New computer-guided scanner for improving CO2 laser-assisted microincision

Un-sedated Office-Based Application of Blue Laser in Vocal Fold Lesions

INTRODUCTION

Office-based laser procedures in laryngology have gained a lot of popularity in the last decade with the use of the KTP, PDL and Thulium lasers. Preliminary investigations currently report on the use of the 445 nm wavelength Blue laser for the treatment of various laryngeal pathologies, given its dual photoangiolytic and cutting properties.

OBJECTIVE

We aim to investigate the safety and efficacy of the Blue laser for the treatment of vocal fold lesions.

METHODS

This is a retrospective chart review of eleven patients with a variety of vocal fold lesions (polyps, Reinke's edema, papilloma, and leukoplakia), that underwent un-sedated office-based treatment using the 445 nm blue laser. The primary outcome was to compare preoperative to postoperative Voice Handicap Index (VHI-10) score and self-reported voice improvement using a visual analog scale (VAS). We also compared fiberoptic laryngeal examination before and after treatment.

RESULTS

Eleven un-sedated office-based procedures using the blue laser were performed. There was improvement in the mean VHI-10 score (n = 8) with a decrease from 15.13 ± 8.77 to 3.50 ± 3.46 (P= 0.015). Similarly, the mean VAS score (n = 7) decreased from 6.14 ± 1.21 to 1.71 ± 1.60 (P< 0.003). All patients had a complete or partial regression of the vocal fold lesions on fiberoptic laryngeal examination. None of the patients had complications after the procedure.

CONCLUSION

Blue laser therapy can be suggested as a safe and effective alternative treatment modality in office-based laryngology procedures for a variety of vocal fold lesions. A larger series is needed to better validate the efficacy of this laser as a new treatment modality.

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

Carbon Dioxide transoral laser microsurgery represents a reliable option for the treatment of early glottic carcinoma (Tis–T2), with good functional and oncological outcomes, nowadays representing one of the main options in larynx preservation protocols. The development and improvement of laser devices means surgeons are able to use more precise instruments compared with classic cold dissection in laser-assisted phonosurgery. Secondary effects on voice, swallowing, or quality of life as well as complications have been well documented. Also, with the introduction of a new proposal for staging systems following the principle of the three-dimensional map of isoprognostic zones, the use of narrow-band imaging in clinical evaluation and intraoperative, and the implementation of diffusion-weighted magnetic resonance during preoperative evaluation, the development of new tools to improve surgical quality and preliminary reports regarding the use of carbon dioxide laser in transoral robotic surgery suggests an exciting future for this technique.

Meta-analytic comparison of robotic and transoral laser surgical procedures in supraglottic carcinoma

Objective

To assess published reports of oncological surgical success rates in patients who underwent transoral laser supraglottic surgery and robotic surgery for supraglottic cancer.

Methods

A systematic review of the literature was conducted and a meta-analysis of published data was performed. PubMed, Sage, Medline and Cochrane data sources were investigated. Overall survival rates, disease-specific survival rates, additional treatments and recurrence rates were investigated to determine the success of the surgical procedures.

Results

The meta-analysis included 24 studies; 1617 studies were excluded. There were no statistically significant differences between the transoral laser supraglottic surgery and transoral robotic supraglottic surgery groups in terms of overall survival (77.0 per cent and 82.4 per cent respectively) and disease-specific survival (75.8 per cent and 87.0 per cent respectively). There was recurrence in 164 out of 832 patients (19.7 per cent) in the transoral laser supraglottic surgery group and in only 6 out of 66 patients (9 per cent) in the transoral robotic supraglottic surgery group.

Conclusion

Transoral laser surgery and robotic surgery appear to have comparable and acceptable oncological success rates.

Design and Study of a Next-Generation Computer-Assisted System for Transoral Laser Microsurgery

Objective

To present a new computer-assisted system for improved usability, intuitiveness, efficiency, and controllability in transoral laser microsurgery (TLM).

Study Design

Pilot technology feasibility study.

Setting

A dedicated room with a simulated TLM surgical setup: surgical microscope, surgical laser system, instruments, ex vivo pig larynxes, and computer-assisted system.

Subjects and Methods

The computer-assisted laser microsurgery (CALM) system consists of a novel motorized laser micromanipulator and a tablet- and stylus-based control interface. The system setup includes the Leica 2 surgical microscope and the DEKA HiScan Surgical laser system. The system was validated through a first-of-its-kind observational study with 57 international surgeons with varied experience in TLM. The subjects performed real surgical tasks on ex vivo pig larynxes in a simulated TLM scenario. The qualitative aspects were established with a newly devised questionnaire assessing the usability, efficiency, and suitability of the system.

Results

The surgeons evaluated the CALM system with an average score of 6.29 (out of 7) in ease of use and ease of learning, while an average score of 5.96 was assigned for controllability and safety. A score of 1.51 indicated reduced workload for the subjects. Of 57 subjects, 41 stated that the CALM system allows better surgical quality than the existing TLM systems.

Conclusions

The CALM system augments the usability, controllability, and efficiency in TLM. It enhances the ergonomics and accuracy beyond the current state of the art, potentially improving the surgical safety and quality. The system offers the intraoperative automated scanning of customized long incisions achieving uniform resections at the surgical site.

Non-Contact Tissue Ablations with High-Speed Laser Scanning in Endoscopic Laser Microsurgery

The use of laser scanners in soft tissue microsurgery results in high quality ablations with minimal thermal damage to surrounding tissue. However, current scanner technologies for microsurgery are limited to free-beam lasers, requiring direct line-of-sight from outside the patient to the surgical site. Developing compact laser manipulation systems is crucial to introduce laser scanning capabilities in hard-toreach surgical sites. Recently, we developed a magnetic laser scanner as a tip module of an endoscopic system. The device provides 2D position control and fast scanning of a laser beam. In this work, the previous prototype is revised to enable its use with a CO₂ laser source. The advantages of non-contact tissue ablations with fast scanning are discussed with comparative tissue ablation experiments coupling the system with a $CO_{2$ laser source. Results show that the magnetic laser scanner provides narrower ablations and less thermal damage compared to ablations performed with a bare flexible waveguide. These results highlight the potential of the proposed technology to improve soft tissue ablation quality in hard-to-reach surgical sites.

Multidimensional vocal assessment after laser treatment for recurrent respiratory papillomatosis

OBJECTIVES/HYPOTHESIS

Recurrent respiratory papillomatosis (RRP) is a benign epithelial tumor that exhibits a high frequency of recurrence. This study assesses the vocal function after laser treatment for RRP, particularly in relation to the frequency of surgery.

STUDY DESIGN

Retrospective study.

METHODS

Thirty RRP patients who underwent laser surgery that controlled the tumor were included. Preoperative and postoperative Grade, Roughness, Breathiness, Asthenia, and Strain Scale, videostroboscopic findings, aerodynamic and acoustic parameters, and self-assessment questionnaires were measured and compared with an age- and sex-matched control group. Subsequently, to evaluate the association between postoperative voice quality and the number of surgeries, the patients were divided into three groups (group 1: single surgery, group 2: 2-5 surgeries, group3: >6 surgeries), and comparative multidimensional vocal assessments were performed.

RESULTS

The mean number of surgeries was 3.4 (range, 1-8). Although all patients exhibited poorer vocal function than the control group preoperatively, they showed improvement in postoperative subjective and objective parameters. However, four patients who underwent one surgery with relatively aggressive ablation exhibited vocal cord scarring and deteriorated objective parameters. All remaining patients showed voice quality that was on par with the control group. Subgroup analysis proved no association between post-therapeutic voice quality and the patient characteristics, including preoperative staging and the number of surgical treatments performed.

CONCLUSIONS

RRP patients can achieve a close to normal voice with high satisfaction even after recurrent surgical treatment when ablation of a subepithelial lesion using sufficient laser energy is adequate.

LEVEL OF EVIDENCE

3b Laryngoscope, 127:679-684, 2017.

Endoscopic treatment of idiopathic subglottic stenosis with digital AcuBlade robotic microsurgery system

Herein, we described a novel method as the use of AcuBlade robotic microsurgery system to manage idiopathic subglottic stenosis in a 73-y-old lady. Compared to traditional CO2 lasers, AcuBlade facilitated the scar resection by the generation of different shape of beams (straight, curved, or disk). The same setting used for phonomicrosurgery (1-mm beam length, power of 10 W and pulse duration of 0.05-s) allowed to obtain fast, long, and uniform cuts. In addition, the reduction of the number of laser passes over the same area prevented injury of adjacent tissue and thus reduced the risk of recurrence.

Safe teleoperation based on flexible intraoperative planning for robot-assisted laser microsurgery

This paper describes a new intraoperative planning system created to improve precision and safety in teleoperated laser microsurgeries. It addresses major safety issues related to real-time control of a surgical laser during teleoperated procedures, which are related to the reliability and robustness of the telecommunication channels. Here, a safe solution is presented, consisting in a new planning system architecture that maintains the flexibility and benefits of real-time teleoperation and keeps the surgeon in control of all surgical actions. The developed system is based on our virtual scalpel system for robot-assisted laser microsurgery, and allows the intuitive use of stylus to create surgical plans directly over live video of the surgical field. In this case, surgical plans are defined as graphic objects overlaid on the live video, which can be easily modified or replaced as needed, and which are transmitted to the main surgical system controller for subsequent safe execution. In the process of improving safety, this new planning system also resulted in improved laser aiming precision and improved capability for higher quality laser procedures, both due to the new surgical plan execution module, which allows very fast and precise laser aiming control. Experimental results presented herein show that, in addition to the safety improvements, the new planning system resulted in a 48% improvement in laser aiming precision when compared to the previous virtual scalpel system.

Picosecond infrared laser (PIRL): an ideal phonomicrosurgical laser?

A comparison of tissue cutting effects in excised cadaver human vocal folds after incisions with three different instruments [scalpel, CO2 laser and the picosecond infrared laser-(PIRL)] was performed. In total, 15 larynges were taken from human cadavers shortly after death. After deep freezing and thawing for the experiment, the vocal folds suspended in the hemilarynx were incised. Histology and environmental scanning electron microscopy (ESEM) analyses were performed. Damage zones after cold instrument cuts ranged from 51 to 135 μm, as compared to 9-28 μm after cutting with the PIRL. It was shown that PIRL incision had smaller zones of tissue coagulation and tissue destruction, when compared with scalpel and CO2 laser cuts. The PIRL technology provides an (almost) atraumatic laser, which offers a quantum jump towards realistic 'micro'-phonosurgery on a factual cellular dimension, almost entirely avoiding coagulation, carbonization, or other ways of major tissue destruction in the vicinity of the intervention area. Although not available for clinical use yet, the new technique appears promising for future clinical applications, so that technical and methodological characteristics as well as tissue experiments seem worthwhile to be communicated at this stage of development.

The digital AcuBlade laser system to remove huge vocal fold granulations following subglottic airway stent

We report a case of granulations that complicated subglottic stent placement and completely destroyed vocal folds with luminal stent obstruction. A microbial aetiology significantly contributed to the occurrence of granulations associated with mechanical irritation. The granulations were successfully resected using a digital AcuBlade laser system, a new generation of CO2 laser used in otorhinolaryngology, particularly in vocal cord disease. It permitted a precise control of the scan line between vocal fold and granulation for several reasons. The scan line was completely electronic and integrated in the scanner. The sweep in speed was constant and the energy distribution was uniform along the entire length of the time. The interpulse pause was of ∼1 ms, allowing the tissue cooling with reduction of thermal spread and quicker healing support. The result was the radical excision of granulations without injuring vocal folds. The respiratory function was restored and no other treatments such as arytenoidectomy or cordectomy associated with the alteration of phonatry function were required. No intraoperative or/and postoperative complications were registered and the patient was discharged 7 days after the procedure.

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.

Design and control of a robotic system for assistive laser phonomicrosurgery

This paper presents the design, implementation and control of a novel robotic system for assistive laser phonomicrosurgeries. The goals here are to improve the precision, the controllability, the safety and the ergonomics of traditional transoral laser laryngeal surgeries. Successful steps achieved by the developed system in those directions are presented here, including the design, control and characterization of a novel laser micromanipulator system. Such system is shown to achieve very fast (181mm/s) and accurate (1µm resolution) laser beam aiming within an 11×11mm target area. The design and implementation of a high-level control system for safe operation of the new laser phonomicrosurgery equipment is also described in this paper. This controller runs on a personal computer, offering a comfortable and safe surgical environment for the surgeon. In addition, it implements safe teleoperation by allowing the definition of safe and exclusion zones for surgical laser aiming. Automation of ablation procedures is also implemented on this high-level controller and described here. This feature adds an extra level of safety for phonomicrosurgeries by allowing the precise execution of surgical plans defined by the surgeon.

Endoscopic Partial Supraglottic Laryngectomies

OBJECTIVE: The aim of this study was to evaluate long-term results of endoscopic surgery for supraglottic carcinoma.

STUDY DESIGN: Case series with chart review.

SETTING: Tertiary care university hospital.

SUBJECTS AND METHODS: From 1992 to 2004, 45 patients diagnosed with supraglottic squamous cell carcinoma (two Tis, nine T1N0, 27 T2N0, two T2N1, one T2N2, four T3N0) underwent different types of endoscopic supraglottic laryngectomies according to the European Laryngological Society (ELS) classification: three limited excision (type I); 27 medial without resection of the preepiglottic space (type IIb); one medial with resection of the preepiglottic space (type IIIa); three medial with resection of the preepiglottic space (type IIIb); nine lateral (type IVa); two lateral (type IVb).

RESULTS: Overall survival was 93 ± 4 percent (SE) after three years and 89 ± 6 percent (SE) after five years. The median follow-up is 3.7 years. Patients with clinically N0 necks were found to have positive nodes in eight (19%) cases. Two cases of postoperative hemorrhage were controlled by electrocautery. All of the patients without previous treatment for larynx cancer regained swallowing function within five days to three weeks after surgery. Mean duration of hospitalization was 12.5 days.

CONCLUSION: Endoscopic partial laryngectomies, as defined by the ELS classification, for selected supraglottic squamous cell carcinoma proved to be an excellent alternative to radiotherapy and open neck surgery.

Current State of Scanning Micromanipulator Applications with the Carbon Dioxide Laser

Objectives:

The development of the scanning system AcuBlade has considerably enhanced carbon dioxide laser energy delivery, improving cutting and ablation modes. The scanning system can be applied with the 2 available high-powered pulsed waves, SuperPulse and UltraPulse. This study was conducted to determine whether there are any differences in phonosurgery between the SuperPulse and UltraPulse lasing applications with regard to thermal diffusion into the surrounding tissues, healing time, and clinical results.

Methods:

Thirteen patients with bilateral and similar vocal fold lesions underwent operation — One side in SuperPulse mode and the other side in UltraPulse mode. The parameters for phonosurgery were depth of 0.2 mm, 10 W, single pulse, and 0.10 second for SuperPulse, and 2 passes, 10 W, single pulse, and 0.10 second for UltraPulse.

Results:

Incisions were sharper with UltraPulse, making the surgery easier, but at the first postoperative follow-up visit, after 8 to 10 days, no differences were observed in the presentation, the healing, or the vibration of the 2 vocal folds. Coagulation along the incision line was 25 μm for SuperPulse and 15 μm for UltraPulse (median values).

Conclusions:

In comparison with SuperPulse, the UltraPulse carbon dioxide laser made the procedure easier, but did not improve the clinical outcome.

Defining phonosurgery: a proposal for classification and nomenclature by the Phonosurgery Committee of the European Laryngological Society (ELS)

The term phonosurgery (PS) refers to any operation designed primarily for the improvement or restoration of voice. It is defined by the intended operative goal, which pertains to quality of life rather than its preservation, and informed consent needs to account for this emphasis. Since the aim is improvement or maintenance of vocal function, it is essential to document voice accurately pre-operatively. As important as the surgery itself is a team approach to perioperative care and rehabilitation. Although not a new concept, the PS portfolio of operations continues to grow rapidly, making this one of the most dynamic field in Laryngology. However, this has also led to confusion regarding terminology and classification, with the result that it is presently difficult to compare results between institutions. The aim of this paper is to establish a practical classification system for PS and to thereby establish a common language for reporting results. We propose four groups of operation: vocal fold surgery (VFS), laryngeal framework surgery (LFS), neuromuscular surgery (NHS) and reconstructive surgery (RCS) (for either partial or total laryngeal replacement).

Proposal for revision of the European Laryngological Society classification of endoscopic cordectomies

A classification of laryngeal endoscopic cordectomies, which included eight different types, was first proposed by the European Laryngological Society in 2000. The purpose of this proposal of classification was an attempt to reach better consensus amongst clinicians and agree on uniformity in reporting the extent and depth of resection of cordectomy procedures, to allow relevant comparisons within the literature when presenting/publishing the results of surgery, and to recommend the use of guidelines to allow for reproducibility amongst practicing laryngologists. A total of 24 article citations of this classification have been found through the science citation index, as well as 3 book chapters on larynx cancer surgery, confirming its acceptance. However, on reflection, and with the passage of time, lesions originating at the anterior commissure have not been clearly described and, for that reason, a new endoscopic cordectomy (type VI) for cancers of the anterior commissure, which have extended or not to one or both of the vocal folds, without infiltration of the thyroid cartilage is now being proposed by the European Laryngological Society Committee on Nomenclature to revise and complete the initially reported classification.