CO2 Laser Research Articles

Effect of moisture content levels on the quality of beech wood cut by CO2 laser

Effect of moisture content levels on the quality of beech wood cut by CO2 laser

Effects of discharge tube and coolant materials on longitudinally excited CO2 laser with fast pulsed discharge

Effects of discharge tube and coolant materials on longitudinally excited CO2 laser with fast pulsed discharge

Up-conversion luminescence and thermal sensing properties of LuYO3: Er3+/Yb3+ phosphor

A series of LuYO3: Er3+/Yb3+ phosphors with different Yb3+ concentrations were prepared through a melting zone method with CO2 laser. The samples emit bright up-conversion luminescence (UCL) under a 980 nm laser. The UCL intensity and the luminescence color change significantly when Yb3+ concentration changes. Besides, when doped with 3 mol% Yb3+, the UCL intensity is maximal. The thermal sensing properties of LuYO3: Er3+(0.5 mol%)/Yb3+(3 mol%) were studied using the fluorescence intensity ratio (FIR) method from 298 K to 848 K. The maximum absolute and relative sensitivities are 0.0050 K−1 at 366 K and 0.0167 K−1 at 298 K, respectively. Thus, the LuYO3: Er3+(0.5 mol%)/Yb3+(3 mol%) fluorescent material is very suitable for thermal sensing because of the wide temperature range and the high sensitivity.

Influence of heat transfer at the graphene–polyimide interface on laser-induced graphene formation

Laser-induced graphene (LIG) provides a three-dimensional porous structure of graphene, which is suitable for application to energy storage devices and flexible electronics. Controlling the morphology and structure of LIG and understanding its underlying principle are important for enhancing the performance of LIG-based devices. Here, we investigated the effects of graphene interfacing with a precursor material on the LIG formation. A CO2 laser with different powers and scan rates was irradiated on a polyimide film covered with mono-, bi-, and trilayer graphene to fabricate in situ LIG contacts. As the number of graphene layers increases, the threshold energy required for the LIG formation decreases. In addition, the interfacing graphene causes spreading and smoothing of the LIG electrodes in the in-plane direction. A numerical study on the effect of the interfacing graphene on heat transfer was also conducted. The simulation results showed that the graphene layer enhances thermal diffusion to facilitate the LIG formation; this was also observed in the experimental results. Our study on the interfacial effects of a nanomaterial on the LIG formation provides design guidelines for considering heat transfer in LIG electronics fabricated with heterogeneous materials and structures.

THE USE OF SUBCISION IN CONJUNCTION WITH FRACTIONAL CARBON DIOXIDE LASER TO IMPROVE ATROPHIC ACNE SCARS

Objective: Acne is a prevalent skin condition affecting a wide range of age groups, often leading to severe scarring if left untreated. The use of subcision combined with fractional CO2 laser therapy has been posited as a potentially more effective treatment method for atrophic acne scars compared to standalone laser treatment. Methods: This clinical trial was conducted at Asha Derma Clinic, Gorakhpur, Uttar Pradesh, from 30th March 2023 to 30th March 2024. Thirty patients with ice pick and rolling-type atrophic acne scars were enrolled. Participants were treated on one side of their face with five sessions of fractional CO2 laser and on the other side with one session of subcision with fractional CO2 laser combined with four sessions of fractional CO2 laser alone. Outcomes were assessed through scar improvement and patient satisfaction at 1, 2, and 6 mo post-treatment, with data analysis performed using ANOVA and the Wilcoxon rank-sum test. Results: Significant improvements were observed in both recovery levels and patient satisfaction. The combined method showed higher recovery percentages (40-65%, Mean±SD: 54.7±7) compared to the laser alone (30-55%, Mean±SD: 43±11.1), with a p-value of 0.0005. Patient satisfaction also favored the combined method (1.8-3, Mean±SD: 6.6±1.2) over laser treatment alone (1.6-4, Mean±SD: 5.2±1.8), with a p-value of 0.0007. Conclusion: The study demonstrated that subcision combined with fractional CO2 laser therapy significantly enhances recovery levels and patient satisfaction in the treatment of atrophic acne scars, suggesting a robust advantage of integrating both treatments.

445nm Blue Laser for Cricopharyngeal Myotomy/Zenker's Diverticulotomy: Proof of Concept and Use.

Treatment for Zenker's diverticulum and cricopharyngeal dysfunction has evolved to include flexible endoscopic approaches. Currently, no flexible modalities combine the precision cutting of CO2 laser and the hemostasis of knife electrocautery. We present the first series describing fiber-based 445nm blue light (BL) laser for endoscopic cricopharyngeal myotomy/Zenker's diverticulotomy. We describe usage characteristics and laser parameters with rigid esophagoscopy to determine the feasibility of use with flexible endoscopy. Retrospective review and literature review. The first nine cases of endoscopic diverticulotomy (n = 5) and cricopharyngeal myotomy (n = 4) with BL were reviewed. Rigid exposure was achieved with the Dohlman Slimline diverticuloscope. Mean age was 75.6 years. Average diverticulum depth was 0.89 cm ±1.0 cm. Pulsed mode was used in seven cases with mean of 6.86 W, 54 ms pulse on, and 286 ms pulse pause and overall mean of 6.00 W and 405 J. Complete myotomy with intact buccopharyngeal fascia and without bleeding limiting view was achieved in all patients. One of two patients in whom continuous wave setting was used developed subcutaneous emphysema following vigorous cough on POD0; this resolved after 7 days nothing per oral (NPO). Eight patients were started on oral intake without evidence for leak. Pulsed mode with fiber-to-tissue contact provided effective muscle cutting without disruption of buccopharyngeal fascia. Literature review yielded three articles examining flexible approach with laser for Zenker's and none with BL. BL provides safe and effective fiber-based cutting and hemostasis in endoscopic cricopharyngeal myotomy/Zenker's diverticulotomy. Future use in flexible endoscopic approaches appears feasible, though continuous wave should be avoided. IV Laryngoscope, 2024.

Multifaceted Impact of CO2 Laser Therapy on Genitourinary Syndrome of Menopause, Vulvovaginal Atrophy and Sexual Function.

Genitourinary syndrome of menopause (GSM) encompasses a range of distressing symptoms in the vulvovaginal and/or bladder-urethral regions related to menopause changes, negatively influencing woman's quality of life and sexual activity. Fractional micro-ablative CO2 laser therapy has shown the potential to reinstate the vaginal epithelium to a condition akin to the premenopausal state, thereby ameliorating the subjective symptoms associated with GSM. We conducted a prospective, pilot study in 73 sexually active postmenopausal women treated with CO2 laser for their GSM symptoms, while assessing Vaginal Health Index Score (VHIS) and sexual function through the Female Sexual Function Index (FSFI) Questionnaire. The laser treatment resulted in a decrease in VHIS and patient-reported vulvovaginal atrophy (VVA) symptoms, with a significantly lower prevalence of vaginal itching, dryness, and burning (p < 0.001), as well as dyspareunia (p = 0.002). The occurrence of urinary incontinence, urgency, and vaginal heaviness significantly reduced, with an improvement in the staging of cystocele, either to Stage 1 or complete resolution (p < 0.001). FSFI total and domain scores were significantly higher after the treatment, indicating better sexual function, with a post-treatment score median of 25 (p < 0.001). Therefore, using a three-cycle fractional CO2 laser was an effective choice for reducing urogenital discomfort related to GSM in postmenopausal women.

Combined CO2 Laser Vaporization and Bleomycin Injection to Treat Huge Adult Laryngeal Vascular Anomalies: Innovative Application of CO2 Laser in Otolaryngology.

The aim of this study was to assess the value of CO2 laser vaporization in treating huge adult laryngeal vascular anomalies (HALVAs) by combining it with bleomycin injection. This study retrospectively reviewed the records of 13 adult patients who underwent 18 different procedures. Methods to treatHALVAs include traditional bleomycin injectionand CO2 laser vaporization combined with bleomycin injection between September 2009 andJanuary 2023. Treatment results were evaluatedby the grade of lumen constriction. A total of five males and eight females, with an average age of 46.3 years (range, 22-66 years), were included in the study. The huge adult laryngeal vascular anomalies in our study were greater than 1633.71 mm3, and the long diameters of the bases were longer than 15 mm. Compared with the bleomycin injection-only group, the results with the CO2 laser vaporization and bleomycin injection combined were better. Both bleomycin injection and CO2 laser vaporization are safe treatment methods. Their combination may produce better results for huge adult laryngeal vascular anomalies.

Effect of laser power on the structure and specific surface area of laser-induced graphene

Laser-induced graphene (LIG) is a highly porous carbon material with prospects for application in various fields of modern electronics, energy and medicine. In this work, LIG film samples with the size of 5 × 10 mm were synthesized on the surface of polyimide film using line-by-line scanning of focused radiation from a cw carbon dioxide laser. Studies using scanning electron microscopy and Raman spectroscopy revealed that the structure of the resulting material depends significantly on the laser power. Measurements of the specific surface area Ssa of the synthesized carbon material, carried out by the well-known BET method during adsorption and desorption of gaseous nitrogen, showed that Ssa significantly depends on the laser power. At a line scanning speed of 220 mm/s, 25 μm spacing between lines and a focused laser beam diameter of 120 μm, an increase in power from ~1.7 to 8.2 W leads to a decrease in Ssa from ~370 to ~100 m2/g. At the same time, the ratio of the total area of all LIG pores to the area of the obtained film varies in the range ~ 365–660 and reaches its maximum value of 660 at a power ~ 4.3 W.

Utilizing Laser-Induced Fluorescence to Evaluate the Efficiency of Carbon Dioxide and Diode Lasers in Dentin Sealing after Tooth Preparation: An in-vitro Study.

Adhesive dentistry has made it feasible to design restorations with high aesthetic qualities and little invasiveness. However, the freshly cut dentin after the tooth preparation needs to be sealed to prevent its contaminations, bacterial leakage, and hypersensitivity. Consequently, the immediate dentin sealing (IDS) method has been advised. This study examines different dentinal tubule sealing methods via CO2 laser, diode laser (980-nm) and a two-step self-etch adhesive system applied directly to the fresh cut dentin preceding the placement of the provisional phase. The sealing efficiency of each laser and bond system was evaluated based on the laser-induced fluorescence (LIF) properties and image analysis by scanning electron microscopy. Moreover, the obtained LIF spectra were evaluated using partial least square progression. A two-step adhesive containing a high concentration of S-PRG fillers produced a thick layer that was not perfectly uniform at all sites due to uneven filler distribution in the bond with totally and partially closed dentinal tubules. However, the peaks of the LIF spectra dropped after applying laser because of its sealing effectiveness. Accordingly, CO2 and diode lasers have strong evidence in dentinal tubule sealing and a definitive treatment modality for dentinal hypersensitivity. Moreover, IDS with an adhesive system is superior in occluding dentinal tubules in a biomimetic manner based on its filler content and bioactive properties.

Laser synthesis of oxide nanoparticles with controlled gas condensation

In this work, the oxide nanopowders of Al2O3, ZrO2, Y2O3, Gd2O3, CeO2, and SiO2 were synthesized by CW CO2 laser vaporization technique with controlled gas condensation in an inert atmosphere. Methods for controlling the size of the resulting nanoparticles by adjusting the gas composition and pressure during the vaporization process have been demonstrated. The potential for producing ultrasmall oxide nanoparticles with dimensions less than 5 nm has been shown. The size distribution of nanoparticles taken from different parts of the evaporation-condensation tract was studied using scanning (SEM) and transmission (TEM) electron microscopy methods. The effect of synthesis conditions (pressure and composition of the inert gas) on characteristics of the nanoparticles is discussed. Using a wide class of simple oxides as the example, it is shown that the powders synthesized by the laser method consist of three types of particles: target spherical particles with a diameter of 3–20 nm (more than 98%), larger spherical particles with a diameter of 50–200 nm, and shapeless large particles with sizes more than 200 nm. The possibility of separating large particles from the main particles using the original labyrinth system for gas pumping is shown. The obtained particles with controlled sizes can be effectively used in various applications, in particular, for the preparation of catalysts and adsorbents.

Addressing Burn Hypertrophic Scar Symptoms Earlier: Laser Scar Revision May Begin as Early as 3-6 Months After Injury.

Fractional ablative CO2 laser (FLSR) is used to treat hypertrophic scars (HTSs) resulting from burn injuries,which are characterized by factors, such as erythema, contracture, thickness, and symptoms of pain and itch. Traditionally, waiting a year after injury for scar maturation before starting laser treatment has been recommended;however, the potential benefits of earlier intervention have gained popularity. Still, the optimal timing for beginning laser intervention in patients with HTSs remains uncertain. This study aims to evaluate the ideal timing for the initiation of FLSR for HTSs using several qualitative and quantitative assessment measures. It was hypothesized that early intervention would lead to similar improvement trends as later intervention, however, would be more ideal due to the shortened time without symptom relief for patients. Patients who received three or more laser treatment sessions and completed both pre- and posttreatment evaluations were included in this analysis (n = 69). FLSR treatment was administered at 4-8-week intervals. Patients starting treatment before 6 months after injury were classified as the early-stage intervention group and those beginning treatment at 6-12 months after injury were classified as the late-stage intervention group. Demographic data, including the age of patients at the time of first treatment, age of scars at the time of first treatment, biological sex, ethnicity, Fitzpatrick skin type, and use of laser-assisted drug delivery, were collected by retrospective chart review. Patients were evaluated on six subjective scales and objectively for scar stiffness with durometry. For all scales, higher scores indicate worse scars. A two-way ANOVA, Student's t-test, and Mann-Whitney U-test were used to compare scores from the pre- to posttreatment evaluations. There were no significant differences between the groups for any of the demographic or scar-specific variables; thus, differences in outcome can be attributed to the timing of intervention. Both groups demonstrated an improvement in scars with treatment over time (p < 0.05). Both early- and middle-stage initiation showed scar symptom improvement in five out of six scales. In the late-stage intervention, the Patient and Observer Scar Assessment Scale-Patientaverage score did not show improvement. In the early-stage intervention, the Vancouver Scar Scaletotal did not show improvement. Quantitative evaluation of scar stiffness by durometry did not show symptom improvement in either group. The Scar Comparison Scaledemonstrated the greatest improvement across groups. Laser treatment led to scar improvement in at least one scale at each stage of initiation. Both intervention timelines resulted in equivalent outcomes, and early intervention should be considered when initiating FLSR treatment in burn scars to alleviate symptoms earlier.

ANN Prediction of Laser Power, Cutting Speed, and Number of Cut Annual Rings and Their Influence on Selected Cutting Characteristics of Spruce Wood for CO2 Laser Processing.

In this work, we focus on the prediction of the influence of CO2 laser parameters on the kerf properties of cut spruce wood. Laser kerf cutting is mainly characterized by the width of kerf and the width of the heat-affected zone, which depend on the laser power, cutting speed, and structure of the cut wood, represented by the number of cut annual rings. According to the measurement results and ANN prediction results, for lower values of the laser power (P) and cutting speed (v), the effect of annual rings (ARs) is non-negligible. The results of the sensitivity analysis show that the effect of v increases at higher energy density (E) values. With P in the range between 100 and 500 W, v values between 3 and 50 mm·s-1, and AR numbers between 3 and 11, the combination of P = 200 W and v = 50 mm·s-1, regardless of the AR value, leads to the best cut quality for spruce wood. In this paper, the main goal is to show how changes in the input parameters affect the characteristics of the cutting kerf and heat-affected zones for all possible input parameter values.

Fractional Carbon Dioxide Laser versus Cryotherapy in the Treatment of Alopecia Areata: A Pilot Comparative Study

Abstract Alopecia areata, one or more round bald patches appear suddenly, most often on the scalp. It can affect males and females at any age. The exact mechanism is not yet understood and there is not yet any reliable cure for alopecia areata. Several topical treatments used for alopecia areata are reported to result in temporary improvement in some people. Superficial cryotheray is introduced as a possible treatment for Alopecia Areata with minimal side effects and being less painful. In addition, fractional CO2 laser is introduced as a effective option in AA treatment. Aim of the Study the current study aimed to assess the efficacy and safety of FCO2 laser in comparison to cryotherapy in the treatment of AA. Patients and Methods this study included 22 patients (with patchy AA (at least three patches) of both sexes. Patients were subjected to full history taking, complete general and dermatological examination then digital photography and dermoscopic examination were performed. The three patches in each patient were divided according to therapy used; one patch was treated with Fractional CO2 laser, second one was treated with superficial cryotherapy and the third was left without treatment as control. Results Regarding FCO2 laser treated patches, trichoscopic assessment revealed that BDs, YDs and EMHs count showed significant decrease after treatment compared to before treatment. In addition, SVHs count showed significant increase after treatment compared to before treatment. Concerning cryotherapy treated patches, trichoscopic assessment revealed that BDs, YDs and EMHs count showed significant decrease after treatment compared to before treatment. Also, there was as increase in the TH and SVHs count after treatment in comparison to before treatment, but the results were statistically insignificant. Conclusion Both cryotherapy and fractional CO2 laser therapy are safe and effective modalities in the treatment of AA with superiority for FCO2 laser.

Stapedoplasty as a Method of Hearing Loss Treatment in Patients with Tympanosclerosis

Objectives: The aim of this study is to evaluate the efficacy of stapedoplasty as a method of hearing loss treatment in patients with stapes tympanosclerotic fixation. Materials and Methods:The first group included 25 patients with CPOM and TSC who under-went a two-stage surgery (2nd stage – stapedoplasty). The second group included 25 patients with CPOM and TSC who underwent a one-, two-, or three-stage surgery with a typical sta-pedoplasty as a final step, but using a surgical CO2 laser. Results: Analysis data of ABG mean values (35.3±8.6 dB before surgery) in TSC2 group showed their decrease in 1 month up to 22.1±9.5 dB; in 6 months – up to 17.0±8.0 dB, and in 12 months – up to 14.9±7.4 dB. Stapedoplasty with laser assistance was also effective, but its best results were shown in 6-12 months after surgery. ABG values &lt; 20 dB were reached in 76% pa-tients; from 20 to 30 dB – in 92%, and 30 dB – in 100% patients. Analysis data of BC values (30.3±11.3 dB before surgery) showed their consistency in 1 month after surgery – 31.1±13.2 dB; in 6 months – 28.9±13.1 dB, and in 12 months – 28.3 ± 12.8 dB. Conclusion: Laser assistance during stapes crus crossing stage and stapedotomy in the early fol-low-up period results in absence of inner ear reaction for surgery.

Fractional Ablative Carbon Dioxide Laser-Assisted Photodynamic Therapy for keloids: Clinical, Histopathological and Immunohistochemical Evaluation

Abstract Background Keloids present a therapeutic challenge due to lack of satisfactory treatment and high rate of recurrence. Various treatment modalities exist, including intralesional steroids, photodynamic therapy (PDT), lasers and different combinations have been used to reach better results. Aim To study whether fractional ablative CO2-assisted delivery of Methylene blue-PDT is an effective method of treatment of keloids. Methods twenty patients with untreated keloids have been treated with 3 monthly sessions of fractional CO2 laser and methylene blue PDT. In the first session debulking of the keloid’s height by at least 50% with ablative CO2 was performed. Patients were photographed and assessed before treatment and 2 months after last session, clinically using modified Vancouver Scar Scale (mVSS) &amp; patient and observer scar assessment scale (POSAS), histopathologically by H&amp;E, Masson trichrome and immunohistochemically by TGF-b. Results total score for mVSS dropped from 8.25 ± 2.489 to 6.45 ± 2.8 (p = 0.013) after treatment, with a percentage change of -18.6 ± 39.6. Also, POSAS (observer) decreasaed from 26.90 ± 6.545 to 18.75 ± 8.045 (p = 0.001). POSAS (patient) decreased from 27.40 ± 6.644 to 19.05 ± 7.722 (p = 0.0001) Histopathologically, collagen improved from 3.45 ± 1.05to 2.65 ± 0.875. The TGFb staining increased post treatment but not significantly. Conclusions clinical and histopathological improvement was seen after MB-PDT but further controlled studies are needed to compare its effectiveness with other established modalities. Also compare results of different parameters of fractional CO2-PDT, more treatment sessions and study the long term follow up results.

Histomorphological evaluation of thermal injury following palatoplasty performed with CO2 laser or LigaSure device in dogs with brachycephalic obstructive airway syndrome

The elongated soft palate is an abnormality that characterizes most brachycephalic dogs and contributes to the brachycephalic obstructive airway syndrome (BOAS). Palatoplasty is routinely performed in brachycephalic dogs; several surgical techniques exist. The use of surgical instruments such as monopolar electrocoagulation, CO2 or diode laser, bipolar vessel sealing device and harmonic shears has become routine to reduce the operating time, the intraoperative risk of bleeding and the postoperative oedema. This prospective study aimed to compare the histomorphological effect of a CO2 laser and LigaSure device in palates of dogs undergoing palatoplasty. Twenty owned brachycephalic dogs were included, 10 palatoplasties were performed using CO2 laser and 10 using LigaSure™ device. The dogs were positioned in sternal recumbency. A transoral approach was performed: the elongated soft palate was grasped with Allis forceps and brought rostrally, the palatoplasty was performed using the tonsillar crypts as anatomical landmarks. Surgical specimens were routinely fixed in 10 % formalin. Two sections perpendicular to the surgical margins were trimmed from each sample, paraffin-embedded and stained with hematoxylin and eosin (H&E). Tissue damage induced by the two types of surgical devices was graded (1–4, from minimal to severe) and the depth of thermal injury measured in μm on captured images (using an image analysis program - ImageJ). Mean values and standard deviations (SD) were calculated based on six measurements for each sample.The tissue damage was graded 3.7±0.48 in group LigaSure™ and 2.8±1 in group Laser. The mean depth of thermal injury was 874.94±184.92 μm in the LigaSure™ group and 451,76±137,86 μm in the Laser group. The comparison between the two groups showed significant lower grade and extension of thermal injury in the palate samples obtained with CO2 laser (p<0.05).Additionally, there is a lack of literature that correlates the histological changes with the clinical outcomes of the different palatoplasty methods in brachycephalic dogs. By comparing histological changes and clinical outcomes, we aim to provide valuable insights for optimizing the surgical approach for palatoplasty in brachycephalic dogs, ultimately improving postoperative outcomes for these patients.

The effect of narrow band imaging in CO2 laser therapy in early-stage glottic cancer

Objective:To explore efficacy of narrow band imaging（NBI） technique in CO2laser therapy in Early-Stage Glottic cancer. Methods:The clinical data of patients with Early-Stage Glottic cancer who underwent CO2laser vocal cord resection from June 2011 to August 2022 were retrospectively analyzed. Among these, 27 patients who underwent surgery assisted by NBI were assigned to the observation group, while 25 patients who underwent conventional CO2 laser microsurgery with a suspension laryngoscope were assigned to the control group. The differences between the two groups were analyzed in terms of intraoperative frozen pathology results, postoperative recurrence rates, 5-year cumulative disease-free survival rates, complications, and voice recovery. Results:All 52 patients were operated successfully. Temporary tracheostomy and serious complications did not occur during the operation. The postoperative patient's pronunciation was satisfactory. One patient experienced vocal cord adhesion, but there were no severe complications such as breathing difficulties or bleeding, with an overall complication rate of 1.92%. Postoperative follow-up was 1-5 years. The 5 years recurrence free survival in the general group was 77.90％, and the 5 years recurrence free survival in the NBI group was 100％, the difference was statistically significant（P<0.05）. NBI endoscopy is safer and more accurate than the general group in determining the safe margin of tumor mucosal resection（P<0.05）. Among the patients who accepted the voice analysis, the difference was no statistically significant（P>0.05）. Conclusion:Compared with conventional CO2laser surgery under microscope, NBI guided laser resection of Early-Stage Glottic cancer is more accurate. NBI guided laser resection could improve 5 years recurrence free survival rate. In a word, narrow-band imaging endoscopy can has very high value in clinical application.

Spectral characterization of a Cryo-Cooled CO laser operating with CO2 laser gas mixture

This study explores the emission spectra and performance characteristics of a cryo-cooled CO laser system operating with CO2 laser gas mixture under various operating conditions, viz., N2 free gas mixture, different coolant temperatures and in grating tuned configuration. The narrow operational window in case of N2 free gas mixture, increased output power and richer emission spectrum obtained with the addition of N2 gas indicates enhanced discharge stability and efficient excitation in presence of Nitrogen. The emission spectrum revealed shifting of the trapping levels towards lower vibrational quantum number with reducing coolant temperature and the same was also corroborated by theoretical calculations. No lasing was observed for vibrational levels V>15 which is attributed to the higher partial pressure of oxygen inherently present in the gain medium formed due to dissociation of CO2. The system lased on more than 20 transitions in grating tuned configuration with power exceeding 100mW on several lines. The presence of higher concentration of O2 in the discharge prevents carbon deposition − a common issue in CO lasers. This study underscores the significance of this unconventional CO laser system offering reliable operation in the 5 µm wavelength region without the usage of extraneous CO gas.

Radiofrequency Versus CO2 Laser in Posterior Cordotomy for Managing Bilateral Abductor Vocal Fold Immobility

PurposeThis study aimed to assess the outcomes of posterior cordotomy in cases with Bilateral abductor vocal fold immobility (BAVFI), either by radiofrequency or CO2 laser. MethodsThis prospective comparative randomized study included 80 patients with BAVFI of different etiologies. They were divided randomly into two groups. Group A included 44 patients for whom radiofrequency was used for posterior cordotomy, while the other group (Group B) included 36 patients managed by CO2 laser-assisted posterior cordotomy. ResultsThe postoperative respiratory chink improved significantly in both groups, with a significant improvement in the dyspnea, especially in group B. The postoperative voice handicapped index (VHI-10) scores showed significant deterioration in both groups. ConclusionsCO2 laser and radiofrequency assisted posterior cordotomy were effective and safe for managing cases with BAVFI. Moreover, the CO2 laser has the upper hand regarding breathing and exercise tolerance outcomes, significantly impacting the quality of life.