Out-patient flexible carbon dioxide laser surgery for benign laryngopharyngeal pathologies via transnasal flexible laryngo-oesophagoscopy

Comparative Results of Vocal Fold Injury According to the Fiber-Based Laser in a Rabbit Vocal Fold Model

OBJECTIVES

We assessed the safety of flexible fiber-based lasers including the potassium-titanyl-phosphate (KTP), CO2, and Holmium lasers using a rabbit vocal fold model and provided the safety evidence of laser before human clinical trial.

METHODS

In all, 120 male New Zealand white rabbits were used. Each laser was used to induce acute and chronic vocal fold injuries in 40 rabbits. The same laser energy with the same intensity and frequency were used in all cases, and we evaluated outcomes via surface scanning electron microscopy (SEM) and histological examination 1 day after injury. Histological and high-speed vocal fold vibration examinations were evaluated 1 month after injury. Surface injury roughness grading was done via SEM, and the Acute injury ratio and lamina propria (LP) ratio were also calculated. The dynamic glottal gap was measured through functional analyses based on recordings from a high-speed digital camera.

RESULTS

The Holmium laser caused significantly more vocal fold damage than did the KTP and CO2 lasers as revealed by SEM and evaluation of acute and chronic injuries. Functional analysis with high-speed digital camera indicated that the holmium laser reduced dynamic glottal gap compared with the normal vocal fold, where the other lasers did not.

CONCLUSIONS

The histological and functional analyses of rabbit vocal fold experiments indicated that fiber-based laryngeal laser surgery for vocal fold lesions could be performed relatively safely using a KTP or CO2 laser.

Extended role of transnasal oesophagoscopy: a review of the literature

BACKGROUND

Advances in endoscopic technology have allowed transnasal oesophagoscopy to be used for a variety of diagnostic and therapeutic procedures.

METHOD

A review of the literature was carried out to look into the extended role of transnasal oesophagoscopy within otolaryngology, using the Embase, Cinahl and Medline databases.

RESULTS

There were 16 studies showing that transnasal oesophagoscopy is safe and cost effective and can be used for removal of foreign bodies, tracheoesophageal puncture, laser laryngeal surgery and balloon dilatation.

CONCLUSION

This study presents a summary of the literature showing that transnasal oesophagoscopy can be used as a safe and cost-effective alternative or adjunct to traditional rigid endoscopes for therapeutic procedures.

Optimizing Settings for Office-Based Endoscopic CO2 Laser Surgery Using an Experimental Vocal Cord Model

OBJECTIVES/HYPOTHESIS

To provide insight in the thermal effects of individual laser settings in target tissues to optimize flexible endoscopic CO₂ laser surgery treatment.

STUDY DESIGN

Experimental laboratory study.

METHODS

Thermal effects of the CO₂ laser using a fiber delivery system were visualized using the color Schlieren technique in combination with a polyacrylamide gel tissue model. Variable settings were used for emission mode, power, laser fiber distance, and laser duration, which were evaluated in every possible combination. Collateral thermal expansion and incision depth were measured. To validate the model, the results were compared to histology after CO₂ laser irradiation of ex vivo human vocal cords, and the intraclass correlation coefficient was calculated. Thermal damage and incision depth were measured by a blinded pathologist.

RESULTS

Of all parameters studied, duration of laser irradiation had the greatest effect on thermal expansion. Increased distance between laser tip and target tissue resulted in significantly reduced incision depth and increased thermal expansion. Pulsed emission modes led to increased incision depths. The intraclass correlation coefficient for consistency between the model setup and the ex vivo human vocal cords was classified as "fair."

CONCLUSIONS

By using high-intensity pulsed lasers at minimal distance to the target tissue, exposure times and subsequent damage to surrounding tissue can be reduced. If an evaporation technique is used, lower power in continuous wave at a larger distance to the target tissue will lead to superficial but broader thermal effects. The model setup used in this study is a valid model to investigate laser-induced thermal effects in vocal cord tissue.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:E680-E685, 2020.

Assessment and Treatment of Pain during In-Office Otolaryngology Procedures: A Systematic Review

OBJECTIVE

To qualitatively assess practices of periprocedural pain assessment and control and to evaluate the effectiveness of interventions for pain during in-office procedures reported in the otolaryngology literature through a systematic review.

DATA SOURCES

PubMed, CINAHL, and Web of Science searches from inception to 2018.

REVIEW METHODS

English-language studies reporting qualitative or quantitative data for periprocedural pain assessment in adult patients undergoing in-office otolaryngology procedures were included. Risk of bias was assessed via the Cochrane Risk of Bias or Cochrane Risk of Bias in Non-Randomized Studies of Interventions tools as appropriate. Two reviewers screened all articles. Bias was assessed by 3 reviewers.

RESULTS

Eighty-six studies describing 32 types of procedures met inclusion criteria. Study quality and risk of bias ranged from good to serious but did not affect assessed outcomes. Validated methods of pain assessment were used by only 45% of studies. The most commonly used pain assessment was patient tolerance, or ability to simply complete a procedure. Only 5.8% of studies elicited patients' baseline pain levels prior to procedures, and a qualitative assessment of pain was done in merely 3.5%. Eleven unique pain control regimens were described in the literature, with 8% of studies failing to report method of pain control.

CONCLUSION

Many reports of measures and management of pain for in-office procedures exist but few employ validated measures, few are standardized, and current data do not support any specific pain control measures over others. Significant opportunity remains to investigate methods for improving patient pain and tolerance of in-office procedures.

Feasibility of transnasal flexible carbon dioxide laser surgery for laryngopharyngeal lesions

OBJECTIVE

The fiber-guided carbon dioxide (CO₂) laser is a useful device for laryngopharyngeal surgery. The flexible CO₂ wave-guide laser has been developed and commercially available for several years. However, the transnasal use of CO₂ flexible wave-guided laser surgery through the instrument channel of a flexible endoscope (CO₂ TNFLS) is not permitted in Japan. This feasibility study aimed to assess the value and the safety of an in-office CO₂ TNFLS procedure.

METHODS

Patients with small laryngopharyngeal diseases were enrolled from June 2015. Eligible patients had indications with lesions generally localized superficial lesions such as the benign tumor, leukoplakia, and premalignant lesion-like carcinoma in situ (CIS). Patients were locally well anesthetized using xylocaine. After removing as much of the lesion(s) as possible with flexible forceps, the remainder of the lesions were evaporated using CO₂ TNFLS through the instrument channel of a flexible endoscope under local anesthesia.

RESULTS

Eighteen surgeries involving 13 patients, including 9 papilloma (7 recurrent respiratory papilloma [RRP]), 2 carcinoma in situ, 1 leukoplakia, and 1 large epiglottic cyst), were performed. Four patients with RRP required multiple surgeries. Except for 3 patients with RRP, all patients achieved disease control without additional intervention. All procedures were completed with no severe adverse events.

CONCLUSION

Office-based CO₂ TNFLS is safe and feasible for patients with laryngopharyngeal pathologies. It is especially valuable for RRP patients with small lesions to avoid surgery under general anesthesia.