A comparison between full-length 16S rRNA Oxford nanopore sequencing and Illumina V3-V4 16S rRNA sequencing in head and neck cancer tissues.

Describing the microbial community within the tumour has been a key aspect in understanding the pathophysiology of the tumour microenvironment. In head and neck cancer (HNC), most studies on tissue samples have only performed 16S rRNA short-read sequencing (SRS) on V3-V5 region. SRS is mostly limited to genus level identification. In this study, we compared full-length 16S rRNA long-read sequencing (FL-ONT) from Oxford Nanopore Technology (ONT) to V3-V4 Illumina SRS (V3V4-Illumina) in 26 HNC tumour tissues. Further validation was also performed using culture-based methods in 16 bacterial isolates obtained from 4 patients using MALDI-TOF MS. We observed similar alpha diversity indexes between FL-ONT and V3V4-Illumina. However, beta-diversity was significantly different between techniques (PERMANOVA - R2 = 0.131, p < 0.0001). At higher taxonomic levels (Phylum to Family), all metrics were more similar among sequencing techniques, while lower taxonomy displayed more discrepancies. At higher taxonomic levels, correlation in relative abundance from FL-ONT and V3V4-Illumina were higher, while this correlation decreased at lower levels. Finally, FL-ONT was able to identify more isolates at the species level that were identified using MALDI-TOF MS (75% vs. 18.8%). FL-ONT was able to identify lower taxonomic levels at a better resolution as compared to V3V4-Illumina 16S rRNA sequencing.

Sinonasal Chondrosarcoma With Unusual Orbital Invasion.

A case is presented of a 43-year-old male with a chronic history of progressive nasal obstruction and epiphora. MRI confirmed a heterogeneous mass involving the middle and superior turbinates with T2 hyperintense and calcified components, with extension into the inferomedial orbit. Tissue biopsy revealed a grade 2 chondrosarcoma of the conventional subtype. Endonasal wide local resection of the lesion was performed with clear margins. The patient had no functional sequelae and will undergo routine surveillance.

Identification of consensus head and neck cancer-associated microbiota signatures: a systematic review and meta-analysis of 16S rRNA and The Cancer Microbiome Atlas datasets.

Introduction. Multiple reports have attempted to describe the tumour microbiota in head and neck cancer (HNSC).Gap statement. However, these have failed to produce a consistent microbiota signature, which may undermine understanding the importance of bacterial-mediated effects in HNSC.Aim. The aim of this study is to consolidate these datasets and identify a consensus microbiota signature in HNSC.Methodology. We analysed 12 published HNSC 16S rRNA microbial datasets collected from cancer, cancer-adjacent and non-cancer tissues to generate a consensus microbiota signature. These signatures were then validated using The Cancer Microbiome Atlas (TCMA) database and correlated with the tumour microenvironment phenotypes and patient's clinical outcome.Results. We identified a consensus microbial signature at the genus level to differentiate between HNSC sample types, with cancer and cancer-adjacent tissues sharing more similarity than non-cancer tissues. Univariate analysis on 16S rRNA datasets identified significant differences in the abundance of 34 bacterial genera among the tissue types. Paired cancer and cancer-adjacent tissue analyses in 16S rRNA and TCMA datasets identified increased abundance in Fusobacterium in cancer tissues and decreased abundance of Atopobium, Rothia and Actinomyces in cancer-adjacent tissues. Furthermore, these bacteria were associated with different tumour microenvironment phenotypes. Notably, high Fusobacterium signature was associated with high neutrophil (r=0.37, P<0.0001), angiogenesis (r=0.38, P<0.0001) and granulocyte signatures (r=0.38, P<0.0001) and better overall patient survival [continuous: HR 0.8482, 95 % confidence interval (CI) 0.7758-0.9273, P=0.0003].Conclusion. Our meta-analysis demonstrates a consensus microbiota signature for HNSC, highlighting its potential importance in this disease.

Transorbital Endoscopic Approach to the Foramen Rotundum for Infraorbital Nerve Stripping.

PURPOSE: To develop and evaluate a transorbital endoscopic approach to the foramen rotundum to excise the maxillary nerve and infraorbital nerve branch. METHODS: Cadaveric dissection study of 10 cadaver heads (20 orbits). This technique is predicated upon 1) an inferior orbital fissure release to facilitate access to the orbital apex and 2) the removal of the posterior maxillary wall to enter the pterygopalatine fossa (PPF). Angulations along the infraorbital nerve were quantified as follows: the first angulation was measured between the orbitomaxillary segment within the orbital floor and the pterygopalatine segment suspended within the PPF, while the second angulation was taken between the pterygopalatine segment and maxillary nerve as it exited the foramen rotundum. With refinement of the technique, the minimum amount of posterior maxillary wall removal was quantified in the final 5 cadaver heads (10 orbits). RESULTS: The mean distance from the inferior orbital rim to the foramen rotundum was 45.55 ± 3.24 mm. The first angulation of the infraorbital nerve was 133.10 ± 16.28 degrees, and the second angulation was 124.95 ± 18.01 degrees. The minimum posterior maxillary wall removal to reach the PPF was 11.10 ± 2.56 mm (vertical) and 11.10 ± 2.08 mm (horizontal). CONCLUSIONS: The transorbital endoscopic approach to an en bloc resection of the infraorbital nerve branch up to its maxillary nerve origin provides a pathway to the PPF. This is relevant for nerve stripping in the context of perineural spread. Other applications include access to the superior portion of the PPF in selective biopsy cases or in concurrent orbital pathology.

The anatomy of the foramina and efferent nerve fibers from the pterygopalatine ganglion in posterolateral nasal wall.

Background: The advance of endoscopic surgery has enabled selective section of the postganglionic nerve branches from pterygopalatine ganglion (PPG) as a modification of the vidian neurectomy. Recent microanatomic studies have suggested that the nasal mucosa is also innervated by multiple efferent rami associated with the sphenopalatine artery (SPA) in the procedure "posterior nasal neurectomy." This anatomic cadaveric study aims to identify all postganglionic nerve fibers in the lateral nasal wall which should inform future surgical procedures aimed at interrupting these nerve fibers. Methods: Two cadaver heads, with a total of three individual sides, were dissected. All neurovascular structures penetrating the vertical plate of palatine bone were carefully identified following meticulous removal of the overlying mucosa layers. The efferent nerve fibers were identified and dissected back to their origin-the PPG or greater palatine nerve. Results: Several foramina with efferent PPG nerves were identified on the vertical plate of the palatine bone and medial pterygoid plate. The superior, middle, and inferior turbinates (IT) were innervated by efferent nerves from the PPG via the anterior region of the SPA. The IT was innervated from nerves originating from behind the SPA through bony foramina. The lateral wall of inferior meatus was innervated by efferent nerves that originated from greater palatine nerve and pharyngeal nerve. Conclusion: This study demonstrated the anatomical positions of the postganglionic nerves that innervate the lateral nasal wall. These nerves are located anterior to the SPA as well as posterior to the SPA, where they penetrate the palatine bone.Level of evidence: NA.

Prognosis of oral squamous cell carcinoma with perineural invasion: A comparative study of classification types.

OBJECTIVE: To investigate the histological location and extent of perineural invasion (PNI) as prognostic factors. DESIGN: Retrospective review of medical records and histological analysis of 116 patients with oral squamous cell carcinoma (OSCC). SETTING: Two major public tertiary hospitals treating head and neck cancer, Royal Adelaide Hospital and Flinders Medical Centre, in South Australia. PARTICIPANTS: Patients diagnosed with OSCC who underwent primary surgical treatment with curative intent at these two centres from January 1, 2005 through December 31, 2015. MAIN OUTCOME MEASURES: The primary end points were disease-free survival (DFS) and disease-specific survival (DSS). RESULTS: The presence of PNI as a binary factor alone did not significantly influence the clinical outcomes. Extratumoural (ET) PNI as measured from the tumour edge was associated with worse DFS on multivariate analyses. Multifocal PNI was associated with worse DFS and DSS. DFS in multifocal PNI was worse irrespective of whether adjuvant therapy was administered. CONCLUSIONS: The presence of multifocal and ET PNI in OSCC is associated with poor clinical outcomes. Patients with multifocal PNI were associated with worse DFS even with adjuvant therapy.

Cerebrospinal Fluid Leak From the Orbital Roof During Orbital Exenteration.

Cerebrospinal fluid leaks are rarely encountered by orbital surgeons, but can occur during dacryocystorhinostomy, orbital decompression, orbital exenteration, and enucleation. The authors present a case of cerebrospinal fluid leak from an injury to the orbital roof during orbital exenteration with the use of monopolar cautery. This was repaired with multilayer closure. Surgeons performing orbital exenteration must be aware of the possibility of this complication when using monopolar electrocautery to transect the orbital contents at the apex during an exenteration.Injury to the orbital roof with monopolar cautery during orbital exenteration can result in cerebrospinal fluid leak, and orbital surgeons must be aware of the possibility of its occurrence.

The efficacy of a novel budesonide chitosan gel on wound healing following endoscopic sinus surgery.

BACKGROUND: Adhesion formation and ostial stenosis are common causes of surgical failure after endoscopic sinus surgery (ESS). Postoperative topical steroid application has been shown to improve wound healing. Chitosan-dextran gel (CD gel) is an effective hemostatic nasal dressing. This study aims to determine the effect of the addition of budesonide to CD gel on postoperative ostial stenosis and adhesion formation following ESS. METHODS: This prospective, blinded, randomized controlled trial was conducted between October 2012 and April 2015. Thirty-six patients over 18 years undergoing ESS were randomized to receive either: no treatment, CD gel, CD gel with 1 mg/ 2 mL budesonide, or topical steroid cream to their left or right sinuses (different treatment each side). Each sinus ostium and endoscopic features of wound healing was measured intraoperation, and 2 weeks, 3 months, and 12 months postoperation. RESULTS: Data was analyzed using the analysis of variance (ANOVA) and post hoc Tukey honestly significant difference (HSD) tests. There was a significant reduction in stenosis within all 3 sinuses ostia sites when CD + budesonide was compared to control, with the greatest effect seen at 12 months: The mean ± standard deviation (SD) percentage of baseline areas at 12 months were 76% ± 6.2% vs 37% ± 23.5%, 76% ± 6.3% vs 52% ± 4.9%, and 83% ± 6.5% vs 58% ± 5.0% (all p < 0.05), for CD + budesonide compared to control in the frontal, sphenoid, and maxillary sinuses, respectively. The incidence of adhesions was 4% in the CD + budesonide group compared to 15% in the control group. CONCLUSION: This study has shown that CD gel, when combined with topical budesonide solution, improves long-term sinus ostial patency and prevents ostial stenosis post-ESS.

Stress response and communication in surgeons undergoing training in endoscopic management of major vessel hemorrhage: a mixed methods study.

BACKGROUND: Major vessel hemorrhage in endoscopic, endonasal skull-base surgery is a rare but potentially fatal event. Surgical simulation models have been developed to train surgeons in the techniques required to manage this complication. This mixed-methods study aims to quantify the stress responses the model induces, determine how realistic the experience is, and how it changes the confidence levels of surgeons in their ability to deal with major vascular injury in an endoscopic setting. METHODS: Forty consultant surgeons and surgeons in training underwent training on an endoscopic sheep model of jugular vein and carotid artery injury. Pre-course and post-course questionnaires providing demographics, experience level, confidence, and realism scores were taken, based on a 5-point Likert scale. Objective markers of stress response including blood pressure, heart rate, and salivary alpha-amylase levels were measured. RESULTS: Mean "realism" score assessed posttraining showed the model to be perceived as highly realistic by the participants (score 4.02). Difference in participant self-rated pre-course and post-course confidence levels was significant (p < 0.0001): mean pre-course confidence level 1.66 (95% confidence interval [CI], 1.43 to 1.90); mean post-course confidence level 3.42 (95% CI, 3.19 to 3.65). Differences in subjects' heart rates (HRs) and mean arterial blood pressures (MAPs) were significant between injury models (p = 0.0008, p = 0.0387, respectively). No statistically significant difference in salivary alpha-amylase levels pretraining and posttraining was observed. CONCLUSION: Results from this study indicate that this highly realistic simulation model provides surgeons with an increased level of confidence in their ability to deal with the rare but potentially catastrophic event of major vessel injury in endoscopic skull-base surgery.

Simulation Training for Vascular Emergencies in Endoscopic Sinus and Skull Base Surgery.

Carotid artery injury during endonasal surgery is a feared and potentially catastrophic complication. Simulation training provides the opportunity for a realistic experience with management of major vascular injuries. The sheep model of carotid artery injury reproduces the challenges of dealing with vascular emergencies during endoscopic sinus and skull base surgery, which include working in narrow nasal confines, high-flow/high-pressure vascular injury, and the immediately challenging surgical field. Simulated vascular emergencies allow for research and development; training using various surgical techniques to control the field, including hemostatic products or direct vascular closure techniques; and consequently improved patient care and outcomes.

Management of arterial injury during endoscopic sinus and skull base surgery.

PURPOSE OF REVIEW: The most feared complication during endonasal surgery is a carotid artery injury. The sheep model of carotid injury provides training for this event by giving a realistic endoscopic experience of major vascular injuries and tissue hemostasis. RECENT FINDINGS: The sheep model of carotid artery injury recreates the narrow nasal confines and high-flow/high-pressure vascular injury accurately reproducing the endoscopic challenges seen in such vascular emergencies. This has led to the development of surgical techniques that quickly and effectively control the field of bleeding and achieve reliable hemostasis including the crushed muscle patch new direct vascular closure technologies. Vascular emergency simulation training is achieving better outcomes for our patients. SUMMARY: All skull base surgeons are at risk of the unexpected carotid artery injury and recently, the sheep model not only effectively recreates this situation but has identified clinically tried and tested techniques at managing this situation and is improving patient outcomes.

Coping with catastrophe: the value of endoscopic vascular injury training.

BACKGROUND: Inadvertent injury to the internal carotid artery (ICA), if poorly managed, not only presents a risk of exsanguination but can also result in significant long-term morbidity. Through the implementation of a novel animal model of endoscopic carotid artery injury (CAI), effective techniques to manage this scenario have been developed. The Vascular Injuries Workshop has trained over 110 surgeons in these techniques. This study reviews events of major arterial hemorrhage managed by surgeons who completed this vascular injury workshop training. METHODS: We report a retrospective multicenter case series of patients who required endoscopic management of intranasal major arterial hemorrhage. Delegates who had attended the course were contacted by e-mail and surveyed with regard to instances of major arterial bleeding and the management undertaken. Patient demographics, tumor type, factors influencing injury, management technique, and outcomes were reviewed. RESULTS: The cases reported herein are characterized as follows: 9 cases are reported in total, 3 male, 6 female; age range 37 to 82 years; 1 basilar artery, and 8 ICA injuries. Each case was successfully managed endoscopically with intraoperative muscle patch application. There were no deaths, 1 case of pseudoaneurysm with successful endovascular treatment, 2 cases of impaired carotid flow, and 1 carotid dissection was conservatively managed. There were no permanent neurological sequelae or other permanent morbidity. CONCLUSION: The Vascular Injuries Workshop arms surgeons with a structured approach to managing the surgical field and provides effective hemostatic techniques in the face of impending catastrophe. In comparison to the existing literature on ICA rupture, our results show trained surgeons are well equipped to achieve safe outcomes for their patients.

Endoscopic direct vessel closure in carotid artery injury.

BACKGROUND: Internal carotid artery (ICA) injury represents one of the most challenging management scenarios for the endoscopic skull base surgeon. Techniques developed through use of an animal model of carotid injury have shown direct vessel closure techniques to be effective in gaining hemostasis and preventing subsequent complications. The aim of this study was to investigate the effectiveness of the novel AnastoClip vessel closure system in ICA injury. METHODS: Nine sheep underwent ICA dissection/isolation followed by the artery placement within a modified "sinus model otorhino neuro trainer" (SIMONT) model. Standardized linear injuries were made and treated endoscopically with the AnastoClip device. Specific outcome measures included attainment of primary hemostasis, procedure time, blood loss, pseudoaneurysm formation and carotid patency on follow-up magnetic resonance imaging (MRI). RESULTS: Primary hemostasis was achieved in all cases. No instances of secondary bleeding. Procedure times averaged 5 minutes and 25 seconds. Average blood loss was 146 mL. All 9 sheep reached the 3-month end point. Eight showed normal carotid flow on MRI, with 1 case of pseudoaneurysm. CONCLUSION: Direct vessel closure is an effective endoscopic technique in ICA injury. It allows for visual confirmation of hemostasis and carotid flow and permits the surgeon to continue with surgery despite the complication. The novel design of the AnastoClip can maintain normal vessel patency as well as accommodate pulsatile flow.

The relationship between hypotension, cerebral flow, and the surgical field during endoscopic sinus surgery.

OBJECTIVES/HYPOTHESIS: Hypotensive anesthesia is often used in endoscopic sinus surgery (ESS) to improve surgical visibility; however, its safety and efficacy in this role are yet to be justified. This study aimed to evaluate the effect of hypotensive anesthesia on both real-time middle cerebral artery blood flow velocity (Vmca) and the severity of surgical bleeding in patients undergoing ESS. STUDY DESIGN: Prospective, observational cohort study. METHODS: Thirty-two patients undergoing hypotensive anesthesia for ESS at a single tertiary institution during February 2011 to July 2012 were recruited for the study. Transcranial Doppler ultrasonography measured periodic Vmca, which were time-matched for hemodynamic and respiratory factors. One-minute video segments corresponding with each Vmca reading were randomized and distributed to two blinded observers for bleeding assessment. RESULTS: Three hundred and fifty-six data time points were recorded for systolic, diastolic, and mean arterial blood pressure (MAP), pulse rate, respiratory rate, end-tidal carbon dioxide concentration, Vmca, and bleeding assessment score (BAS). A direct relationship exists between MAP and Vmca (r = 0.77, P < .0001) as well as MAP and BAS (r = 0.36, P < .0001). MAP levels above 60 mm Hg maintained at least 50% of baseline Vmca flow in almost 90% of all time points. CONCLUSIONS: Hypotensive anesthesia is an effective method of controlling intraoperative bleeding during endoscopic sinus surgery; however the effect is clinically small in low MAP ranges. In otherwise healthy patients undergoing ESS with general anesthesia, reducing MAP to below 60 mm Hg may increase the risk of cerebral ischemia.

Early and late complications of endoscopic hemostatic techniques following different carotid artery injury characteristics.

BACKGROUND: The most dreaded hemorrhagic complication in endoscopic endonasal surgery is injury to the internal carotid artery (ICA). Although a number of treatment protocols are currently used, none have been formally investigated. This study aims to compare the efficacy of the muscle patch, bipolar diathermy, and aneurysm clip on hemostasis, pseudoaneurysm formation, and long-term vessel patency for different injury types in a sheep model of carotid bleeding. METHODS: Twenty-seven sheep underwent ICA dissection/isolation followed by the artery placement within a modified "sinus model otorhino neuro trainer" (SIMONT) model. Standardized linear, punch, and stellate injuries were made. Randomization of sheep to receive 1 of 3 hemostatic techniques was performed (muscle, bipolar, clip). Specific outcome measures included attainment of primary hemostasis, time to hemostasis, blood loss, pseudoaneurysm formation, and carotid patency on follow-up magnetic resonance imaging (MRI). RESULTS: Bipolar achieved primary hemostasis in 7 of 9 cases and 2 cases of secondary hemorrhage. It had no associated pseudoaneurysm formation. Carotid patency was variable on follow-up MRI. Muscle patch achieved 100% primary hemostasis with 2 cases of secondary hemorrhage. There were 2 cases of pseudoaneurysm and 100% patency rate on follow-up MRI. Aneurysm clip achieved 100% primary hemostasis with 1 case of secondary hemorrhage. No pseudoaneurysm formation and a 50% rate of carotid insufficiency on MRI. CONCLUSION: This study shows that the crushed muscle patch and aneurysm clip can be viable options in the management of ICA injury with short-term and long-term benefits. Complications associated with these techniques were comparable if not reduced when compared to the published literature.

Management of carotid artery injury in endonasal surgery.

Introduction Carotid artery injury (CAI) is the most feared and potentially catastrophic intraoperative complication an endoscopic skull base surgeon may face. With the advancement of transnasal endoscopic surgery and the willingness to tackle more diverse pathology, evidence-based management of this life-threatening complication is paramount for patient safety and surgeon confidence. Objectives We review the current English literature surrounding the management of CAI during endoscopic transnasal surgery. Data Synthesis The searched databases included PubMed, MEDLINE, Cochrane database, LILACS, and BIREME. Keywords included "sinus surgery," "carotid injury," "endoscopic skull base surgery," "hemostasis," "transsphenoidal" and "pseudoaneurysm." Conclusions Review of the literature found the incidence of CAI in endonasal skull base surgery to be as high as 9% in some surgeries. Furthermore, current treatment recommendations can result in damage to critical neurovascular structures. Management decisions must be made in the preoperative, operative, and postoperative setting to ensure adequate treatment of CAI and the prevention of its complications such as pseudoaneurysm. Emphasis should be placed on surgical competency, teamwork, and technical expertise through education and training.