The ligand binding domain of a type IV pilus chemoreceptor PilJ has a different fold from that of another PilJ-type receptor McpN.

Bacterial chemoreceptors sense the extracellular signals and regulate bacterial motilities, biofilm formation, etc. The periplasmic ligand binding domains of chemoreceptors occur as different structural folds and recognize a diversity of chemical molecules. In Pseudomonas aeruginosa (PAO1), two bacterial chemoreceptors, McpN (PA2788) and PilJ (PA0411), are proposed to both contain a PilJ-like ligand-binding domain (LBD) (Pfam motif PF13675) and involved in nitrate chemotaxis and type IV pilus-mediated motility, respectively. The LBDs of McpN and PilJ consist of 135 and 263 residues, respectively, and share very low sequence identity, suggesting they might occur as different structures. Here, we found that PilJ-LBD folded into an HBM module, the same as the sensor domains of McpS-LBD and TorS-LBD, but it differed from that of McpN-LBD. We also observed a trimer in SEC and AUC and proposed a trimeric model based on the crystal structure. Based on the sequence, we classified the Pfam containing McpN-LBD and PilJ-LBD into three classes: sPilJ (single PilJ) represented by McpN-LBD with only one PilJ domain, dPilJ (dual PilJ) that contained dual PilJ domains, and hPilJ (hybrid PilJ) that comprises of a PilJ domain and another non-PilJ domain. Our work indicates a significant structural difference between the ligand binding domains of PilJ and McpN and will help our further study on both kinds of chemoreceptors.

Primary Tumour Detection in Carcinoma of Unknown Primary with Transoral Robotic Surgery (TORS) Tongue Base Mucosectomy: A Meta-analysis.

BACKGROUND: Head and neck carcinoma of unknown primary (CUP) represents a challenging diagnostic process when standard work-up fails to identify the primary tumour site. The aim of this systematic review and meta-analysis was to evaluate the diagnostic utility and complication profile of transoral robotic surgery (TORS) tongue base mucosectomy (TBM) in the management of CUP. PATIENTS AND METHODS: An electronic database search was performed in the EMBASE, MEDLINE, PubMed and Cochrane databases. A meta-analysis of proportions was performed to obtain an estimate of the overall proportion for the detection and complication rates. RESULTS: Nine studies representing 235 patients with CUP who had TORS TBM were included in the final analysis. The overall pooled tumour detection rate was 66.2% [95% confidence interval (CI) 56.1-75.8]. The incidence of tumour detection in human papilloma virus (HPV)-positive cases (81.5%, 95% CI 60.8-96.4) was significantly higher than HPV-negative cases (2.3%, 95% CI 0.00-45.7). Weighted overall complication rate was 11.4% (95% CI 7.2-16.2). The majority were grade I or II (80%) according to the Clavien-Dindo classification. CONCLUSIONS: This meta-analysis suggests TORS to be safe and effective in localising the primary tumour site in patients with CUP. While the current data supports the use of TORS in patients who are HPV positive, larger numbers of HPV-negative cases are required to determine the true diagnostic effect with TORS before any valid conclusions can be inferred in this particular subgroup. Further research should focus on high quality prospective trials with stringent methodological work-up to minimise heterogeneity and allow for more accurate statistical analysis.

TorS - Reframing a rational for type 2 diabetes treatment.

The mammalian target of rapamycin complex 1 syndrome (Tors), paradigm implies an exhaustive cohesive disease entity driven by a hyperactive mTORC1, and which includes obesity, type 2 diabetic hyperglycemia, diabetic dyslipidemia, diabetic cardiomyopathy, diabetic nephropathy, diabetic peripheral neuropathy, hypertension, atherosclerotic cardiovascular disease, non-alcoholic fatty liver disease, some cancers, neurodegeneration, polycystic ovary syndrome, psoriasis and other. The TorS paradigm may account for the efficacy of standard-of-care treatments of type 2 diabetes (T2D) in alleviating the glycaemic and non-glycaemic diseases of TorS in T2D and non-T2D patients. The TorS paradigm may generate novel treatments for TorS diseases.

Features related to temporary tracheotomy in patients undergoing Transoral Robotic Surgery (TORS) for supraglottic squamous cell cancer of the larynx: A systematic review.

OBJECTIVE: The aim of this systematic review is to assess a relation between demographical, clinical and tumoral features and the need for a prophylactic tracheotomy during TORS procedure in patients affected by supraglottic laryngeal cancer. METHODS: PRISMA 2020 guidelines were applied in this systematic literature review. A computerized search was performed using the Embase/Pubmed, Scopus and Cochrane database, for articles published from 2007 to December 2023. A statistical univariate analysis including selected papers with low or intermediate risk of bias was performed. RESULTS: Through a study selection process 8 full texts were eligible for statistical univariate analysis. The most relevant factor related to a prophylactic tracheotomy was a contextual bilateral cervical nodes dissection, which increased the need for a tracheotomy of about 3 times. Other factors contribute with a minor impact, such as a patients age >60 years at the time of the diagnosis, a cervical lymph node metastasis and a false vocal fold involvement. Each ones increase by 20-70 % the need for a tracheotomy. However, this rate is decreased by about 60 % by the epiglottis involvement. CONCLUSIONS: The prophylactic tracheotomy is considered a temporary protection strategy to achieve a valid recovery after TORS procedure. However, there are no guidelines regarding its routinely use. Only 25 % of patients undergone tracheotomy during TORS to treat supraglottic laryngeal cancer. These preliminary results may add more significant evidence regarding the use of tracheotomy during the TORS procedure, in order possibly to help the surgeon decide preoperatively whether to perform it or not.

Prospective development study of the Versius Surgical System for use in transoral robotic surgery: an IDEAL stage 1/2a first in human and initial case series experience.

PURPOSE: Transoral robotic surgery is well established in the treatment paradigm of oropharyngeal pathology. The Versius Surgical System (CMR Surgical) is a robotic platform in clinical use in multiple specialities but is currently untested in the head and neck. This study utilises the IDEAL framework of surgical innovation to prospectively evaluate and report a first in human clinical experience and single centre case series of transoral robotic surgery (TORS) with Versius. METHODS: Following IDEAL framework stages 1 and 2a, the study evaluated Versius to perform first in human TORS before transitioning from benign to malignant cases. Iterative adjustments were made to system setup, instrumentation, and technique, recorded in accordance with IDEAL recommendations. Evaluation criteria included successful procedure completion, setup time, operative time, complications, and subjective impressions. Further evaluation of the system to perform four-arm surgery was conducted. RESULTS: 30 TORS procedures were successfully completed (15 benign, 15 malignant) without intraoperative complication or conversion to open surgery. Setup time significantly decreased over the study period. Instrumentation challenges were identified, urging the need for TORS-specific instruments. The study introduced four-arm surgery, showcasing Versius' unique capabilities, although limitations in distal access were observed. CONCLUSIONS: TORS is feasible with the Versius Surgical System. The development of TORS-specific instruments would benefit performance and wider adoption of the system. 4-arm surgery is possible however further evaluation is required. Multicentre evaluation (IDEAL stage 2b) is recommended.

Transoral robotic styloidectomy for Eagle syndrome: A systematic review.

OBJECTIVES: The aim of the study is to conduct a systematic review of the existing literature on styloidectomy performed through transoral robotic surgery (TORS) in Eagle syndrome (ES). DESIGN AND SETTING: Two independent reviewers (RC and AC) conducted a systematic review of PubMed and Embase databases, seeking articles on TORS performed for ES treatment. The search was conducted in July 2023. The review was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PARTICIPANTS: The review included a total of 17 adult patients, comprising 12 females and 5 males, with an average age of 52.2 years, all diagnosed with ES. MAIN OUTCOME MEASURES: For each patient, we assessed the overall length of the styloid process, the affected side, total intervention duration, hospitalization duration, pre and postoperative Visual Analogue Scale (VAS) scores, and the presence of minor and major complications. RESULTS: We identified 4 articles describing 17 instances of TORS as a surgical treatment for ES in the literature, totaling 18 styloidectomies. The mean age of the patients was 52.2 years, with 12 females and 5 males. The average operation time, inclusive of the docking phase, was 68.8 minutes. Sixteen patients (94.1% of the total) experienced complete symptom disappearance or near-complete resolution after surgery. One patient (5.9%) showed improvement categorized as 'non-meaningful.' Only one case of minor complication was reported among the 17 procedures (5.9%).

Indications for oropharyngeal biopsy in head and neck squamous cell carcinoma of unknown primary: A systematic review (HNSCCUP).

INTRODUCTION: Patients presenting with head and neck squamous cell carcinoma of unknown primary (HNSCCUP) remain challenging clinical scenarios as large variation exists in practices used to locate the primary. OBJECTIVE: The objective of this systematic review is to review of the literature and offer recommendations for oropharyngeal biopsies in HNSCCUP. METHOD: Pubmed, Medline and Embase were searched to identify studies from inception to October 2021. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. RESULTS: A total of 483 articles were included and screened, 41 studies met the inclusion criteria, including over 3400 patients from the original articles (122 of these patients were reported on in two sequential articles by a single author - table 1) and 4 large metaanalyses including 1852 patients. The primary site identification rate following random biopsies or deep tissue biopsies is less than 5% in most studies. The mean detection rate following ipsilateral tonsillectomy is 34%; two pooled analyses indicate that the mean detection rate following tongue base mucosectomy is 64%, with this figure rising when the tonsils are negative. CONCLUSIONS: High level evidence is lacking, with heterogeneity in the reported studies. Published meta-analyses are based on retrospective data. There is little evidence supporting the practice of random/non-directed oropharyngeal biopsies. Available evidence supports palatine tonsillectomy and tongue base mucosectomy compared to deep tissue biopsies.

Compartmental Transoral Robotic Lateral Oropharyngectomy with the da Vinci Single-Port System: Surgical Technique.

BACKGROUND: Transoral robotic surgery (TORS) has renovated the surgical management of oropharyngeal squamous cell carcinoma (OPSCC), allowing a minimally invasive surgical approach with optimal oncological outcomes. The recent introduction of the da Vinci Single Port (SP) system resulted in a considerable improvement of TORS technique. METHODS: In this video, we illustrate the transoral robotic lateral oropharyngectomy performed with the da Vinci SP system in a 50-year-old male patient suffering from a p16+ oropharyngeal squamous cell carcinoma cT4N1M0. RESULTS: The transoral robotic lateral oropharyngectomy is illustrated step by step. The structures encountered during the resection are described, and the surgical margins are defined based on anatomical landmarks. The most critical regions encountered during resection are pointed out, and the tip and tricks of this surgery are reported. CONCLUSIONS: A step-by-step transoral lateral oropharyngectomy is described to increase its reproducibility. The da Vinci SP system owns various benefits for performing transoral lateral oropharyngectomy due to the increased maneuverability in the narrower oral cavity working spaces.

Comparison of margins and survival between transoral robotic surgery (TORS) and non-robotic endoscopic surgery for oropharyngeal cancer.

OBJECTIVE: To evaluate the impact of transoral robotic surgery (TORS) and non-robotic transoral endoscopic surgery on margin positivity, rates of adjuvant therapy and survival in early stage oropharyngeal squamous cell carcinoma. STUDY DESIGN: Retrospective cohort review. SUBJECTS AND METHODS: The National Cancer Database was queried to form a cohort of patients with T1-T2 N0-N1 MO oropharyngeal squamous cell carcinoma who underwent TORS or Non-robotic endoscopic surgery from 2010 to 2015. Demographics, disease characteristics and rate of positive margin and adjuvant therapy were summarized. A binary logistic regression and a cox-proportional hazard model were performed to evaluate patient demographic, disease, and treatment factors that could predict margin positivity and survival respectively. RESULTS: 1026 patients received TORS treatment while 734 patients received non-robotic endoscopic primary surgery. Non-robotic surgery was more likely to have residual tumor (31.6 % of all cases) compared to TORS procedures (13.6 % of TORS cases); p < .0001. Non-robotic surgery more frequently had non-evaluable margins at 8.1 % compared to only 1.4 % of TORS cases (p < .0001). Non-robotic cases had a significantly higher proportion of patients receiving adjuvant radiotherapy and systemic therapy compared to TORS (66.4 % vs 51.3 % for radiotherapy; p < .0001 and 33.4 % vs 22.2 % for chemotherapy; p < .0001). There was no difference in mortality between the two modalities (non-robotic vs TORS, HR 1.357, 95 % CI 0.937-1.967). CONCLUSION: TORS and non-robotic surgery may have a similar impact on survival in early-stage OPSCC, but non-robotic surgery was found to have a higher likelihood of positive margins and a higher rate of adjuvant chemoradiation therapy.

Circulating tumor DNA in head and neck cancer: Early successes and future promise.

LAY SUMMARY: The genetic components (DNA) of human papillomavirus-related throat cancer (in the oropharynx) might be measured after surgery to help to predict whether treatment has been successful.

Transoral robotic surgery adoption and safety in treatment of oropharyngeal cancers.

BACKGROUND: Transoral robotic surgery (TORS) was approved by the Food and Drug Administration in 2009 for the treatment of oropharyngeal cancers (oropharyngeal squamous cell carcinoma [OPSCC]). This study investigated the adoption and safety of TORS. METHODS: All patients who underwent TORS for OPSCC in the National Cancer Data Base from 2010 to 2016 were selected. Trends in the positive margin rate (PMR), 30-day unplanned readmission, and early postoperative mortality were evaluated. Outcomes after TORS, nonrobotic surgery (NRS), and nonsurgical treatment were compared with matched-pair survival analyses. RESULTS: From 2010 to 2016, among 73,661 patients with OPSCC, 50,643 were treated nonsurgically, 18,024 were treated with NRS, and 4994 were treated with TORS. TORS utilization increased every year from 2010 (n = 363; 4.2%) to 2016 (n = 994; 8.3%). The TORS PMR for base of tongue malignancies decreased significantly over the study period (21.6% in 2010-2011 vs 15.8% in 2015-2016; P = .03). The TORS PMR at high-volume centers (≥10 cases per year; 11.2%) was almost half that of low-volume centers (<10 cases per year; 19.3%; P < .001). The rates of 30-day unplanned readmission (4.1%) and 30-day postoperative mortality (1.0%) after TORS were low and did not vary over time. High-volume TORS centers had significantly lower rates of 30-day postoperative mortality than low-volume centers (0.5% vs 1.5%; P = .006). In matched-pair analyses controlling for clinicopathologic cofactors, 30-, 60-, and 90-day posttreatment mortality did not vary among patients with OPSCC treated with TORS, NRS, or nonsurgical treatment. CONCLUSIONS: TORS has become widely adopted and remains safe across the country with a very low risk of severe complications comparable to the risk with NRS. Although safety is excellent nationally, high-volume TORS centers have superior outcomes with lower rates of positive margins and early postoperative mortality.

Assessing the learning curve associated with a novel flexible robot in the pre-clinical and clinical setting.

BACKGROUND: Transoral robotic surgery has been successfully used by head and neck surgeons for a variety of procedures but is limited by rigid instrumentation and line-of-sight visualization. Non-linear systems specifically designed for the aerodigestive tract are needed. Ease of use of these new systems in both training and clinical environments is critical in its widespread adoption. METHODS: Residents, fellows, and junior faculty performed four tasks on an anatomical airway mannequin using the Medrobotics FLEX™ Robotic System: expose and incise the tonsil, grasp the epiglottis, palpate the vocal processes, and grasp the interarytenoid space. These tasks were performed once a day for four days; after a 4-month time gap, subjects were asked to perform these same tasks for three more days. Time to task completion and total distance driven were tracked. In addition, a retrospective analysis was performed analyzing one attending physician's experience with clinical usage of the robot. RESULTS: 13 subjects completed the initial round of the mannequin simulation and 8 subjects completed the additional testing 4 months later. Subjects rapidly improved their speed and efficiency at task completion. Junior residents were slower in most tasks initially compared to senior trainees but quickly reached similar levels of efficiency. Following the break there was minimal degradation in skills and continued improvement in efficiency was observed with additional trials. There was significant heterogeneity in the analyzed clinical cases, but when analyzing cases of similar complexity and pathology, clear decreases in overall operative times were demonstrable. CONCLUSION: Novice users quickly gained proficiency with the FLEX™ Robotic System in a training environment, and these skills are retained after several months. This learning could translate to the clinical setting if a proper training regimen is developed. The Medrobotics FLEX™ Robotic System shows promise as a surgical tool in head and neck surgery in this study.

The impact of socioeconomic and geographic factors on access to transoral robotic/endoscopic surgery for early stage oropharyngeal malignancy.

OBJECTIVE: To evaluate the role of social and geographic factors on the likelihood of receiving transoral robotic surgery (TORS) or non-robotic transoral endoscopic surgery treatment in early stage oropharyngeal squamous cell carcinoma (OPSCC). MATERIALS AND METHODS: The National Cancer Database was queried to form a cohort of patients with T1-T2 N0-N1 M0 OPSCC (AJCC v.7) who underwent treatment from 2010 to 2016. Demographics, tumor characteristics, treatment type, social, and geographic factors were all collected. Univariate analysis and multivariate logistic regression were then performed. RESULTS: Among 9267 identified patients, 1774 (19.1%) received transoral robotic surgery (TORS), 1191 (12.9%) received transoral endoscopic surgery, and 6302 (68%) received radiation therapy. We found that lower cancer stage, lower comorbidity burden and HPV- positive status predicted a statistically significant increased likelihood of receiving surgery. Patients who reside in suburban or small urban areas (>1 million population), were low-to- middle income, or rely on Medicaid were less likely to receive surgery. Patients that reside in Medicaid-expansion states were more likely to receive TORS (p > .0001). Patients that reside in states that expanded Medicaid January 2014 and after were more likely to receive non-robotic transoral endoscopic surgery (p > .0001). CONCLUSIONS: Poorer baseline health, lower socioeconomic status and residence in small urban areas may act as barriers to accessing minimally invasive transoral surgery while residence in a Medicaid-expansion state may improve access. Barriers to accessing robotic surgery may be greater than accessing non-robotic surgery.

National analysis of positive surgical margins in oropharyngeal salivary gland malignancies.

OBJECTIVE: Positive surgical margins (PSM) are associated with worse survival in oropharyngeal salivary gland malignancies (OPSGM), but existing literature is limited to small series. Our objective was to identify risk factors for PSM using the national cancer database (NCDB), including a transoral robotic surgical (TORS) approach. METHODS: NCDB was queried for patients with T1-T4a OPSGM undergoing resection between 2010 and 2017. Risk factors for PSM were determined using logistic regression. Overall survival (OS) was analyzed using Kaplan-Meier and Cox proportional hazards models. RESULTS: Of 785 patients, 165 (21.0 %) had PSM. Age, stage T4a tumors (OR 2.00, 95 % Confidence Interval [CI]: 1.03-3.88), adenoid cystic carcinoma (OR 2.02, 95 % CI: 1.29-3.18), and treatment at lower volume institutions (OR 1.68, 95 % CI: 1.09-2.59) were all independently associated with PSM. TORS versus a non-robotic approach was not associated with PSM (23.9 % vs 20.4 %, p 0.358), respectively. Positive margins were independently associated with a worse OS than negative margins (HR 1.63, 95 % CI: 1.03-2.59). Adjuvant radiation therapy was associated with improved survival in high grade tumors with positive margins. CONCLUSION: This study represents the largest review assessing risk factors for positive margins in OPSGM. Histologic type (adenoid cystic carcinoma), age, T4a tumor stage and treatment at a lower volume institution were all predictive of positive margins. With increasing use of TORS over the last decade, there does not appear to be a greater risk of positive margins using this modality in select patients. LEVEL OF EVIDENCE: N/A.

Transoral robotic cordectomy for glottic carcinoma: a rapid review.

OBJECTIVE: The objective of this study was to investigate feasibility, surgical, oncological, and functional outcomes of transoral robotic cordectomy (TORS-Co) and whether TORS-Co reported comparable outcomes of transoral laser microsurgery (TLM). METHODS: PubMed, Scopus, and Cochrane Library were searched by three laryngologists for studies investigating feasibility, surgical, oncological, and functional outcomes of patients benefiting from TORS-Co. The following outcomes were investigated according to the PRISMA statements: age; cT stage; types of cordectomy; surgical settings; complications; and functional and feasibility features. RESULTS: Nine studies published between 2009 and 2021 met our inclusion criteria, accounting for 114 patients. There was no controlled study. TORS-Co was performed in cT1 or cT2 glottic cancer through types II, III, IV, V, or VI cordectomies. The exposure was inadequate in 4% of cases, leading to conversion in transoral laser cordectomy. Margins were positive in 4.5% and local recurrence occurred in 10.7% (N = 8/75). Tracheotomy and feeding tube requirement varied across studies, depending on the types of TORS-Co. The mean duration of robot installation/vocal cord exposure and operative times ranged from 20 to 42 min and 10 to 40 min, respectively. The mean duration of hospital stay ranged from 2 to 7 days. Complications included dyspnea, bleeding, granuloma, synechia, and tongue hematoma and dysesthesia. CONCLUSION: The current robotic systems do not appear adequate for TORS-Co. TORS-Co was associated with higher rates of complications and tracheotomy than TLM.

[Role of Robotic Surgery in ENT]. / Bedeutung der transoralen robotischen Chirurgie in der HNO.

Since the beginning of the 21st century, surgical robots have been used in the ENT-environment. They primarily support surgeons in minimal invasive transoral operations, especially in multidisciplinary treatment concepts of head and neck tumors, but also in snoring surgery the robot provides a complement to the established transoral laser surgery. In the meantime there is a large number of data that deals with the importance of oncological results, function maintenance, economics and future perspectives.Operation areas of the current robot devices are still limited in the ENT-environment. As the number of cases are small, efforts are being made to connect centres on a national and international level. Thus, uniform training standards, targeted knowledge and data exchange as well as further development of systems would be managed better. The creation of small and agile ENT-specific equipment could expand the possibilities as a next step for the future and finally lead to a wide scale of ENT-surgical applications.

Current indications and patient selection for transoral robotic surgery in head and neck cancer - a brief review.

Transoral robotic surgery (TORS) continues to gain momentum in minimally invasive surgery. Not only is TORS potentially curative in many cases, but it also addresses the growing emphasis on functional outcomes and quality of life. The main anatomical areas in which TORS is used are the oropharynx and larynx; however, it is becoming increasingly common in thyroid surgery and neck dissections. With growing popularity, the number of indications for TORS in oropharyngeal and laryngeal cancer also increases. However, not all patients are good candidates for this technique, and thus patient selection is essential, with careful assessment of patient-related factors (e.g. comorbidities and endoscopic access) and disease-related variables, such as tumour location, disease staging, and the involvement of surrounding anatomical structures. The aim of the present article is to briefly review the current and emerging indications for TORS in head and neck cancer and the main factors related to patient selection.

HPV/p16-positive oropharyngeal cancer treated with transoral robotic surgery: The roles of margins, extra-nodal extension and adjuvant treatment.

PURPOSE: Human papilloma virus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) treatment outcomes are re-defining management. Traditional margins, the role of extranodal extension (ENE) and adjuvant treatment intensity continue to be debated. This study aimed to determine the impact of margins, ENE and adjuvant therapy on survival following transoral robotic surgery (TORS). METHODS: Patients treated with TORS at an academic center were retrospectively identified (2013-2019). Survival outcomes were evaluated using Kaplan-Meier curves. RESULTS: 48 patients were included. 40 (83%) were male. Mean age was 61.2 years. 43 (90%) were stage I. 22 (45.8%) had ENE. 31 (65%) had margins >1 mm. 38 (79%) had indications for radiation therapy; 9 (24%) refused. Chemotherapy was recommended in 36 (75%) patients; 24 (67%) refused. Locoregional control was 98%, metastasis-free survival was 96%, and disease-specific survival was 100% at 5-years. Overall survival was 95%. CONCLUSIONS: Given the high survival rate seen after TORS, it is likely that margins, ENE and adjuvant treatment may not significantly contribute to outcomes.

Upper airway stimulation: Fewer complications, ED presentations, readmissions, and increased surgical success.

OBJECTIVES: Evaluate the rate of complications, readmissions, emergency department presentations, and surgical success rates amongst three standard surgical treatment options for obstructive sleep apnea: upper airway stimulation, transoral robotic surgery, and expansion sphincter pharyngoplasty. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary care center. METHODS: Patients were included who were aged ≥18 years old and underwent upper airway stimulation, transoral robotic surgery, or expansion sphincter pharyngoplasty between January 2011 and May 2020. RESULTS: 345 patients were identified: 58% (n = 201) underwent upper airway stimulation, 10% (n = 35) underwent transoral robotic surgery, and 32% (n = 109) patients underwent expansion sphincter pharyngoplasty. There were 22 emergency department presentations and 19 readmissions, most of which were experienced by patients receiving transoral robotic surgery (six emergencies, seven readmissions) and expansion sphincter pharyngoplasty (12 emergencies, 11 readmissions). Patients with upper airway stimulation had four emergencies and one readmission. Only 2% of the upper airway stimulation cohort had a complication, whereas this was 20% and 12% for the transoral robotic surgery and expansion sphincter pharyngoplasty cohorts, respectively. Patients experienced the highest surgical success rate with upper airway stimulation (69%), whereas patients who received transoral robotic surgery and expansion sphincter pharyngoplasty had success rates of 50% and 51%, respectively. CONCLUSION: Treating obstructive sleep apnea with upper airway stimulation led to lower rates of complications, emergency department presentations, and readmissions in this series. In those for whom upper airway stimulation is appropriate, it may be more effective in successfully treating obstructive sleep apnea than transoral robotic surgery and expansion sphincter pharyngoplasty.

Evaluation of a curved surgical prototype in a human larynx.

PURPOSE: It is not always possible to create linear access to the larynx using a rigid operating laryngoscope for microlaryngoscopy. In this study, we evaluate the usability of a novel curved surgical prototype with flexible instruments for the larynx (sMAC) in a simulation dummy and human body donor. METHODS: In a user study (n = 6), head and neck surgeons as well as medical students tested the system for visualization quality and accessibility of laryngeal landmarks on an intubation dummy and human cadaver. A biopsy of the epiglottis was taken from the body donor. Photographic and time documentation was carried out. RESULTS: The sMAC system demonstrated general feasibility for laryngeal surgery. Unlike conventional microlaryngoscopy, all landmarks could be visualized and manipulated in both setups. Biopsy removal was possible. Visibility of the surgical field remained largely unobstructed even with an endotracheal tube in place. Overall handling of the sMAC prototype was satisfactorily feasible at all times. CONCLUSION: The sMAC system could offer an alternative for patients, where microlaryngoscopy is not applicable. A clinical trial has to clarify if the system benefits in clinical routine.