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.

Comparative Efficacy of the KTP Laser and Cold Steel in Office-Based Surgery for Oropharyngeal Papilloma.

Objective: This study aims to compare the efficacy of the potassium-titanyl-phosphate (KTP) laser and cold steel surgery in treating oropharyngeal papilloma. Methods: Between 2017 and 2020, we enrolled 242 patients with oropharyngeal papilloma who were treated with either the KTP laser (n = 160) or cold steel surgery (n = 82). Patient charts were reviewed for demographic data (age and gender), pathology, anatomical location of lesions, operative duration, pain rating, residual disease, and recurrence. Results: The oropharyngeal papillomas were successfully removed in all patients, except one with a significant pharyngeal reflex. There was no significant difference in the average time for lesion resection between KTP laser and cold steel group (18.11 ± 13.96 s vs 19.43 ± 16.91 s, P > .05). However, all patients who underwent cold steel surgery experienced bleeding during the operation and required postoperative observation (about 20 min), making the total procedure time longer than that of the KTP laser procedure, which did not cause any intraoperative bleeding or require postoperative observation. After KTP laser treatment, the pain rating was .49 ± .98, whereas after cold steel surgery, it was .74 ± 1.12 (P = .058). Twenty-five samples were sent for human papillomavirus (HPV) testing, and one tested positive for both HPV 6 and 11 strains, while another tested positive for HPV 16. No residual disease or recurrence was observed at the treatment sites after a long period of follow-up (M = 15.35 ± 10.79 mo; range = 6-39 mo). Conclusion: The KTP laser provided a better hemostasis effect and a good surgical field of vision during the operation, allowing the surgeon to complete the procedure in less time. No significant difference in terms of pain rating, incision recovery, and postoperative recurrence between the KTP laser treatment and cold steel surgery.

A 532-nm KTP Laser for Vocal Fold Polyps: Efficacy and Relative Factors.

OBJECTIVE: We retrospectively analyzed the laryngoscopy results and voice outcomes of patients with vocal polyps who received potassium titanyl phosphate (KTP) laser treatments in a clinician's office, in order to establish the effectiveness and relative factors affecting the efficacy of this treatment. MATERIAL AND METHODS: We enrolled 25 patients with vocal polyps who had undergone KTP laser treatment in the Department of Otorhinolaryngology at our hospital between July 2017 and November 2019. Pre- and postoperative evaluations were measured using laryngovideostroboscopy (LVS), the Voice Handicap Index questionnaire (VHI-30), the GRBAS scale (G hoarseness, R roughness, B breathiness, A asthenia, S strain), and objective acoustic parameters. The reduction rate of lesions was calculated and relative factors affecting efficacy (size, side, location, the position of lesions, type, gender, and occupation) were tested. RESULTS: Areas of lesions decreased from 101.95 ± 70.16 before surgery to 30.49 ± 35.80 after surgery (Z = 5.234, P < .001). The LVS data showed that the postoperative proportions of normal to mild conditions were the same or higher than the preoperative data in 3 instances: glottal closure (100% vs 100%), amplitude (90.91% vs 63.64%), and mucosal wave (81.82% vs 54.55%). A significant improvement was observed in VHI-30 scores, GRBAS scores, and acoustic parameters (P < .05). The size of lesions had an effect on the GRBAS scores (P < .001) but not on VHI-30 scores and objective acoustic parameters (P > .05). Other factors we tested did not affect voice outcomes. CONCLUSION: Potassium titanyl phosphate laser treatment can effectively reduce the lesion area of vocal polyps and improve the voice quality. The presence of small lesions seems to predict good subjective assessments of voice quality, but it remains to be seen whether this correlates with true voice quality.

[Contribution of Emissions from the Iron and Steel Industry to Air Quality in China].

Based on the data from a continuous emission monitoring systems network in 2015, this study analyzed the compliance rates of exhaust gas in the processes of China's iron and steel industry, and established a high-resolution steel plant emission inventory for China (HSEC, 2015), based on the bottom-up method. The contribution of emissions from the iron and steel industry to regional air quality was quantitatively simulated using a CAMx model. The results showed that in 2015, the total emissions of SO2, NOx, PM10, PM2.5, PCDD/Fs, VOCs, CO, BC, OC, EC, and F were 374800 t, 720500 t, 334800 t, 150300 t, 1.91 kg, 842900 t, 34788500 t, 6400 t, 8300 t, 800 t, and 7700 t, respectively. From a regional perspective, the iron and steel industry in Shanghai and Tianjin has the highest emission intensity per unit area and contributes a high proportion to regional air pollution. From a process perspective, in 2015, the exhaust concentration of flue gas in the main process gradually decreased, with a high compliance rate, and the emission factor significantly decreased to lower than that in the existing research results. From a species perspective, in 2015, NOx emission from the steel industry contributed the most to regional air quality, and there is therefore a great emission reduction potential for NOx.

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-ß1 levels in the two groups were lower than in the scar group. There were also significant differences in the levels of IL-1ß, 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.

[Characterization of scarred vocal fold regeneration after the intervention of extracellular matrix and human amniotic epithelial cells transplanting].

OBJECTIVE: To investigate the treatment for scarred vocal folds by transplanting human amniotic epithelial cells (hAECs)and injecting collagenase as well as hyaluronic acid (HA) for the intervention of the extracellular matrix(EMC), to observe the growth, distribution of hAECs and to assess the abilities of them for scarred vocal fold regeneration. METHODS: The lamina propria was injured by localized resection in thirty-eight vocal folds of twenty rabbits. hAECs were isolated from human amnion and marked by Lenti-GFP. After the formation of vocal fold scarring, hAECs were transplanted into ten vocal folds, collagenase and HA were injected into ten vocal folds, all three were injected into ten vocal folds, none were injected into eight vocal folds, and two normal vocal folds were used as control. At 1 month and 2 months after the transplanting, the survival, the distribution and the cytoactive of hAECs were examined by immunofluorescence method. Meanwhile, at 1 month, 2 months, 3 months and 6 months after the operation, HE staining was performed for histopathological research, Masson trichrome staining and immunohistochemical staining were used for collagen and fibronectin respectively. RESULTS: After implanted into the scarred vocal folds, hAECs could survive in vocal fold lamina propria for two months. The immunofluorescence analysis showed the cytoactive of hAECs.Six months postoperatively, compared with that in the normal vocal folds, collagen in the untreated scarred vocal folds more increased and disorderly distributed; the changes in other three groups were between the two groups above, but the group injected with all of hAECs, collagenase and HA was better than other two groups. Besides, the mean density of fibronectin in the scarred untreated control group was more significantly increased than that in the normal vocal folds; the changes in other three groups were between the two groups above, but the group injected with all of hAECs, collagenase and HA was better than other two groups. CONCLUSION: The transplanting of hAECs and the interventions of EMC by injecting collagenase as well as HA have better abilities in rabbit scarred vocal fold reparation and regeneration by promoting ECM secretion, rational distribution and part ordering arrangement.