COMPARISON OF A HIGH FOWLER DIODE-LASER WITH THE ND-YAG LASER USING IN-SITU WOUND STRENGTH ANALYSIS OF HEALING CUTANEOUS INCISIONS

Background and Objective: The laser-tissue interaction of a high power semiconductor diode laser was compared to the continuous wave neodymi um yttrium aluminum garnet (Nd:YAG) laser by evaluating primary wound healing of cutaneous incisions in rats. Study Design/Materials and Met hods: Full thickness incisions were made in rat skin using a diode las er (805 nm, 10 W, contact mode), an Nd:YAG laser (1,064 nm, 10 W, cont act mode), and a stainless steel scalpel blade (control). In situ woun d breaking strength measurements were obtained at 7, 14, and 21 days u sing a specially designed tensiometer. Cross sectional area of non-dis rupted wounds was calculated in two groups prior to testing to allow f or calculation of tensile strength. Blinded histopathologic analysis w as also performed. Results: Analysis of variance (P less than or equal to 0.05) was used to determine differences in breaking strengths and tensile strengths due to incision method. There was no significant dif ference in the breaking strengths (group 1) or tensile strengths (grou ps 2 and 3) of the diode and Nd:YAG laser incisions. As predicted, bre aking strengths and tensile strengths of scalpel blade incisions were significantly greater than those of incisions made with laser energy. Histopathologic evaluation revealed that through day 14, the degree of inflammation and collagen production was similar for diode and Nd:YAG laser incisions. Laser incisions had greater inflammation and a lag i n fibroblast invasion and collagen production compared with scalpel in cisions. By day 21, all incisions were similar in fibroblast populatio n and collagen production, but laser incisions had slightly more infla mmation than scalpel incisions. Conclusion: In the primary wound heali ng model described, the tissue effect, cellular response, and developm ent of wound strength were essentially the same for the high power dio de laser at 10 W and the Nd:YAG laser at 10 W. (C) 1997 Wiley-Liss, In c.