Background

Preliminary case series have reported clinical feasibility and safety of a transoral minimally invasive technique to approach parapharyngeal space masses. With the assistance of the surgical robotic system, tumors within the parapharyngeal space can now be excised safely without neck incisions. A detailed technical description is included.

Methods

After developing compressive symptoms from a parapharyngeal space lipomatous tumor, the patient was referred by his primary otolaryngologist because of poor open surgical access to the nasopharyngeal component of the tumor.

Results

Transoral robotic assisted resection of a 54- × 46-mm parapharyngeal space mass was performed, utilizing 97 minutes of robotic surgical time. Pictorial demonstration of the robotic resection is provided.

Conclusion

Parapharyngeal space tumors have traditionally been approached via transcervical skin incisions, typically including blunt dissection from tactile feedback. The transoral robotic approach offers magnified 3D visualization of the parapharyngeal space that allows for complete and safe resection.

Background

The surgical treatment of glottic, or vocal cord, cancer has seen considerable progression over the past several decades. Specifically, there has been a stark transition from open partial laryngectomy surgery to endoscopic laser microsurgical techniques which have been inspired in large part by two landmark studies: Professor Wolfgang Steiner's original case series describing transoral laser microsurgery for glottic cancer (1993) and the European Laryngological Society's (ELS) classification scheme (2000). We performed a comprehensive review of published literature to characterize the pattern of this novel modality as compared with two landmark studies over the past four decades.

Methods

An English literature search was conducted on PubMed for available original investigations on surgical treatment of glottic laryngeal cancer published over the past 40 years. Our Boolean criteria included the following terms: cancer, glottic, laryngeal, surgery, endoscopic, and laser. The publication rates were calculated as annual compound growth as well as corrected growth rates as defined by the Fisher equation for inflation effects.

Results

Our review identified 13,372 studies covering larynx cancer and 3,557 studies covering glottic cancer original studies. Among these, we analyzed the compound annual growth rates and correct growth rates for three distinct publication periods or epochs, prior to 1993, 1993-1999, and 2000-2017. For all but two of the search term groups covering both glottic cancer as well as larynx cancer, there was a substantial growth improvement in the time period following the ELS classification scheme as compared with the growth rate of the time period following Steiner's case series.

Conclusion

The progress toward minimally invasive treatment of glottic cancer has progressed steadily over the past several decades. Analysis of publication show increased growth during the time period following the ELS classification scheme over the time period following Steiner's landmark study. A mistake would be concluding any diminished importance of Professor Steiner's work, instead, our analysis demonstrates the wide-spread adoption of the endoscopic laser cordectomy procedure following the ELS classification system. Complex surgical techniques such as transoral laser microsurgery are optimally disseminated within well-defined classification schemes, though further validation is warranted.

Objectives/hypothesis

The voice effects following laser cordectomy for early glottic cancer are poorly described. We investigated the voice outcomes of subligamentous cordectomy of progressive anterior-posterior extent of excision.

Study design

Physical phonatory modeling.

Methods

The influence of vocal fold surgical defects and corresponding scar was experimentally investigated using a self-oscillating physical model of the vocal folds and compared with the baseline model without defects or scar.

Results

Results showed that increasing anterior-posterior extent of resection increased phonation threshold pressure and flow rate and reduced excitation of high-order harmonics, resulting in a more breathy and rough voice production. However, it was found that voice production was improved with the placement of scar, which increased both excitation of high-order harmonics and the harmonic-to-noise ratio.

Conclusions

Although large anterior-posterior surgical resections resulted in progressive impact on vocal measures, a limited excision of the vocal fold cover surprisingly demonstrated minimal voice changes. Further investigations are required to define the acceptable extent of surgical resection that may result in optimal voice outcomes.

Objective

When total laryngectomy is not required, organ preservation surgery or radiotherapy is considered the standard of care for primary glottic cancer. These accepted treatment options are available for early and advanced glottic cancers due to equivalent locoregional control and survival rates. However, in today's climate of accountable care, the financial burden of treatment choices continues to increase in significance. We therefore compared hospital charges and treatment-related morbidity between organ-preserving surgery and radiation with or without chemotherapy-herein, (chemo)radiation-in the primary treatment of glottic cancer.

Study design

Nationwide Inpatient Sample Database was analyzed to assess clinical and financial information.

Setting

Population-based analysis.

Subjects

Patients (N = 5499) with primary glottic cancer undergoing treatment with laryngeal preservation strategies.

Methods

Patients were subdivided by ICD-9 codes into 3 treatment groups: endoscopic resection, open partial laryngectomy, and (chemo)radiation. Treatment-related outcomes, charges, and length of hospitalization were analyzed among treatment groups.

Results

When adjusting for sex, age, race, comorbidity, and primary payer, (chemo)radiotherapy was associated with increased direct charges (P < .001; coefficient, $23,658.99; 95% confidence interval [95% CI]: $10,227.15-$37,090.84) and length of hospitalization (P < .001; hazard ratio, 0.593; 95% CI: 0.502-0.702) when compared with endoscopic surgery. As compared with open surgery, endoscopic surgery was associated with reduced hospital charges (P = .012; coefficient, $11,967.01; 95% CI: $2,784.17-$21,249.85) and duration of hospitalization (P < .001; hazard ratio, 0.749; 95% CI: 0.641-0.876).

Conclusions

This analysis suggests that increased utilization of endoscopic surgery in patients with primary glottic cancer not requiring total laryngectomy may lead to reduced financial burden and duration of hospitalization when compared with open surgery or (chemo)radiation therapy.

Objectives/hypothesis

The direct study of human phonation is limited by the invasive and painful nature of human laryngeal neuromuscular manipulation. As a platform for the study of human phonation, indirect models have been utilized for decades such as animal, cadaveric, and computational. We sought to develop a research method allowing direct scientific control of virtually living larynges to expand our ability to understand human phonation.

Study design

Canine and porcine models.

Methods

Nineteen canine larynges were surgically removed and reperfused with progressively adapting methodologies to create ex vivo phonation.

Results

Full neuromuscular stimulation and phonation were ultimately achieved in the ex vivo larynx. As compared with alternative perfusate solutions, heparinized whole blood was found to result in the most robust neuromuscular response. Modification of the reperfusion technique from a continuous flow to a pulsatile pump system resulted in dramatic increases in neuromuscular response and longevity of the organ. The experimental findings were repeated to demonstrate reliability of the ex vivo model.

Conclusions

The ex vivo larynx model is demonstrated to be a repeatable platform for phonatory research. The process of development has been comprehensively described in the present report. Although the described experimental model was designed for phonatory research, this model can be readily adapted for investigations of organ transplant preservation techniques, effects of organ ischemia, and neuromuscular reinnervation capabilities.

Level of evidence

NA.

Importance

Scientific understanding of human voice production to date is a product of indirect investigations including animal models, cadaveric tissue study, or computational modeling. To our knowledge, direct experimentation of human voice production has previously not been possible owing to its invasive nature. The feasibility of an ex vivo perfused human phonatory model has recently allowed systematic investigation in virtually living human larynges with parametric laryngeal muscle stimulation.

Objective

To investigate the association between adductor muscle group stimulation and the open quotient (OQ) (the fraction of the cycle during which the glottis remains open) of vocal fold vibration.

Design, setting, and participants

An ex vivo perfused human tissue study was conducted at a physiology laboratory. Human larynx recovered from organ donors within 2 hours of cardiac death was used. The study was performed on May 19, 2014; data analysis took place from June 1, 2014, to December 15, 2014.

Interventions

Perfusion with donated human blood was reestablished shortly after cardiac death. Ex vivo perfused human phonation was then achieved by providing subglottal airflow under graded neuromuscular electrical stimulation bilaterally to the intrinsic adductor groups and cricothyroid muscles.

Main outcomes and measures

Phonation resulting from the graded states of neuromuscular stimulation was evaluated using high-speed vibratory imaging; the OQ was derived through digital kymography and glottal area waveform analysis.

Results

During constant glottal flow, a stepwise increase in adductor muscle group stimulation decreased the OQ. Quantitatively, OQ values decreased with increased stimulation levels from 2 V (OQ, 1) to 5 V (OQ, 0.68) and reached a lower limit of 8 V (OQ, 0.42). Increased stimulation above maximal muscle deformation was unable to affect OQ beyond this lower limit.

Conclusions and relevance

To our knowledge, a negative association between adductor muscle group stimulation and phonatory OQ has been demonstrated for the first time in a neuromuscularly activated human larynx. Further experience with the ex vivo perfused human phonatory model will aid in systematically defining this causal relationship.

Objectives/hypothesis

To objectively assess the initial and long-term retention of robotic surgical skills of otolaryngology residents.

Study design

This study was performed in an academic otolaryngology residency training program. Between October 2015 and November 2016, residents were invited to complete a prospective, multiphase robotic surgical skills training course: 1) online da Vinci Surgical System Assessment and didactic, 2) faculty-supervised robotic simulator training, 3) robotic docking and draping training, 4) robotic dry-lab exercises. To optimize surgical skill retention, the training laboratory was repeated 2 weeks after the initial training session.

Methods

Twenty otolaryngology residents were included. Primary outcome was measured as robotic skill assessment scores on three tasks: camera targeting, peg board, and needle targeting. Skill assessments were completed prior to training, between the two training sessions, and at 1 month and 6 months after training. Residents were also asked to complete a self-assessment questionnaire.

Results

Camera targeting scores were improved at midtraining (P < .001) and 1-month posttraining (P = .010). Peg board scores were improved at 1 month training (P = .043). Needle targeting scores were improved at midtraining (P = .002), 1 month (P = .002), and 6 months posttraining (P < .001). Resident self-assessment scores demonstrating comfort with using the robotic console (P < .01) and docking/draping (P < .01) improved significantly following the training.

Conclusions

Following a multiphase robotic training program, otolaryngology residents demonstrated significant, objective skill acquisition and retention at 1 month and 6 months follow-up. Although the proposed training strategy may be considered an important step in otolaryngology residency training, additional innovations are being designed toward a formal robotic training curriculum.

Level of evidence

NA Laryngoscope, 129:1380-1385, 2019.

Study Objective. To describe the clinical presentation, evaluation, and treatment of a hypoglossal schwannoma. Methods. We report an unusual case of a hypoglossal schwannoma presenting as a pulsatile level II neck mass at the bifurcation of the external and internal carotid arteries, mimicking a carotid body tumor. Radiologic findings are reviewed in detail. Results. A 59-year-old female presented to a tertiary care medical center with complaints of a pulsatile right-sided neck mass. An MRA of the neck was obtained demonstrating a 5 cm mass located at the carotid artery bifurcation and causing splaying of the internal and external carotids. Based on clinical presentation and imaging, a diagnosis of a carotid body tumor was conferred and the patient scheduled for excision. Intraoperatively, the mass was noted to arise from the hypoglossal nerve, remaining independent of the carotid artery. On histopathologic analysis, the mass was determined to be consistent with hypoglossal schwannoma. Conclusion. Though rare, the hypoglossal schwannoma should remain a consideration in the evaluation of a parapharyngeal space mass. As this report demonstrates, the clinical and radiologic presentation of a hypoglossal schwannoma may closely mimic that of the more common carotid body tumor.

Objective

Although high-speed imaging (HSI) has been identified as a valuable tool in phonatory biomechanics research, to date, there have only been a selected number of reports investigating the clinical utility of HSI. We aim to elucidate the role of HSI in the diagnosis of the dysphonic patient.

Methods

The video files from 28 consecutive dysphonic patients with concurrently acquired videostroboscopy and HSI were retrospectively collected. Stroboscopy video files were edited to include vibratory motion only. Videos were then anonymously and randomly presented to four academic laryngologists. Experts were asked to assign a single best diagnosis for each video file. Assigned diagnoses were then compared with treatment diagnoses conferred based on medical history, phonatory evaluation, laryngeal examination, and response to treatment.

Results

Interrater analysis for the four laryngologists demonstrated significant and meaningful correlations for the diagnoses of polyps, cysts, nodules, and normal examination using stroboscopy (kappa > 0.40, P < 0.001). The experts demonstrated significant and meaningful correlations for the diagnoses of polyps, presbyphonia, and normal examination using HSI (kappa > 0.40, P < 0.001). Combined intrarater analysis performed by comparing single rater's diagnosis for single patient across both modalities resulted in poor correlation without statistical significance (kappa = 0.30, P = 0.07). Both stroboscopy- and HSI-assigned diagnoses matched the treatment diagnoses at equal predicted frequencies (32.3%), as demonstrated through multivariate logistic regression analysis (P < 0.001).

Conclusion

Overall, HSI did not improve the diagnostic accuracy above stroboscopy alone. Although specific laryngeal states such as presbyphonia may be better diagnosed with HSI, further studies are required to define HSI's precise role in the clinical setting.

Importance

This study reviews a single center's experience of performing staged laryngotracheoplasty (LTP) for the treatment of laryngotracheal stenosis with the ultimate goal of attaining long-term airway patency without restenosis.

Objective

To identify staged LTP as an efficacious surgical treatment option for laryngotracheal stenosis.

Design, setting, and participants

From January 2000 to January 2012, patients at a tertiary care academic institution presenting with diagnoses of laryngeal or laryngotracheal stenosis were retrospectively identified. Medical records from adult patients were inspected, and patient demographics, clinical data, and clinical outcomes were recorded. All patients undergoing staged LTP were initially included. Patients with history of head and neck malignant neoplasm were excluded.

Interventions

Staged LTP.

Main outcomes and measures

The primary outcome was long-term decannulation, defined as decannulation for duration of at least 6 months.

Results

Sixty-one patients were included in this study. The mean (SD) patient age was 47.1 (16.7) at the time of first-stage LTP and had a mean (range) follow-up of 5.32 (0.5-17.3) years from the first-stage reconstruction. Etiology of stenosis included prolonged intubation in 27 patients (44%), autoimmune disease in 9 (15%), idiopathic causes in 11 (18%), blunt laryngeal trauma in 10 (16%), and other causes in 4 (7%). Forty-nine patients (80%) were successfully decannulated, while to date 12 (20%) remain tracheostomy or tympanostomy tube dependent. Univariate analyses showed no significant association between decannulation and age (P = .35), sex (P = .52), history of intubation (P = .22), surgeon (P = .20), etiology of stenosis (P = .91), or length of stenosis (P = .31). Multivariate logistic regression analysis showed a significant inverse relationship between grade of stenosis and probability of decannulation (P = .01).

Conclusions and relevance

Staged LTP is an option for the reconstruction laryngotracheal stenosis. Our experience shows excellent decannulation rates in the selected patients with stenosis, many of whom have failed treatment with other surgical modalities.