CO2 Laser Vaporization Research Articles

Microstructure, mechanical properties and low temperature degradation resistance of 2Y-TZP ceramic materials derived from nanopowders prepared by laser vaporization

Starting from commercially available powders of tetragonal zirconia polycrystals (TZP) doped with 3mol% yttria (Tosoh grade TZ-3YS-E) and yttria-free monoclinic zirconia (Tosoh grade TZ-0) powders with an overall Y2O3 content of 2mol% (2Y/TZP) were fabricated by CO2 laser vaporization (LAVA) and wet mixing, respectively. The obtained powders were compacted by spark plasma sintering. The influence of the Y3+ distribution on the mechanical properties and on the low temperature degradation (LTD) of the obtained ceramics was investigated. 2Y/TZP ceramics sintered from LAVA nanoparticles showed significantly enhanced mechanical properties and improved LTD resistance due to the homogeneous yttria and grain size distributions in the ceramic structure. For the first time, the present research has demonstrated the effectiveness and reproducibility of the LAVA process for the preparation of tailored zirconia nanopowders enabling microstructural homogeneity and therefore optimized mechanical properties and degradation resistance of Y-TZP ceramics.

CO2 laser vaporization for the treatment of vaginal intraepithelial neoplasia: effectiveness and predictive factors for recurrence.

To evaluate the outcome of vaginal intraepithelial neoplasia (VaIN) treatment with CO2 laser vaporization in terms of local recurrence and progression to vaginal carcinoma. Additionally, the authors investigated the predictive factors for first recurrence. The medical records of all patients treated for VaIN with CO2 laser vaporization at Sant'Anna Hospital in Turin (1995-2012), were retrospectively reviewed. A univariate logistic model was applied to evaluate selected clinical features as predictive factors for recurrence. A multivariate logistic regression analysis was then carried out including significant risk factors after univariate analysis (p < 0.05). The analysis included 285 out of 302 patients. Seventy-one (25%) women relapsed; of these 24 VaIN 1 (22%), 37 VaIN 2 (27%), and ten VaIN 3 (26%). The median time to the first recurrence was 5.2 months (1.4-127.8) for VaIN 1, 6.6 months (1-85.2) for VaIN 2, and 3.6 months (1.2-62) for VaIN 3. Sixty-one out of 71 patients were retreated with CO2 laser vaporization. At the last follow-up visit, 273 (96%) women were free from VaIN. No patients progressed to vaginal carcinoma. The multivariate model showed a higher risk of VaIN recurrence in the case of previous hysterectomy (HR 3.3, 95% CI 1.7-6.3, p < 0.001) and concomitant H-SIL on the Pap smear (HR 1.9, 95% CI 1.2-3.1, p = 0.008). CO2 laser vaporization is an effective low impact treatment for VaIN. Despite this, VaIN recur, in particular in cases of previous hysterectomy and concomitant H-SIL on the Pap smear. An intensive follow-up is proposed for women with a high risk of VaIN relapse.

Dilemma of Inferior Turbinate Surgery

Background and objectives: Inferiorturbinate surgery is considered as one of most commonly performed surgery in rhinology. It is usually done to reduce the bulk of inferior turbinates. It can be conducted for different indications such as relieving the mechanical nasal obstruction due to hypertrophied inferior turbinates, or to achieving a sufficient nasal surgical access during endoscopic sinus surgery, or removing the inferior turbinates as a part of wide and complete resection of rhino-sinus neoplastic lesions. The inferior turbinates have important role in the maintenance of nasal breathing function by providing the nasal valve mechanism necessary for the regulation of air flow through the nose. In spite of availability of well-established variable techniques for this surgery, the main goal of this surgery is yet not completely achieved. This could bean effect of different factors that are difficult to be predicted and controlled. Hence this pattern of surgery has become dilemmas in rhinology which need to be deeply evaluated and subsequently resolved. In order to evaluate and resolve this dilemma, this serial study was conducted prospectively. Patients and methods: 1337 patients aged 3 to -65 years suffering from hypertrophied inferior turbinates, presented with clinical pictures of mechanical nasal obstruction at ENT department – of Althowra central hospital and Al-tarahom private center Elbyda city- Libya between September 2005 to September 2014 they were operated by variable techniques of inferior turbinate surgery, namely sub-mucosal diathermy (SMD) (n=864 ), partial inferior turbinectomy (PIT) (n=427), CO2 laser vaporization of inferior turbinate (n=21), and turbinoplasty (n=25) . Post-operative atrophic rhinitis, and persistence, or recurrence of mechanical nasal obstruction the outcomes are that were studied in relation to different factors to shed-light on existing dilemma. Results and Conclusion: Proper selection of patient for this pattern of surgery is considered one of the main aspects of this issue and one of significant steps towards resolving of this dilemma. On the other hand, type of the technique for this surgery is an important selection criterion. In addition the amount of the inferior turbinate needed to be resected must be decided.

Apport de la microscopie confocale par réflectance dans le diagnostic de la maladie de Paget extra-mammaire

Paget's disease (PD) denotes an initially intra-epidermal adenocarcinoma that can later invade the dermis and metastasise. Among the extramammary forms of PD (EMPD), penoscrotal presentations are rarer than the vulvar and perianal forms. Once diagnosis has been confirmed by histopathological examination, a search for associated neoplasia must be conducted, although penoscrotal EMPD is less frequently associated with underlying neoplasia than mammary PD (MPD). The associated cancer most often involves a neighbouring organ, with prostate cancer being the most common, or in some cases consists of underlying cutaneous adnexal tumours. First-line therapy consists of surgical excision. Alternatives to surgery (imiquimod, CO2 laser vaporisation, dynamic phototherapy) may be considered in certain cases.

Risk factors for treatment failure of CO2 laser vaporization in cervical intraepithelial neoplasia 2

The aim of our study was to evaluate the risk factors for treatment failure of CO2 laser vaporization in patients with cervical intraepithelial neoplasia 2 (CIN2). Medical records of patients who received either shallow or deep CO2 laser vaporization with biopsy-proven CIN2 during March 2007 to April 2011 were reviewed retrospectively. After laser vaporization, liquid-based cytology and human papilloma virus (HPV) DNA testing were checked in every follow-up visit. Treatment failure was defined when the follow-up biopsy was more than CIN2, needing secondary surgical treatment. During that period, 141 patients with CIN2 underwent CO2 laser vaporization. After laser ablation, 14 of 141 women needed the secondary treatment, a success rate of laser vaporization of 90.1 %. In multivariate analysis, the previous loop electrosurgical excision procedure (LEEP) history (adjusted OR = 13.649; P value = 0.025) and the ablation depth (adjusted OR = 11.279; P value = 0.006) were independent factors associated with treatment failure. Both ablation depth and previous LEEP history were the important factors increasing the risk for the treatment failure of CO2 laser vaporization in CIN2.

Nanoparticles for Biomedical Applications Prepared by CO&lt;sub&gt;2&lt;/sub&gt; Laser Vaporization

Functional ceramic nanopowders with emphasis on biomedical applications were engineered by gas-phase condensation using the CO2 laser vaporization (LAVA) technique. Europium doped strontium aluminate nanoparticles (NP) were prepared from a SrO/α-Al2O3/Eu2O3 powder mixture. Excited with ultraviolet radiation (UV), the as-prepared amorphous NP revealed red photoluminescence emission. After annealing in reductive atmosphere crystalline SrAl2O4:Eu2+ nanopowder was obtained showing strong green emission at UV excitation. Ferrimagnetic iron oxide (FexOy) nanopowders were prepared starting from α-Fe2O3 powder. In oxygen-free condensation atmosphere γ-Fe2O3 NP were obtained. Oxygen as condensation gas yielded γ-and ε-Fe2O3 NP. Superparamagnetic NP were prepared starting from α-Fe2O3/SiO2 mixtures. Depending on the mixing ratio γ-Fe2O3 nanocrystallites embedded in a SiO2 glass matrix or γ-Fe2O3-SiO2 Janus NP were obtained. These NP provide a reactive SiO2 interface for subsequent functionalizing. The co-vaporization of α-Al2O3 as the main proportion and t-ZrO2 yielded zirconia-toughened-alumina NP. Reinforcing effects of Al2O3-ZrO2 dispersion ceramics will be increased using NP with an intraparticle dispersion of these phases. Future applications of the LAVA prepared NP include biological fluorescence labeling, and drug targeting, magnetic resonance imaging, and hyperthermic cancer therapy, as well as sintering of load bearing ceramic implants, respectively.

Treatment of Vulvar Intraepithelial Neoplasia With CO2 Laser Vaporization and Excision Surgery

To evaluate the recurrence rate after a single treatment of vulvar intraepithelial neoplasia (VIN) with CO(2) laser vaporization. Fifty women with usual-type or differentiated VIN (grades 2 and 3) treated with CO(2) laser vaporization or surgery excision (cold knife or CO(2) laser) were retrospectively evaluated. Of the 50 patients, 41 (82.0%) had usual-type VIN and 9 (18.0%) had differentiated VIN. Moreover, 24 (48.0%) were treated with surgery excision and 26 (52.0%) underwent CO(2) laser vaporization. Laser-treated patients were significantly younger (p < .01) with more multifocal (p < .05) and multicentric lesions (p < .01) than in the surgery group. Recurrence-free survival (RFS) rates at 1 year were 91.0% for the surgery and 65.2% for the laser vaporization groups (p < .01). At 5 years, RFS rates were unchanged for the surgery group and dropped to 51.3% (p < .01) for the laser group. On the univariate analysis, current smoker (p = .03), multicentric VIN (p = .02), and laser vaporization treatment (p < .01) had a statistically significant impact on RFS. One patient progressed to invasive cancer (2%). The recurrence rate after CO(2) laser vaporization requires regular, close, and extended monitoring.

Control of the Crystal Phase Composition of FexOyNanopowders Prepared by CO2Laser Vaporization

Crystalline magnetic iron oxide nanopowders are prepared by CO2 laser vaporization (LAVA) of a hematite (α-Fe2O3) raw powder. Condensation at normal pressure leads to maghemite (γ-Fe2O3) as the main phase in the nanopowders. With an increasing oxygen partial pressure in the zone of condensation, an increasing amount of Fe2O3 polymorph ε-Fe2O3 is found. The LAVA-prepared Fe2O3 nanopowders are characterized by X-ray diffraction, transmission electron microscopy, and chemical analysis and with respect to their magnetic properties. A mechanism for the initial nucleation is proposed to explain the formation of ε-Fe2O3 with an increasing oxygen content in the condensation atmosphere. The model is based on the evidence of ozone in oxygen-rich condensation atmospheres. Density functional theory calculations indicate that ozone facilitates the formation of 6-fold oxygen-coordinated Fe ions acting as building units for the emerging crystal structure during the solidification of the nanoparticles. This insight into early nucleation stages will be useful for the functional design and crystal engineering of either isostructural materials like alumina (Al2O3) or, more generally, vapor phase synthetic routes for ceramic materials.

Synthesis of Eu-doped SrAl2O4 nanophosphors by CO2 laser vaporization

A new method of synthesizing spherical nanoparticles with photoluminescent spinel structures using a CO2 laser co-vaporization technique (CoLAVA) is presented. The method applies homogeneous mixtures of oxidic precursors such as Al2O3, SrO and Eu2O3 and allows the fabrication of quantities exceeding 10gh−1. During the CoLAVA process, the educt oxides are reacted by a gas phase condensation yielding amorphous spherical particles with diameters ranging from 10 to 100nm. The as-prepared materials exhibit red emission at 625nm (1.98eV) due to the incorporated Eu3+. Temperature treatment up to 1200°C under a reducing atmosphere yielded crystalline particles of the same size, which were slightly sintered. These particles consisted of >90wt.% SrAl2O4 with minor fractions of Sr3Al2O6 and SrCO3. The amount of the SrAl2O4 spinel increased with increasing temperature, whereas the accompanying phases were decreased. A strong green emission centered at 525nm (2.36eV) detected at RT was observed at an onset temperature of 900°C, which is due to the presence of Eu2+ in the crystal lattice of SrAl2O4. The red emission was not observed at higher annealing temperatures. The CoLAVA method represents a fast and facile route for the fabrication of nano- to microstructured phosphor materials for a variety of engineering applications.

Idiopathic subglottic stenosis: An evolving therapeutic algorithm

Idiopathic subglottic stenosis (ISS) is a rare type of airway stenosis of unclear etiology. Open resection, while effective, remains a complex surgery and requires a hospital stay. Endoscopic management is often preferred but has historically been associated with a high recurrence rate. We aimed to analyze our experience, consisting of a standardized endoscopic approach combined with an empiric medical treatment. Retrospective cohort study. All patients with ISS managed with standardized endoscopic treatment at our institution between 1987 and 2012 were identified, and their electronic medical records were reviewed. The treatment consisted of CO2 laser resection without dilatation and local infiltration with steroids and application of mitomycin C. Patients were also treated with antireflux medications, inhaled corticosteroids, and occasionally trimethoprim-sulfamethoxazole. The influence of medical management on annual recurrence rate was analyzed using negative binomial logistic regression. A total of 110 patients treated with standardized endoscopic management were included in our analysis. The procedure was well tolerated by all patients without complications. Recurrences were observed in approximately 60% of patients at 5 years. There was a trend suggesting an association between aggressive medical treatment and a reduction in the rate of recurrence/person/year (relative risk = 0.52, P = 0.051). A standardized endoscopic management of ISS consisting of CO2 laser vaporization of the fibrotic scar appears effective in symptom control, with 40% of patients not requiring retreatment in the follow-up period, and with recurrence noted in a majority of patients. Aggressive medical treatment may have a role, but further prospective studies are required to confirm these findings. 4.

The influence of organobentonite clay on CO2 laser grooving of nylon 6 composites

The popular polycaprolactam (polyamide PA6), commonly referred to as nylon 6, widely used as a construction plastic, is not a typical material for micromachining by CO2 laser vaporization. In this paper, we describe investigations of the pulsed CO2 laser grooving of both the chemically pure and the organobentonite clay modified nylon 6. Our results indicate that doping of nylon 6 with nanoparticles of organophilized bentonite significantly improves the grooving ability, predictability of the process, and its quality. In order to determine the nature of the changes in the depth and width of the grooves as a function of the laser process parameters, theoretical modeling of the laser grooving of nylon was carried out. The basic parameters of the laser grooving process versus laser beam intensity, pulse repetition rate, scanning speed of the material and various compositions of the organophilized bentonite dopant are presented. Additionally, an example of a three-dimensional engraving/milling of tested materials as well as the impact of doping on the channel profile are examined. The modification of nylon 6 by appropriate doping with bentonite clay radically improves the quality of micromachining with a CO2 laser.

Malignant transformation of oral leukoplakia in a well‐defined cohort of 144 patients

Oral leukoplakia is a potentially malignant disorder of the oral mucosa. The aim of this retrospective study was to identify the factors that possibly predict malignant transformation in a well-defined cohort of patients with a long-term follow-up. All leukoplakias were staged according to a clinicopathological classification and staging system. Furthermore, a certainty factor has been used with which the diagnosis has been established. The group consisted of 144 patients. The size, presence and degree of epithelial dysplasia were incorporated into a clinicopathological classification and staging system. Initial management consisted of surgical excision, CO2 laser vaporisation or observation only. The mean follow-up period was 51.2months (s.d.=39.33, range 12-179months). In 16 of 144 patients (11%), malignant transformation occurred between 20 and 94months (mean 57.0months) after the first visit, the annual malignant transformation rate being approximately 2.6%. A large size of the lesion (≥4cm) showed to be the only statistically significant predictor of malignant transformation (P=0.034). A size of ≥4cm showed to be the only significant predicting factor of malignant transformation in oral leukoplakia. No other epidemiological, aetiological, clinical or histopathological parameters were of statistical significance.

Use of CO2 Laser Vaporization for the Treatment of High-Grade Vaginal Intraepithelial Neoplasia

In a series of cases of high-grade vaginal intraepithelial neoplasia (VaIN) at our institution, to analyze its clinicopathologic characteristics, diagnostic methodology, and therapeutic results obtained with the use of CO2 laser vaporization. Between January 2003 and December 2009, 28 patients with a diagnosis of high-grade VaIN were treated in our department using CO2 laser vaporization. Of the 28 patients, 7 were lost to follow-up; 21 patients were followed up with cytological examination and colposcopy for therapeutic response. Median follow-up was 25 months (range = 12-78 months). The setting is an urban referral center, a private hospital with a high-grade complexity. Of the 21 patients evaluated, 18 are currently disease free after having undergone a single application of CO2 laser vaporization with a cure rate of 86% (95% CI = 63.7%-97%). Three patients (14%) presented with persistence/recurrence and required a second application. Of these 3 patients, 2 are currently disease free, whereas 1 patient progressed to invasive carcinoma 11 months after a second procedure and was managed with partial colpectomy and pelvic lymphadenectomy. CO2 laser vaporization was effective for the initial treatment of high-grade VaIN. However, a long-term follow-up is required due to the recurrent character of this disease.

Laser Vaporization of Magnetic Fe&lt;sub&gt;x&lt;/sub&gt;O&lt;sub&gt;y&lt;/sub&gt; and Fe&lt;sub&gt;x&lt;/sub&gt;O&lt;sub&gt;y&lt;/sub&gt;-SiO&lt;sub&gt;2&lt;/sub&gt; Nanoparticles for Biomedical Applications

Magnetic iron oxide (FexOy) and iron oxide/silica (FexOy/SiO2) composite nanoparticles were synthesized by CO2 laser vaporization (LAVA) of an α-Fe2O3 raw powder and α-Fe2O3/quartz sand mixtures, respectively. Particle morphology, composition and iron oxide phase formation were investigated by transmission electron microscopy and X-ray diffraction. The resulting nanopowders mainly consisted of magnetite (Fe3O4) and maghemite (γ-Fe2O3). Increasing the oxygen partial pressure in the LAVA process gas an additional iron oxide phase, ε-Fe2O3, occurred. The saturation magnetization of the iron oxide nanoparticles was determined with vibrating sample magnetometry and was found to decrease with increasing oxygen partial pressure in the process gas. FexOy/SiO2 composite nanoparticles are of particular interest for biomedical applications because their silica surface can be functionalized very easily.

Treatment results of CO2 laser vaporisation in a cohort of 35 patients with oral leukoplakia

The aim of the present study was to evaluate the treatment results of CO2 laser vaporisation in a well-defined cohort of patients with oral leukoplakia (OL). The group consisted of 35 patients. Before treatment, a clinical photograph and an incisional biopsy were performed in all cases. Also posttreatment results were documented with clinical photographs. The assessment of the treatment results was performed by an independent clinician who had not performed the treatment. The mean follow-up period was 61.9 months (range 12-179 months). In 14/35 patients, there was a recurrence between 1 and 43 months (mean 18.7 months), the annual recurrence rate being approximately 8%. In three of these patients, malignant transformation occurred at a later stage. In two other patients, a malignancy occurred without a prior recurrence. In altogether 5 of 35 patients, malignant transformation occurred in a mean period of 54 months, the annual malignant transformation rate being approximately 3%. The results in the present study are worse than those reported in the literature, perhaps owing to the use of different diagnostic criteria for OL, differences in the employed laser technique and assessment of possible recurrences by an independent clinician.

Adjacent Flaps for Lower Lip Reconstruction After Mucocele Resection

Mucocele forms because of salivary gland mucous extravasation or retention and is usually related to trauma in the area of the lower lip. It is a common benign lesion in the oral region. Although there are many conservative treatments such as the creation of a pouch (marsupialization), freezing (cryosurgery), micromarsupialization, and CO2 laser vaporization, surgical resection is the most commonly used means. Generally speaking, an elliptic incision was made to fully enucleate the lesion along with the overlying mucosa and the affected glands, then direct suturing is adequate. However, in some cases, direct suturing could cause lower lip deformity, and adjacent flaps for lower lip reconstruction after mucocele resection might be quite necessary. Based on our experience, adjacent mucosal flaps could be used when lesions were close to or even break through the vermilion border or their diameters were much more than 1 cm. A-T advancement flaps and transposition flaps were the mostly applied ones. Follow-up showed that all patients realized primary healing after 1 week postoperatively with satisfactory lower lip appearance, and there was no sign of increasing incidence of relapse.

Different CO2 laser vaporization protocols for the therapy of oral precancerous lesions and precancerous conditions: a 10-year follow-up

Use of the CO(2) laser (λ = 10.6 μm, continuous wave, defocused) is an established procedure for the treatment of premalignant lesions. Through employment of the sp-mode as well as scanners, thermal laser effects can be reduced but, on the other hand, a lesser degree of destruction of dysplastic cells could lead to an increased recurrence rate. The purpose of this study was to prospectively evaluate the recurrence rates resulting from different methods of CO(2) laser vaporization. From May 1995 to May, 2005, 145 patients with a total of 148 premalignant lesions of the oral mucosa were treated in a prospective clinical study. Sixty-two lesions in 62 patients were vaporized with the defocused CO(2) laser (group 1). In a further 45 lesions (43 patients, group 2), a scanner was additionally employed. In the remaining 41 lesions (40 patients, group 3), vaporization was carried out in the sp-mode in which the scanner was also used. In September, 2005, recurrence rates in the three groups were evaluated. Use of the scanner in sp-mode resulted in the most irregular tissue vaporization. This can be accounted for by the irregular paths of the laser beam and the pulsed delivery of the laser energy. Statistically significant lowest recurrence rates were yielded by the defocused cw-technique followed by the cw-scanner and the sp-mode. These results indicate that for CO(2) laser treatment of premalignant lesions of the oral mucosa, the best results can be achieved with the defocused technique. It may be assumed that other methods with lesser penetration of thermal effects (e.g. sp, scanner) do not reach the deeper-lying cells and, consequently, render higher rates of recurrence.

Preparation of Spherical Titania Nanoparticles by CO2 Laser Evaporation and Process‐Integrated Particle Coating

The CO2 laser vaporization (LAVA) method was used to prepare titania nanopowders. Because this versatile method does not require special precursors, a coarse anatase raw powder was applied as starting material. Powder samples produced under varied process parameters were characterized by transmission electron microscopy (TEM), X‐ray diffraction measurements, and Brunauer–Emmett–Teller surface area measurements. The laser‐generated powders consist of spherical, single crystalline and pure anatase nanoparticles, merely softly agglomerated by weak van der Waals forces. Using TEM analysis, the influence of the process parameters on the resulting particle size distribution was investigated. The results are discussed with respect to the particle formation by gas phase condensation. The potential of a process integrated, i.e. in situ, coating procedure for the surface modification of the anatase nanoparticles is demonstrated. As an exemplary representative of organic layer materials stearic acid was chosen. The organic coating was characterized by TEM and Raman spectrometry. Because of the unavoidable soft agglomeration the coating covers entire agglomerates rather than individual primary particles. Thus, the influence of the LAVA process parameters on the agglomerate sizes was systematically studied using a scanning mobility particle sizer.

Primary Vaginal Adenocarcinoma Arising in Vaginal Adenosis After CO2 Laser Vaporization and 5-Fluorouracil Therapy

We present a case of a 45-year-old woman with a long-standing history of persistent cervical dysplasia that resulted in a hysterectomy. Subsequent vaginal smears revealed high-grade vaginal intraepithelial neoplasia (VAIN III) on Pap smear with positive human papilloma virus (HPV) testing. Over the course of 2 years, the patient underwent 2 CO(2) laser vaporization procedures of the upper vagina and intermittent 5-fluorouracil therapy. A biopsy performed at the time of the second laser procedure revealed endocervical-type well-differentiated adenocarcinoma, associated with VAIN III. HPV in situ hybridization for HPV types 16 and 18 was positive in both the glandular and squamous mucosa. The patient has no known history of intrauterine diethylstilbestrol exposure or mullerian developmental abnormalities. Subsequently, the patient underwent a radical upper vaginetcomy with bilateral pelvic lymph nodes dissection and bilateral salpingo-oophorectomy. The vaginectomy specimen showed residual adenocarcinoma associated with VAIN-III and extensive vaginal adenosis with free resection margins. This is the second reported case in the literature of adenocarcinoma arising in vaginal adenosis after 5-fluorouracil. Herein, we highlight these important findings and shed some light on the pathogenesis of vaginal adenosis and the subsequent development of vaginal adenocarcinoma.

Actinic cheilitis: Evolution to squamous cell carcinoma after carbon dioxide laser vaporization. A study of 43 cases

Background: Actinic cheilitis (AC) is a precancerous lesion of the lip. Treatment of AC is indicated for prevention of squamous cell carcinoma (SCC), although the exact transition rate of AC to SCC is unknown. Carbon dioxide (CO2) laser vaporization seems to be an adequate therapy for AC, but there are no references about the evolution rate of AC to SCC after this treatment. Objective: To evaluate the results obtained after treatment of AC by CO2 laser vaporization in comparison with other treatment modalities and the evolution rate of AC to SCC after CO2 laser treatment. Methods: A retrospective review identified 43 patients with AC treated with CO2 laser vaporization at our hospital from 2002 to 2006. Clinical and therapeutic information was evaluated. All patients were followed for more than 15 months after treatment. Results: After a mean follow-up period of 29.4 months, 3/43 treated AC showed local recurrence. Another two patients developed SCC in the treated field. A residual scar was clinically evident in two patients. Conclusions: CO2 laser vaporization with an adequate postoperative follow-up is an effective treatment for chronic AC. Nevertheless, some patients (4,6%) went on to develop lip SCC. The follow-up of these patients is mandatory.