CO2 Transoral Laser Microsurgery in Benign, Premalignant and Malignant (Tis, T1, T2) Lesion of the Glottis. A Literature Review

Voice Outcome After Carbon Dioxide Transoral Laser Microsurgery for Glottic Cancer According to the European Laryngological Society Classification of Cordectomy Types - A Systematic Review

BACKGROUND

Voice outcome after carbon dioxide transoral laser microsurgery (CO2TOLMS) for glottic cancer is of prime importance. However, a comprehensive overview according to the European Laryngological Society (ELS) classification of cordectomies is still lacking. The aim of this systematic review is to summarize data on voice outcome associated with individual types of ELS glottic cordectomy after CO2TOLMS.

MATERIALS AND METHODS

A systematic review of the literature was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. The initial search identified 936 records of which 25 publications were then included. Voice outcome data (Voice Handicap Index [VHI] version 30, grade of dysphonia [G] and maximum phonation time [MPT]) were extracted per resection type. Weighted averages were calculated.

RESULTS

Data show a gradual increase in the VHI scores although they were still similar for all cordectomy types (range 14.2 to 21.5). The grade of dysphonia showed a gradual increase with increasing resection depth (range 1.0 to 1.9). There was a gradual decrease in the MPT (range 15.2 to 7.2).

CONCLUSION

Voice outcome is related to cordectomy type with mild dysphonia characterizing ELS type I, II and III cordectomies, while more extended cordectomies (ELS type IV, V and VI) result in moderate dysphonia and shortness of breath during phonation. The voice handicap experienced by patients is limited even in the more extended cordectomies.

CT imaging-based nomogram for predicting early-stage glottic cancer recurrence following transoral laser microsurgery

OBJECTIVE

To explore the differences between clinical features and computed tomography (CT) findings of early-stage glottic cancer (EGC) with or without recurrence after transoral laser microsurgery (TLM) and to establish a preoperative nomogram to predict postoperative recurrence.

METHODS

The clinical and CT features of 168 consecutive patients with EGC with or without recurrence were analyzed retrospectively. Multivariate logistic regression analysis was used to determine the independent predictors of recurrence. A nomogram was constructed to preoperatively predict recurrence. To assess the nomogram's performance, the C-index and calibration plot were used.

RESULTS

EGCs with and without recurrence differed significantly in T-stage, depth, and normalized CT values in the arterial phase (NCTAP) and venous phase (NCTVP) (all P < 0.05). T-stage, depth, and NCTVP were independent predictors of recurrence in EGCs (all P < 0.05). The C-index (0.765, 95% confidence interval: 0.703-0.827) and calibration plot showed that the nomogram has good prediction accuracy. Nomograms based on T-stage and CT variables provided numerically predicted recurrence rates and were better than those based on only T-stage (C-index of 0.765 vs. 0.608).

CONCLUSIONS

Using clinical and CT variables, we developed a novel nomogram to predict the recurrence of EGC before TLM, which may be a potential noninvasive tool for guiding personalized treatment.

Transoral Flexible Laser Surgery of the Larynx with Blue Laser

INTRODUCTION

Laser surgery of the larynx is currently the standard of clinical practice in a multitude of procedures. Lasers with photoangiolytic properties have a wide application in endolaryngeal lesions. One of their most prominent features is the ability to coagulate blood vessels, reducing unwanted tissue damage. Our objective is to expose the uses of the blue laser (445 nm) in the larynx.

MATERIAL AND METHODS

A retrospective study was carried out including 47 patients treated with blue photoangiolytic laser from October 2021 to January 2023 at a university hospital. Demographic data, type of lesion presented, date of intervention and scope of the procedure, as well as the parameters of the laser used, were recorded. The number of sessions received per patient, the result and complications were also collected.

RESULTS

A total of 47 patients with laryngeal lesions were treated, including vascular angiomas, laryngeal sulcus vocali, vocal cord polyps, Reinke's edemas, laryngeal papillomatoses, subglottic stenosis, laryngeal synechiae, subglottic granulomas, glottic scars, vocal fold leukoplakias, laryngeal dysplasias and tracheostomal granulomas. The mean age was 52.5 years, and 64.3% of the patients were women. The range of power used in the resective surgeries was 2-10 Watts with a 20-millisecond window. The average number of sessions received was 2.1 (range 1-4). A satisfactory situation was obtained in 45 of the 47 patients treated (95.75%), and an evident decrease in lesions was seen in the remaining two. There was no evidence of any complications directly derived from the use of the blue laser. Twenty-seven cases (54%) were treated exclusively in-office.

CONCLUSIONS

The blue laser is safe and effective in the treatment of a wide range of laryngeal pathologies. Its advantages include its portability, its photoangiolytic qualities as well as its ability to vaporize tissue in contact mode, which can treat subepithelial vessels or resect lesions.

[Modern aspects of organ-preserving surgery for laryngeal cancer]

A review of the literature on modern aspects of organ-preserving surgery for laryngeal cancer - endolaryngeal and open resections - is presented. The indications for these operations are determined depending on the location and extent of the tumor, as well as on the anatomical features. The advantages and disadvantages of each method, complications, functional and oncological results are shown.

Sub-millisecond 2D MRI of the vocal fold oscillation using single-point imaging with rapid encoding

OBJECTIVE

The slow spatial encoding of MRI has precluded its application to rapid physiologic motion in the past. The purpose of this study is to introduce a new fast acquisition method and to demonstrate feasibility of encoding rapid two-dimensional motion of human vocal folds with sub-millisecond resolution.

METHOD

In our previous work, we achieved high temporal resolution by applying a rapidly switched phase encoding gradient along the direction of motion. In this work, we extend phase encoding to the second image direction by using single-point imaging with rapid encoding (SPIRE) to image the two-dimensional vocal fold oscillation in the coronal view. Image data were gated using electroglottography (EGG) and motion corrected. An iterative reconstruction with a total variation (TV) constraint was used and the sequence was also simulated using a motion phantom.

RESULTS

Dynamic images of the vocal folds during phonation at pitches of 150 and 165 Hz were acquired in two volunteers and the periodic motion of the vocal folds at a temporal resolution of about 600 µs was shown. The simulations emphasize the necessity of SPIRE for two-dimensional motion encoding.

DISCUSSION

SPIRE is a new MRI method to image rapidly oscillating structures and for the first time provides dynamic images of the vocal folds oscillations in the coronal plane.

Current Intraoperative Imaging Techniques to Improve Surgical Resection of Laryngeal Cancer: A Systematic Review

Simple Summary

Laryngeal cancer is a prevalent head and neck malignancy, with poor prognosis and low survival rates for patients with advanced disease. The recurrence rate for advanced laryngeal cancer is between 25 and 50%. In order to improve surgical resection of laryngeal cancer and reduce local recurrence rates, various intraoperative optical imaging techniques have been investigated. In this systematic review we identify these technologies, evaluating the current state and future directions of optical imaging for this indication. Evidently, the investigated imaging modalities are generally unsuitable for deep margin assessment, and, therefore, inadequate to guide resection in advanced laryngeal disease. We discuss two optical imaging techniques that can overcome these limitations and suggest how they can be used to achieve adequate margins in laryngeal cancer at all stages.

Abstract

Laryngeal cancer is a prevalent head and neck malignancy, with poor prognosis and low survival rates for patients with advanced disease. Treatment consists of unimodal therapy through surgery or radiotherapy in early staged tumors, while advanced stage tumors are generally treated with multimodal chemoradiotherapy or (total) laryngectomy followed by radiotherapy. Still, the recurrence rate for advanced laryngeal cancer is between 25 and 50%. In order to improve surgical resection of laryngeal cancer and reduce local recurrence rates, various intraoperative optical imaging techniques have been investigated. In this systematic review, we identify these technologies, evaluating the current state and future directions of optical imaging for this indication. Narrow-band imaging (NBI) and autofluorescence (AF) are established tools for early detection of laryngeal cancer. Nonetheless, their intraoperative utility is limited by an intrinsic inability to image beyond the (sub-)mucosa. Likewise, contact endoscopy (CE) and optical coherence tomography (OCT) are technically cumbersome and only useful for mucosal margin assessment. Research on fluorescence imaging (FLI) for this application is sparse, dealing solely with nonspecific fluorescent agents. Evidently, the imaging modalities that have been investigated thus far are generally unsuitable for deep margin assessment. We discuss two optical imaging techniques that can overcome these limitations and suggest how they can be used to achieve adequate margins in laryngeal cancer at all stages.

The Thermal Damage of Canine Vocal Fold by CO2 Laser Under Different Laser Emission Mode

OBJECTIVE

The purpose of this study is to review the differences between continuous wave (CW) and UltraPulse (UP) on thermal damage of the laser with different power.

METHODS

Four adult beagle dogs underwent transoral laser microsurgery (TLM) using CO₂ laser. The laser emission mode and power was CW (3 W, 5 W, and 8 W) and UP (3 W and 5 W), respectively. The tissue from 4 animals was evaluated histologically on postoperative days 1 and 3. The thermal damage of the laser was measured using slide scan system via SlideViewer version 1.5.5.2 software.

RESULTS

All dogs underwent TLM uneventfully. Under microscope examined, the laser damage area was composed of 2 parts: the vaporized zone (VPZ) and thermal damage area. The thermal damage area can be divided into thermal coagulative necrosis area (TCN) and hydropic degeneration area. The width of VPZ and TCN in UP mode was less than that in CW mode (P < .01). The data indicate that lower laser power created less thermal damage (P < .01). In addition, the width of VPZ on postoperative day 3 was less than that on postoperative day 1 (P < .01).

CONCLUSION

CO₂ laser with UP and lower power could decrease the laser thermal damage and may offer more prompt wound healing.

Preclinical experience with a novel single-port platform for transoral surgery

BACKGROUND

We investigated a novel minimally invasive surgical platform for use in the oropharynx, hypopharynx, and larynx for single-port transoral surgery used in concert with standard transoral laryngeal and pharyngeal instrumentation.

METHODS

The preclinical investigational device by Fortimedix Surgical B.V. (Netherlands) features two channels for manually controlled flexible articulating surgical instruments. A third central channel accepts both rigid and flexible endoscopes. The system is coupled to a standard laryngoscope for transoral access. In three cadaver models, we evaluated the surgical capabilities using wristed grasping instruments, microlaryngeal scissors, monopolar cautery, and a laser fiber sheath. Procedures were performed within the oropharynx, supraglottis, glottis, subglottis, and hypopharynx.

RESULTS

Within the oropharynx, we found adequate strength, range of motion, and dexterity to perform lateral oropharyngectomy and tongue base resection. Within the larynx, visualization was achieved with a variety of instruments including a flexible, 0° and 30° rigid endoscope. The glottis, supraglottis, pyriform sinuses, post-cricoid space, and esophageal inlet were readily accessible. Visualization and manipulation of grasping, laser, and monopolar cautery instruments were also possible within the subglottis. Instrument reach and accuracy facilitated completion of a delicate micro-flap on the true vocal fold. Other procedures included vocal fold resection, cricopharyngeal myotomy, and resection of subglottic mucosa.

CONCLUSIONS

From this initial proof of concept experience with this novel platform, we found a wide range of procedures within the oropharynx, larynx, and hypopharynx to be feasible. Further work is needed to evaluate its applicability to the clinical setting. The ability of this platform to be used with conventional instrumentation may provide an opportunity for complex transoral surgery to be performed in a facile manner at greatly reduced cost.

Lasers in Οtolaryngology: A Laser Odyssey From Carbon Dioxide to True Blue

In this special issue of the Ear Nose and Throat (ENT) journal entitled Lasers in Otolaryngology, we attempted to cover and accommodate different experiences from around the globe on both established and some not so well-known techniques and indications for Lasers in most ENT subspecialties. Despite the COVID 19 pandemic, authors from all over the world have expressed their interest in publishing their Laser experiences with ENT journal and for this we are very grateful.

Transoral Carbon Dioxide Microsurgery of the Larynx as a Day-Case Outpatient Procedure: An Observational, Retrospective, Single-Center Study

INTRODUCTION

Despite good results of transoral laser CO₂ microsurgery (CO₂TOLMS) of the larynx, a lack of data related to the safety of this technique as a day-case procedure across the literature is evident.

MATERIALS AND METHODS

An observational, retrospective, non-randomized study.

RESULTS

One hundred four (62.6%) patients met the inclusion criteria, 96 (92.3%) patients were male, and 8 (7.7%) patients were female. The mean age of the study group was 66 ± 11 years (min: 34/max: 90). All the patients underwent CO₂TOLMS were treated as an outpatient procedure. The glottis was the most common location affecting 97 (93.3%) patients, regarding the need of readmission, just 4 (3.8%) patients needed to be readmitted after surgery due to dyspnea secondary to laryngeal edema in 2 cases by laryngeal bleeding, and cervical emphysema in one case, respectively. Being just necessary to reintubate 1 patient (<1%) to control the bleeding. We didn't find any statistical correlation between variables and the need for readmission of reintubation.

CONCLUSION

According to our results, CO₂TOLMS of the larynx can be safely performed as an outpatient procedure. To establish a proper protocol and to perform a careful preoperative assessment are essential to increase our success rate and to prevent any potential complication.

Early Glottic Cancer Treated by Transoral Laser Surgery Using Toluidine Blue for the Definition of the Surgical Margins: A Pilot Study

Background and objectives: Transoral laser microsurgery (TLM) is widely accepted for its advantages, which consist of a brief hospital stay, rapid functional recovery, low management costs and the fact that it can be easily repeated in cases of recurrence. However, a high incidence of positive or narrow surgical margins has been reported in the literature, even if controversy still exists on the prognostic significance of positive resection margins. The aim of the study was to evaluate the utility of toluidine blue staining in defining the resection margins of early glottic cancer (T1a–T2) treated with TLM. Materials and Methods: This retrospective study was conducted on patients with early glottic cancer (T1a–T2) managed by TLM. A group of patients treated between 2010 and 2014 underwent toluidine blue staining (TB group) of the lesions before starting the cordectomy by TLM, and a group of patients treated by TLM between 2006 and 2009 was considered the control group. Results: A total of 44 subjects were included in this study: 41 were men, and 3 were women. The mean age was 58 ± 9.0 years (median 59.0, range 41–77). Twenty-three of the 44 patients were included in the TB group and 21 in the case control group. In the TB group, only the positivity of the deep margin was a predictor of local recurrence (p = 0.037), while in the control group, positive or close margins and the type of cordectomy were predictive factors of local recurrence (p = 0.049). Considering the TB group and control cases, the 5-year local recurrence-free survival was 95.6% and 80.9%, respectively (p = 0.14). Conclusions: From this first study, toluidine blue staining seems to be a useful modality to improve the rate of the negative resection margins of early glottic cancer (T1a–T2) treated by TLM.

Systematic review and meta-analysis of transoral laser microsurgery in hypopharyngeal carcinoma

BACKGROUND

Transoral laser microsurgery has been suggested as an alternative treatment modality for hypopharyngeal carcinoma. The purpose of this study is to systematically review the oncologic and functional outcomes of patients with hypopharyngeal carcinoma when treated with primary transoral laser microsurgery.

METHODS

A comprehensive literature search was performed using PRISMA methodology on OVID MEDLINE and EMBASE. Meta-analysis was completed for oncological outcomes.

RESULTS

Six studies reported quality of life outcomes five reported oncologic outcomes. A median of 95% (range 0.83-0.98) patients achieving gastrostomy independence, a median of 3% (range 0%-6%) were tracheostomy dependent, and a median of 97% (Range 0.89-1.0) were able to preserve their larynx. Pooled five-year overall survival was 54% (CI, 0.50-0.58, I2 = 29%), pooled disease-specific survival was 72% (CI, 0.68-0.77, I2 = 46%), and pooled local control rate was 78% (CI, 0.72-0.85, I2 = 69%).

CONCLUSION

Systematic review supports improvements in functional outcomes and oncologic outcomes with transoral laser microsurgery.