Endoscopic treatment of subglottic stenosis with flexible bronchoscopy via laryngeal mask airway.

OBJECTIVE: To evaluate the safety and efficacy of endoscopic treatment of subglottic stenosis with flexible bronchoscopy via laryngeal mask airway (LMA) approach. METHODS: The records of all patients who underwent endoscopic surgery for subglottic stenosis (SGS) from November 2019 to January 2023 at an academic medical center were reviewed with attention to demographics, patient comorbidities, airway stenosis characteristics, operative time details, surgical complications, and post-operative course. All patients, >18 years old, with one or more surgeries for SGS using (LMA) for intraoperative airway management were included. Surgeries with suspension microlaryngoscopy were excluded. Patients with glottic stenosis or tracheotomy were excluded. RESULTS: Thirty-five patients underwent 52 procedures meeting inclusion criteria. Mean age was 55 years (range 31-78, SD 13.3) and 33 patients (94%) were female. Mean BMI was 30.9 (range 18.4-60.5, SD 8.8). The most common etiology of stenosis was intubation injury in 17 patients (49%), followed by idiopathic in 13 patients (37%). Cotton-Meyer grade 3 (71-99% narrowing) was seen in 25 patients (71%). Mean anesthesia and surgical operative times were 75.9 min (SD 13.5 min) and 39.7 min (SD 11.0 min), respectively. Mean SpO2 nadir was 94.5% (SD 6.3%). No patients required intraoperative change to rigid laryngoscopy, intubation, or tracheotomy. There were no post-operative complications. Mean surgery-free interval was 12.2 months (SD 6.3). CONCLUSION: Endoscopic treatment of subglottic stenosis with flexible bronchoscopy and spontaneous ventilation via LMA approach is a safe and effective option, especially in patients with limitations for rigid laryngoscopy and elevated BMI. LEVEL OF EVIDENCE: Level Four (case series) Laryngoscope, 2023.

Reproducibility of laryngeal force sensor measurements.

OBJECTIVE: The laryngeal force sensor (LFS) measures force during suspension microlaryngoscopy (SML) procedures, and has been previously shown to predict postoperative complications. Reproducibility of its measurements has not been described. STUDY DESIGN: Prospective cohort study. SETTING: Academic medical center. METHODS: 291 adult patients had force data collected from 2017 to 2021 during various SML procedures. 94 patients had passive LFS monitoring (surgeon blinded to intraoperative recordings) and 197 had active LFS monitoring (surgeon able to see LFS recordings). 27 of these patients had repeat procedures, with unique LFS metrics for each procedure. The 27 patients were divided into three groups. Group 1 had passive use for both procedures, group 2 had passive use for the first procedure and active use for the second, and group 3 had active use for both procedures. Force metrics from the two procedures were compared with a paired samples t-test. RESULTS: For airway dilation procedures and cancer resection procedures, average force variances were significantly lower with active versus passive use of the LFS. Group 1-no significant changes in maximum force (procedure 1 = 163.8 N, procedure 2 = 133.8 N, p = 0.324) or average force (procedure 1 = 93.6 N, procedure 2 = 78.3 N, p = 0.617). Group 2-maximum force dropped by 35 % between procedures 1 (219.2 N) and 2 (142.5 N), p = 0.013. Average force dropped by 42.5 % between procedures 1 (147.2 N) and 2 (84.6 N), p = 0.007. Group 3-no significant changes in maximum force (procedure 1 = 158.6 N, procedure 2 = 158.2 N, p = 0.986) or average force (procedure 1 = 94.2, procedure 2 = 81.8, p = 0.419). CONCLUSIONS: LFS measurements were reproducible for similar procedures in the same patient when the type of LFS monitoring was not a confounder.

Informed consent for suspension microlaryngoscopy: what should we tell the patient? A consensus statement of the European Laryngological Society.

INTRODUCTION: Informed consent for any surgical intervention is necessary, as only well-informed patients can actively participate in the decision-making process about their care, and better understand the likely or potential outcomes of their treatment. No consensus exists on informed consent for suspension microlaryngoscopy (SML). MATERIALS AND METHODS: Informed consent procedures in nine countries on five continents were studied. RESULTS: Several risks can be discerned: risks of SML as procedure, anesthesiologic risks of SML, specific risks of phonosurgery, risks of inadequate glottic exposure or unexpected findings, risks of not treating. SML has recognized potential complications, that can be divided in temporary (minor) complications, and lasting (major) complications. CONCLUSION: SML is a safe procedure with low morbidity, and virtually no mortality. Eleven recommendations are provided.

Anesthetic Management for Awake Tubeless Suspension Microlaryngoscopy.

OBJECTIVES/HYPOTHESIS: Patients' eligibility for bilateral selective laryngeal reinnervation surgery is evaluated by suspension microlaryngoscopy (SML) examination with laryngeal electromyography (LEMG). Maintaining spontaneous ventilation, with remifentanil sedation/analgesia without endotracheal tube, to allow the patient to phonate with the surgeon during awake, LEMG is a major challenge for the anesthesiologist and the otorhinololaryngologist. The objective of this study was to evaluate the safety and efficacy of a novel anesthesia protocol to manage airway access during awake tubeless SML. STUDY DESIGN: Retrospective study. METHODS: Anesthesia records of patients undergoing awake SML with LEMG were retrospectively analyzed. Procedures were performed with remifentanil sedation/analgesia with targeted controlled infusion (TCI) in combination with local anesthesia. The main outcome was the failure rate of the anesthesia protocol during the procedure. Secondary outcomes were as follows: rate of apnea requiring ventilation, airway bleeding, regurgitation, hemodynamic data as well as vasopressor use, complications, and surgeon satisfaction with the procedure. RESULTS: Data were obtained for 39 patients between November 2017 and September 2019, the mean age was 52 years and 29 (74%) were female. All procedures were completed without complications (0% [0-9]). Three patients (8% [1.6-20.8]) had an intraoperative episode of hypoxemia requiring mask reventilation. There was no airway bleeding, no regurgitation, and no hypotensive episode. Three patients (8% [1.6-20.8]) had noninvasive ventilation for respiratory distress after the end of the procedure. CONCLUSIONS: Our results show that awake tubeless SML allowing phonation during LEMG can be realized under sedation and local anesthesia. However, further data are needed concerning the intraoperative and postoperative safety of the procedure. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E2669-E2675, 2021.

Laryngeal Force Sensor for Suspension Microlaryngoscopy: A Prospective Controlled Trial.

OBJECTIVES: The laryngeal force sensor (LFS) provides real-time force data for suspension microlaryngoscopy. This study investigates whether active use of the LFS can prevent the development of complications. STUDY DESIGN: Prospective controlled trial. SETTING: Academic tertiary center. METHODS: The LFS and custom software were developed to track intraoperative force metrics. A consecutive series of 100 patients had force data collected with operating surgeons blinded to intraoperative readings. The subsequent 100 patients had surgeons actively use the LFS monitoring system. Patients were prospectively enrolled, completing pre- and postoperative surveys to assess the development of tongue pain, paresthesia, paresis, dysgeusia, or dysphagia. RESULTS: On univariate analysis, the active monitoring group had lower total impulse (P < .001) and fewer extralaryngeal complications (P < .01). On multiple logistic regression, maximum force (odds ratio [OR], 1.08; 95% CI, 1.01-1.16; P = .02) was a significant predictive variable for the development of postoperative complications. Similarly, active LFS monitoring showed a 29.1% (95% CI, 15.7%-42.4%; P < .001) decrease in the likelihood of developing postoperative complications. These effects persisted at the first postoperative visit for maximum force (P = .04) and active LFS monitoring (P = .01). Maximum force (OR, 1.11; 95% CI, 1.04-1.18; P < .01) and active LFS monitoring (16.6%; 95% CI, 2.7%-30.5%; P = .02) were also predictive for the development of an abnormal 10-item Eating Assessment Tool score. These effects also persisted at the first postoperative visit for maximum force (P = .01) and active LFS monitoring (P = .01). CONCLUSION: Maximum force is predictive of the development postoperative complications. Active monitoring with the LFS is able to mitigate these forces and prevent postoperative complications. LEVEL OF EVIDENCE: 2.

Tongue Edema Secondary to Suspension Laryngoscopy.

OBJECTIVES: Suspension microlaryngoscopy (SML) is generally a safe, same-day procedure. Complications have been linked to prolonged operative time and substantial force applied to the tongue. This report of two cases describes marked tongue edema following SML, a complication not yet reported in the literature. METHODS: This is a retrospective review of two cases of severe tongue edema following SML. We reviewed the literature for similar reports and proposed treatment plans. RESULTS: Two patients, age 67 and 75, underwent SML for an interval of 247 minutes and 224 minutes for patient 1 and patient 2 respectively. Both developed severe tongue edema requiring inpatient monitoring and steroids. In both patients, the edema improved over several days and returned to baseline. There are no reported cases of this complication in the literature. CONCLUSION: Prolonged SML can lead to tongue edema requiring close airway monitoring. The edema was self-limited and resolved with steroids and close monitoring.

Force Metrics and Suspension Times for Microlaryngoscopy Procedures.

OBJECTIVE: To determine the difference in force metrics measured by the laryngeal force sensor for various suspension microlaryngoscopy (SML) procedures and their perioperative narcotic requirements. STUDY DESIGN: Prospective observational study. SETTING: Academic tertiary center. METHODS: The laryngeal force sensoris a force sensor designed for SML procedures. Prospectively enrolled patients had dynamic recordings of maximum force, average force, suspension time, and total impulse. Procedures were grouped into excision of striking zone lesions, nonstriking zone lesions, endoscopic cancer surgery with margin control, and airway dilation. Narcotic administration in the intraoperative period and postanesthesia care unit was also recorded and converted into IV morphine equivalents. Surgeons were blinded to the force recordings during surgery to prevent operator bias. RESULTS: In total, 110 patients completed the study. There was no significant difference in average force across different procedures, however, a significant difference was seen for maximum force (P = 0.025), suspension time (P < 0.001), and total impulse (P = 0.002). The highest values were seen for endoscopic cancer surgeries with margin control with a mean maximum force of 49.4 lbf (95%CI, 37.1-61.7), mean suspension time of 60.2 minutes (95%CI, 40.5-79.9), and mean total impulse of 31.3 ton*s (95%CI, 15.2-47.3). A significant difference (P < 0.01) in perioperative narcotic requirements was also seen, with endoscopic cancer surgery cases having the highest requirements at 27.6 mg of ME (95%CI, 16.1-39.2 mg). CONCLUSION: Significant differences in force metrics exist between various SML procedures. Endoscopic cancer surgery is associated with higher force metrics and perioperative narcotic requirements.

Tongue symptoms, suspension force and duration during operative laryngoscopy.

PURPOSE: Suspension laryngoscopy is a commonly performed procedure in otolaryngology. During the procedure, the laryngoscope applies direct force to the tongue. Postoperative tongue symptoms include pain, swelling, numbness, taste disturbance, and rarely motor deficits. Duration and magnitude of force applied have previously been associated with post-operative throat and tongue pain, respectively. We sought to correlate postoperative tongue symptoms with magnitude of force applied and/or duration of suspension and investigate any risk factors for tongue morbidity. MATERIALS AND METHODS: A sample of patients undergoing suspension laryngoscopy between 2015 and 2018 were prospectively recruited. Those with preexisting tongue symptoms, disease or surgery were excluded. Patients completed preoperative and postoperative questionnaires evaluating tongue swelling, numbness, motion and taste disturbance. Symptoms were subjectively scored on a visual scale from 0 to 10. Patient demographics, past medical and social history were also recorded. Intraoperative pressures were measured using a spring force scale, positioned between the suspension arm and Mayo stand. Initial and end suspension forces and duration of suspension were recorded. RESULTS: 120 patients met inclusion criteria, of which 63 completed both preoperative and postoperative questionnaires. 6 patients (9.5%) experienced postoperative tongue symptoms. Suspension force and duration of suspension were not significantly predictive of postoperative tongue symptoms. While all symptomatic patients were current or former cigarette smokers, smoking status was not found to be a statistically significant factor. CONCLUSIONS: Neither suspension forces nor duration of suspension were predictive of postoperative tongue morbidity. Further research is needed to evaluate the role of smoking status on postoperative tongue symptoms.

Consistent Technique Limits Suspension Laryngoscopy Complications

Abstract Introduction Suspension laryngoscopy (SL) is a commonly performed procedure among otolaryngologists. Several studies have shown that adverse effects occur regularly with SL. Objective To evaluate the postoperative complications of SL, and to determine if protecting the dentition and the oral mucosa and limiting suspension times decrease the overall incidence of oral cavity and pharyngeal complications of SL. Methods All of the cases of SL performed by 1 surgeon from November 2008 through September 2014 were retrospectively reviewed. A consistent technique for dental and mucosal protection was utilized, and suspension times were strictly limited to 30 consecutiveminutes. The incidence of postoperative complications was calculated and analyzed with respect to gender, smoking status, dentition, laryngoscope type, and suspension system. Results A total of 213 consecutive SL cases were reviewed, including 174 patients (94 male, 80 female). The overall postoperative complication rate was of 3.8%. Four patients experienced tongue-related complications, two experienced oral mucosal alterations, one had a dental injury, and one experienced a minor facial burn. The complication incidence was greater with the Zeitels system(12.5%) compared with the Lewy suspension system (3.3%), although it was not significant (p = 0.4). Likewise, the association of complications with other patient factors was not statistically significant. Conclusion Only 8 out of 213 cases in the present series experienced complications, which is significantly less than the complication rates observed in other reports. Consistent and conscientious protection of the dentition and of the oral mucosa and limiting suspension times to 30 minutes are factors unique to our series that appear to reduce complications in endolaryngeal surgery.

Consistent Technique Limits Suspension Laryngoscopy Complications.

Introduction Suspension laryngoscopy (SL) is a commonly performed procedure among otolaryngologists. Several studies have shown that adverse effects occur regularly with SL. Objective To evaluate the postoperative complications of SL, and to determine if protecting the dentition and the oral mucosa and limiting suspension times decrease the overall incidence of oral cavity and pharyngeal complications of SL. Methods All of the cases of SL performed by 1 surgeon from November 2008 through September 2014 were retrospectively reviewed. A consistent technique for dental and mucosal protection was utilized, and suspension times were strictly limited to 30 consecutive minutes. The incidence of postoperative complications was calculated and analyzed with respect to gender, smoking status, dentition, laryngoscope type, and suspension system. Results A total of 213 consecutive SL cases were reviewed, including 174 patients (94 male, 80 female). The overall postoperative complication rate was of 3.8%. Four patients experienced tongue-related complications, two experienced oral mucosal alterations, one had a dental injury, and one experienced a minor facial burn. The complication incidence was greater with the Zeitels system (12.5%) compared with the Lewy suspension system (3.3%), although it was not significant ( p = 0.4). Likewise, the association of complications with other patient factors was not statistically significant. Conclusion Only 8 out of 213 cases in the present series experienced complications, which is significantly less than the complication rates observed in other reports. Consistent and conscientious protection of the dentition and of the oral mucosa and limiting suspension times to 30 minutes are factors unique to our series that appear to reduce complications in endolaryngeal surgery.

Management of Difficult Laryngeal Exposure During Suspension Microlaryngoscopy.

Difficult laryngeal exposure during suspension microlaryngoscopic surgeries is a common situation encountered by the phonosurgeons nowadays. It leads to unnecessary trauma, incomplete surgery and even abortion of the procedure. Although various methods have been described to counter the situation, they might not be adequate in some cases with very anteriorly placed larynx. This study is intended to determine the utility of angled rigid endoscope along with malleable endoscopic instruments to improve surgical access in cases with inadequate glottic exposure during suspension microlaryngoscopy. In this cross sectional study conducted at Lokmanya Tilak Municipal Medical College and General Hospital in Mumbai, 50 patients of voice disorders who underwent Suspension Microlaryngoscopy from July 2014 to December 2017 were included. Out of these patients, 5 patients (10%) presented with difficult laryngeal exposure that were operated using readily available angled rigid endoscope along with malleable endoscopic instruments, without requirement of any specially designed instruments. There was improvement in laryngeal exposure in all the cases following utilisation of angled endoscopes. The surgeries were carried out under video monitor guidance with complete excision of the vocal cord lesions. Our study concluded that the cases in which the laryngeal exposure cannot be improved even by various external procedures, can be enhanced by application of angled rigid endoscopes and the vocal cord lesions can be excised completely by using malleable endoscopic instruments.

Laryngeal force sensor metrics are predictive of increased perioperative narcotic requirements.

OBJECTIVES/HYPOTHESIS: To determine the relationship between force metrics measured by the laryngeal force sensor (LFS) during suspension microlaryngoscopy (SML) and perioperative narcotic requirements. STUDY DESIGN: Prospective observational study. METHODS: Compressive tissue forces were recorded during SML using the LFS and correlated with postoperative narcotic requirements in the postanesthesia care unit (PACU) at an academic tertiary center. Patients were prospectively enrolled and had force metrics recorded throughout each procedure including maximum force, average force, suspension time, and total impulse. Narcotic administration in the intraoperative period and PACU were also recorded and converted into intravenous morphine equivalents (ME). Surgeons were blinded to the force recordings during surgery to prevent operator bias. RESULTS: Eighty-two patients completed the study. Of these patients, the mean perioperative ME requirement was 16.96 mg (range, 0.15-79.82 mg). Univariate analysis demonstrated a positive correlation between perioperative narcotic requirements and total suspension time (P < .001) as well as total impulse (P = .007). A positive correlation was also seen with maximum force, although not significantly. On multiple linear regression, total suspension time was a significant predictive variable for perioperative narcotic use, with a marginal incremental increase of 0.273 mg of ME per minute of total suspension time (0.273 mg/min, 95% confidence interval: 0.040-0.507 mg/min, P = .022). CONCLUSIONS: Intraoperative force metrics including total suspension time are predictive of increased perioperative narcotic requirement after SML. Total impulse during SML may also correlate with increased perioperative narcotic requirements. LEVEL OF EVIDENCE: 2 Laryngoscope, 129:2563-2567, 2019.

Laryngeal Force Sensor: Quantifying Extralaryngeal Complications after Suspension Microlaryngoscopy.

Objectives To develop a novel sensor capable of dynamically analyzing the force exerted during suspension microlaryngoscopy and to examine the relationship between force and postoperative tongue complications. Study Design Prospective observational study. Setting Academic tertiary care center. Methods The laryngeal force sensor is a designed for use during microphonosurgery. Prospectively enrolled patients completed pre- and postoperative surveys to assess the development of tongue-related symptoms (dysgeusia, pain, paresthesia, and paresis) or dysphagia (10-item Eating Assessment Tool [EAT-10]). To prevent operator bias, surgeons were blinded to the force recordings during surgery. Results Fifty-six patients completed the study. Of these, 20 (36%) developed postoperative tongue symptoms, and 12 (21%) had abnormal EAT-10 scores. The mean maximum force across all procedures was 164.7 N (95% CI, 141.0-188.4; range, 48.5-402.6), while the mean suspension time was 34.3 minutes (95% CI, 27.4-41.2; range, 7.1-108.1). Multiple logistic regression showed maximum force (odds ratio, 1.15; 95% CI, 1.02-1.29; P = .019) and female sex (30.1%; 95% CI, 22.7%-37.5%; P < .001) as significant predictors for the development of tongue-related symptoms. The only significant predictor of an abnormal postoperative EAT-10 score was an increased maximum force (odds ratio, 1.03; 95% CI, 1.00-1.06; P = .045). Conclusions The laryngeal force sensor is capable of providing dynamic force measurements throughout suspension microlaryngoscopy. An increase in maximum force during surgery may be a significant predictor for the development of tongue-related symptoms and an abnormal EAT-10 score. Female patients may also be at greater risk for developing postoperative tongue symptoms.

Quantitative Evaluation of Adult Subglottic Stenosis Using Intraoperative Long-range Optical Coherence Tomography.

OBJECTIVES: To determine the feasibility of long-range optical coherence tomography (LR-OCT) as a tool to intraoperatively image and measure the subglottis and trachea during suspension microlaryngoscopy before and after endoscopic treatment of subglottic stenosis (SGS). METHODS: Long-range optical coherence tomography of the adult subglottis and trachea was performed during suspension microlaryngoscopy before and after endoscopic treatment for SGS. The anteroposterior and transverse diameters, cross-sectional area (CSA), distance from the vocal cords, and length of the SGS were measured using a MATLAB software. Pre-intervention and postintervention airway dimensions were compared. Three-dimensional volumetric airway reconstructions were generated using medical image processing software (MIMICS). RESULTS: Intraoperative LR-OCT imaging was performed in 3 patients undergoing endoscopic management of SGS. Statistically significant differences in mean anteroposterior diameter (P < .01), transverse diameter (P < .001), and CSA (P < .001) were noted between pre-intervention and postintervention data. Three-dimensional airway models were viewed in cross-sectional format and via virtual "fly through" bronchoscopy. CONCLUSIONS: This is the first report of intraoperative LR-OCT of the subglottic and tracheal airway before and after surgical management of SGS in humans. Long-range optical coherence tomography offers a practical means to measure the dimensions of SGS and acquire objective data on the response to endoscopic treatment of SGS.

Pingyangmycin Local Injection Under Suspension Microlaryngoscopy for Hemangioma at Laryngopharyngeal and Laryngeal in 22 Cases / 医药导报

Objective To study the therapeutic effect of pingyangmycin local injection under suspension microlaryngoscopy for treatment of laryngopharyngeal and laryngeal hemangioma. Methods The total of 44 cases of patients with laryngopharyngeal or laryngeal hemangioma were randomly divided into the experimental group ( n=22 ) and the control group (n=22). They were treated with bleomycin 5 mg or pingyangmycin 4-8 mg injection under suspension microlaryngoscopy in the hemangioma, respectively. If the treatments were not curative, repeated one more times in intermittent 15 d, but not more than 3 times. Therapeutic effect and adverse effect were recorded and analyzed. Results The total effective rate (95. 4%)in the experimental group was significantly better than that (59. 1%) in the control group (P<0. 05),and side reaction in two groups showed no significant variation. Conclusion Pingyangmycin local injection for treating laryngopharyngeal and laryngeal hemangioma is effective, less adverse reaction.

Effect of mandibular tori on glottic exposure during simulated suspension microlaryngoscopy.

OBJECTIVES: Mandibular tori have been identified as a contributing factor in difficult exposure during intubation. However, no investigation has measured the effect of mandibular tori on glottic exposure during suspension microlaryngoscopy (SML). The objective of this study was to measure how the size and location of mandibular tori affect glottic exposure during simulated SML at different thyromental distances. METHODS: Suspension microlaryngoscopy was modeled on an anatomically accurate skull and larynx with thyromental distances between 6 and 12 cm. Mandibular tori were simulated by protruding screws 5 to 15 mm from the lingual aspect of the mandible. The tori were positioned either 15 mm (anterior) or 25 mm (posterior) from the midline of the symphysis. The glottic exposure for the various-size tori in each location was measured by recording the displacement of the glottiscope tip relative to the most anterior exposure achievable without tori. The glottiscope angle relative to the horizontal plane was measured for each condition. RESULTS: Mandibular tori of more than 10 mm had a significant impact on glottic exposure. Displacement of the glottiscope tip ranged from 2 to 9 mm for anteriorly placed tori and from 7 to 29 mm for posteriorly placed tori, with larger tori causing greater displacement. Increasing the thyromental distance increased the posterior glottiscope tip displacement regardless of torus size or location. The glottiscope angle increased with larger tori (12º to 28º), but this angle did not change with increasing thyromental distance. CONCLUSIONS: Larger size and more-posterior location of mandibular tori more significantly reduce glottic exposure during SML. The inner table of the mandible is the most relevant anatomic constraint on glottic exposure, which varies with the presence or absence of mandibular tori independent of thyromental distance.