Comparison of fiber delivered CO2 laser and electrocautery in transoral robot assisted tongue base surgery

A Double-Anonymised Histopathological Comparative Study of CO2 Laser and Coblation in Head and Neck Surgery

CO2 Laser and Coblation are widely used in Head and neck Surgeries. This study compares the tissue changes produced by these two techniques. 50 Patients who underwent complete excision of benign and malignant pathologies in the Oral Cavity, Oropharynx, and Larynx with Coblation and CO2 Laser were included in the study. The primary excised specimen and another separate specimen from the base of the excised lesion were evaluated histologically based on criteria by Vescovi et al. (1). On histopathological examination, thermal effects (epithelial, connective tissue and vascular) produced by both techniques were comparable. However vascular changes were seen more in tissues CO2 Laser (P = 0.727). Incision margins were more regular in the CO2 Laser group (73%) than in Coblation (55%) but not statistically significant (P = 1.80). Depth of thermal damage (P = 0.171) and connective tissue changes(P = 0.279) was more with Coblation. Both Coblation and CO2 Laser can be used effectively in Head and Neck cases. CO2 Laser, when available, is a better option because of its precise excision, and less collateral tissue damage.

Deep learning-assisted 3D laser steering using an optofluidic laser scanner

Laser ablation is an effective treatment modality. However, current laser scanners suffer from laser defocusing when scanning targets at different depths in a 3D surgical scene. This study proposes a deep learning-assisted 3D laser steering strategy for minimally invasive surgery that eliminates laser defocusing, increases working distance, and extends scanning range. An optofluidic laser scanner is developed to conduct 3D laser steering. The optofluidic laser scanner has no mechanical moving components, enabling miniature size, lightweight, and low driving voltage. A deep learning-based monocular depth estimation method provides real-time target depth estimation so that the focal length of the laser scanner can be adjusted for laser focusing. Simulations and experiments indicate that the proposed method can significantly increase the working distance and maintain laser focusing while performing 2D laser steering, demonstrating the potential for application in minimally invasive surgery.

Transoral robotic surgery - time for consensus on pain assessment. A review

BACKGROUND

In Head and Neck surgery Transoral Robotic Surgery (TORS) is evolving as a key treatment option for benign and malignant lesions in the oropharynx. Even so, postoperative pain is one of the primary early complaints following TORS. Well established evidence-based procedure specific pain treatment guidelines are available for a variety of other surgical specialties. However, there are no guidelines for TORS.

AIM

This review describes the available data of early pain intensity following TORS during rest and procedure related activity.

METHODS

Literature concerning pain in the immediate postoperative phase following TORS were obtained from two literature databases.

RESULTS

Most data on pain intensity following TORS are based upon a numeric rating scale, e.g. the Visual Analogue Scale and/or analgesic demands. Only one randomized clinical trial is available reflecting that the literature is mainly based on retrospective and a few prospective studies. Only one study analyzed pain during relevant functionality, i.e. swallowing. Overall, the studies suffer from a non-standardized approach and there is a need for transparent information concerning the timing of pain ratings and methodology.

CONCLUSIONS

The evidence for optimal pain control is limited, particularly during surgical relevant activity. Postoperative pain rating during activity is a fundamental element in pain trials in order to enhance recovery thereby calling for future consensus on assessment methodology.

Preclinical implementation of a steerable, Da Vinci Xi® compatible CO2 -laser fibre carrier for transoral robotic surgery (TORS): A cadaveric feasibility study

INTRODUCTION

Monopolar electrocautery is the most common dissection and coagulation tool during transoral robotic surgery (TORS) but causes significant collateral tissue damage as opposed to CO₂ laser. We aimed at combining both modalities in one robotic instrument arm.

METHODS

We developed a steerable CO₂ -laser fibre carrier serving as an add-on to the existing Endowrist® monopolar spatula of the Da Vinci Xi. Feasibility and safety were assessed in a preclinical setting.

RESULTS

One radical tonsillectomy with monopolar cautery and three with the instrument prototype were performed in two cadavers by two surgeons. No serious prototype-related intra-operative difficulties were observed. Safe and efficient switching between energy sources proved possible in all simulated intra-operative bleeding events. Prototype use allowed for the identification of the majority of key anatomical structures and was scored favourably on NASA-TLX questionnaires.

DISCUSSION

The reported prototype successfully combines the advantages of CO₂ -laser with the advantages of TORS.

Soft robotic manipulator for intraoperative MRI-guided transoral laser microsurgery

Magnetic resonance (MR) imaging (MRI) provides compelling features for the guidance of interventional procedures, including high-contrast soft tissue imaging, detailed visualization of physiological changes, and thermometry. Laser-based tumor ablation stands to benefit greatly from MRI guidance because 3D resection margins alongside thermal distributions can be evaluated in real time to protect critical structures while ensuring adequate resection margins. However, few studies have investigated the use of projection-based lasers like those for transoral laser microsurgery, potentially because dexterous laser steering is required at the ablation site, raising substantial challenges in the confined MRI bore and its strong magnetic field. Here, we propose an MR-safe soft robotic system for MRI-guided transoral laser microsurgery. Owing to its miniature size (Ø12 × 100 mm), inherent compliance, and five degrees of freedom, the soft robot ensures zero electromagnetic interference with MRI and enables safe and dexterous operation within the confined oral and pharyngeal cavities. The laser manipulator is rapidly fabricated with hybrid soft and hard structures and is powered by microvolume (<0.004 milliter) fluid flow to enable laser steering with enhanced stiffness and lowered hysteresis. A learning-based controller accommodates the inherent nonlinear robot actuation, which was validated with laser path-following tests. Submillimeter laser steering accuracy was demonstrated with a mean error < 0.20 mm. MRI compatibility testing demonstrated zero observable image artifacts during robot operation. Ex vivo tissue ablation and a cadaveric head-and-neck trial were carried out under MRI, where we employed MR thermometry to monitor the tissue ablation margin and thermal diffusion intraoperatively.

Flexible fiber-based CO2 laser vs monopolar cautery for resection of oral cavity lesions: A single center randomized controlled trial assessing pain and quality of life following surgery

IMPORTANCE

This study reports the impact of laser surgery on quality of life in patients with oral cavity lesions.

OBJECTIVE

To compare postoperative pain and quality of life in patients treated with flexible fiberoptic CO2 laser vs electrocautery in patients with oral cavity precancerous lesions and early stage cancers.

DESIGN

Randomized controlled trial.

SETTING

Single center.

PARTICIPANTS

Patients with premalignant oral cavity lesions and early stage oral cancer.

INTERVENTION

Patients were randomized to have surgical resection using either flexible fiber carbon dioxide laser (Laser) or electrocautery (EC). The patients were then followed over a period of 28 days to assess for outcomes including pain, quality of life, performance status, return to work, and return to diet. Quality of life was measured by the University of Washington Quality of Life (UWQOL) questionnaire and the performance status score (PSS).

MAIN OUTCOME MEASURE

The primary endpoint for this study was the numerical pain rating on postoperative day (POD) 7.

RESULTS

Sixty-two patients were randomized (32 laser and 30 electrocautery). Lesions excised were carcinoma in 30(48%), dysplasia in 31(50%) and benign in 1(2%). There was no difference in the location of lesion, size of lesion, defect size, type of closure, resection time, and blood loss between Laser and EC arms. Patients who had Laser had less pain compared to EC (mean pain score on POD 7 L = 2.84 vs EC = 3.83, P = 0.11). better UW QOL scores and PSS scores, quicker return to normal diet (median days L = 26.0 vs EC = 28.5, P = 0.17) and faster return to work (median days L = 13.0 vs EC = 16.5, P = 0.14). However, these results were not statistically significant.

CONCLUSION

There was a trend for patients treated with laser to have less pain and better quality of life scores but these result were not statistically significant. Based on the actual observed difference, a large multicenter RCT with 90 patients in each arm is required to determine the clinical relevance of our results.

Surgical, clinical, and functional outcomes of transoral robotic surgery used in sleep surgery for obstructive sleep apnea syndrome: A systematic review and meta-analysis

We investigated safety and efficacy of transoral robotic surgery (TORS) for base of tongue (BOT) reduction in obstructive sleep apnea syndrome (OSAS) patients. PubMed, Cochrane Library, and Scopus were searched. A meta-analysis was performed. Random effects models were used. Thirty-one cohorts met our criteria (1693 patients). The analysis was based mostly on retrospective studies. The summary estimate of the reduction of Apnea-Hypoxia Index (AHI) was 24.25 abnormal events per hour (95% CI: 21.69-26.81) and reduction of Epworth Sleepiness Scale (ESS) was 7.92 (95% CI: 6.50-9.34). The summary estimate of increase in lowest O₂ saturation was 6.04% (95% CI: 3.05-9.03). The success rate of TORS BOT reduction, either alone or combined with other procedures, was 69% (95% CI: 64-79). The majority of studies reported low level of evidence but suggested that TORS BOT reduction may be a safe procedure associated with improvement of AHI, ESS, and lowest O₂ saturation.

Microrobotic laser steering for minimally invasive surgery

The creation of multiarticulated mechanisms for use with minimally invasive surgical tools is difficult because of fabrication, assembly, and actuation challenges on the millimeter scale of these devices. Nevertheless, such mechanisms are desirable for granting surgeons greater precision and dexterity to manipulate and visualize tissue at the surgical site. Here, we describe the construction of a complex optoelectromechanical device that can be integrated with existing surgical tools to control the position of a fiber-delivered laser. By using modular assembly and a laminate fabrication method, we are able to create a smaller and higher-bandwidth device than the current state of the art while achieving a range of motion similar to existing tools. The device we present is 6 millimeters in diameter and 16 millimeters in length and is capable of focusing and steering a fiber-delivered laser beam at high speed (1.2-kilohertz bandwidth) over a large range (over ±10 degrees in both of two axes) with excellent static repeatability (200 micrometers).

Comparison of transoral robotic surgery with other surgeries for obstructive sleep apnea

This study compared the characteristic surgical parameters and clinical effects of transoral robotic surgery (TORS) and other available methods used to alleviate obstructive sleep apnea. Articles on TORS and other surgeries for obstructive sleep apnea were identified in the PubMed and EMBASE databases. Two investigators independently reviewed the articles and classified the data for meta-analysis. The pooled effect sizes of TORS (standardized mean difference; SMD = − 2.38), coblation tongue base resection (CTBR; SMD = − 2.00) and upper airway stimulation (UAS; SMD = − 0.94) revealed significant improvement in the apnea–hypopnea index (AHI; p < 0.05). The lowest O₂ saturation reported was significantly increased following TORS (SMD = 1.43), CTBR (SMD = 0.86) and UAS (SMD = 1.24, p < 0.05). Furthermore, TORS (SMD = − 2.91) and CTBR (SMD = − 1.51, p < 0.05) significantly reduced the Epworth Sleepiness Scale (ESS) score. No significant difference in operation time, success rate, or instances of complication were observed between TORS and the other compared interventions. The use of TORS in obstructive sleep apnea has the same rate of success and failure as other methods of surgical intervention for obstructive sleep apnea with no statistical difference in operation times. The reported clinical effects on the AHI, lowest O₂ saturation, and ESS scores of TORS were similar to those of other surgeries.

Novel Energy Devices in Head and Neck Robotic Surgery - A Narrative Review

The advent of trans-oral robotic surgery (TORS) has facilitated removal of tumors previously deemed unresectable, by providing access to the deep structures of the head and neck. Despite this, the wider dissemination of TORS has been restricted due to issues with line of access, as the da Vinci robot was never designed with head and neck surgery in mind. Flexible instruments and novel energy delivery devices offer great potential in overcoming some of the existing challenges surrounding TORS. This review aimed to summarize the existing literature surrounding energy delivery in TORS and highlight areas of future innovation. MEDLINE was searched for studies relating to energy delivery in TORS in November 2019. The existing literature surrounding monopolar and bipolar electrocautery, LASER (CO₂, Tm:YAG and blue LASER), Ligasure and Harmonic was reviewed. Additionally, the latest iteration of the da Vinci; the SP, and the FLEX robot were evaluated as novel methods of energy delivery in TORS. Overall, these novel energy devices and robotic systems are predicted to further improve energy delivery to the head and neck. The use of flexible LASER in particular is well substantiated in the literature. This has the potential to achieve treatment de-escalation, based on the excellent outcomes demonstrated for disease-free margins and post-operative morbidity.

Transoral Robot-Assisted Surgery in Supraglottic and Oropharyngeal Squamous Cell Carcinoma: Laser Versus Monopolar Electrocautery

BACKGROUND

Monopolar electrocautery (EC) is the surgical cutting and haemostatic tool most commonly used for transoral robotic surgery (TORS). The aim of this study was to retrospectively compare EC efficacy in the treatment of patients affected by T1 or T2 oropharyngeal and supraglottic squamous cell carcinomas with the more recently introduced laser fibres.

METHODS

We considered all TORS patients admitted to our department from January 2010 to June 2019. The outcomes of patients treated with Thulium: yttrium aluminium garnet (YAG) laser (TY-TORS), CO₂ laser (CO₂-TORS) and EC (EC-TORS) were analysed in order to assess surgical performances, functional outcomes and postoperative complications.

RESULTS

Twenty patients satisfied the enrolling criteria, of which nine underwent laser-TORS, and the remaining 11 underwent EC-TORS. In all candidates, TORS procedures were completed without the need for microscopic/open conversion. Close or positive margins were significantly more frequent in EC-TORS (p = 0.028). A considerable difference was found in overall functional parameters: times of nasogastric tube and tracheostomy removal and time of hospital discharge were significantly shorter in laser-TORS (p = 0.04, p = 0.05, p = 0.04, respectively).

CONCLUSIONS

Laser-TORS showed better results in comparison with EC-TORS in term of tumour resection margins and patient functional outcomes. Our findings can be justified with the greater tissue thermal damage caused by EC-TORS, despite prospective randomized trials and increased patient numbers being needed to confirm these preliminary conclusions.

Transoral 980-nm/1470-nm dual-wavelength fiber laser microsurgery for early-stage glottic carcinoma

OBJECTIVES

To investigate the effective and safety of transoral 980-nm/1470-nm dual-wavelength fiber laser microsurgery for early-stage glottic carcinoma by compared with CO2 laser surgery.

MATERIALS AND METHODS

From September 2015 to July 2018, 44 patients with early glottic carcinoma underwent transoral microsurgery were divided into 980-nm/1470-nm dual-wavelength fiber laser surgery (Dual-wavelength fiber laser group) and CO2 laser surgery (CO2 laser group). The operative time, number of other hemostatic devices used, postoperative blood loss, surgical complications and postoperative length of hospital stay The time of mucosal epithelialization and Voice Handicap Index-10(VHI-10) in pre-operation, 1-month postoperation and 6-month postoperation in both two groupswere retrospectively analyzed.

RESULTS

All the patients underwent successful operation and all the tumors received en-bloc resection with negative margins. The median operative time in Dual-wavelength laser group was faster than CO₂ laser group (32.00 min vs 37.50 min, p = 0.014). There was no statistically significant difference between the two groups in the median postoperative hospital stay and the median time of mucosal epithelialization. No patient need feeding tubes place temporarily or permanently in both two groups. Tongue numbness, tear of the palatal arch, postoperative vocal cord adhesion, VHI-10 score in Pre-operation, 1-month postoperation and 6-month postoperation were similar in both two group. No recurrence was reported in both groups during follow-up.

CONCLUSION

Compared to the CO₂ laser surgery, transoral 980-nm/1470-nm dual-wavelength fiber laser microsurgery is a safe and feasible procedure for early-stage glottic carcinoma. It can provide clearer surgical field without hemorrhage and make the operation simpler, smoother and faster.

Open partial horizontal laryngectomy using CO2 fiber laser

BACKGROUND

The application of CO₂ fiber laser technology to ENT surgery has led to new interesting scenarios, both in endoscopic and in open surgical approaches.

METHODS

The current video shows three examples of open partial horizontal laryngectomies (OPHLs) performed using CO₂ fiber laser for resection procedures.

RESULTS

CO₂ fiber laser helped the surgeon in improving the accuracy of resection and the quality of surgical margins on specimen. The low thermal damage on tissues resulted in minor postoperative edema and a fast recovery of laryngeal function.

CONCLUSIONS

In our experience, the application of CO₂ fiber laser showed some very useful features for performing OPHLs: a high cutting precision with very low tissue damage, the possibility of delivering energy without touching the organ, a modulable power for the various surgical steps, a very good maneuverability of the fine fiber holder during the procedure allowing the surgeon to "draw" the resection with a great accuracy.