Effect of steroids or tissue precooling on edema and tissue thermal coagulation after CO2 laser impact

Uvulopalatopharyngoplasty

Uvulopalatopharyngoplasty is a generally safe and widely accepted surgical procedure for the treatment of obstructive sleep apnea. Unfortunately, uvulopalatopharyngoplasty does not always result in success, and patients who initially experienced improvement in the severity of their obstructive sleep apnea may relapse. Proper patient selection and performing uvulopalatopharyngoplasty in conjunction with other surgical procedures that are directed at other sites of upper airway collapsibility may yield favorable outcomes.

Anesthetic and postoperative management of the obstructive sleep apnea patient

Sleep apnea patients pose a challenge for surgeons, anesthesiologists, and surgical facilities as there is increased risk for anesthetic and postoperative complications. Precautions before and after surgery minimize these risks. Screening for sleep apnea should be done for all surgical patients. Safe perioperative management requires judicious use of narcotics and sedating medications, reducing upper airway edema, prevention of aspiration and deep vein thrombosis, blood pressure control, use of positive airway pressure, and proper postoperative monitoring. Although the literature lacks specific recommendations, the guidelines presented in this article are based on more than 20 years of experience and supported by peer-reviewed medical literature.

Comparative study in swines' vocal cords healing after excision of fragment with CO2 laser with mitomycin and 5-fluorouracil postoperative topical application

PURPOSE: To evaluate the deposition of collagen fibers at pig's vocal folds after topical use of mitomycin or 5-fluorouracil, when partial exeresis of mucosa layer had been promoted by CO2 laser. METHODS: There were used 18 Larger white pigs which were anesthetized and submitted to mucosa fragment's exeresis, bilaterally, at its free border. The animals were divided into 3 groups, each one with 6 animals: control group, without topical drug application; mitomycin group; and 5-fluorouracil group. After 30 days, the animals were subjected to euthanasia, and samples of the vocal folds were collected and stained by picrosirius red technique with polarization for quantification of total collagen deposition. RESULTS: In control group, the mean rate of right vocal fold's collagen deposition at submucosa consisted in a 3428.66 micrometers area. There was found an area whose size had, in average, 2196.36 micrometers, in mitomycin group, and 2269.19 micrometers, in 5-fluorouracil group. CONCLUSION: Mitomycin and 5-fluorouracil had promoted beneficial change in vocal fold's cicatrization with less collagen deposition, but there was no significant statistically difference when they were compared between themselves.

Preoperative and postoperative management of obstructive sleep apnea patients

Safe perioperative management of patients with obstructive sleep apnea (OSA) requires special attention to preoperative and postoperative care. Patients with OSA are more likely to have comorbidities including hypertension, esophageal and laryngopharyngeal reflux disease, coronary artery disease, and obesity. Obesity may also contribute to deep vein thrombosis and pulmonary emboli. OSA increases the risk for anesthetic and postoperative complications. The recommendations for measures for preoperative and postoperative management of OSA presented in this article are based on a culmination of 20 years experience supported by the peer-reviewed medical literature.

Reduction in lateral thermal damage using heat-conducting templates: a comparison of continuous wave and pulsed CO2 lasers

BACKGROUND AND OBJECTIVES

The advantages of the continuous wave (c.w.) CO(2) laser are offset by the delay in laser wound healing secondary to thermal damage. We have developed novel heat-conducting templates to reduce laser thermal damage. Because shortened pulse durations also decrease thermal damage, we tested the effectiveness of heat-conducting templates with a c.w. CO(2) clinical laser and a short-pulsed CO(2) laser to determine the best method and mechanism to minimize thermal damage.

STUDY DESIGN/MATERIALS AND METHODS

Comparison of 0.2-second shuttered c.w. and 5-microsecond pulsed CO(2) lasers were made by doing incisions on 150 tissue samples from reduction mammoplasties and abdominoplasties. Copper, aluminum, glass, and Plexiglass heat-conducting templates were tested against no template (air) with both lasers. Histological samples were evaluated using computerized morphometrics analysis.

RESULTS

Statistically significant reductions in lateral thermal damage were seen with the copper (50%) and aluminum (39%) templates used with the c.w. CO(2) laser. Only the copper template (39%) significantly reduced thermal damage when used with the pulsed CO(2) laser. Less thermal damage was seen using the pulsed CO(2) laser compared to the c.w. CO(2) laser with each template.

CONCLUSIONS

Heat-conducting templates significantly reduced the amount of lateral thermal damage when used with the c.w. CO(2) laser (copper and aluminum) and short-pulsed CO(2) laser (copper). The c.w. CO(2) laser with the copper template compared favorably to the short-pulsed CO(2) laser without a template. Therefore, both heat conductive templates and short-pulse structure provide successful methods for reducing lateral thermal damage, and a combination of the two appears to provide optimal results.

Free-electron laser and heat-conducting templates: a study of reducing cutaneous lateral thermal damage

BACKGROUND AND OBJECTIVES

We developed novel heat-conducting templates, and tested whether they could effectively remove damaging heat from the tissue during laser ablation. The reduction of lateral thermal damage during cutaneous incisional laser procedures should decrease the time in wound healing. In addition, we selected various infrared wavelengths to determine whether the template effects would be influenced by the laser penetration depth and the particular chromophore absorbing the laser light.

STUDY DESIGN/MATERIALS AND METHODS

This study utilized the Free-Electron Laser at wavelengths of 3.0, 5.5, 6.45, 7.5, and 7.7 microm to produce 1.0 cm incisions on in vitro lightly pigmented human skin. At each of these wavelengths, copper, aluminum, glass, and Plexiglas heat conducting templates were tested. At wavelength 5.5 microm, the study was duplicated using in vitro darkly pigmented skin. Histological samples were evaluated using computerized morphometric analysis.

RESULTS

The adjunct use of both the copper and aluminum templates provided a decrease in thermal damage at each wavelength. Using the copper template reduced lateral thermal damage an average of 67% with no apparent wavelength dependence. The aluminum template reduced thermal damage an average of 54% with no apparent wavelength dependence. The glass and Plexiglas templates did not reduce the lateral thermal damage. At 5.5 microm, no statistically significant difference in lateral thermal damage was observed between darkly and lightly pigmented tissues.

CONCLUSIONS

Heat-conducting templates are an effective new method to reduce lateral thermal damage from thermal laser incisions.

Short-term objective and long-term subjective results of laser-assisted uvulopalatoplasty for obstructive sleep apnea

OBJECTIVES

To determine the short-term and long-term effects of laser-assisted uvulopalatoplasty (LAUP) on symptoms and polysomnographic measures in patients with obstructive sleep apnea syndrome (OSAS).

STUDY DESIGN

Prospective assessment of outcomes after LAUP in patients with OSAS.

METHODS

Fifty-nine patients with OSAS underwent LAUP, and 36 completed postoperative sleep studies. Questionnaires ranking snoring and apneic symptoms were completed by the patient and bed partner before LAUP, 6 to 12 weeks after LAUP, and in the long term (> 2 years).

RESULTS

The apnea index decreased from 14.4 to 5.8 (P = .0012), respiratory disturbance index (RDI) decreased from 28.1 to 7.9 (P = .0046), and the mean lowest oxyhemoglobin saturation increased from 80.6% to 84.0% (P = .055). The RDI was reduced to 10 or less in 44.4% of patients. Subjective questionnaires showed statistically significant improvements in snoring, morning fatigue, morning headaches, daytime somnolence, and daytime psychometric measures. The symptomatic improvement persisted in the long term.

CONCLUSIONS

LAUP is an effective method for the management of OSAS. We have demonstrated short-term improvement in polysomnographic measures and short-term and long-term improvement in subjective measures.

A new pharyngitis model using capsaicin in rats

1. Application of capsaicin solution onto the rat pharyngeal mucosa caused a well-reproducible increase in vascular permeability in the pharynx. 2. Capsaicin-induced pharyngeal inflammation was unaffected by a histamine H1 blocker and non-steroidal anti-inflammatory agents, whereas dexamethasone was effective in its inhibition. 3. FK224, a dual antagonist of tachykinin NK1 and NK2 receptors, and FK888, a selective antagonist of NK1 receptor, significantly inhibited capsaicin-induced plasma exudation in the pharynx. 4. In capsaicinized animals, the application of capsaicin solution in the pharyngeal mucosa did not induce pharyngitis. 5. These results suggest that the mechanism of the capsaicin-induced pharyngitis primarily involves tachykinins.