Transoral robotic surgery for pediatric upper airway pathology: An institutional update.

OBJECTIVE: Provide an update on our institution's experience with utilizing transoral robotic surgery (TORS) in pediatric airway surgery and compare these results to surgery by traditional methods. METHODS: Pediatric patients who underwent TORS for treatment of upper airway pathology between 2010 and 2021 at our institution were retrospectively identified and compared to patients with the same or similar pathology who underwent a traditional (open or endoscopic) surgical approach over the same time period. Outcomes of interest included patient demographics, operative times, adverse events, hospital length of stay (LOS), and modified barium swallow (MBSS) results. RESULTS: Forty children (19M, 21F) underwent 46 TORS procedures. Mean age was 6.4 years (range: 6 days-17 years). Most commonly treated pathology included: laryngeal clefts (LC) (n = 18), lymphatic malformations (n = 9), and base of tongue masses (n = 7). Surgical time was decreased in traditional type I LC repairs (mean: 111 vs 149 min, P = 0.04) and lymphatic malformation excisions (59 vs 120 min, p = 0.005). Hospital LOS was increased in TORS type I LC repairs (2.6 vs 1.2 days, P = 0.04). Adverse event rate was similar between TORS and traditional cohorts (17 % vs 16 % cases, P = 0.9). Postoperative MBSS results were improved for TORS type I LC repairs at 6 months (70 % vs 33 %, P = 0.09) and 12 months (82 % vs 43 %, P = 0.05). CONCLUSIONS: Pediatric TORS is practical and safe and has comparable outcomes to traditional surgery. Robotic-assisted LC repair displayed improved postoperative swallow results versus traditional approaches and may be particularly useful in recurrent cases.

Transoral robotic parapharyngeal space dissection.

Transoral robotic surgery (TORS) provides a minimally invasive approach to address tumors in selected and challenging anatomical locations. Among the critical areas where TORS demonstrates its prowess is the oropharynx. Oropharyngeal tumors can invade parapharyngeal space (PPS) which contains vital structures such as the carotid artery, internal jugular vein, and cranial nerves IX-XII. A deeper understanding of the endoscopic anatomy of the parapharyngeal space could reduce the morbidity associated with tumor resection in this dense neurovascular area. This video-article provides a step-by-step cadaveric dissection of the lower PPS though a transoral robotic approach.

Neoadjuvant chemotherapy followed by transoral robotic surgery versus upfront surgery for locoregionally advanced oropharyngeal carcinoma: A propensity score matched analysis.

BACKGROUND: Transoral robotic surgery (TORS) performed after neoadjuvant chemotherapy (NAC) is a promising treatment for advanced-stage oropharyngeal carcinoma (OPSCC) able to reduce the adjuvant therapy administration rate. METHODS: A retrospective bi-centric study was conducted to analyze NAC + TORS versus upfront TORS patients. A 1:1 propensity score matching was used to compare the two groups. RESULTS: Among the 300 patients with stage III-IV OPSCC, 204 patients were matched for comparing NAC + TORS versus upfront TORS. Between the two groups, no significant difference was observed in recurrences and in survival for RFS, OS, and DSS. In the NAC + TORS p16-positive population, adjuvant therapy could be spared in 51% versus 16% in the upfront surgery cohort (p < 0.001) due to the lower frequency of pathological risk factors after NAC. CONCLUSIONS: NAC followed by TORS for locoregionally advanced OPSCC demonstrated to achieve non-inferior survival outcomes to upfront surgery, while in the p16-positive population allowed to significantly spare adjuvant therapy.

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.

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.

A Scoping Review of Pain Management After Transoral Robotic Surgery.

OBJECTIVE: Pain following transoral robotic surgery (TORS) is a driver of adverse outcomes and can lead to readmission and treatment delays. A scoping review was conducted to characterize TORS-related pain and identify key management strategies utilized in the literature. DATA SOURCES: OVID Medline, CINAHL, Cochrane, Pubmed, and Embase databases were queried. REVIEW METHODS: Two team members independently screened titles and abstracts and completed full-text reviews. Studies examining TORS for OPSCC with quantitative pain data were included. The study followed the PRISMA guidelines. RESULTS: A total of 1467 studies were imported for screening and 25 studies were ultimately included. The average study sample size was 89 participants. 68% were conducted in a single-center academic setting. Pain was assessed on varying timelines up to 3 years using 13 different metrics. Pain peaks days-weeks postoperatively and returns to baseline thereafter. Postoperative pain is a significant cause of morbidity and limited data exist about optimal management. CONCLUSION: Prospective studies are needed to characterize and address TORS-related pain.

A Comparison of Transoral Versus Transcervical Surgical Approaches to Retropharyngeal Lymphadenectomy: A Scoping Review.

IMPORTANCE: A gap in knowledge exists concerning the functional outcomes and complications when comparing various surgical approaches for retropharyngeal lymph node (RPLN) metastases. OBJECTIVE: To explore perioperative outcomes, functional outcomes, and complications associated in the treatment of RPLN metastases. DESIGN: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR) protocol was used to conduct a scoping review of the PubMed and Scopus databases. REVIEW METHODS: We systematically searched 2 databases from inception to January 2023 for articles examining the treatment approaches and postoperative outcomes in the retropharyngeal space. We included English records about surgical approaches, complications, functional outcomes for patients >18 years old with retropharyngeal lymphadenopathy. RESULTS: One-hundred ninety-nine articles were identified, of which 17 were included in the analysis. Three studies assessed RPLN dissection in the postradiation setting. We identified limited knowledge about functional outcomes and complications following surgery for retropharyngeal lymphadenopathy. Overall, acute postoperative dysphagia was documented in 35/170 patients (20.5%). However, the assessment of dysphagia was limited, and not described in the majority of studies. The overall rate of postoperative neuropathy and hematoma were 4.1% and 4.7%, respectively. No postoperative hematomas were documented in the transcervical approach. CONCLUSION: Our findings underscore the need for further research on postoperative outcomes following RPLN dissection. We recommend further studies focusing on objective swallow assessments and long-term outcomes of either surgical approaches.

Quality of life outcomes comparing primary Transoral Robotic Surgery (TORS) with primary radiotherapy for early-stage oropharyngeal squamous cell carcinoma: A systematic review and meta-analysis.

BACKGROUND: Transoral Robotic Surgery (TORS) and radiotherapy are considered oncologically equivalent primary treatment options for early-stage HPV-positive oropharyngeal squamous cell carcinoma (OPSCC). Quality of Life (QoL) and Patient Reported Outcome Measures (PROMs) are therefore imperative in supporting clinical decision-making and optimising patient-centred care. The aim of this article is to evaluate how these primary treatment modalities compare in terms of QoL. MATERIALS AND METHODS: Systematic review and meta-analysis of studies comparing primary TORS and primary radiotherapy for OPSCC using validated QoL tools. Swallowing and global QoL were the primary endpoints with secondary endpoints including all other QoL domains. An inverse variance random-effects model was employed to calculate the weighted estimate of the treatment effects across trials. RESULTS: A total of six studies collectively reporting on 555 patients were included (n = 236 TORS and n = 319 radiotherapy). Meta-analysis showed no significant difference for swallowing (mean difference = -0.24, p = 0.89) and global QoL (mean difference = 4.55, p = 0.14). For the remaining QoL domains (neck/shoulder impairment, neurotoxicity, voice, xerostomia, speech, and distress), the scarcity of data did not permit meta-analysis. However, the existing data showed no significant difference for any except for xerostomia where TORS appears favourable in the sole study reporting on this. CONCLUSIONS: TORS and radiotherapy appear to be comparable primary treatment options for early stage OPSCC when it comes to QoL. However, a substantial proportion of patients in the TORS group received adjuvant (chemo)radiotherapy rendering it difficult to establish the 'true' QoL outcomes following surgery alone. There are also minimal studies reporting QoL outcomes beyond swallowing and global QoL. Further research is therefore needed, including more randomised trials adequately powered to detect differences in QoL outcomes.

Role of TORS as De-Escalation Strategy in HPV-Related Oropharyngeal Cancer, What We Need to Know.

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) presents unique challenges and opportunities for treatment, particularly regarding de-escalation strategies to reduce treatment morbidity without compromising oncological outcomes. This paper examines the role of Transoral Robotic Surgery (TORS) as a de-escalation strategy in managing HPV-related OPSCC. We conducted a comprehensive literature review from January 2010 to June 2023, focusing on studies exploring TORS outcomes in patients with HPV-positive OPSCC. These findings highlight TORS's potential to reduce the need for adjuvant therapy, thereby minimizing treatment-related side effects while maintaining high rates of oncological control. TORS offers advantages such as precise tumor resection and the ability to obtain accurate pathological staging, which can guide the tailoring of adjuvant treatments. Some clinical trials provide evidence supporting the use of TORS in specific patient populations. The MC1273 trial demonstrated promising outcomes with lower doses of adjuvant radiotherapy (RT) following TORS, showing high locoregional tumor control rates and favorable survival outcomes with minimal side effects. ECOG 3311 evaluated upfront TORS followed by histopathologically directed adjuvant therapy, revealing good oncological and functional outcomes, particularly in intermediate-risk patients. The SIRS trial emphasized the benefits of upfront surgery with neck dissection followed by de-escalated RT in patients with favorable survival and excellent functional outcomes. At the same time, the PATHOS trial examined the impact of risk-adapted adjuvant treatment on functional outcomes and survival. The ongoing ADEPT trial investigates reduced-dose adjuvant RT, and the DART-HPV study aims to compare standard adjuvant chemoradiotherapy (CRT) with a reduced dose of adjuvant RT in HPV-positive OPSCC patients. These trials collectively underscore the potential of TORS in facilitating treatment de-escalation while maintaining favorable oncological and functional outcomes in selected patients with HPV-related OPSCC. The aim of this scoping review is to discuss the challenges of risk stratification, the importance of HPV status determination, and the implications of smoking on treatment outcomes. It also explores the evolving criteria for adjuvant therapy following TORS, focusing on reducing radiation dosage and volume without compromising treatment efficacy. In conclusion, TORS emerges as a viable upfront treatment option for carefully selected patients with HPV-positive OPSCC, offering a pathway toward treatment de-escalation. However, selecting the optimal candidate for TORS-based de-escalation strategies is crucial to fully leverage the benefits of treatment de-intensification.

Transoral robotic surgery for supraglottic cancer. A review of oncological and functional outcomes compared to open surgery.

Objective: Supraglottic squamous cell carcinoma (SCC) represents a major surgical challenge in organ-preserving treatment. Type I open partial horizontal laryngectomy (OPHL I) is considered the most popular. To date, minimally-invasive approaches such as laser microsurgery and transoral robotic surgery (TORS) have gained increasing relevance. The aim of this narrative review is to obtain a descriptive comparison of functional and oncological outcomes from studies on patients with supraglottic SCC treated with OPHL I and TORS, respectively. Material and methods: A computerised search was performed using the Pubmed database for articles published from 2000 to 2023. A comparative analysis on functional and oncological outcomes of patients treated by TORS and OPHL I was performed. Results: The present narrative review shows a superiority of TORS compared to open surgery for supraglottic SCC in terms of functional outcomes, while maintaining comparable oncological outcomes. Conclusions: Although recently introduced in the treatment of laryngeal pathology, TORS has been shown to be a reliable technique not only for functional but also for oncological outcomes, ensuring good overall survival, disease-free survival, and disease control rates comparable to OPHL I.

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.

Modified Frailty Index Associates With Transoral Robotic Surgery Complications and Survival: A National Database Study.

OBJECTIVE: The modified frailty index (mFI-5) is a National Surgical Quality Improvement Program-derived 5-factor index that has been proven to reflect frailty and predict morbidity and mortality. We hypothesize that mFI-5 is a valid predictive measure in the transoral robotic surgery (TORS) population. METHODS: Retrospective study utilizing the TriNetX US-collaborative health records network querying for TORS patients. Cohorts were stratified by mFI-5 score which uses five ICD-10 codes: nonindependent functional status, hypertension, obstructive respiratory disease, heart failure, and diabetes mellitus. Cohorts were matched by age using propensity score matching. Outcome measures included survival, infection, pneumonia, tracheostomy dependence, and percutaneous endoscopic gastrostomy dependence. Reported odds ratios were normalized to mFI-5 = 0. RESULTS: A total of 9,081 patients were included in the final analysis. Greater mFI-5 scores predicted decreased survival and increased incidence of postoperative infection and pneumonia. Odds of 5-year mortality were 1.93 (p = 0.0003) for mFI-5 = 2 and 1.90 (p = 0.0002) for mFI-5 = 3. Odds of 2-year mortality were 1.25 (p = 0.0125) for mFI-5 = 1, 1.58 (p = 0.0002) for mFI-5 = 2, and 1.87 (p = 0.003) for mFI-5 = 3. Odds of postoperative infection were 1.51 (p = 0.02) for mFI-5 = 2 and 1.78 (p = 0.05) for mFI-5 = 3. Two-year odds of developing pneumonia were 1.69 (p = 0.0001) for mFI-5 = 2 and 2.84 (p < 0.0001) for mFI-5 = 3. Two-month odds of pneumonia were 1.50 (p = 0.0259) for mFI-5 = 2 and 2.55 (p = 0.0037) for mFI-5 = 3. mFI-5 = 4 or 5 had too few patients to analyze. Using polynomial regression to model age versus incident 5-year post-TORS death (R2 = 0.99), mFI-5 scores better predicted survival than age alone. CONCLUSION: This study demonstrates that mFI-5 predicts mortality, pneumonia, and postoperative infection independently of age. LEVEL OF EVIDENCE: 4 Laryngoscope, 2024.

Outcomes of transoral robotic surgery for early-stage oropharyngeal squamous cell carcinoma with low rates of adjuvant therapy: A consecutive single-institution study from 2013 to 2020.

INTRODUCTION: The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has increased in recent decades, driven by infection with human papillomavirus (HPV). Transoral robotic surgery (TORS) and neck dissection (ND) has been employed as an alternative to radiotherapy/chemoradiotherapy. The current literature is lacking studies providing an exhaustive overview of recurrence characteristics and long-term outcomes in TORS-treated OPSCC-patients. METHODS: All patients treated for OPSCC with primary TORS + ND in Eastern Denmark between 2013 and 2020 were included in the study. The aim was to explore overall survival (OS), recurrence-free survival (RFS), recurrence patterns, and ultimate failure rate (UFR). OS and RFS were examined using the Kaplan-Meier method. Cox proportional regression analyses were employed to examine effect of different variables on risk of death and recurrence. RESULTS: The study included 153 patients of which 88.9 % (n = 136) were treated with TORS alone while 11.1 % (n = 17) received adjuvant therapy. The 1-, 3-, and 5-year OS were 97.4 %, 94.1 %, and 87.6 % while 1-, 3-, and 5-year RFS were 96.6 %, 87.8 %, and 84.9 %. The UFR was 6.5 % in the cohort. Patients with HPV+/p16 + OPSCC had a significantly better 5-year OS of 92.3 % than patients with discordant or double-negative HPV/p16 status (OS = 73.3 %). No differences in outcomes between patients treated with or without adjuvant therapy were found in regression analysis. CONCLUSION: Excellent survival and disease control was obtained with TORS + ND in this cohort, despite lesser application of adjuvant therapy than other TORS-centers, implying that TORS without adjuvant therapy can be successfully applied in treatment of early-stage OPSCC.

Transoral robotic surgery with free flap reconstruction: Functional outcomes of 241 patients at a single institution.

BACKGROUND: Transoral robotic surgery (TORS) for oropharyngeal malignancy optimizes oncologic outcomes while preserving functionality. This study identifies patterns of functional recovery after TORS with free flap reconstruction (FFR). METHODS: Retrospective cohort study at a tertiary care center of patients with primary oropharyngeal tumors treated with TORS with FFR between 2010 and 2022. Patients were categorized into: adjuvant chemoradiation or radiation, or no adjuvant therapy (NAT). Functional outcomes were measured by functional oral intake scale (FOIS). RESULTS: 241 patients were included. FOIS declined at first postoperative appointment (median = 7.0 to 2.0, IQR = [7.0, 7.0], [2.0, 4.0]), and progressively improved to 6.0 (5.0, 6.0) after 1 year, with NAT having the highest FOIS (7.0, p < 0.05). Predictors of poor long-term FOIS included RT and hypoglossal nerve (CN XII) involvement (p < 0.05). CONCLUSIONS: TORS with FFR leads to good long-term function with minimal intake restrictions. Radiation therapy and CN XII involvement increase risk of worse functional outcomes.

First Bite Syndrome in Transoral Surgery for Oropharyngeal Cancer.

OBJECTIVE: First bite syndrome (FBS) is a rare complication of transoral surgery (TOS) for oropharyngeal cancer (oropharyngeal squamous cell carcinoma [OPSCC]). Risk factors for developing this complication are not well described. In this study, we attempt to identify risks for developing FBS in TOS. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary care medical center. METHODS: This study was exempted by the Mayo Clinic institutional review board. We performed a review from January 2017 to November 2022 of all patients who underwent TOS for OPSCC by a single provider. Exclusion criteria included less than 6 months follow up, prior treatment of head and neck cancer, or incomplete records. Demographic data, comorbidities, tumor characteristics, surgical details, adjuvant treatment details, functional outcomes, and oncologic outcomes were assessed. Fisher's Exact test and Kruskal-Wallis rank sum test were used to identify significant variables, and multivariable logistic regression was used to address confounding. RESULTS: One hundred and one patients were identified. Eighty-nine met the inclusion criteria. The mean follow-up was 34 months (median 33). Seven patients (7.9%) developed FBS. Palatine tumor primary (P = .041), resection of styloglossus/stylopharyngeus (P = .039), and parapharyngeal fat manipulation (P = .015) were associated with the presence of FBS. After adjusting for tumor location, manipulation of parapharyngeal fat maintained significance (P = .025). T and N staging, tumor volume, adjuvant radiation, and ligation of lingual/facial arteries were not associated with the development of FBS. Eighty-six percent (6/7) of patients had a resolution of FBS at an average of 11.3 months. CONCLUSION: Manipulation of the parapharyngeal space is independently associated with developing FBS in TOS in our cohort. Further confirmatory studies are warranted.

Transoral Robotic Surgery for Oral Cancer: Evaluating Surgical Outcomes in the Presence of Trismus.

Trismus, defined as restricted mouth opening, is a common complication among Taiwanese oral cancer patients, especially those who chew betel quid. However, the impact of trismus on survival outcomes in oral cancer patients undergoing transoral robotic surgery (TORS) is unclear. This study aimed to investigate the associations between trismus and surgical outcomes in Taiwanese male oral cancer patients treated with TORS. We conducted a retrospective propensity score-matched cohort study of 40 Taiwanese male oral cancer patients who underwent TORS between 2016 and 2022. Overall, 20 patients with trismus were matched to 20 patients without trismus. TORS achieved similar operative and short-term clinical outcomes in trismus patients to non-trismus patients. There were no significant differences between groups in operation time, blood loss, margin status, flap reconstruction rates, duration of nasogastric tube feeding, or length of hospital stay. Kaplan-Meier and Cox proportional hazard regression analyses were performed to compare overall survival (OS) and disease-free survival (DFS) between the two groups. The overall survival (OS) rate at three years was significantly lower in patients with trismus than those without trismus (27.1% vs. 95.0%, log-rank p = 0.02). However, there was no significant difference in disease-free survival (DFS) rates between the trismus and non-trismus groups (36.6% vs. 62.7%, log-rank p = 0.87). After adjusting for confounders, trismus was independently associated with a 13-fold increased risk of mortality (adjusted HR 12.87, 95% CI 1.55-106.50, p < 0.05). In conclusion, trismus appears to be an independent prognostic factor for reduced long-term OS in Taiwanese male oral cancer patients undergoing TORS, though short-term surgical outcomes were non-inferior in the trismus patients. Further research is warranted to clarify the mechanisms linking trismus and survival in this population.

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.

Effect of palatine tonsil tumor resection on postoperative velopharyngeal insufficiency in transoral surgery.

BACKGROUND: Velopharyngeal insufficiency (VPI) is a known complication of transoral surgery (TOS) for oropharyngeal HPV-mediated squamous cell carcinoma. Controversy exists regarding adequate resection margins for balancing functional and oncologic outcomes. METHODS: This retrospective study was exempted by the IRB. Patients who underwent TOS from January 2017 to October 2022 were included. Patient characteristics, treatment details, and oncologic and functional outcomes were evaluated. RESULTS: Fifty-five patients were included. Mean and median follow-up was 34 months. 98% of patients were AJCC stage I/II. Recurrence-free survival was 96% with no local recurrences. Univariate analysis demonstrated an association between VPI and pT stage (p = 0.035), medial pterygoid resection (p = 0.049), and palatal attachment sacrifice (p < 0.001). Multivariate analysis showed sacrifice of the palatal attachments remained a significant risk for VPI (p = 0.009). CONCLUSION: Loss of soft palate pharyngeal attachments is an independent risk factor for VPI. When oncologically appropriate, the palatal attachments to the pharynx may be preserved.

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.

Treatment package time < 14 weeks improves recurrence free and disease specific survival in HPV positive OPC with high-risk features.

BACKGROUND: Guidelines recommend treatment package time < 85 days and time from surgery to radiation initiation < 6 weeks in head and neck cancer patients. However, HPV positive primaries treated with TORS and adjuvant radiotherapy traditionally demonstrate favorable outcomes. METHODS: Single center retrospective chart review of patients diagnosed with HPV positive treatment naïve primary squamous cell carcinoma treated with TORS and postoperative radiation therapy with or without Chemotherapy from 2012 to 2022 with data collection from December 2022-April 2023. Kaplan-Meier survival analysis with log-rank testing assessed the impact of time intervalsbetween diagnosis, TORS, radiation initiation and radiation completion on recurrence free and disease specific survival. Univariate Cox proportional hazards regression analysis was performed to identify factors associated with recurrence free and disease specific survival. Subgroup analysis was done with high risk (positive lymph nodes > 5, >1mm extracapsular extension, positive margins) patients who underwent concurrent Chemotherapy. RESULTS: Of 255 patients (225 males [89 %], average age 58 years, 163 [64 %] high-risk, median follow-up 4.3 years), 22 (8.6 %) had recurrence and 14 died due after disease recurrence.Only radiation length of 5-7 weeks prolonged survival in the entire population. In the high-risk cohort, time from TORS to radiation initiation < 6 weeks improvedrecurrence free survival, while total package time < 14 weeks wasassociated with greater recurrence free and disease specific survival.