Objective Measures of Stroboscopy and High-Speed Video.

Transient voice change associated with endotracheal intubation has generally been attributed to vocal fold trauma. To assess the role of altered vocal fold function in transient voice change, a study was designed to evaluate the audioacoustic, endoscopic, and laryngostroboscopic characteristics of the postintubation voice. Vocal function of 10 patients undergoing short-term outpatient surgical procedures using general anesthesia and endotracheal intubation were studied preoperatively and postoperatively. A second group of 10 patients that did not have surgery or general anesthesia was used as an age-matched control. Fundamental frequency, frequency perturbation, electroglottography, endoscopy (including laryngeal stroboscopy), and subjective speech analysis by experienced listeners were used to assess vocal function. No consistent differences in fundamental frequency were observed, although patient-to-patient variation was marked. Statistically significant increases in cycle-to-cycle fundamental frequency variation (jitter) were found postoperatively in the majority of the postintubation patients (P less than 0.05). Electroglottography, laryngeal endoscopy, and stroboscopic laryngoscopy did not demonstrate consistent changes in glottic mucosal function. Listener judgments characterized the postintubation voice change by decreased intensity, increased roughness, and lowered affect without consistent changes in pitch. The perception of decreased affect in the voices (characterized by reduction in pitch variation, vocal stress, and increases in pause times) was a strong perceptual marker for change in the post-intubation voice. Objective measures of laryngeal function suggest that the glottic contribution to postintubation voice change is minimal and that this dysphonia is probably multifactorial.

A patient undergoing a radical cystectomy for bladder cancer developed an acute, postopera tive bilateral vocal cord paralysis. This was due to a preexisting, unrecognized right vocal cord paralysis from bulbar polio and a new left vocal cord paralysis from intraoperative injury to the left recurrent laryngeal nerve. This case illustrates the need to evaluate laryngeal function in postbulbar polio patients. Case Report A 72-yr-old man with bladder cancer was admitted for radical cystectomy. He had a history of bulbar polio (no current symptoms) diagnosed in 1951, hypothyroidism, and glaucoma. Physical examination revealed a healthy appearing elderly man with a Mallampati Class 3 airway. An epidural catheter was inserted through the L1-2 interspace, and T6 sensory level was achieved after an injection of 15 mL of 2% lidocaine. General anesthesia was induced with 100 micro g fentanyl and 250 mg thiopental intravenously (IV). Tracheal intubation was facilitated by the administration of succinylcholine IV. During laryngoscopy with a Miller 3 blade, the vocal cords were visualized without difficulty, and an 8.0 endotracheal tube was placed in the trachea. Anesthesia was maintained with 50% oxygen, isoflurane, and epidural lidocaine. The 6-h surgical procedure finished with normal hemodynamic and arterial blood gas data. The patient received 2 units of packed red blood cells, 500 mL of 5% albumin, and 7.5 L of crystalloid. Hydromorphone (0.6 mg) was inserted epidurally for postoperative analgesia. Before tracheal extubation at the end of the case, the respiratory rate was 18 breaths/min, negative inspiratory pressure equaled 35 cm H2 0, and hemoglobin oxygen saturation was 100% (fraction of inspired oxygen 0.4). The patient responded appropriately to verbal commands, including raising his head for 5 s. Because of significant head edema, the endotracheal tube cuff was deflated to confirm that the patient could breathe easily around the endotracheal tube with the tube manually occluded. After tracheal extubation, cyanosis developed due to airway obstruction. Multiple attempts to reintubate the trachea, including laryngoscopy and awake oral and nasal fiberoptic intubation, were unsuccessful because of airway edema. The patient did not receive a neuromuscular blocking drug and normal SpO2 could only be maintained with hand bag positive pressure ventilation via a face mask. The otolaryngology service performed a tracheostomy, through which the patient breathed spontaneously without difficulty. Bronchoscopy was performed immediately after the tracheostomy and revealed significant laryngeal edema and bilateral vocal cord paralysis. Both vocal cords were in the paramedian position, resulting in a 3- to 4-mm glottic airway. Initially, this was attributed to acute bilateral recurrent laryngeal nerve injury from endotracheal intubation. One week postoperatively, the left vocal cord regained normal function and the voice returned to baseline. The final diagnosis was a preexisting right vocal cord paralysis from bulbar polio, with a new acute left vocal cord paralysis. The patient was discharged home without a tracheostomy on the 8th postoperative day. Right vocal cord function was not regained. Discussion Bronchoscopy confirmed that the airway obstruction in this patient was caused by bilateral vocal cord paralysis. Etiologies of vocal cord paralysis include lung cancer [1], central venous catheter insertion [2], trauma from an endotracheal tube [3,4] or a laryngeal mask airway, nasogastric tube placement [6], and thyroid surgery [7]. This patient had a preexisting, unrecognized right vocal cord paralysis from bulbar polio and a new intraoperative left vocal cord paralysis, probably resulting from endotracheal cuff injury to the anterior branch of the recurrent laryngeal nerve [the area vulnerable to neuropraxic injury is 6-10 mm below the posterior free edge of the vocal cord [8]]. Polio-related disease falls into one of three classes. The first, abortive poliomyelitis, is a nonspecific febrile illness without signs of central nervous system localization. A second group of patients additionally develop aseptic meningitis with rapid and complete recovery within a few days. A third subset of patients develops paralytic poliomyelitis. Of these patients, 6%-25% have bulbar disease. A minority of polio patients have progressive muscle weakness known as postpolio syndrome, which usually begins 20-30 years after the initial infection. Symptoms consistent with postpolio syndrome include new muscle weakness, atrophied limbs, and diminished physical endurance [9]. Clinical or subclinical involvement of the bulbar and respiratory musculature may lead to dysphagia, dysphonia, choking, aspiration, or sleep apnea. This patient did not report these symptoms. Laryngeal function in patients who have had polio has been studied. Driscoll et al. [10] reported nine patients who underwent a history and physical examination, acoustical voice analysis, and laryngeal videostroboscopic endoscopy. Three patients underwent laryngeal electromyographic evaluation. All nine patients demonstrated some degree of phonatory or laryngeal deficit. Four of the nine patients had evidence of unilateral vocal cord paralysis; however, these four patients had near normal acoustical voice measurements. This can be explained by compensatory adaptive changes during laryngeal closure in the opposing vocal cord and/or supraglottic structures. Postpolio patients may be at risk of laryngeal pathology. Careful preoperative history and physical examination are warranted, with particular attention to history of swallowing deficits, dysphonia, sleep apnea, and aspiration. However, because of the compensatory changes that may develop in patients with unilateral vocal cord paralysis, a thorough history and physical examination may be unrevealing. The anesthesiologist should be aware of the potential for pre-existing unilateral vocal cord paralysis in postpolio patients and should consider further evaluation (i.e., indirect laryngoscopy) in procedures with potential for additional paralysis.

A patient undergoing a radical cystectomy for bladder cancer developed an acute, postopera tive bilateral vocal cord paralysis. This was due to a preexisting, unrecognized right vocal cord paralysis from bulbar polio and a new left vocal cord paralysis from intraoperative injury to the left recurrent laryngeal nerve. This case illustrates the need to evaluate laryngeal function in postbulbar polio patients. Case Report A 72-yr-old man with bladder cancer was admitted for radical cystectomy. He had a history of bulbar polio (no current symptoms) diagnosed in 1951, hypothyroidism, and glaucoma. Physical examination revealed a healthy appearing elderly man with a Mallampati Class 3 airway. An epidural catheter was inserted through the L1-2 interspace, and T6 sensory level was achieved after an injection of 15 mL of 2% lidocaine. General anesthesia was induced with 100 micro g fentanyl and 250 mg thiopental intravenously (IV). Tracheal intubation was facilitated by the administration of succinylcholine IV. During laryngoscopy with a Miller 3 blade, the vocal cords were visualized without difficulty, and an 8.0 endotracheal tube was placed in the trachea. Anesthesia was maintained with 50% oxygen, isoflurane, and epidural lidocaine. The 6-h surgical procedure finished with normal hemodynamic and arterial blood gas data. The patient received 2 units of packed red blood cells, 500 mL of 5% albumin, and 7.5 L of crystalloid. Hydromorphone (0.6 mg) was inserted epidurally for postoperative analgesia. Before tracheal extubation at the end of the case, the respiratory rate was 18 breaths/min, negative inspiratory pressure equaled 35 cm H2 0, and hemoglobin oxygen saturation was 100% (fraction of inspired oxygen 0.4). The patient responded appropriately to verbal commands, including raising his head for 5 s. Because of significant head edema, the endotracheal tube cuff was deflated to confirm that the patient could breathe easily around the endotracheal tube with the tube manually occluded. After tracheal extubation, cyanosis developed due to airway obstruction. Multiple attempts to reintubate the trachea, including laryngoscopy and awake oral and nasal fiberoptic intubation, were unsuccessful because of airway edema. The patient did not receive a neuromuscular blocking drug and normal SpO2 could only be maintained with hand bag positive pressure ventilation via a face mask. The otolaryngology service performed a tracheostomy, through which the patient breathed spontaneously without difficulty. Bronchoscopy was performed immediately after the tracheostomy and revealed significant laryngeal edema and bilateral vocal cord paralysis. Both vocal cords were in the paramedian position, resulting in a 3- to 4-mm glottic airway. Initially, this was attributed to acute bilateral recurrent laryngeal nerve injury from endotracheal intubation. One week postoperatively, the left vocal cord regained normal function and the voice returned to baseline. The final diagnosis was a preexisting right vocal cord paralysis from bulbar polio, with a new acute left vocal cord paralysis. The patient was discharged home without a tracheostomy on the 8th postoperative day. Right vocal cord function was not regained. Discussion Bronchoscopy confirmed that the airway obstruction in this patient was caused by bilateral vocal cord paralysis. Etiologies of vocal cord paralysis include lung cancer [1], central venous catheter insertion [2], trauma from an endotracheal tube [3,4] or a laryngeal mask airway, nasogastric tube placement [6], and thyroid surgery [7]. This patient had a preexisting, unrecognized right vocal cord paralysis from bulbar polio and a new intraoperative left vocal cord paralysis, probably resulting from endotracheal cuff injury to the anterior branch of the recurrent laryngeal nerve [the area vulnerable to neuropraxic injury is 6-10 mm below the posterior free edge of the vocal cord [8]]. Polio-related disease falls into one of three classes. The first, abortive poliomyelitis, is a nonspecific febrile illness without signs of central nervous system localization. A second group of patients additionally develop aseptic meningitis with rapid and complete recovery within a few days. A third subset of patients develops paralytic poliomyelitis. Of these patients, 6%-25% have bulbar disease. A minority of polio patients have progressive muscle weakness known as postpolio syndrome, which usually begins 20-30 years after the initial infection. Symptoms consistent with postpolio syndrome include new muscle weakness, atrophied limbs, and diminished physical endurance [9]. Clinical or subclinical involvement of the bulbar and respiratory musculature may lead to dysphagia, dysphonia, choking, aspiration, or sleep apnea. This patient did not report these symptoms. Laryngeal function in patients who have had polio has been studied. Driscoll et al. [10] reported nine patients who underwent a history and physical examination, acoustical voice analysis, and laryngeal videostroboscopic endoscopy. Three patients underwent laryngeal electromyographic evaluation. All nine patients demonstrated some degree of phonatory or laryngeal deficit. Four of the nine patients had evidence of unilateral vocal cord paralysis; however, these four patients had near normal acoustical voice measurements. This can be explained by compensatory adaptive changes during laryngeal closure in the opposing vocal cord and/or supraglottic structures. Postpolio patients may be at risk of laryngeal pathology. Careful preoperative history and physical examination are warranted, with particular attention to history of swallowing deficits, dysphonia, sleep apnea, and aspiration. However, because of the compensatory changes that may develop in patients with unilateral vocal cord paralysis, a thorough history and physical examination may be unrevealing. The anesthesiologist should be aware of the potential for pre-existing unilateral vocal cord paralysis in postpolio patients and should consider further evaluation (i.e., indirect laryngoscopy) in procedures with potential for additional paralysis.

Flexible Fiber-Optic High-Speed Imaging of Vocal Fold Vibration: A Preliminary Report

After thyroid surgery, a change in voice from baseline is considered to be the most common complication. The presence or absence of recurrent laryngeal nerve (RLN) dysfunction does not solely predict functional voice outcome after thyroidectomy, as other mechanisms can affect vocal fold function. Nonetheless, when reading the pertinent literature, it becomes obvious that the true incidence of temporary and permanent vocal fold paralysis (VFP) after thyroid surgery is still unknown. The majority of previous studies that have examined the incidence of VFP have lacked adequate assessment of postoperative vocal fold function. The reason for this variance in practice is due to the lack of consensus from the surgical professional societies and the difference in the professional background and training of today’s thyroid surgeons. Such statistics about the true risk of RLN injury with subsequent temporary or permanent VFP rates are important in obtaining informed patient consent before proceeding with thyroidectomy. Pre- and postoperative assessment of vocal fold function for patients undergoing thyroid surgery may help to detect an existing preoperative RLN palsy or an early iatrogenic RLN injury. Knowing this information may help to develop an appropriate surgical plan preoperatively and intervene supportively in a patient who may have vocal fold motion impairment postoperatively. Herein, we discuss the technical considerations for voice assessment during thyroid surgery and the rationale for routine pre- and postoperative laryngeal assessment of the larynx.

You have accessPerspectives on Voice and Voice DisordersCE Questions1 Jul 2011SIG 3 Perspectives Vol. 21, No. 2, July 2011Earn 0.2 CEUs on This Issue Ruth Epstein, Angélique Remacle and Dominique Morsomme Ruth Epstein Google Scholar More articles by this author , Angélique Remacle Google Scholar More articles by this author and Dominique Morsomme Google Scholar More articles by this author https://doi.org/10.1044/vvd21.2.1-ce SectionsAboutPDF ToolsAdd to favoritesDownload CitationTrack Citations ShareFacebookTwitterLinked In “From Reactive Intervention to Proactive Prevention: The Evolution of Occupational Dysphonia,” Epstein, Remacle, & Morsomme 1. Voice disorders among occupational voice users: 1. are rarely accompanied by related physical complaints 2. are a phenomena recognized by all European governments 3. may result in trillions of dollars of lost economy 4. have little to do with background noise levels 2. Voice disorders among teachers: 5. are no more frequent than voice disorders reported among other high-risk populations 6. often consist of periods of exacerbation followed by lengthy periods of remission 7. tend to worsen over time 8. are considered an occupational disease in the United Kingdom 3. Researchers investigating the relationship between occupation type and voice disorders: 9. have shown a link between the two in level 1 studies 10. have shown a link between the two in multiple prospective studies 11. have yet to show a link between the two 12. do not take mood and coping abilities into account 4. Roy's findings about risk factors and dysphonia among female teachers: 13. have yet to be corroborated 14. have been corroborated by at least two additional studies 15. fail to account for vocal load 16. find that voice disorders are more prominent in younger teachers 5. Optimum ratios for speaking time and vocal downtime are: 17. not yet established 18. well established in the literature 19. recognized by the International Organization of Standardization 20. currently applicable to teachers only “Ambulatory Monitoring of Daily Voice Use,” Hillman & Mehta 6. Ambulatory voice use devices made in the 1970s were: 21. referred to as vocal accelerometers 22. unobtrusive 23. commercially available 24. prototypes that demonstrated potential benefits of measuring vocal parameters over time 7. Studies cited by the author suggest: 25. no measurable differences in vocal use as a function of occupation 26. that speakers tend to overestimate actual phonation time for a given time period 27. no measurable differences in vocal complaints as a function of occupation 28. that speakers tend to underestimate actual phonation time for a given time period 8. As described by the author, miniature accelerometers: 29. capture phonatory events over brief time periods only 30. are acutely sensitive to environmental sounds 31. collect data on distance dose 32. capture signals filtered by the vocal tract 9. The Ambulatory Phonation Monitor, Vocalog, and VoxLog all: 33. provide biofeedback 34. measure F0 and SPL 35. are available for clinical use 36. feature a microphone to sense background noise 10. Few clinical practitioners have adopted ambulatory monitoring devices into clinical practice because of the: 37. high cost of the devices 38. lack of current data to suggest vocal behavior change 39. paucity of long-term normative data to demonstrate diagnostic capabilities 40. lack of evidence that accelerometers provide measures of vocal function “Green Voice Project: Preserving the Healthy Voice in Teachers,” Chan & Yiu 11. Voice disorders among teachers are: 41. inevitable 42. mostly preventable 43. over-reported 44. rarely considered a factor in quality of life outside the classroom 12. With respect to past studies investigating voice problems in teachers, voice care protocols have: 45. varied from study to study 46. been controlled for the number of contact hours 47. been administered only to those with dysphonia 48. been controlled for the number of training sessions 13. One strength of self-reporting surveys in voice research is that they: 49. are consistently valid and reliable 50. tend to strongly agree with perceptual evaluations by experienced clinicians 51. tend to identify subtle voice changes not observed by researchers 52. tend to strongly agree with acoustic changes in vocal quality 14. In the current study, attrition was: 53. experienced primarily by the control group 54. of little concern 55. experienced primarily by the voice care group 56. experienced primarily by the voice care and voicing technique group 15. The authors suggest that the increased frequency range demonstrated by the control group after one year: 57. reflects an increased awareness of vocal capabilities 58. was directly attributable to home practice 59. was matched by an increase in the Voice Handicap Index 60. reflects a reduced awareness of the threat of vocal fold damage “Voice Disorders in Teachers,” Roy 16. The majority of teachers who experience vocal dysfunction: 61. seek medical help 62. do not alter classroom activities as a result of dysphonia 63. are more likely to miss work because of concomitant physical sensations than the dysphonia itself 64. do not exceed vibration dose 17. Voice amplification: 65. is ineffective in classrooms that exceed recommended reverberation levels 66. has been shown to increase vocal load 67. reveals increased listening ease and improved concentration in students 68. is effective only when combined with a vocal hygiene program 18. Based on extensive literature review and prospective study findings, the author suggests that vocal hygiene programs are: 69. effective dysphonia prevention measures 70. effective when combined with other voice production therapies 71. more powerful than vocal function exercises and amplification in reducing vocal overload 72. effective approaches to reversing dysphonias 19. The training approach that directly encourages forward focus and vocal folds that barely touch during vibration is: 73. resonant therapy 74. vocal function exercise 75. vocal hygiene 76. respiratory muscle training 20. Hackworth's study on vocal behavior modification suggests that the most efficacious approach to healthy voicing involves: 77. increasing hydration 78. increasing expiratory pressures 79. charting daily vocal habits 80. encouraging vocal hygiene with one-on-one individualized instruction Additional Resources FiguresReferencesRelatedDetails Volume 21Issue 2July 2011 HistoryReceived: Jul 1, 2011Accepted: May 30, 2014 Published in issue: Jul 1, 2011 Get Permissions Add to your Mendeley library Metrics Downloaded 104 times Topicsasha-topicsleader-topicsasha-article-typesasha-sigsCopyright & Permissions© 2011 American Speech-Language-Hearing AssociationPDF DownloadLoading ...

Team Management of Voice Disorders in Singers

Does an Exercise Aimed at Improving Swallow Function Have an Effect on Vocal Function in the Healthy Elderly?

Funktionelle Roentgendiagnostik des Mediastinums am Beispiel des Bronchial-karzinoms Demonstriert. By R. Kraus. Stuttgart: Georg Thieme. Pp. 55. 33 Illustrations.

Evaluation of preoperative and postoperative vocal fold function is important in patients undergoing thyroid or parathyroid surgical procedures. Transcutaneous laryngeal ultrasonography (TLUSG) has been proposed as a promising noninvasive technique and alternative to flexible fiberoptic laryngoscopy. To determine whether TLUSG can be an alternative to flexible laryngoscopy in evaluating vocal fold function. A prospective study was performed from March 1, 2013, to July 31, 2014. Patients who were scheduled to undergo thyroid or parathyroid surgery by a single surgeon at a North American, university-based tertiary care center and who agreed to undergo preoperative and postoperative TLUSG and flexible fiberoptic laryngoscopy were enrolled. Patients were divided into 2 groups: nonoverweight (body mass index [calculated as weight in kilograms divided by height in meters squared] <25) and overweight or obese (body mass index ≥ 25). Follow-up was completed on February 28, 2015, and data were analyzed from March 1, 2013, to February 28, 2015. Preoperative and postoperative TLUSG and flexible fiber optic laryngoscopic assessments of vocal fold function. The findings of TLUSG and flexible fiber optic laryngoscopy were compared for all patients and each body mass index group to assess the accuracy of TLUSG in assessing vocal fold function. A total of 250 patients (500 vocal folds) underwent evaluation, of whom 208 (83.2%) were women and with a mean (SD) age of 52.7 (14.3) years. On flexible fiberoptic laryngoscopy findings, 13 patients had preoperative vocal fold paralysis (VFP), and 14 postoperative new incidents of VFP were identified. Only 7 (53.9%) of the preoperative cases of VFP and 15 (55.6%) of the postoperative cases of VFP were identified by TLUSG. The sensitivity, specificity, and accuracy of preoperative TLUSG were 53.8%, 50.5%, and 50.6%, respectively; for postoperative TLUSG, 55.6%, 38.7%, and 39.6%, respectively. In the nonoverweight group, the preoperative TLUSG sensitivity, specificity, and accuracy were 100%, 70.0%, and 70.5%, respectively; in the overweight-obese group, 45.4%, 43.4%, and 43.5%, respectively (odds ratio, 3.16; 95% CI, 2.06-4.84; P < .001). Postoperative visualization of the vocal folds was more challenging, with a sensitivity, specificity, and accuracy of 83.3%, 55.6%, and 56.8%, respectively, in the nonoverweight group, and 47.6%, 32.6%, and 33.4%, respectively, in the overweight-obese group (odds ratio, 2.62; 95% CI, 1.75-3.94; P < .001). When evaluation of vocal fold function is indicated in patients undergoing thyroid and parathyroid surgery, TLUSG should not be considered as an alternative to the current practice of flexible fiberoptic laryngoscopy. Adequate ultrasonographic visualization of the vocal folds and arytenoids is challenging, especially in overweight and obese patients and in the postoperative setting.

Although many quantitative parameters have been devised to describe abnormalities in vocal fold vibration, little is known about the priority of these parameters. We conducted a prospective study using high-speed digital imaging to elucidate disease-specific key parameters (KPs) to characterize the vocal fold vibrations of individual voice disorders. From 304 patients with various voice disorders and 46 normal speakers, high-speed digital imaging of a sustained phonation at a comfortable pitch and loudness was recorded and parameters from visual-perceptual rating, laryngotopography, digital kymography, and glottal area waveform were calculated. Multivariate analysis was then applied to these parameters to elucidate the KPs to explain each voice disorder in comparison to normal subjects. Four key parameters were statistically significant for all laryngeal diseases. However, the coefficient of determination (R2) was very low (0.29). Vocal fold paralysis (8 KPs, R2 = 0.76), sulcus vocalis (4 KPs, R2 = 0.74), vocal fold scarring (1 KP, R2 = 0.68), vocal fold atrophy (6 KPs, R2 = 0.53), and laryngeal cancer (1 KP, R2 = 0.52) showed moderate-to-high R2 values. The results identified different KPs for each voice disorder; thus, disease-specific analysis is a reasonable approach.

In a group of persons using the voice occupationally, the frequent symptoms are hoarseness, voice fatigability and aphonia. Pathological changes in the larynx may have organic or functional character which require different methods of treatment and rehabilitation. Visualization of vibrations of the vocal folds is an essential condition for an appropriate assessment of the causes of dysphonia. The purpose of the study is assessment of the usefulness of a high-speed imaging (HSI) system in the diagnosis of functional and organic dysphonia of occupational character, compared with digital kymography (DKG) and digital stroboscopy (DS) with a high resolution module. The study group consisted of 64 patients with voice quality disorders with features of occupational dysphonia. The control group consisted of 15 patients with euphonic voice. Analysis of the voice quality parameters during phonation of the 'e' vowel was performed using HSI, DKG and stroboscopy of high resolution, by means of a digital HS camera (HRES Endocam, Richard Wolf GmbH, Knittlingen, Germany). Vocal folds vibrations were registered at the rate of 4,000 frames per second. HSI is the most reliable diagnostic tool giving the possibility of an analysis of the true vibrations of the vocal folds. It also enables an observation of the aperiodicity of vibrations of the vocal folds, while DS with high resolution allows diagnosis of the periodicity of the vibrations. HSI is particularly useful in the diagnosis of neurologically-based pathology of the voice (paralytic dysphonia) and organic dysphonia. The quickest method of diagnosing the phonatory paresis of the glottis is DKG. The advantage of both HSI and DKG is the non-invasiveness of examinations; however, their limitations are time-consuming and the high cost of equipment.

CO2 laser cordectomy has been the workhorse of laser surgery for early glottic squamous cell carcinoma (GSCC) since the early 1970s. During the last decades, potassium titanyl phosphate (KTP) laser surgery for early GSCC gained popularity, introducing the tumor ablation technique. Yet, there are no previous randomized controlled trials (RCT) that compare the oncologic and functional outcomes of KTP Laser ablation versus CO2 laser cordectomy for early GSCC. This study aims to compare by means of an RCT, CO2 laser cordectomy with KTP laser ablation for early GSCC, in terms of cure rates and vocal function. A RCT conducted between 2013 and 2017. Patients with early GSCC were enrolled, and randomly assigned for either CO2 cordectomy or KTP-ablation surgery with curative intent. All CO2 cordectomies and most KTP-ablation procedures were performed under general anesthesia. Some KTP cases with residual disease were treated also under local anesthesia. Videostroboscopy measures, voice handicap index (VHI), GRBAS (a hoarseness scale for Grade, Roughness, Breathiness, Asthenia and Strain) score, andacoustic analyses were performed pre-operatively, 6 months and 3 years after surgery. Twenty-four patients, 12 in each group, were enrolled. Nine in each group had T1a carcinoma, the remaining had either carcinoma in situ or T1b. The average number of procedures was 1.67( ± 0.89) and 1.33( ± 0.89) for the KTP and CO2 groups, respectively. Although the tumor depth was comparable in both groups, patients in the KTP-ablation group underwent more superficial surgeries. Eleven (91.7%) procedures in the KTP group spared the vocal ligament, compared with 5 (41.7%) in the CO2 group, (P = 0.023). All patients were alive and disease-free after four years. On post-operative videostroboscopy, normal mucosal waves appeared in 5 (42%) of the KTP patients versus none (0%) of the CO2 (P = 0.02). The median post-operative non-vibrating portion was smaller in the KTP group (10%) compared with CO2 (50%), P = 0.043. Nevertheless, GRBAS and VHI scores improved comparably in both groups. KTP ablation technique offers similar curative outcome as CO2 cordectomy but may allow for better preservation of vocal fold's architecture and function. Yet, the clinical significance of these findings is unclear, since the subjective measures improved comparably for these two treatment modalities. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

This multicenter study aimed to 1) evaluate early postoperative vocal fold function in relation to intraoperative amplitude recovery, and 2) determine optimal absolute and relative thresholds of intraoperative amplitude recovery heralding normal early postoperative vocal fold function, both after segmental type 1 and after global type 2 loss of signal (LOS). Prospective outcome study. This study, encompassing nine surgical centers from four countries, correlated intraoperative amplitude recovery with early postoperative vocal fold function using receiver operating characteristic analysis. Included in this study were 68 patients, 48 women and 20 men, who sustained transient recurrent laryngeal nerve injury during thyroid surgery under continuous intraoperative nerve monitoring. Early transient vocal fold palsy was seen in 18 (64%) of 28 patients with ipsilateral segmental LOS type 1, and in 10 (25%) of 40 patients with ipsilateral global LOS type 2. On receiver operating characteristic analysis, relative amplitude thresholds were superior to absolute amplitude thresholds in predicting vocal fold function after LOS type 2 (area under the curve [AUC]: 0.83 vs. 0.65; P = .01 vs. P = .15; Youden index 44% and 253 µV) and LOS type 1 (AUC: 0.96 vs. 0.97; P < .001 each; Youden index 49% and 455 µV). Amplitude recovery ≥50% of baseline after LOS always indicated intact vocal fold function. When the nerve amplitude recovers ≥50% of baseline after segmental LOS type 1 or global LOS type 2, it is appropriate to extend completion thyroidectomy to the other side during the same session. 2b Laryngoscope, 129:525-531, 2019.

A Meta-Analysis of Outcomes of Hydration Intervention on Phonation Threshold Pressure