Post-laser hypersensitivity and the atopic patient

Laser resurfacing has become an extremely popular modality in the treatment of the aging face. Reported complications associated with carbon dioxide laser resurfacing are on the increase. One such complication involves the occurrence of significant hypersensitivity in laser and non-laser-treated areas, often occurring for weeks or months after the original treatment and necessitating topical or systemic steroid therapy. In an effort to identify patients at risk, those with significant hypersensitivity reactions were interviewed retrospectively. Questions regarding their background atopic characteristics were posed. Their responses to certain questions were then compared with those of a control group of 50 patients from the same pool who suffered no ill effects after laser therapy. A total of 151 patients were included in the study (pool). Of these, 14 patients (9.3 percent) suffered significant hypersensitivity. Detailed history in these patients revealed possible prior "allergic sensitivity" in 78.6 percent of patients. In contrast, only 30 percent of 50 nonsymptomatic laser-treated patients admitted to any positive allergic tendencies. It is likely that carbon dioxide laser resurfacing may trigger a sensitivity reaction in susceptible individuals.     

Nd-YAG Laser Treatment of Tracheal Stenosis

We administered Nd-YAG laser treatments in four patients aged 56 to 68 years for severe tracheal stenosis, the tracheal diameters varying between 2.5 and 5 mm. These patients were all dyspneic at rest with talking or dressing and their peak flows ranged from 8% to 36% of predicted. They were not felt to be candidates for surgical excision. Immediate palliative relief was achieved in all patients and lasted two to four months after a single treatment in three patients. One patient died three weeks after laser treatment due to respiratory failure from underlying emphysema. There were no complications of laser therapy. Postlaser therapy the tracheal diameter in each patient was at least 9 mm and peak flow improved to between 25% and 76% of predicted. The results suggest that laser treatment may be beneficial in cases of severe tracheal stenosis.     

A surgical approach for earlobe keloid: keloid fillet flap

Earlobe keloid can form after cosmetic ear piercing, trauma, or burns, and it poses several difficulties in treatment and distinctive cosmetic implications. Treatment methods for earlobe keloids include both surgical and nonsurgical methods. After excision of the earlobe keloid, healing by secondary intention, primary suture, skin graft, or local flap has revealed some disadvantages. The authors approached this problem with a new excision and covering method. The surgery was performed under local anesthesia. Skin over the keloid was dissected from the keloid mass as a flap, which they termed a "keloid fillet flap," and the keloid mass was completely removed. Subcutaneous sutures were not used, and the keloid fillet flaps were closed with 6-0 nylon sutures after trimming. Other intraoperative or postoperative preventive procedures, such as steroid injection, pressure device, or irradiation, were not applied primarily. In the period from May of 1999 to October of 2000, nine earlobe keloids in eight patients were treated with this protocol. One patient had bilateral keloids. Of the eight patients, there were six women and two men, ranging in age from 21 to 61 years (mean age, 28.5 years). The causes of keloids were ear piercing in six cases and trauma in three cases. The largest lesion was 3 cm in its greatest dimension, and the smallest was 1.5 cm (mean, 2.3 cm). All flaps survived completely. There were four cases of recurrence. Seven cases, including two recurrences, showed good results. The authors believe the recurrence of earlobe keloid was closely related to the method for coverage of the defect after its surgical excision, and the "5 As and one B" (Asepsis, Atraumatic technique, Absence of raw surface, Avoidance of tension, Accurate approximation of wound margin, and complete Bleeding control) are important factors in reducing the recurrence rate of earlobe keloids in surgical excision. The authors' protocol is very effective in closing the defect after surgical excision of earlobe keloids and offers many advantages over other surgical approaches. The recurrence rate of earlobe keloid may be lower than in their results if other intraoperative and postoperative treatment procedures are combined with their protocol.     

Different therapeutic modalities in a patient with multiple spontaneously developed keloids--a case report

Keloids are benign tumors that usually develop as an excessive healing response to injury. They remain a challenging therapeutic problem to this day. Numerous treatment approaches are available, yet therapeutic results are often not satisfactory. A female patient with multiple spontaneously developed keloids on her trunk is presented. In this patient, four different therapeutic options were employed at different sites, with variable responses. The first option included cryotherapy, with poor effect. Slight flattening was observed after intralesional corticosteroid therapy. Treatment with excision followed by radiotherapy resulted in recurrence after 3 months. The best effect was noticed when excision and injection of corticosteroids into surgical margins were followed by radiotherapy. To the authors' knowledge, this is the first report of three-modal therapy in the management of keloids, which resulted in no recurrences over a 3-year follow-up.     

Treatment of burn scar depigmentation by carbon dioxide laser-assisted dermabrasion and thin skin grafting

Permanent depigmentation occasionally develops after deep partial-thickness and full-thickness burn injuries, which heal by secondary intention. This problem can be solved by dermabrasion and thin split-thickness skin grafting. However, mechanical dermabrasion is a bloody procedure that risks exposing medical professionals to infectious diseases transmitted by blood products, and it is difficult to assess the extent of tissue ablation. In this study, dermabrasion of depigmented burn scar area was performed by using flash-scanned carbon dioxide laser treatment, followed by thin split-thickness skin grafting. This method was applied to 13 patients on whom burn scar depigmentation sites were located as follows: two in the facial area, four on the trunk, and seven on the extremities. Skin graft take was excellent in all patients except for one. The follow-up period for these patients ranged from 1 to 12 months, with an average of 8 months. Repigmentation appeared soon after grafting, and no depigmentation occurred again in the treated areas. In conclusion, depigmented burn scar areas can be dermabraded in a short time; depth of tissue ablation can be well controlled; and a bloodless and smooth raw surface can be created by using a flash-scanned carbon dioxide laser. These raw surfaces sustain thin skin grafts well.     

Nondébridement of laser char after two carbon dioxide laser passes results in faster reepithelialization

Skin repair following laser injury can be accelerated by using techniques that promote rapid reepithelialization. In this article, the benefit of intraoperative nondébridement of laser debris after two laser passes is discussed. After carbon dioxide laser resurfacing of the face, skin specimens were examined using indirect immunofluorescence with antibodies to specific epidermal and basement membrane proteins. Biopsy specimens obtained immediately after resurfacing showed a greater injury to epidermal and basement membrane proteins when skin was wiped with saline-soaked gauze after laser passes than when there was no débridement after two passes. Later examination of skin specimens obtained from nine patients 2 days after carbon dioxide resurfacing showed that nondébrided, occluded skin had faster reepithelialization than the other treatments. Nondébridement of the skin at the time of resurfacing along with the use of postoperative occlusive dressings led to the rapid reestablishment of a multilayered epidermis only 2 days after resurfacing. Nondébridement along with occlusive dressings results in rapid reepithelialization of the skin after two carbon dioxide laser passes for skin rejuvenation.     

Computer-interactive stereotactic resection of deep-seated and centrally located intraaxial brain lesions

The carbon dioxide laser has been incorporated into a computer-interactive stereotactic system for precision resection of deep-seated intraaxial neoplasma defined by stereotactic computed tomography and magnetic resonance imaging. One hundred and ninety-seven procedures were performed on 191 patients having deep-seated lesions. Postoperative results have been satisfactory as regards the postoperative condition of the patient in consideration of the completeness of tumor removal achieved.     

Carbon dioxide laser resurfacing and thin skin grafting in the treatment of "stable and recalcitrant" vitiligo

Various surgical methods have been used in the treatment of small stable vitiliginous areas, but there is no established surgical approach for larger vitiligo areas and therapy-resistant anatomic sites, such as the hands. Two years ago, we successfully treated large burn scar depigmentation areas at different anatomic sites using carbon dioxide laser resurfacing and thin (0.2 to 0.3 mm) skin grafting. The purpose of this study was to investigate the effectiveness of our method in treating large, stable, and recalcitrant vitiligo areas. Thirteen anatomic sites of seven male patients, whose ages ranged from 20 to 22 years, were treated. The locations of the treated areas were as follows: seven areas on the dorsum of the hands, two areas on the forearms, two areas in the pretibial region, one area on the lateral thigh, and one area in the presternal region. The surface area of treated vitiligo sites ranged from 0.5 to 6 percent of total body surface area (mean, 2.5 percent). Skin graft take was excellent in all patients except for one. The follow-up period for these patients ranged from 6 to 18 months, with an average follow-up period of 14 months. Early and complete repigmentation was achieved and the color match was good or excellent in all patients. No depigmentation occurred again in the treated areas or graft donor sites. In conclusion, with careful patient selection and delicate surgical technique, our method was effective in treating large areas of vitiligo over the extremities and dorsum of hands, which were refractory to other therapies and could not be hidden.     

Root excision decreases nutrient absorption and gas fluxes

The roots of barley plants (Hordeum vulgare L. cv Steptoe) were monitored before and after excision for net uptake of carbon dioxide, oxygen, ammonium, potassium, nitrate, and chloride and for their content of sucrose, glucose, fructose, and malic acid. All fluxes began to attenuate within 2 hours after excision. Net potassium uptake returned to control levels 6 hours after excision, but carbon dioxide, oxygen, ammonium, and nitrate fluxes continued to diminish for the remainder of the observation period. The addition of 0.1 molar glucose or 0.1 molar sucrose to excision medium had no significant effect on these changes in ion and gas fluxes. Net chloride uptake was negligible for all treatments. Sugar and malic acid content of the root declined after excision. Sucrose and glucose levels remained depressed for the entire observation period, whereas fructose and malic acid returned to control levels after 9 hours. These results indicate that excision has profound, adverse effects on root respiration and the absorption of mineral nitrogen.     

二氧化碳激光治疗联合5-氟尿嘧啶对扁平疣的疗效分析

目的:探讨二氧化碳激光治疗联合5-氟尿嘧啶对扁平疣的疗效。方法:选择2012年2月~2015年9月在我院进行诊治的扁平疣患者121例,男62例,女59例,其中观察组61例给予二氧化碳激光联合5-氟尿嘧啶注射液治疗,对照组60例给予二氧化碳激光治疗,比较两组的疗效,T淋巴细胞亚群,复发率及不良反应。结果:观察组总有效率为98.36%,明显高于对照组91.67%(P0.05);经治疗后,两组治疗后的CD4+、CD8+和CD4+/CD8+均较治疗前有显著性差异(P0.05);与对照组相比,观察组治疗后的CD4+和CD4+/CD8+明显升高,CD8+明显降低,差异均有统计学意义(P0.05);观察组的复发率为5.88%,明显低于对照组的15.00%(P0.05);两组的不良反应发生情况无明显差异(P0.05)。结论:二氧化碳激光治疗联合5-氟尿嘧啶对扁平疣疗效显著,可明显提高患者免疫功能,降低扁平疣的复发率,值得临床应用推广。     

Carbon dioxide laser dermabrasion for giant congenital melanocytic nevi

The management of giant congenital melanocytic nevi remains controversial. There is a balance to be achieved between minimizing the disfiguring appearance of these lesions, both before and after surgical treatment, and limiting the risk of malignant change. A series of seven patients who were treated in the same manner, with carbon dioxide laser dermabrasion, is presented. It has been 6 years since the first patient was treated in this way, and no cases of recurrence have been observed. This technique enables the removal of all or most of the pigmented lesion, with minimal scarring and without the need for disfiguring skin grafts. It has been well proved that there is an increased risk of malignant changes among patients with these lesions, although the amount of increased risk for the patient is not clear. Evidence from a review of the currently available literature is presented to indicate why this management method, at best, should decrease this risk and, at worst, should make no difference to the overall risk for individual patients.     

Ruby laser treatment of congenital melanocytic nevi: a review of the literature and report of our own experience

The authors describe the possibilities and advantages of ruby laser treatment of large congenital nevi as an alternative to surgical excision. The literature (from 1980 to 2002) is reviewed and a case report is presented. Literature and the authors' experience show good cosmetic results after ruby laser treatment. Skin texture is improved and there is a considerable reduction in pigmentation and unsightly hair growth. Ruby laser treatment does not result in scarring, mutilation, or functional impairments, in contrast to surgical treatment. Only short outpatient sessions are required, recovery periods are extremely short, and no rehabilitation period is needed. No malignant changes have been reported after treatment with the ruby laser, even after 8 years of follow-up. The results imply that ruby laser treatment could be a valuable new treatment modality for large congenital nevi. It should be considered when patients refuse to undergo surgery, or when surgery would cause severe morbidity. More research should be initiated to assess possible risks and long-term results.     

Treatment of keloids by surgical excision and immediate postoperative single-fraction radiotherapy

The authors report the outcomes of patients with keloid scars treated with a protocol of extralesional excision and immediate single-fraction adjuvant radiotherapy. The design of the study was a retrospective analysis with up to 5-year outcome data. The setting was a single treatment team, University Teaching Hospital in London, United Kingdom. Participants (n = 80) were treated for 80 keloid scars (59 percent female patients, 76 percent nonwhite), and 44 percent of keloids were located on earlobes. For all patients, prior treatment without radiotherapy had failed. The salvage treatment reported in this article is combined extralesional excision and immediate postoperative external-beam radiotherapy. A 10-Gy dose of superficial 60-kV or 100-kV photon irradiation was given within 24 hours of the operation. The main outcome measure was freedom from recurrence of keloid scars. Results were that all keloid scars were controlled at 4-week follow-up. Probability of relapse at 1 year was 9 percent; at 5 years, probability of relapse was 16 percent. The earlobe showed no greater chance of relapse than other sites on the body. The authors' report shows that extralesional excision of keloid followed by early, single-fraction, postoperative radiotherapy is both simple and effective in preventing recurrence at excision sites.     

Oxygen as a driving gas for nebulisers: safe or dangerous?

Changes in blood gas tensions occurring when 100% oxygen or air was used as the driving gas for nebulised salbutamol were studied in 23 patients with severe airways obstruction. The patients fell into three groups: nine had chronic bronchitis and emphysema with carbon dioxide retention, seven had emphysema and chronic bronchitis without carbon dioxide retention, and seven had severe asthma (no carbon dioxide retention). When oxygen was used as the driving gas patients who retained carbon dioxide showed a mean rise of 1.03 kPa (7.7 mm Hg) in their pressure of carbon dioxide (Pco2) after 15 minutes (p less than 0.001) but the Pco2 returned to baseline values within 20 minutes of stopping the nebuliser. The other two groups showed no rise in Pco2 with oxygen. When air was used as the driving gas none of the groups became significantly more hypoxic. Although it is safe to use oxygen as the driving gas for nebulisers in patients with obstructive airways disease with normal Pco2, caution should be exercised in those who already have carbon dioxide retention.     

Penoscrotal extramammary Paget's disease: a review of 33 cases in a 20-year experience

Extramammary Paget's disease in men most frequently involves the penoscrotal area. The uncertainty of the outcome and of the relationship to the underlying adnexal carcinoma and associated internal malignancy still exists. From 1982 to 2001, 33 patients with penoscrotal extramammary Paget's disease were treated and followed up. Therapeutic modalities included carbon dioxide laser ablation (two patients) and local wide excision (31 patients). Split-thickness skin graft (22 patients), local scrotal flap (six patients), and primary closure (three patients) were utilized to reconstruct the penoscrotal defects after local wide excision. An underlying adnexal carcinoma occurred in seven of 33 patients (21.2 percent). The incidence of associated internal malignancy was 9.1 percent (three of 33 patients), including one concurrently and two nonconcurrently associated malignancies. Eight of 33 patients had local recurrence, representing an incidence of 24.2 percent. Three patients (9.1 percent) had distant metastasis and ultimately died of metastatic carcinoma. Of these patients, 31 were grouped according to the degrees of involvement: limited to the epidermis (group 1, n = 14), involvement of the adnexal gland and/or hair follicle (group 2, n = 10), and the presence of an underlying adnexal carcinoma (group 3, n = 7). Local wide excision with subsequent reconstruction by split-thickness skin graft was favored in this series. Patients with an underlying adnexal carcinoma or pathological invasion of the dermis (group 2 or 3) had a worse prognosis than patients without. From this study, it is difficult to address the particular relationship between the outcome and the associated internal malignancy.     

Histopathologic and morphometric evaluation of the skin abnormalities induced by erbium:YAG and carbon dioxide lasers in 10 patients

In the 1960s, carbon dioxide (CO2) laser therapy started to be applied to eliminate wrinkles, actinic scars, and acne because of its capacity of induce intracellular water vaporization. However, recent studies have shown the efficacy of the erbium laser in removing delicate and moderate scars. Furthermore, the postoperative lesions induced by the erbium laser seem to resolve faster and with less erythematous pattern compared with lesions induced by the CO2 laser. The purpose of this study was to determine the immediate pathologic alterations caused by single applications of CO2 and erbium lasers and their association in human skin shreds.Ten white female patients aged 30 to 63 years underwent rhytidectomy, and their respective shreds, which were prepared for excision, were tattooed with the CO2 laser, the erbium laser, or a combination of both in random order and number of applications, before final removal. This project was approved by the local ethical committee. After surgical removal, these tattooed shreds were fixed in 10% buffered formalin and submitted to histopathologic analysis. Morphometric studies demonstrated the normal skin thickness and thickness of the laser-treated area, and their subtraction resulted in the ablation damage values. Residual thermal damage corresponded to the thickness of the affected skin from the most superficial layer of tissue in the laser-treated area down to the deepest dermal area with basophilic degeneration of collagen fibers.Our results showed that two CO2 applications resulted in greater ablation and residual thermal damage when compared with only one CO2 application. The same was true in comparisons of one and two applications of the erbium laser. Both results were statistically significant (p < 0.05). When one isolated erbium and one isolated CO2 application were compared, ablation damage was greater in the former group, although with no statistical significance. One CO2 plus one erbium application compared with one isolated CO2 application showed similar ablation damage but greater residual thermal damage in the latter group (p < 0.05). These observations might contribute to our understanding of the lesions caused in the human skin by erbium and CO2 lasers and eventually help determine the ideal laser combination for the appropriate surgical treatment.     

Intraductal laser photocoagulation of the bilateral parotid ducts for reduction of drooling in patients with cerebral palsy

Patients with cerebral palsy who experience drooling are often isolated from social interaction. Surgical treatment is effective in reducing abnormal, profuse drooling in patients who have low cognitive function, but it has a risk of complications. In this study, a new, simple procedure using laser intervention that minimizes surgical complications is described. Forty-eight patients with cerebral palsy and persistent drooling after more than 6 months of conservative treatment were enrolled in this study. An Nd:YAG laser (1064 nm) was used for intraductal laser photocoagulation of the bilateral parotid ducts at 7 to 10 W for 10 seconds. The outcome was evaluated by questionnaire-based, semiquantitative assessments of drooling severity and frequency, collection and measurement of stimulated saliva, and salivary amylase measurement. The entire procedure was completed in 25 to 65 minutes, with a mean duration of 38.4 minutes. Early complications included transient facial swelling in all patients. Swelling persisted for 6 to 37 days (mean, 11 days). One hematoma (2.1 percent of patients), two infections (4.2 percent of patients), and two cystic formations (4.2 percent of patients) also occurred. No obvious xerostomia or visible scar was noted after the procedure. In the final assessment, a significant improvement in drooling severity (p < 0.05) and frequency (p < 0.05) was noted in the majority of cases. Forty patients (83.3 percent) demonstrated remarkable improvement in drooling severity, seven patients (14.6 percent) showed significant improvement, and one patient (2.1 percent), who was also autistic, continued to experience severe drooling after the laser procedure. The decrease in the amount of saliva produced ranged from 20 to 60 percent at 12 weeks after surgery. The decrease in the amount of salivary amylase measured ranged from 4 to 97 percent at 12 weeks after surgery (p < 0.05). In conclusion, the intraductal laser photocoagulation of bilateral parotid ducts is a simple, effective procedure for reducing drooling in patients who have cerebral palsy. This procedure minimizes risks and complications, compared with those associated with conventional surgery.     

The carbon dioxide laser: an alternative surgery technique for the treatment of common cutaneous tumors in dogs

Background

Tumors of the skin and subcutaneous tissue are the largest group of canine neoplasms. Total excision is still the most effective method for treatment of these skin tumors. For its universal properties the carbon dioxide (CO₂) laser appears to be an excellent surgical instrument in veterinary surgery. Laser techniques are alternatives to traditional methods for the surgical management of tumors. The aim of this study was to compare various types of laser techniques in skin oncologic surgery: excision, ablation and mixed technique and to suggest which technique of CO₂ laser procedure is the most useful in particular case of tumors in dogs.

Findings

The study was performed on 38 privately-owned dogs with total number of 40 skin tumors of different type removed by various CO₂ laser operation techniques from 2010–2013. The treatment effect was based on the surgical wound evaluation, the relative time of healing and possible local recurrence of the tumor after 3 months post surgery. Local recurrence was observed in two cases. The study showed that in 30 cases time needed for complete resection of lesions was less than 10 minutes. Time of healing was longer than 12 days in 6 cases (42.8%) with tumor excision and in 14 cases (87.5%) where excision with ablation technique was performed.

Conclusions

The advantages of the CO₂ laser surgery were better hemostasis, precision of working, non-contact dissection, less instruments at the site of operation and minimum traumatization of the surrounding tissues.     

Effect of Oxygen on the Rate of Photorespiration in Detached Tobacco Leaves

The rate of carbon dioxide exchange in both light and darkness by detached tobacco leaves placed at various oxygen concentrations was measured by an Infra-Red CO₂ Analyzer and a Clark oxygen electrode. It was observed that during illumination oxygen had two different effects. One was to stimulate carbon dioxide evolution and the other to inhibit carbon dioxide absorption. Concentration of carbon dioxide at compensation point was found to be a linear function of oxygen concentration and this has been explained as due mainly to an increased evolution of carbon dioxide. Such an evolution during illumination has been called photorespiration. Increased concentrations of oxygen also had a stimulating effect on the magnitude of the initial post-illumination burst of carbon dioxide in darkness, but no effect on the subsequent steady rates. These data have been explained as due to the suspension of regular respiration in darkness and its replacement by a different process, tentatively called photorespiration. A second effect of oxygen was to reduce the efficiency (called “carboxylation efficiency”) with which a leaf was able to remove carbon dioxide from the atmosphere.