open cholecystectomy to incision of the abdominal wall by either carbon dioxide laser, scalpel, or electrosurgery. All patients initially received a superficial skin incision with the scalpel (for cosmetic reasons); the remainder of the incision was completed with laser, scalpel, or electrosurgery. Treatment arms were limited to one modality (other than for the skin incision), and evaluation was limited to the incision itself, to make comparisons as clean as possible.
We found that laser incisions took about 3 to 5 minutes longer than scalpel or