532 nm pulsed potassium-titanyl-phosphate laser treatment of laryngeal papillomatosis under general anesthesia

Diode Laser for Juvenile Recurrent Respiratory Papillomatosis: A Case Series of 13 Patients

Juvenile recurrent respiratory papillomatosis (JRRP) is the most common benign tumor in the larynx. It is uncommon; however, it is potentially life-threatening because it compromises the respiratory tract and required several surgeries to manage recurrences. Currently, the carbon dioxide laser is the treatment of choice. There are no studies about the role of the diode laser which is easy to use and has lower usage cost. This case series presentation reported on the therapeutic effects and recurrence rate of JRRP when using Diode laser. This is a case series presentation of 13 children, who were diagnosed with JRRP and operated for laryngeal papillomatosis with Diode laser in Otorhinolaryngology and Head and Nick Surgery Department et al. Mouwasat Hospital, Damascus, Syria between 2015 and 2022. 13 children required 56 surgeries at a rate of 1-2 surgeries/year, mean number of surgeries for each child was 4.31. That suggests that Diode laser might have a role in reducing the number of surgeries compared to a study used cold instrument and CO2 laser. The complications rate was 30.8%, which is considered a high rate compared to the other studies. In conclusion, we encourage using it when the CO2 laser device is not available. However, we suggest, reducing the power as low as possible and avoiding of two opposing raw surfaces, especially at the anterior commissure and deep excision. Further longitudinal studies are recommended to validate these results.

Minimizing Thermal Damage During Thulium Laser-Assisted Partial Arytenoidectomy: Pulsed Versus Continuous Cutting in an Ex-Vivo Calf Model

OBJECTIVES

The 2 µm-wavelength thulium laser is an effective cutter during partial arytenoidectomy, but thermal trauma can damage adjacent laryngeal tissue. Pulsing laser energy may reduce trauma when compared to continuous-wave cutting. This study measured temperature changes, thermal trauma, and time to complete partial arytenoidectomy, with and without pulsing, in an ex-vivo calf model.

METHODS

Tissue temperature and time to complete a trans-cartilaginous cut were measured during partial arytenoidectomy on ex-vivo calf vocal folds (N = 24) using a thulium laser in continuous-wave (CW, N = 12) and pulsed-wave (PW, N = 12) modes. Energy was 5 W for CW and PW cuts; pulse-widths were 250, 500, and 750 ms. Thermal damage was analyzed histologically by measuring the depth of lactate dehydrogenase (LDH) inactivation perpendicular to the laser-cut edge at the vocal process. Paired t-tests compared CW and PW modes.

RESULTS

Change in temperature was lower using CW (6.5°C) compared to PW modes (250 ms = 18°; 500 ms = 16°; 750 = 19°; P < .05). Trans-cartilaginous cuts were completed faster using CW (37 seconds) compared to PW (250 ms = 136 seconds; 500 ms = 61 seconds; 750 = 44 seconds; P < .05), and both modes delivered the same total Joules. The average depth of LDH depletion (thermal damage) was similar for all cuts.

CONCLUSIONS

1. Thulium laser cuts in continuous-mode unexpectedly produced less tissue heating yet created similar thermal damage than pulsed-mode cuts during simulated partial arytenoidectomy. 2. Trans-cartilaginous cuts were completed significantly faster in continuous-mode as compared to pulsed-mode cutting. 3. Pulsing the thulium laser does not minimize thermal damage compared to continuous wave cutting during thulium laser-assisted partial arytenoidectomy.

Blue light laser recontouring for pediatric benign fibrovascular vocal fold lesions

INTRODUCTION

Up to 40% of children with hoarseness due to benign fibrovascular vocal fold lesions do not respond to voice therapy and could benefit from further intervention to improve their communication abilities. Currently there are limited surgical options for children too young to comply with post-operative voice rest. We have begun using the 445 nm laser to recontour benign fibrovascular vocal fold lesions without post-operative voice rest in young children with hoarseness due to vocal fold nodules that is unresponsive to voice therapy. This report presents pilot data on the effect of this treatment on pediatric voice-related quality of life.

METHODS

Pediatric patients with benign fibrovascular lesions and severe subjective dysphonia (per parents or teachers) were given the option of undergoing surgery or continuing voice therapy. Those that opted for surgery underwent 445 nm laser recontouring of their vocal folds. They were discharged home the same day with no voice rest required. Pre- and post-demographic, acoustic measures, auditory perceptual assessments, and validated patient quality of life measures were collected.

RESULTS

Four patients (ages 3-8y, all male) were selected for surgery. The mean pre- and post-op PVRQOL scores were 59.4 (range: 22.5-80) and 98.1 (range: 97.5-100), respectively (low scores suggest lower voice-related QOL), and a mean change of 38.8 (previously established minimum clinically important difference: 12). Pre- and post-acoustic and aerodynamic measures similarly reflected this improvement.

CONCLUSION

This pilot case series addresses a commonly seen population (children with benign fibrovascular lesions and significant dysphonia despite voice therapy) where the best practice for timing and types of surgical intervention is unclear. Photoangiolytic lasers (including the 445 nm laser) are gaining popularity for the treatment of benign laryngeal pathologies, and their use may expand treatment possibilities for children with severe dysphonia due to benign vocal fold lesions that do not respond to voice therapy. Further longitudinal investigations are necessary to confirm the safety and efficacy.

Office-based 532-nm KTP laser as a therapeutic modality for recurrent laryngeal papillomatosis: efficacy and relative factors

This study aims to investigate the efficacy of office-based potassium-titanyl-phosphate (KTP) 532-nm laser in the management of recurrent laryngeal papillomatosis (RLP) following other treatments. A retrospective assessment was performed on 55 patients in 259 cases of RLP between 2012 and 2019. Derkay scores were obtained for all patients who underwent 532-nm KTP laser procedure (6 W of power with a continuous output mode) prior to treatment and after treatment. Analysis of parameters is based on the distribution characteristics of data. An ordinal logistic regression was also performed. Patients received a median of 3 (range 1-24) office-based KTP laser treatments. Among them, 96.36% (53 patients) were previously on cold steel equipment, CO₂ laser, or microdebrider treatment under general anesthesia, and all previous treatments on them had failed. One patient progressed to invasive cancer, so he was excluded from the following analyses. After final KTP treatment, 36 patients (66.67%) received complete resolution with follow-up time ranging from 12.9 to 80.53 months (median 55.54 months). Results of subjective voice-quality indicators such as VHI-30 and GRBAS all improved greatly at the last follow-up. The initial Derkay scores and treatment intervals were found to be predictive of complete lesion remission. Arytenoid involvement may also correlate with lesion resolution. Serial office-based KTP treatment is an effective option for RLP patients, with ideal disease control and voice quality preservation. KTP laser therapy should be repeated with an interval of 1 month from the beginning of treatment until the lesion has been evaluated and subsided. Non-bulk or scattered laryngeal papilloma is an appropriate indication for KTP laser treatment.

Fractional treatment of rosacea by LBO 532 nm laser with “one shot” procedure: A preliminary study

Rosacea is a chronic skin disease prevalently affecting the center of the face. The permanent erythema of skin face represents its typical sign. Further common features are face flushing, telangiectasias, and inflammatory presence of oedema, papules and pustules. The aim of this study was to investigate the use of LBO 532nm laser in the treatment of this disease. Ten subjects of both sex and middle age affected by rosacea in erithemato/teleangectatic stage were treated by a LBO 532nm laser single session. Discomfort evaluation during and after the treatment, one session results as well as incidence of the side effects were evaluated, with 6 months follow up. Positive results were obtained after only one session in total safety with minimal patients discomfort and without undesired effects during treatment. The study confirmed International literature data suggesting the use of laser and light devices as elective treatment of this disease. IPL, dye lasers and 532nm laser are the devices more used and the last seems to represent the gold standard for 1,2,3 phototypes. This clinical trial, with the limitations due to the small number of patients, indicated that “one session LBO 532nm laser treatment” represents an interesting and innovative approach in the therapy of the erythemato/telangectatic rosacea.

Safety of different surgical modalities for recurrent respiratory papillomatosis resection: A systematic review and meta-analysis

BACKGROUND

Currently, the most common surgical modalities used for recurrent respiratory papillomatosis (RRP) resection are microdebrider, carbon dioxide (CO₂ ) laser and potassium-titanyl-phosphate (KTP) laser. However, complication rates vary among different surgical modalities and have been controversial in different studies.

OBJECTIVE OF REVIEW

This study systematically reviews the available studies which reported intra-operative and post-operative complications, aiming to compare the safety of microdebrider, CO₂ laser and KTP laser.

TYPE OF REVIEW

Meta-analysis.

SEARCH STRATEGY

Seven electronic databases (PubMed/MEDLINE, EMBASE[Ovid], Scopus, Cochrane Library and Web of Science) were searched from inception through 28 April 2022. Randomised controlled, prospective or retrospective observational studies that recorded the complications of three different surgical modalities for RRP resection were included in the meta-analysis.

EVALUATION METHOD

Outcomes of interest were intra-operative and post-operative complications, and complication rate was calculated to evaluate the safety of surgical methods.

RESULTS

Twenty different studies were included in quantitative synthesis. Only one study compared outcomes of those three kinds of treatment modalities simultaneously, two studies compared microdebrider and CO₂ laser, and the remaining studies focussed on only one of three treatments. The weighted average complication rate for microdebrider was 0.03 (95% confidence interval [CI] 0.00-0.21), n = 6, for CO₂ laser treatment was 0.16 (95% CI 0.09-0.25), n = 14 and for KTP laser treatment was 0.04 (95% CI 0.00-0.14), n = 4.

CONCLUSION

The limited evidence demonstrated that CO₂ lasers in the surgical treatment of RRP may lead to more surgical complications, and microdebrider and KTP lasers may be safer. However, the heterogeneous data limit any strong comparison of outcomes of different treatment of laryngeal papillomas. Future randomised controlled trials that directly compare the safety of different surgical modalities are needed.

Surgery and Adjuvant Therapy Improve Derkay Scores in Adult and Pediatric Respiratory Papillomatosis

OBJECTIVES/HYPOTHESIS

Comparing Derkay anatomical score at time of procedure, disease characteristics, and mean treatment interval among adult and pediatric patients with recurrent respiratory papillomatosis (RRP).

STUDY DESIGN

Restrospective study.

METHODS

Retrospective review of juvenile-onset (JO) and adult-onset (AO) RRP patients treated longitudinally at pediatric and adult institutions from 1999 to 2019. Patients were included if they had a tissue diagnosis of papilloma and had at least a 12-month follow-up.

RESULTS

One hundred and twelve patients met inclusion criteria (68 JO-RRP and 44 AO-RRP). All patients were stratified into either potassium titanyl phosphate (KTP) (n = 42), CO₂ (n = 21), or microdebrider (n = 49) treatment groups. The Derkay score improved between first and last procedure in the KTP group (mean difference, 3.5; P < .001), CO₂ group (mean difference, 4.4; P < .001), and microdebrider group (mean difference, 4.1; P < .001), but overall improvement did not differ across groups (P = .73). Baseline mean to last mean Derkay score improved for nine patients during bevacizumab treatments (mean difference, 3.0; P = .01) but did not improve for these same patients during an interval prior to receiving bevacizumab treatments. Baseline mean to last mean Derkay score improved for 19 patients during cidofovir treatments (mean difference, 3.84; P < .001) but did not improve for these same patients during the interval prior to receiving cidofovir treatments. The AO-RRP population had more patients with dysplasia (50%) compared to JO-RRP population (10%) (P < .001).

CONCLUSION

Various surgical modalities appear to be equally effective treatments for RRP. Adult and pediatric patients have decreased recurrent disease burden when receiving bevacizumab or cidofovir. AO-RRP patients have more concomitant dysplasia.

LEVEL OF EVIDENCE

3 Laryngoscope, 132:2420-2426, 2022.

Comparing KTP and CO2 laser excision for recurrent respiratory papillomatosis: A systematic review

Objective

The CO2 laser and 532 nm potassium titanyl phosphate (KTP) laser have been applied to treat recurrent respiratory papillomatosis (RRP). This systematic review sought to compare outcome differences between these two methods.

Data Sources

Embase, Web of Science, PubMed, and the Cochrane Library.

Review Methods

CO2 laser and KTP laser studies were obtained by keyword searches of four authoritative medical databases. Articles were screened and retained when conforming to inclusion criteria. The primary outcome was cure rate; the secondary outcomes were recurrence, death, remission, clearance, and human papillomavirus (HPV)-detected rates, as well as laser effectiveness rates. Postoperative complications rate was the safety outcome measure. All outcomes were summarized within the CO2 and KTP groups, with results statistically compared (p < .05).

Results

Overall, the cure rates were 87.25% (KTP group) and 75.98% (CO2 group; p < .05). Complication rates significantly differed between the KTP (2.32%) and CO2 (17.71%) groups (p < .0001). There was a relatively higher but not significant difference in the recurrence rates between the CO2 (18.6%) and KTP (10.87%) groups (p = .1595). The CO2 group remission rate was considerably lower (38.9%) than the KTP group (88.46%, p < .0001). HPV-detected and clearance rates were only reported for the CO2 group. The bias risks were 13.1 ± 1.45 (CO2) and 13.6 ± 1.52 (KTP) for the two groups, indicating evidence was of fair quality.

Conclusion

Overall, KTP laser excision showed significantly better postoperative clinical outcomes than the CO2 laser, with a lower failure rate. Available fair-quality evidence suggests KTP laser excision might be better for treating RRP. Nevertheless, more high-quality randomized controlled studies are needed to compare these two surgical techniques, particularly in terms of reporting functional data such as vocal outcomes.

Use of 532 nm Potassium Titanyl Phosphate Laser on Vocal Fold Scars Under Topical Anesthesia: A Pilot Study

OBJECTIVE

This pilot study aims to evaluate the efficacy of 532 nm potassium titanyl phosphate (KTP) laser under topical anesthesia in patients with vocal fold scars.

METHODS

A series of 18 patients with vocal fold scars of varying degrees were treated. The KTP laser was used under local anesthesia in the outpatient clinic. It was set to deliver 6 W of power using a continuous output mode. Close-to-contact mode was used for laser irradiation, and contact mode was used for ablation and excision of the lesions. Some of the patients received laser scar ablation on both vocal folds; the scarred vocal fold on one side and the hypertrophic vocal fold on the other. Parameters include glottic closure, amplitude, and mucosal wave pattern were measured using laryngeal stroboscopic examination. Aerodynamic and voice evaluations were carried out using maximum phonation time (MPT), jitter, shimmer, Voice Handicap Index questionnaire (VHI-30), and GRBAS scale.

RESULTS

In total, 21 surgeries were performed on 18 patients. Glottic closure, amplitude, and mucosal wave pattern showed improvement 2 months postoperatively (P < .05). There was significant improvement in the postoperative scores for VHI-30, VHI-emotional sub-scale, VHI-physical sub-scale, and GRBAS (P < .05). There was no significant difference in the MPT and VHI-functional sub-scale before and after the operation (P > .05). Re-adhesion of the anterior commissure was observed in 2 patients with Type III scars.

CONCLUSION

The 532 nm KTP laser is an effective tool for the treatment of vocal fold scars. Further research is required to determine if serial laser applications could improve outcomes for this challenging condition.

LEVEL OF EVIDENCE

Level IV.

Sublesional Bevacizumab Injection for Recurrent Respiratory Papillomatosis: Evaluation of Utility in a Typical Clinical Practice

OBJECTIVES

The goal of this study was to evaluate the benefit of sublesional bevacizumab injection for recurrent respiratory papillomatosis (RRP) as used in a typical clinical practice.

METHODS

A retrospective review of patients with RRP treated between 2011 and 2016 was undertaken. All patients were treated with in-office potassium titanyl phosphate (KTP) laser photoablation. Sublesional bevacizumab injection was used based on joint patient-physician decision making. Papilloma burden was objectively measured on prior recordings by 2 blinded reviewers and described as vocal fold segments affected (VFSA) by papilloma. Each patient served as their own control by comparing times when bevacizumab was or was not used. Mixed model for longitudinal data was used to determine if the previous use of bevacizumab decreased the disease burden.

RESULTS

A total of 19 patients met inclusion criteria and all prior laryngoscopic exams were reviewed for VFSA as described above. The mean (SD) number of VFSA when bevacizumab was not used at the prior procedure was 15 (14) as compared to 8 (11) when bevacizumab was used. When adjusted for age, time from initial presentation and baseline disease burden, mixed model showed a decrease of 11 VFSA (95% CI 6.5, 15.5, P < .0001) when bevacizumab was used as compared to when bevacizumab was not used at the prior procedure. In mixed model analysis, there was not a significant association between bevacizumab dose used and VFSA at the subsequent visit (P = .8).

CONCLUSION

Using sublesional bevacizumab intermittently based on clinical findings appears to be effective in improving disease control. Papilloma burden is significantly decreased at the subsequent clinical follow-up following injection of sublesional bevacizumab. The beneficial effect of sublesional bevacizumab may be not be dose-dependent.

Longitudinal Voice Outcomes Following Serial Potassium Titanyl Phosphate Laser Procedures for Recurrent Respiratory Papillomatosis

OBJECTIVE

Repeated surgical interventions are usually required to control recurrent respiratory papillomatosis (RRP), but at considerable risk of worsened postoperative voice quality. Potassium titanyl phosphate (KTP) laser has been reported to effectively manage RRP; however, voice quality after repeated procedures has not been investigated.

METHODS

This study recruited 16 patients with RRP treated using KTP laser between 2013 and 2019. KTP laser procedures were performed under general anesthesia via direct suspension laryngoscope or under local anesthesia via flexible endoscope, depending on the need for pathological proof, patient tolerance, and lesion size and location. Disease control was investigated by videolaryngostroboscopy. Voice outcome was evaluated using a 10-item voice handicap index (VHI-10), acoustic and perceptual analyzes.

RESULTS

We reviewed the medical records of 11 male and 5 female patients with RRP (age range: 23-73 years). Five patients received KTP laser once, six patients received it 2 to 5 times, and five patients received 6 to 15 procedures. Median VHI-10 decreased from 28.3 to 12.0 points after the initial procedure and were maintained at 10.1 to 11.0 points following subsequent procedures (P < .01, generalized estimating equation). Acoustic and perceptual analysis of voice quality also revealed significant improvements (P < .01), which remained stable even after 6 to 10 KTP laser procedures. Minor adverse events included slight fibrotic change of vocal folds and glottic web, but these did not significantly alter postoperative voice quality.

CONCLUSION

This longitudinal follow-up study revealed that serial KTP laser procedures can effectively control RRP while preserving phonatory function and maintaining adequate voice quality.

LEVEL OF EVIDENCE

4.

532-nm second harmonic generation with enhanced efficiency using subharmonic cavity modulation-based quasi-Q-switched-mode-locked pulses

We report the results of our investigation of the second harmonic generation (SHG) green pulse generation with an active, quasi-Q-switched-mode-locked (QML) fiber laser based on subharmonic cavity modulation. First, we investigate the working principle of the quasi-QML pulse generation technique, based on subharmonic cavity modulation through analytical calculation. We show that the stable QML-like pulse generation by subharmonic cavity modulation is induced by phase-locked interference of a large number of subharmonic modulation-induced frequency components within a cavity. Next, we experimentally realize a 1064 nm quasi-QML fiber laser with an ytterbium (Yb)-doped fiber ring cavity incorporating an acousto-optic modulator. Finally, using the implemented quasi-QML laser, we experimentally show that the use of 1064 nm quasi-QML pulses could result in the increase of the SHG conversion efficiency in a MgO:PPLN, compared to the use of continuous mode-locked (ML) pulses. For our particular experimental configuration, we could readily achieve a noticeable SHG efficiency increase of 8% by using quasi-QML pulses with a subharmonic order of 80, compared to continuous ML pulses.

Recurrent Respiratory Papillomatosis Office versus Operating Room: Systematic Review and Meta-Analysis

OBJECTIVES

Recurrent respiratory papillomatosis can be treated in the office or operating room (OR). The choice of treatment is based on several factors, including patient and surgeon preference. However, there is little data to guide the decision-making. This study examines the available literature comparing operative treatment in-office versus OR.

METHODS

A systematic review was performed following Preferred Reporting Items for Systematic Reviews guidelines. Of 2,864 articles identified, 78 were reviewed full-length and 18 were included. Outcomes of interest were recurrence and complication rates, number of procedures, time interval between procedures, and cost.

RESULTS

Only one study compared outcomes of operative in-office to OR treatments. The weighted average complication rate for OR procedures was 0.02 (95% confidence interval [CI] 0.00-0.32), n = 8, and for office procedures, 0.17 (95% CI 0.08-0.33), n = 6. The weighted average time interval between OR procedures was 10.59 months (5.83, 15.35) and for office procedures 5.40 months (3.26-7.54), n = 1. The weighted average cost of OR procedures was $10,105.22 ($5,622.51-14,587.83), n = 2 versus $2,081.00 ($1,987.64-$2,174.36), n = 1 for office procedures.

CONCLUSION

Only one study compares office to OR treatment. The overall data indicate no differences aside from cost and imply that office procedures may be more cost-effective than OR procedures. However, the heterogeneous data limits any strong comparison of outcomes between office and OR-based treatment of laryngeal papillomas. More studies to compare the two treatment settings are warranted.

The Effects of Photobiomodulation on Vocal Fold Wound Healing: In Vivo and In Vitro Studies

Background: Photobiomodulation (PBM) is increasingly used in dermatology and dentistry due to its benefit of promoting wound healing and relieving pain; however, there is no corresponding research report on the application of PBM to vocal fold wound healing. Objective: To assess the potential wound-healing effects of PBM on the vocal folds via in vivo and in vitro experiments. Materials and methods: In in vitro study, vocal fold fibroblasts (VFFs) were irradiated under a diode laser with wavelength of 635 nm at energy density of 8 J/cm². The Cell Counting Kit-8 (CCK-8) assay was used to study the viability of VFFs, and the gene expressions of COL1A2, COL3A1, IL-6, HAS2, and COX-2 were investigated by real-time polymerase chain reaction (RT-PCR). In in vivo study, 15 rabbits were used. Lamina propria of the left vocal folds of 12 rabbits was unilaterally stripped, and 6 of them were treated with PBM. The remaining three rabbits served as normal controls. After 3 months, all animals were sacrificed to obtain histological results. We used laryngoscope to record images of the healing phase. Results: Irradiation with energy density of 8 J/cm² resulted in a 2.8% increase in cell proliferation (p < 0.05). However, the difference between the experimental and the control group became larger after 48 and 72 h of subsequent irradiation. RT-PCR results showed that the expression of COL1A2, COL3A1, and HAS2 was higher, and the expression of IL-6 and COX-2 was lower. Histological examination showed that, compared with the injury group, hyaluronic acid (HA) increased significantly, collagen deposition decreased, and the configuration of collagen was more organized after PBM treatment. Conclusions: PBM can inhibit inflammatory reaction and promote the secretion of HA to decrease the deposition of collagen and regenerate vocal fold tissue without scar.

Doppler optical coherence tomography for energy seal evaluation and comparison to visual evaluation

Laser energy sealing systems have attracted much attention over the past decade given the general shift in surgical paradigm toward less invasive surgical approaches. Given this, it is paramount to have an objective method with which the quality of energy seals can be evaluated. Current methodologies used for this purpose can be problematic in the evaluation of small vessel seals. A methodology employing Doppler optical coherence tomography (DOCT) for the evaluation of energy seals is introduced. Avian chorioallantoic membrane vessels were subjected to thulium laser irradiation and were then scanned via OCT. Outcomes were classified based on several markers, predominantly the presence or absence of flow postirradiation. Vessel diameter and general morphology were also taken into consideration. Vessels were classified into four groups: seal (29%), rupture (30%), partial seal (19%), and unaffected (22%). All vessels were also evaluated visually by a trained neurovascular surgeon, and these visually classified outcomes were compared with DOCT evaluated outcomes. It was found that whether the vessel was considered sealed or not sealed was dependent on the evaluation method (p  =  0.01) where visual classification resulted in 18% more seals than DOCT classification. Further, the specificity of visual classification was found to be strongly dependent on the number of partial seals (p  <  0.0001). DOCT has shown to be an indispensable method for the evaluation of energy seals not only solely due to its high velocity resolution but also due to valuable microscopic morphological insight regarding the biological mechanisms responsible for energy sealing.

Angiolytische Laserverfahren am Kehlkopf

Durch transorale Lasermikrochirurgie wurden bei der Larynxkarzinomtherapie temporäre Tracheotomien reduziert, die Organerhaltraten erhöht und funktionelle Resultate verbessert. Goldstandard für die laserbasierte transorale Resektion eines Larynxkarzinoms ist der Einsatz des CO2-Laser, dabei sind onkologische Radikalität und postoperative Stimmfunktion individuell abzuwägen. Angiolytische Lasereffekte ermöglichen eine Beeinflussung des Tumormikromilieus durch zielgerichtete Gefäßobliteration und Blockierung der Angiogenese mit Schonung von schwingungsfähigem Gewebe für eine gute Stimmfunktion. Mit der Verabschiedung der S3-Leitlinie zur Diagnostik, Therapie und Nachsorge des Larynxkarzinoms wird eine nationale evidenzbasierte Standardisierung gefördert. International nimmt die Evidenz zur Kalium-Titanyl-Phosphat-Laser-Therapie laryngealer Schleimhautdysplasien und von T1a-Larynxkarzinomen zu. Auch bei juveniler Papillomatose und der Stützlaryngoskopie unter Narkose sowie für ausgewählte Patienten in Lokalanästhesie werden angiolytische Laser eingesetzt.

The Use of 532-Nanometer-Pulsed Potassium-Titanyl-Phosphate (KTP) Laser in Laryngology: A Systematic Review of Current Indications, Safety, and Voice Outcomes

OBJECTIVE

To investigate the indications, efficacy, safety, and outcomes of potassium-titanyl-phosphate (KTP) laser procedures for treatment of laryngeal disease.

METHODS

PubMed, Cochrane Library, and Scopus were searched for studies providing information about the indications, efficacy, and safety of both in-office and operative suspension microlaryngoscopy KTP laser procedure in treatment of laryngeal disease. Diagnostic criteria and clinical outcome evaluation of included studies were analyzed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

RESULTS

Of the initial screened 140 papers, 17 met our inclusion criteria. Six papers involved KTP laser procedures for benign and malignant vocal fold lesions in suspension microlaryngoscopy only, 10 papers focused on only in-office KTP laser procedures for benign vocal fold lesions, and 1 paper included both in-office and suspension microlaryngoscopy procedures. The following lesions may be considered as indications for KTP laser procedures: Reinke's edema, sulcus vocalis, vocal fold hemorrhage, polyp, granuloma, cyst, scar, papillomatosis, dysplasia, leukoplakia, and early vocal fold malignancies. Irrespective of the types of procedure (in-office vs suspension microlaryngoscopy), the KTP laser is associated with a low complication rate and overall good vocal fold vibration recovery. There is an important heterogeneity among studies concerning laser settings, indications, and outcomes used for the assessment of treatment effectiveness. There are no controlled studies directly comparing KTP laser with other lasers (ie, carbon dioxide laser).

CONCLUSION

The use of KTP laser procedures for treatment of laryngeal disease has increased over the past decade, especially for office-based management of vocal fold lesions. Future controlled studies are needed to compare the safety and outcomes of the KTP laser to other techniques.

Implication and Management of Incidental Oropharyngeal Papillomas-A Retrospective Case Series Review

INTRODUCTION

Incidental papillomas of the pharynx can be found while examining the nasopharynx, oropharynx, and hypopharynx for other disorders of the head and neck. Purpose of the study is to explore the location, biopsy protocol, and decision to perform office-based versus operative management via potassium titanyl phosphate (KTP) laser when an oropharyngeal papilloma is discovered incidentally.

METHODS

A retrospective review of the senior author's patient population was performed using Current Procedural Terminology and/or International Classification of Diseases codes to identify patients who had KTP laser removal of incidental oropharyngeal papillomas. Patients were included based on the incidental nature of the papilloma and confirmed pathology report of squamous papilloma. Demographics, presenting complaint, lesion location, pathological analysis, type of intervention, and outcomes were recorded. When available, human papillomavirus (HPV) subtype was noted.

RESULTS

A total of 26 cases were identified, 13 females and 13 males. The median age at time of surgery was 58 years (range: 21-77). The most common presenting symptoms were difficulty swallowing and throat pain. The most common locations were the base of tongue, uvula, tonsils, and the soft palate. Of the 26 patients, 23 patients received KTP laser ablation therapy as an office-based procedure, while the remaining 3 were performed under general anesthesia in the operating room. Only 5 patients had a recorded recurrence that required reoperation. There were no operative or postoperative complications. There were 16 biopsy samples tested for HPV, where 12 were negative for HPV and 4 were positive for HPV.

CONCLUSION

Oropharyngeal papillomas, when present, can be found incidentally during examination of the oropharynx for other symptoms. Office-based biopsy and KTP laser is a safe and efficient means of identifying and removing most oropharyngeal papillomas.

Infectivity of murine papillomavirus in the surgical byproducts of treated tail warts

OBJECTIVES/HYPOTHESIS

Human papillomavirus (HPV) is a highly stable DNA virus that causes disease in human organ systems, including the larynx and oropharynx. The treatment of HPV-associated diseases with scalpels, lasers, and other surgical instruments has the potential to release infectious particles, placing healthcare workers at risk. The objectives of this study were to create a reproducible in vivo animal model of papillomavirus infectivity and to compare the infectivity of byproducts of surgically treated mouse papillomavirus (MmuPV1) warts.

STUDY DESIGN

Animal study.

METHODS

Nude laboratory mice (Mus musculus) with established MmuPV1 tail warts were treated with scalpel excision, potassium titanyl phosphate (KTP) laser ablation, and coblator treatment. Uninfected nude mice were challenged with surgical byproducts, including ablated and heated tissue, and surgical smoke products. The incidence and time course of the appearance of warts was recorded.

RESULTS

There was rapid transmission of virus in mice challenged with scalpel-treated warts, with 50% penetrance of infection at day 13 and 100% at day 32. For KTP-treated warts, there was the slower development of infection (50% by day 35) but 100% penetrance by day 52. Coblator-treated tissue reached 50% penetrance at day 59 and a maximum of 73% penetrance. Smoke plume captured during treatment with the KTP laser and coblator was highly infectious, as was the material captured in a laser filter.

CONCLUSIONS

MmuPV1 remains infectious in all modes of surgically treated tissue, and the smoke plume is capable of transmitting infection. Healthcare workers should use appropriate precautions to lower their risk of infection when treating papillomavirus-associated diseases.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:712-717, 2020.

Potassium titanyl phosphate laser-induced inflammatory response and extracellular matrix turnover in rabbit vocal fold scar

PURPOSE

The objectives of this study were to observe the regulating effect of KTP laser and Nd:YAG laser in the repair of vocal fold scars.

METHODS

All rabbits were injured in the muscular layer with a sharp instrument, and then the vocal folds were treated with a KTP laser and a Nd:YAG laser at a power of 2, 4, 6 and 8 W 1 month after the injury. One month after treatment, the rabbits were killed and the throats were removed to detect changes in histology and gene expression of the vocal fold scar after laser therapy.

RESULTS

The best efficacy of all KTP laser treatment groups was the KTP laser 6 W group. Regarding the detection of gene expression, in the KTP laser 6 W and Nd:YAG laser 6 W groups, col-3A1 was decreased compared to the scar group (P < 0.05), and col-1A1 was decreased only in the KTP laser 6 W group (P < 0.05). TGF-β1 levels in the two groups were lower than in the scar group. There were also significant differences in the levels of IL-1β, COX-2 and TNF-α in the two laser groups compared with the scar group (P < 0.05).

CONCLUSION

KTP laser and Nd:YAG laser treatments for vocal fold scars have particular therapeutic effects. The KTP laser may be better than the Nd:YAG laser for the regulation of vocal fold scars.

LEVEL OF EVIDENCE

NA.

Recurrent respiratory papillomatosis: current and future perspectives

Although recurrent respiratory papillomatosis is a benign disease of the upper aerodigestive tract caused by infection with human papillomavirus, the disease process is unpredictable, ranging from mild disease and spontaneous remission to an aggressive disease with pulmonary spread and requirement for frequent surgical debulking procedures. It can present a protracted clinical course and cause potentially life-threatening compromise of the airways. Over recent decades, a number of alternative medical therapies to standard surgical treatment have been investigated, with modest outcomes overall. Currently, some additional therapies are being explored, together with novel surgical instrumentation that can help to avoid inevitable long-term stenotic complications, ultimately affecting quality of life. Hopefully, clinicians might soon be able to significantly improve the quality of treatment and outcomes for patients affected with recurrent respiratory papillomatosis, with human papillomavirus vaccination having a potentially important role.

Evaluating the Effects of a 532-nm Fiber-Based KTP Laser on Transoral Laser Surgery Supplies

Objective

The KTP laser has become commonplace in transoral head and neck surgery. The interactions of this laser with commonly used supplies in transoral surgery have not been formally examined. This study evaluates the effects of the KTP laser on surgical supplies.

Study Design

Experimental study.

Setting

The study was conducted in an empty operating room at a university-affiliated medical center.

Methods

An Aura XP 532-nm KTP laser with a 600-nm fiber was used in pulsed and continuous modes. The beam was focused at the shaft and balloon of 3 “laser-safe” endotracheal tubes (ETTs), a polyvinyl chloride (PVC) ETT, and a Codman surgical patty. Time to penetrate was recorded.

Results

The KTP laser beam was unable to penetrate any of the laser-resistant ETTs. It did react with the black number markings on the PVC ETT by producing sparks but was unable to penetrate the shaft of the ETT. The KTP laser was nonreactive with all ETT cuffs except in 1 of 3 trials with the outer balloon cuff of a Rusch Lasertubus ETT when the laser was used in a continuous mode. The KTP laser caused the production of a flame upon contact with the blue radiopaque strip of the surgical patty, even when the patty was wet.

Conclusion

This study demonstrates that a number of safe ETT options may be used during transoral laser microsurgery with a KTP laser. In addition, Codman surgical patties are shown to be a significant fire risk in KTP laser surgery.

KTP 532 nm laser for laryngeal lesions. a systematic review

OBJECTIVE

To evaluate the effectiveness and safety of the 532 nm potassium titanyl phosphate (KTP) laser for vocal fold surgery.

STUDY DESIGN

Systematic literature review.

METHODS

Our systematic review was conducted using the meta-analysis of observational studies in epidemiology guidelines. We applied the criteria of the Oxford Centre for Evidence-based Medicine to assess the level of evidence.

RESULTS

We identified seven observational studies of eight case series, which reported a total of 243 KTP procedures carried out for vocal fold lesions: two series each concerning ectasias and varices, early glottic cancer, and recurrent papillomatosis, and one series each for keratosis with dysplasia and various benign laryngeal pathologies. There was also a retrospective review of the use of KTP laser in 387 endoscopic laryngeal surgeries. No studies compared the use of KTP laser with that of other technologies. Thus, according to the Oxford criteria, there is only level 4 evidence of KTP's efficacy and safety. In selected cases, the KTP instrument can be used without general anesthesia in the clinic setting.

CONCLUSIONS

The use of KTP laser for laryngeal surgery is still relatively innovative. Several surgeons have found KTP laser to be the equivalent of, or superior to, the CO2 or pulsed dye lasers, and none have reported inferiority. However, there are currently no published data to support these conclusions. To establish equality/superiority, it is desirable that further evidence of efficacy and safety be obtained, either through randomized controlled trials or at least through well-documented prospective observational studies with reporting of all relevant input and outcome data.

Photoangiolytic laser treatment of recurrent respiratory papillomatosis: a scaled assessment

OBJECTIVES

To investigate the effectiveness of unsedated office-based photoangiolytic laser surgery (UOLS) for treating recurrent respiratory papillomatosis (RRP) using the Derkay severity scale, Voice Handicap Index-10 (VHI-10), and Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) scale. Although previous studies examined the effect of UOLS on voice quality, few studies evaluated the effect on disease regression or used accepted and validated scales as outcome measures.

STUDY DESIGN

Retrospective case series.

METHODS

Charts were reviewed for patients who underwent UOLS for RRP (2007-2010). Twenty-one patients met the inclusion criteria. Nineteen patients underwent treatment with a 532-nm potassium titanyl phosphate laser and two with a 585-nm pulsed dye laser. The Derkay, VHI-10, and GRBAS scores of posttreatment findings were compared with those of the pretreatment findings.

RESULTS

Twenty-one patients underwent 81 office procedures. Mean follow-up was 18 months. From baseline to latest follow-up, there was significant improvement in the mean Derkay score from 6.1 to 3.0 (P=0.001), VHI-10 score from 24.5 to 15.9 (P=0.04), and GRBAS score from 8.6 to 4.9 (P=0.004).

CONCLUSIONS

UOLS results in patient benefit from disease regression, reduced voice handicap, and improved voice quality without the risks associated with direct laryngoscopy and general anesthesia. UOLS is an effective, safe, nonexperimental treatment modality for RRP that has shifted the therapeutic paradigm while decreasing patient morbidity.

Safety and dosing of bevacizumab (avastin) for the treatment of recurrent respiratory papillomatosis

OBJECTIVES

Increasing evidence supports the use of laryngeal injections of the antiangiogenic agent bevacizumab (Avastin) for the adjuvant treatment of recurrent respiratory papillomatosis (RRP). A recent prospective open-label investigation, approved by the US Food and Drug Administration, employing 12.5 mg of sublesional bevacizumab demonstrated single-site efficacy without complications; however, the safety of multiple-site injections and higher dosing has not yet been reported. The primary objective of this study was to report on the safety of increased doses of bevacizumab for the treatment of RRP.

METHODS

Two cohorts of adult patients were evaluated. In the first group, a prospective analysis was performed on patients with a diagnosis of laryngeal RRP after t heir participation in th e initial clinical trial with a single-site lowerdose (7.5 to 12.5 mg). They received higher doses of sublesional laryngeal bevacizumab (15 to 50 mg total) with detailed physiologic, hematologic, and serum chemistry measurements performed before and after each bevacizumab injection. A second cohort of patients received sublesional laryngeal injections of bevacizumab (15 to 88 mg total) without physiologic measurements and underwent a retrospective analysis of reported complications.

RESULTS

One hundred consecutive laryngeal injection sessions (office, 87; operating room, 13) with bevacizumab were performed in 43 patients, with a mean dose of 30 mg total per treatment (range, 15 to 88 mg). Sixty-three of the 100 sessions were accompanied by KTP laser photoangiolysis of the papilloma prior to bevacizumab injections. Eighteen patients (cohort 1) underwent detailed physiologic assessment, and no dysfunction was observed. There were no local or systemic complications of bevacizumab administration. The second group of 25 patients (cohort 2) also reported no significant local or systemic complications. Neither patient group was observed to have a local wound problem in the larynx.

CONCLUSIONS

This investigation provides evidence that higher doses of bevacizumab are relatively safe in adult patients with laryngeal RRP. Further refinements in pharmacologic concentration and drug delivery will determine the optimal treatment regimens in the future.

Subepithelial Vocal Fold Infusion: A Useful Diagnostic and Therapeutic Technique

Objectives:

Preservation of the maximum amount of subepithelial superficial lamina propria (SLP) remains an important goal during microlaryngoscopic surgery of phonatory mucosa. Volume expansion of the SLP (Reinke's space) with subepithelial infusion of saline solution has been widely adopted since its introduction in 1991. This technique has evolved so that it is currently used to assist with determining the depth of vocal fold disease, defining residual pliable SLP, enhancing microsurgical precision, and identifying unrecognized disease. The purpose of this investigation was to examine the indications, methods, and benefits of subepithelial infusion of saline solution as an adjunct technique during phonomicrosurgery.

Methods:

In a prospective case series, we collected data on 280 consecutive microlaryngoscopy procedures performed over a 12-month period. Subepithelial infusion of saline solution was included in 178 procedures.

Results:

New disease was identified in 20 of the 178 patients (scar in 15, sulcus in 4, and a mucosal bridge in 1). The depth of needle placement varied depending on the specific disease: 118 of the 178 infusions were done just below the epithelial basement membrane, and 60 infusions were performed deeper within the SLP, just superficial to the vocal ligament. The infusion technique provided surgical assistance in multiple ways, including identifying residual SLP (130 patients), defining the SLP-lesion interface (65 patients), lifting scar (60 patients), providing tension for cordotomy (47 patients), expanding the SLP volume to protect against laser damage (45 patients), and providing hydrostatic compression of vascular ectasias or varices for photoangiolysis (7 patients). The microlaryngoscopy procedures during which infusion was not performed (102 of 280 procedures) were primarily for nonglottic cancer (46 patients), stenosis (30 patients), or arytenoid granuloma (13 patients).

Conclusions:

Subepithelial infusion of the SLP with saline solution is a useful microsurgical adjunct during diagnosis and treatment of phonatory mucosal lesions.

Low energy KTP laser in oral soft tissue surgery: A 52 patients clinical study

Objectives: Since 1962 laser appliances have been used for soft tissues surgery of oral cavity with significant advantages compared to the traditional instruments: excellent bleeding control, possibility to avoid the use of suture, good patient compliance thanks to a decrease of intra- and post-operative discomfort and biostimulating effect. Unfortunately, the wavelengths so far used have been seen to cause, in association with an excellent ablation capacity, heat damage of the tissues that can decrease healing process and cause a greater discomfort to patients. The aim of this study was to evaluate the laser-assisted KTP laser surgery at low power in terms of characteristics of intervention and patients compliance. Study design: In this study, we describe the application of a new and recently introduced in dentistry wavelength, the KTP laser (532 nm), used with low power (1 Watt - CW), evaluating the time of interventions and, by a Numerical Rating Scale, the intra and postoperative pain. Results: KTP laser used at low power permits to obtain good pain control during operations that were carried out with only a topic anaesthetic (EMLA, Astratech), as shown in VAS tests. Good healing with limited or absent burning areas in treated portion of tissue. Conclusions: These preliminary study allows us to affirm that KTP laser with low parameters permits to perform oral surgery with good pain control and good wound healing. A greater number of clinical cases are however necessary to confirm the result obtained.

Key words: Laser, KTP, oral surgery, thermal increase.

Local injection of bevacizumab (Avastin) and angiolytic KTP laser treatment of recurrent respiratory papillomatosis of the vocal folds: a prospective study

OBJECTIVES

Photoangiolytic laser treatment of recurrent respiratory papillomatosis (RRP) is effective, but does not reliably prevent recurrence. Therefore, sublesional injections of the antiangiogenic agent bevacizumab (Avastin) were given to assess the adjunctive effect on disease recurrence. Since bevacizumab is a new therapeutic modality for RRP, there were also primary safety objectives to determine whether there was a pegative impact on the voice and whether there were local or systemic complications.

METHODS

A prospective open-label investigation was conducted in 20 adult patients with bilateral vocal fold RRP. The patients underwent planned 532-nm pulsed KTP laser photoangiolysis of bilateral glottal disease 4 times with an approximately 6-week interval between procedures. At each planned laser procedure, the vocal fold that on initial presentation had a greater volume of disease also underwent 4 serial sublesional bevacizumab injections (7.5 to 12.5 mg in 0.3 to 0.5 mL). A sham injection with saline solution was administered to the other vocal fold as a control. Disease resolution was compared between subjects' vocal folds, and objective measures of vocal function (acoustic, aerodynamic), as well as patients' self-assessments of vocal function (Voice-Related Quality of Life survey), were obtained.

RESULTS

All 20 patients completed the study, and there were no local or systemic complications. After 4 injections, 3 of the 20 patients had no discernible disease in either vocal fold. Of the remaining 17 subjects, 16 had less disease in the bevacizumab-treated vocal fold despite starting with more disease. Only 1 of the 17 had more disease in the bevacizumab-treated vocal fold after 4 injections. Moreover, 7 of the 20 patients (35%) did not require a laser procedure in the vocal fold that had received 4 bevacizumab injections, as compared with 3 of the 20 vocal folds (15%) that were treated with laser alone. All of the vocal function measures displayed statistically significant posttreatment improvements, except for average fundamental frequency in the 3 female patients, in whom it fell below the normal range.

CONCLUSIONS

This prospective investigation provided evidence that bevacizumab injections enhanced KTP laser treatment of glottal papillomatosis without systemic or local complications. Coupling the antiangiogenesis agent bevacizumab with KTP laser photoangiolysis is conceptually synergistic and scientifically promising since the mechanisms of action are complementary.

Cause of vocal fold scar

PURPOSE OF REVIEW

The prolonged debilitation, loss of income, and decrement in quality of life caused by vocal fold scar is exacerbated by our inability to successfully treat this difficult problem. As technology focuses on developing innovative treatments, we need to fully appreciate and understand the mechanisms giving rise to glottal scar, on both a macroscopic and microscopic level. This review examines recent literature pertaining to the gross and molecular mechanisms which give rise to vocal fold scar.

RECENT FINDINGS

Mechanisms of vocal fold scar production have been examined in both macroscopic and microscopic detail. Trauma and injury involving any aspect of the lamina propria, particularly the deeper layers, may result in epithelial tethering and scar formation. At the molecular level, early inflammatory cytokines activate and recruit fibroblasts which then drive the fibrotic cascade. Transforming growth factor-β enhances fibrosis and is balanced by tissue matrix metalloproteinases and hepatocyte growth factor activity. Molecular signaling offers novel opportunities to intervene in scar formation.

SUMMARY

New work investigating the cause of vocal fold scar identifies complex molecular processes leading to fibrosis in the lamina propria. Improved mechanistic understanding offers insight into prevention strategies and possible targets for antifibrotic therapies that may help prevent or treat this debilitating condition.

Pulsed potassium-titanyl-phosphate laser photoangiolytic treatment of mucosal squamous cell carcinoma in the hamster cheek pouch

OBJECTIVES/HYPOTHESIS

Early glottic cancer has been involuted by treatment with the 532 nm pulsed potassium-titanyl-phosphate (KTP) laser in initial clinical studies. Selective photoangiolysis of the sublesional circulation that allows for relative sparing of surrounding tissue is the presumed mechanism. No prior controlled animal-model study has analyzed the ability of selective coagulation of lesional microvasculature coagulation with the KTP laser to involute malignant lesions. This study tests the efficacy of photoangiolysis with the KTP laser in treating squamous cell carcinoma in an established animal model.

STUDY DESIGN

In vivo.

METHODS

Malignant lesions were induced unilaterally in the cheek pouches of 21 hamsters by applying 9,10-dimethyl-1,2-benzanthrancene. The contralateral cheek pouch served as a control. Weekly lesion photodocumentation and pulsed KTP laser (30 W, 15 msec pulse width, 2 pulses/sec) treatments were done. The endpoint of each treatment was a uniform white-blanching of the lesion. Hamsters were sacrificed 1 week after the last treatment and cheek pouches were analyzed histologically.

RESULTS

Carcinoma was confirmed in 19 hamsters, and lesions that were initially <2 mm were more effectively treated than lesions that were >2 mm (P = .0004). Every lesion (10/10) that initially measured <2 mm resolved completely after laser treatment with minimal scarring noted at the treatment site based on histology. Lesions measuring between 2 and 5 mm resolved 33% of the time (2/6), and none (0/3) of the lesions >5 mm resolved after completion of the treatment period.

CONCLUSIONS

Pulsed KTP laser photoangiolysis can effectively involute small malignant lesions, but may be less effective at involuting larger (>2 mm) lesions.

Cooling the "oven": a temperature study of air and glottal tissue during laser surgery in an ex vivo calf larynx model

OBJECTIVES

Endoscopic microlaryngeal laser surgery performed with general anesthesia through a laryngoscope speculum generates heat that accumulates at the distal lumen, creating an "oven" effect and potentially causing bystander thermal damage to nontarget tissue such as the contralateral vocal fold. We report the effects of cooling on air and tissue temperatures that occurred during simulated laryngeal laser surgery with KTP and thulium lasers in an ex vivo calf model.

METHODS

Ten fresh excised calf larynges were studied at room temperature. Laser energy was applied to one vocal fold for 2 minutes, with or without cooling, while temperatures were monitored with sensors placed within the glottal lumen or inserted superficially into the contralateral vocal fold. A pulsed KTP laser (525 mJ) was used for 5 larynges, and a thulium laser (7 W, continuous) was used for the other 5 larynges.

RESULTS

Heating was slightly greater for the KTP laser than for the thulium laser with use of these parameters. The lumen temperatures for both lasers increased an average of 13.2 degrees C without cooling, but only 6.7 degrees C with cooling (p < 0.05). The contralateral vocal fold (subepithelial space) temperature increased an average of 6.8 degrees C without cooling, but only 4.2 degrees C with cooling (p > 0.05).

CONCLUSIONS

Cooling with room-temperature air during laryngeal laser surgery reduces luminal air and contralateral vocal fold temperatures. This effect is believed to be due to elimination of the plume of steam and smoke that significantly heats surrounding structures.

[Application of lasers in treatment of larynx diseases]

In otolaryngology, CO2 laser is the first and most commonly applied device. Such lasers as Ny:YAG generating visible light having wavelength 532 nm referred to as KTP laser due to the Name of the crystal where infrared light is converted to visible light. Such wavelenght, having green colour, due to strong absorption in haemoglobin is applied in treatments on tissues having dense blood vessels. The object of the work is to analyze larynx microsurgery laser treatments performer between 1994-2008 in the Otolaryngology Department of the Military Medical Institute CSK MON in Warsaw. The examination covered 445 patients including 142 women (31.9%) and 303 men (68.1%) aged between 12 and 80 (the average age of 48.2 year olds) who Were qualified in 1994-2003 for endoscopic laser surgery of the larynx. The operations field was watched using OPMI-11 operating microscope (Zeiss, Germany) allowing 4-16 times blow-up. Larynx laser microsurgery was performer using white laser beam: CO2 Illumina 40 (Heraeus LaserSonics, Germany) and green laser beam using KTP AURA XP laser (AMS, USA). The total of 445 larynx laser microsurgeries were performer. In recent years our clinic has seen an increase in the number of operations using this technique. The largest group were patients with recognized precancerous conditions (33.0%) and larynx carcinoma (26.4%). The next group in terms of the number of patients were 114 patients (20.6%) with recognized juvenile papilloma. Complications were observed in 180 patients. Table III show the type of recognized complications. The most commonly observed was swelling of the mucous membrane (48.3%), the rarest type was subcutaneous emphysema (3.3%). It was concluded that larynx laser microsurgery is a safe method and a valuable tool in treatment of larynx diseases, especially precancerous conditions and early forms of larynx carcinoma; that complications following procedure are relatively rare, usually mild, not life-threatening, and most often subsiding after a few days.

Diode laser for paediatric airway procedures: a useful tool

OBJECTIVE

A wide range of lasers have been used in the larynx. Diode laser is a portable and relatively inexpensive laser which is delivered via a glass fibre hand-held probe. The objective of this study was to report our experience with the use of diode laser in a variety of paediatric airway pathologies.

METHODS

In this study, 90 diode laser laryngeal procedures were performed on 31 patients in the age range of 1 month to 16 years at the time of the operation. The follow up after the procedure has been in the range of 6 months to 3 years.

RESULTS

As per our records 19/31 (61.3%) patients have been cured of their initial pathologies and were not under further review, 3/31 (9.6%) were having repeated laser treatments. The remaining 9/31 (29.0%) had to undergo further treatment. There was no laser-related intra-operative or postoperative complications.

CONCLUSIONS

Diode laser is a good tool for several paediatric laryngeal pathologies. The ability to guide the laser light using the flexible glass fibre directly onto the area requiring vapourisation enables very precise treatment.

Microlaryngoscopic and office-based injection of bevacizumab (Avastin) to enhance 532-nm pulsed KTP laser treatment of glottal papillomatosis

OBJECTIVES

Photoangiolytic lasers effectively treat glottal papillomatosis, but do not reliably prevent recurrence. Therefore, sublesional injections of the antiangiogenic agent bevacizumab (Avastin) were given to assess the effect on disease recurrence and phonatory function.

METHODS

A retrospective investigation was done in a pilot group of 10 adult patients with bilateral glottal papillomatosis who had prior angiolytic laser treatment with established patterns of recurrence. The patients underwent 5 bevacizumab injections (5 to 10 mg) into the diseased vocal folds along with 532-nm pulsed KTP laser photoangiolysis treatments 4 to 6 weeks apart. Their disease resolution was compared to findings from prior laser treatment alone, and objective measures of vocal function (acoustic, aerodynamic, Voice-Related Quality of Life survey) were obtained.

RESULTS

All 10 patients had a greater than 90% reduction in recurrence. Four of the 10 had resolution. Four of the 10 have limited recurrent or persistent disease, receive injections of bevacizumab at 8- to 12-week intervals, and have not required laser treatment. Two of the 10 have ongoing periodic office-based KTP laser treatment along with bevacizumab injections. No patient has required microlaryngeal surgery with general anesthesia, and all 10 have had substantial improvement in vocal function.

CONCLUSIONS

This pilot investigation provides preliminary evidence that bevacizumab injections enhance photoangiolytic laser treatment of glottal papillomatosis while enhancing phonatory function. Coupling an antiangiogenesis agent with pulsed KTP laser photoangiolysis is conceptually promising, since the mechanisms of action are complementary.

Value and utility of 532 nanometre pulsed potassium-titanyl-phosphate laser in endoscopic laryngeal surgery

Objectives:

Recently, the 532 nm pulsed potassium-titanyl-phosphate laser has emerged as an effective angiolytic laser for treating mucosal lesions of the larynx in the operating theatre and clinic. We sought to assess the current impact of potassium-titanyl-phosphate laser on our laryngeal surgery practice.

Study design:

Retrospective review of 710 patients undergoing endoscopic laryngeal surgery over a one-year period.

Methods:

Medical records of the endoscopic laryngeal procedures were reviewed; 386/710 had been performed in the clinic and 324/710 in the operating theatre under general anaesthesia. Indications for the procedures were classified by pathology.

Results:

Pulsed potassium-titanyl-phosphate laser was used in 209/386 clinic procedures. The indications for these procedures were: dysplasia (114/209 procedures), papillomatosis (89/209), varices or ectasia (three of 209), and ‘other’ (three of 209). Pulsed potassium-titanyl-phosphate laser was used in 178/324 operating theatre endoscopic laryngeal procedures. The indications for these procedures were: cancer (54/178 procedures), dysplasia (52/178), papillomatosis (38/178), varices or ectasia (13/178), polyps (six of 178), nodules (six of 178), stenosis (five of 178), granulation (three of 178), and amyloid (one of 178).

Conclusions:

Due to its versatility, the 532 nm pulsed potassium-titanyl-phosphate laser is our most commonly utilised instrument for performing endoscopic laryngeal surgery.

Use of lasers in laryngeal surgery

Lasers are a relatively recent addition to laryngeal surgery. Since their invention, laser use and applications have expanded rapidly. In this article, we discuss the benefits and disadvantages of lasers for different procedures, as well as ways to overcome commonly faced clinical problems. The use of lasers in surgery has offered a time- and cost-efficient alternative to cold surgical techniques, and has been used in the treatment of numerous laryngeal pathologies, including stenoses, recurrent respiratory papillomatosis, leukoplakia, nodules, malignant laryngeal disease, and polypoid degeneration (Reinke's edema). However, lasers can incur adjacent tissue damage and vocal fold scarring. These problems can be minimized through understanding the mechanisms by which lasers function and correctly manipulating the parameters under a surgeon's control. By varying fluence, power density, and pulsation, tissue damage can be decreased and lasers can be used with greater confidence. The various types of lasers and their applications to the treatment of specific pathologies are reviewed with the intention of helping surgeons select the best tool for a given procedure. Recent applications of lasers to treat benign laryngeal lesions and severe laryngomalacia demonstrate that additional research must be conducted to realize the full potential of this surgical tool.