Ultrasound, LLLT, and the combined use of LLLT and US resulted in greater synthesis of type I collagen; US was also effective in increasing collagen organization in the early stages of the healing process.

Low-level laser therapy resulted in significantly greater amounts of type III collagen (output powers of 60 mW or more) and type I collagen (output power of 80 mW), however, no significant differences between groups were found in the realignment of collagen fibers.

Lidocaine blocks nociceptive fibers, preventing initial wound signaling and mast cell degranulation. It is hypothesized that epinephrine and buffer affect the wound healing by potentiating lidocaine blockage. This double-blind, randomized, self-controlled study investigated this possibility using male Wistar rats, which were injected with 2 mL of different solutions into the left and right sides of the back. Then, each side was incised and sutured. Sixty rats were divided in three groups: saline solution (SS) and lidocaine; lidocaine and lidocaine with buffer; lidocaine with epinephrine and lidocaine with epinephrine and buffer. Half of each group was sacrificed 7 days after surgery and the remaining after 21 days. A sample of each wound was obtained and quantified for the level of collagen present using computer morphometry and for mast cell quantity. There were no differences between animals with regard to the collagen. However, mast cell levels in the same animal significantly differed between SS × lidocaine. Comparison of the same injected substance between animals with different healing dates showed a significant effect on collagen SS and on all mast cells, except SS. Lidocaine affected collagenization and decreased the initial quantity of mast cells at the wound site.

We have compared the liability of four laryngeal mask airway (LMA) devices (standard, flexible, intubating and reusable) and a tracheal tube to thermal damage from KTP and Nd:YAG lasers at two power densities used commonly in airway surgery: 570 W cm-2 and 1140 W cm-2. Eighty-five airway devices were tested: 24 standard LMA (silicone-based), 12 flexible LMA (silicone-based, metal wires), 24 disposable LMA (PVC-based), one intubating LMA (silicone and steel-based) and 24 PVC-based tracheal tubes. Comparisons were made during laser strike to eight different targets: the unmarked and marked part of the airway device tube; the unmarked part of the airway device tube after application of blood; the cuff filled with air or methylene blue dye; the unmarked flexible LMA tube on or between the metal wires; and the epiglottic elevator bar of the intubating LMA. The laser strike was continued for 30 s and each target was tested three times. Three different, but identical, impact sites were used for each target. There was no ignition of any airway device with either power density or laser type. The silicone-based LMA were generally more resistant to flaring and penetration than the PVC-based LMA and tracheal tube, but the intubating LMA tube flared more rapidly with the KTP laser, and the disposable LMA cuff was more resistant to penetration. Print markings, blood and the metal wires of the flexible LMA reduced the thermal resistance of the tube. Filling the cuff with methylene blue dye increased the thermal resistance of all airway devices. We conclude that the silicone-based LMA devices were more thermal resistant to KTP and Nd:YAG laser strike than PVC-based devices with the exception of the disposable LMA cuff and the intubating LMA tube.