Uvulopalatopharyngoplasty with CO2, contact ND-YAG or combined CO2 and ND-YAG laser beams

Longterm comparison of soft palate scars after UPPP made by CO(2), contact Nd-YAG or combined CO (2) and Nd-YAG laser beams

C0(2) laser, contact Nd-YAG laser and Combolaser (combined CO(2) and Nd-YAG laser beam) vary distinctively in the way they interact with target tissue. To study the quality of mature scars produced by these lasers, the ultrastructure and amount of collagen in soft palate scars after 60 uvulopalatopharyngoplasty (UPPP) operations were analysed. The CO(2) laser was used in 19, contact Nd-YAG in 21 and Combolaser in 20 operations. At a clinical follow-up examination carried out, on average, 51 (range 34-74) months postoperatively, a specimen was obtained from the soft palate scar for collagen analysis. Postoperative complaints of the patients were acknowledged. No differences between the laser groups were observed concerning the gross appearance of the scars or the amount and ultrastructure of collagen. Neither the frequency nor the quality of post-operative symptoms showed any differences between the lasers. Although the initial tissue effects are different, long-term remodelling produces nearly identical soft palate scars after the use of CO(2), contact Nd-YAG and Combolaser beams.

Wound healing and soft tissue effects of CO2, contact Nd: YAG and combined CO2-Nd: YAG laser beams on rabbit trachea

Rabbit trachea was used as an experimental model to study tissue effects and healing of full-thickness tracheal lesions produced by CO2, contact Nd: YAG and combined, coaxial CO2-Nd: YAG (Combo) laser beams. Two power settings (10 W and 16 W) were used with CO2 and contact Nd: YAG lasers. Three different CO2/Nd:YAG power ratios (1:1, 1:2 and 1:4) and power settings (12 W 15 W and 16 W) were used with the Combolaser. Histological specimens for light and transmission electron microscopy were prepared immediately and 1, 3, 5, 7, 14 and 21 days postoperatively. The wound with the most precise and fastest healing was produced by contact Nd: YAG laser. CO2 laser produced a moderate amount of charring and the largest amount of coagulated tissue with a slightly prolonged healing period. In the acute phase, tissue defects produced by the Combolaser with power ratios 1:1 and 1:2 resembled the CO2 laser lesions but with slightly less charring. The power ratio 1:4 diminished the cutting properties of the beam considerably. During the healing period the Combolaser produced the most intensive inflammation and granulation tissue formation resulting in delayed regeneration of the lesion. In transmission electron micrographs the most severe damage to chondrocytes was seen after using the Combolaser. These findings indicate that the Combolaser produces deeper tissue damage than CO2 or contact Nd:YAG laser. However, the Combolaser appears to be suitable for tracheobronchial operations, owing to its good simultaneous cutting and haemostatic properties.

Immediate histological changes in soft palate after uvulopalatopharyngoplasty with CO2, contact Nd:YAG or combined CO2 and Nd:YAG laser beams

CO2, contact Nd:YAG and Combolaser (combined, simultaneous and coaxial CO2 + Nd:YAG laser beam) were used for uvulopalatopharyngoplasty (UPPP). It has been proposed that the combined beam geometry diminishes thermal damage to surrounding tissues when compared with single laser radiation. To study the extent of thermal tissue damage produced by the lasers, tissue samples for light (LM) and transmission electron microscopy (TEM) were taken from the surface of the resected area and 2 and 4 mm below the resection plane. The depth of tissue damage and coagulation was measured. The results showed no consistent differences in the inflammatory reactions or the amount and depth of tissue coagulation observed in samples taken immediately after the operation. The CO2 laser typically produced a carbonized and coagulated wound edge. Combolaser and contact Nd:YAG lasers generated slightly less charring but otherwise resembled each other with coagulated and vacuolized resecate margins. These results indicate that the beam geometry in Combolaser does not diminish thermal damage to surrounding tissues.