The radiological unknown primary of the head and neck: Recommendations for imaging strategies based on a systematic review.

OBJECTIVES: To develop recommendations for the radiological investigation of clinically occult primary cancer in the head and neck. DESIGN AND SETTING: In accordance with PRISMA guidelines, a search was performed on Medline, Embase and Cochrane library databases to investigate the efficacy of ultrasound guided Fine Needle Aspiration (US FNAC), contrast enhanced CT (CECT), magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose PET-CT (18F-FDG PET-CT) in the investigation of head and neck squamous cell carcinoma from an unknown primary (HNSCCUP) presenting with a metastatic cervical lymph node (s). The Quality Assessment of Diagnostic Accuracy Studies Version 2 tool and SIGN 50 guidelines were used to assess the risk of bias and quality of the included studies. PARTICIPANTS: Adult patients presenting with metastatic cervical lymph nodes from a HNSCCUP. MAIN OUTCOME MEASURES: Utility of different imaging modalities (PET-CT, MRI, CE CT and US FNAC in the management of HNSCCUP). RESULTS: Twenty-eight studies met inclusion criteria; these were meta-analyses, systematic reviews, prospective and retrospective studies. CONCLUSIONS: The optimal imaging strategy involves utilisation of various imaging modalities. US FNAC can provide the initial diagnosis and HPV status of the occult primary tumour. CECT and MRI detect up to 44% of occult tumours and guide management. FDG PET-CT is the most sensitive imaging modality for the detection of CUP and should be performed prior to panendoscopy.

Incidental uptake of fluorodeoxyglucose in the Waldeyer's ring and risk of oropharyngeal malignancy.

PURPOSE: Fluorodeoxyglucose (FDG) positron emission tomography (PET) is increasingly used to diagnose and stage malignancy. The aim of this article is to investigate the significance of incidental FDG uptake in the Waldeyer's ring and to assess its value in predicting clinically occult oropharyngeal malignancy. METHODS: All FDG-PET/CT scans performed in Imperial College NHS Foundation Trust, UK between January 2012 and November 2018 were included. Patients with known or suspected oropharyngeal malignancy or lymphoma were excluded. Minimum follow-up was 12 months. RESULTS: A total of 724 scans revealed oropharyngeal uptake of FDG. Of these, 102 were included in the study. Most patients (62.1%) were scanned as part of staging for other malignancies. Oropharyngeal FDG uptake was asymmetrical in 57.3% of the cases. Uptake was more common in the tonsils (56.3%), followed by the tongue base (31.1%) and both sites (12.6%). In 41.7% of reports, appearance was described as likely physiological; however, 52.4% of reports advised direct visualisation, clinical correlation or ENT opinion. Only 24.3% (25/102) of patients were referred and seen by ENT, 14.6% (15/102) of which had an interval PET scan and 8.7% (9/102) proceeded to tissue diagnosis. There was one oropharyngeal cancer identified and one unexpected metastasis from esophageal cancer. CONCLUSION: Incidental uptake on PET/CT in the oropharynx is common. However, malignancy is rare (1.9%) and, when present, is associated with high SUVmax and asymmetrical uptake. Imaging results must be correlated clinically. These patients should be seen by an ENT specialist yet most may not require further investigations.

Emergency airway training: "Who are you going to FONA?"

OBJECTIVES: To demonstrate face and content validity of a home-made simulation model as a training tool for front of neck access (FONA) procedures. DESIGN: This was a prospective evaluation study, in which experienced otolaryngologists and trainees were recruited to complete 3 tasks using our FONA model. SETTING: The study was completed during regular simulation training days and international conferences. PARTICIPANTS: A total of 52 participants completed the questionnaire and were included in the study; 25 were experts and 27 were trainees. MAIN OUTCOME MEASURES: All participants completed a validated 15-item questionnaire using a 5-point likert scale to assess the model across 4 domains: face validity (FV), global content (GC), task-specific content (TSC) and curriculum applicability (CTR). RESULTS: There were no statistically significant differences between the groups ratings for FV, GC, TSC or CTR (P = .76, .13, .4 and .67, respectively). The model achieved a median FV of 4 (IQR 4-5) with the agreement of experienced and trainee groups (68.9% and 92%, respectively). The median GC validity score was 5 (IQR 4-5) with the agreement of 87.6% and 98.4% in respected groups. The model achieved a median TSC of 4.8 (IQR 4-5) with the agreement of 54.5% and 99% in respected groups. The median CTR score was 5 (IQR 4-5) with the agreement of 54.4% and 100% in respected groups. CONCLUSION: Our home-made FONA model achieved face and content validity for training and is safe and affordable for teaching basic front of neck access skills to otolaryngology trainees.

Survival outcomes for head and neck cancer patients with N3 cervical nodal metastases.

BACKGROUND: Management of metastatic N3 nodal disease from primary head and neck squamous cell carcinoma (HNSCC) is controversial. Recently, there has been a move to observation of the neck for those who achieve complete response (CR) after chemoradiotherapy (CRT). We sought to determine survival outcomes for N3 nodal disease, particularly for patients with human papilloma virus (HPV)-positive HNSCC. METHODS: We carried out a systematic search of MEDLINE and Embase for articles between 01/2008 and 12/2017. Articles on N3 nodal disease in HNSCC patients treated with CRT or surgery + adjuvant RT/CRT were included if they reported on oropharyngeal or HPV+ subgroups. Local control (LC), nodal control (NC), distant metastasis-free survival (DMFS), disease-free survival (DFS) or overall survival (OS) was assessed. RESULTS: Nine studies met the inclusion criteria. Eight of these studies (N = 5304) allowed further comparison: 4 were on CRT, 2 on surgery + RT/CRT and 2 on both. Four of these eight studies and the remaining included study reported on residual nodal disease on histology after neck dissection (ND) following CRT. Patients treated with CRT achieved LC rates of 77%-94% at 2-3 years; those who had a CR had LC of >90%. Better NC was noted in patients who achieved a CR. Three-year OS was better for HPV+ HNSCC (range, 55.2%-81%). Patients with CR had better survival outcomes (DMFS 77% at 3 years vs 69.8% for HPV+; OS 68.9% at 3 years vs 55.2% for HPV+). Primary surgery demonstrated similar survival for HPV+ vs HPV- and better survival in oropharyngeal cancers. Five-year DFS rates varied from 30% to 87%, and OS from 26.6% to 84%. For patients with non-CR, positive histology rates varied from 27.3% to 100%, with average positive histology rates of 27.3% in HPV+ patients with non-CR vs 60% for HPV- patients with non-CR. CONCLUSION: The current literature does not support the de-escalation of treatment with HPV- N3 disease. Observation of HPV+ patients who achieve a CR post-CRT is reasonable but further prospective studies are required given the heterogeneity and risk of bias within these current studies. Planned ND should remain standard of care for non-CR cohort.

Use of cidofovir in a patient with severe mpox and uncontrolled HIV infection.

A 48-year-old man with poorly controlled HIV presented with severe human monkeypox virus (hMPXV) infection, having completed 2 weeks of tecovirimat at another hospital. He had painful, ulcerating skin lesions on most of his body and oropharyngeal cavity, with subsequent Ludwig's angina requiring repeated surgical interventions. Despite commencing a second, prolonged course of tecovirimat, he did not objectively improve, and new lesions were still noted at day 24. Discussion at the UK National Health Service England High Consequence Infectious Diseases Network recommended the use of 3% topical and then intravenous cidofovir, which was given at 5 mg/kg; the patient made a noticeable improvement after the first intravenous dose. He received further intravenous doses at 7 days and 21 days after the dose and was discharged at day 52. Cidofovir is not licensed for use in treatment of hMPXV infection. Data for cidofovir use in hMPXV are restricted to studies in animals. Four other documented cases of cidofovir use against hMPXV have been reported in the USA in 2022, but we present its first use in the UK. The scarcity of studies into the use of cidofovir in this condition clearly shows the need for robust studies to assess efficacy, optimum dosage, timing, and route of administration.

Antivirals for idiopathic sudden sensorineural hearing loss.

BACKGROUND: Idiopathic sudden sensorineural hearing loss (ISSHL) is characterised by sudden loss of hearing of cochlear or retro-cochlear origin without an identifiable cause. Antivirals are commonly prescribed, but there is no consensus on the treatment regimen or their effectiveness. OBJECTIVES: To determine the effectiveness and side effect profile of antivirals in the treatment of ISSHL. SEARCH METHODS: We systematically searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 5), PubMed, EMBASE, CINAHL and other databases to 12 June 2012. We also scanned the reference lists of identified studies for further trials. SELECTION CRITERIA: Randomised controlled trials comparing different antivirals versus placebo (both with or without other treatment). DATA COLLECTION AND ANALYSIS: Two authors independently extracted data, met to resolve disagreements and contacted study authors for further information. We assessed study risk of bias independently. We considered meta-analysis inappropriate and ultimately not possible due to differing treatment protocols of varying dose and duration, together with differing inclusion criteria and outcome measures between studies. The results of each study are reported individually. MAIN RESULTS: We included four randomised trials (257 participants). The overall risk of bias in the included studies was low. Two trials compared the addition of intravenous acyclovir to a steroid (prednisolone). One included 43 participants, the other 70 patients. Neither demonstrated any hearing improvement with ISSHL. Another (84 patients) did not show any statistically significant difference between groups with the addition of valacyclovir to prednisolone (compared to steroid plus placebo) with respect to change in pure-tone audiogram. Comparing the addition of intravenous acyclovir to hydrocortisone with hydrocortisone alone, the final trial did not show any statistically significant difference between groups (60 patients). No trial documented any serious adverse effects related to the use of antiviral treatment. One study reported slight to moderate nausea equally in the acyclovir and placebo groups (one patient in each). Another reported insomnia, nervousness and weight gain with valacyclovir (number not specified). Even though no meta-analysis was possible, evidence from the four RCTs has demonstrated no statistically significant advantage in the use of antivirals in the treatment of ISSHL. AUTHORS' CONCLUSIONS: There is currently no evidence to support the use of antiviral drugs in the treatment of ISSHL. The four trials included in this review were, however, small and with a low risk of bias. Further randomised controlled trials with larger patient populations, using standardised inclusion criteria, antiviral regimes and outcome measures, are needed in order for adequate meta-analysis to be performed to reach definitive conclusions. A uniform definition of ISSHL should also be established, together with what constitutes adequate recovery.

The impact of mixing surgical subspecialty patients on wound infection rates.

To investigate the impact of mixing surgical subspecialty patients on post-operative wound infections. A retrospective analysis of post-operative wound infections in head and neck surgery patients before and after mixing them with urology patients. We selected two periods that are identical in duration and seasonal spread. The first was from March 2005 to November 2005 and the second was from March 2006 to November 2006. 1,381 patients underwent head and neck surgery at our institution in the two periods; 705 in the first and 676 in the second. Excluding MRSA positive swabs, the rate of positive swabs or "episodes" was 4% in the first group (2005) and 10% in the second group (2006). The monthly breakdown showed a significant increase in the second group (2006) (p = 0.024). Uro-genital microorganisms were the main factor contributing to the increase in wound infection rates in the second period (p = 0.008). Other organisms like MRSA, remained statistically unchanged (p = 0.464). It is recommend that head and neck surgery patients are better managed on separate wards. Clinicians should have a low threshold of suspecting a broader range of microorganisms when other specialty patients are on the same ward.

Swallowing Outcomes in 7 Patients Following Endoscopic Cricopharyngeal Myotomy With Primary Closure.

Cricopharyngeal spasm and pharyngeal pouch can result in severe dysphagia symptoms that can have a significant impact on a patient's quality of life. Several surgical interventions have been demonstrated including balloon dilatation, botox injection, and open and endoscopic cricopharyngeal myotomy. The aim of this case series is to describe our technique for endoscopic cricopharyngeal myotomy and compare pre- and postoperative swallowing outcomes using objective swallowing questionnaires in a small series of patients. Seven patients diagnosed with cricopharyngeal spasm or grade 1 pharyngeal pouch on barium swallow were prospectively observed. MD Anderson Dysphagia inventory (MDADI) and Dysphagia handicap index (DHI) were given to patients before and after their operation. All patients underwent the same surgical technique with the cricopharyngeal bar divided and the defect closed with dissolvable sutures. Mean inpatient stay was 7 days (range 1-8) and mean time to resumption of soft diet was 4 (range 1-7) days. All patients resumed oral diet before discharge. MDADI scores showed improvement across all domains, however only the emotional score achieved statistical significance (P = .04). Dysphagia handicap index scores showed a statistically significant improvement across functional, emotional, and total domains. Postoperative chest infection treated with oral antibiotics occurred in 3 patients (43%) and no other complications were documented. In conclusion, endoscopic cricopharyngeal myotomy with primary sutured endoscopic closure can result in a significant benefit to patient's swallowing symptoms, emotional well-being, and quality of life.

Feasibility of Free Flap Reconstruction Following Salvage Robotic-Assisted Resection of Recurrent and Residual Oropharyngeal Cancer in 3 Patients.

INTRODUCTION: Human papilloma virus (HPV)-positive oropharyngeal cancer carries a good prognosis when managed with primary chemoradiotherapy. However, the dramatically increasing rate of this disease means more patients are now developing recurrence, with surgery remaining the mainstay of treatment. Despite this, there is no agreed technique for excision of recurrent oropharyngeal cancer. OBJECTIVE: We describe the transoral robotic technique employed by our head and neck multidisciplinary team (MDT) in the management of patients with recurrent HPV positive oropharyngeal cancer and assess their symptom severity using quality of life and swallowing questionnaires. METHOD: Three (2 males:1 female, mean age 60.7 years) patients with recurrent or residual p16 positive oropharyngeal cancer following radical chemoradiotherapy were identified. All patients underwent selective neck dissection, tracheostomy, and transoral robotic surgery (TORS)-assisted partial oropharyngeal resection with the resultant defect closed with a robotic assisted radial forearm free flap (RFFF). Patient quality of life, symptom severity, and swallowing were assessed pre- and postoperatively using the University of Washington Quality of Life score and MD Anderson Dysphagia Index (MDADI). RESULTS: Histopathological examination revealed complete clearance of the primary lesion in all cases. Two patients made uneventful recoveries, while one patient developed a chest infection and tracheocutaneous fistula managed conservatively. Mean inpatient stay was 15 days (range 8-27). University of Washington Quality of Life and MDADI scores showed a mild improvement in symptoms following surgery. CONCLUSION: Surgical management of recurrent oropharyngeal cancer remains a technical challenge; however, MDT discussion and judicious use of TORS oropharyngeal resection and RFFF can result in good oncological and quality of life outcomes with acceptable postoperative complications and symptoms.

"No drain, no gain": Validation of novel quinsy simulation model.

OBJECTIVES: To test a novel, low-cost, home-made model for needle aspiration of PTA.To ascertain whether simulation-based teaching using this model was superior to lecture-based teaching in increasing confidence and reducing anxiety relating to PTA aspiration.To assess whether there was an improvement in outcomes for PTA patients at one hospital following the delivery of a simulation-based training session using our model. METHODS: We designed two teaching sessions for junior doctors starting work in ENT: a simulation-based teaching session using a low-cost home-made simulation model and a lecture-based teaching session covering the same content. We asked the participants to complete pre- and post-session surveys regarding confidence and anxiety levels and analyzed this data. We also retrospectively collected data over 3 months for patients referred to ENT with suspected PTA and assessed their outcomes. We assessed patient outcomes before and after the delivery of a simulation-based training course using our model. RESULTS: Simulation-based teaching using our model was shown to be associated with a statistically significant increase in junior doctors' confidence levels. Reaccumulation and reattendance rates for PTA following aspiration were 16.67% and 22.7% respectively preintervention and 0% and 7.14% respectively postintervention. CONCLUSION: A regular simulation-based teaching session should be introduced using a PTA aspiration model for junior doctors as it leads to increased confidence levels, and reduced reaccumulation and recurrence rates of PTA. LEVEL OF EVIDENCE: Level 4.

Oligometastatic renal cell carcinoma in the palatine tonsil: successful resection using trans-oral robotic surgery.

A man in his mid 70s was referred to head and neck outpatients with bulky tissue in the left tonsillar fossa. He had previously been treated for oligometastatic renal clear cell carcinoma (diagnosed over 15 years prior to disease recurrence) by tonsillectomy and adjuvant radiotherapy (years from primary treatment), followed by trans-oral laser surgery to his oropharyngeal recurrence 3 years later. Examination under anaesthetic and biopsy confirmed further recurrence of disease in the left tonsillar fossa, with parapharyngeal extension, which has not been previously reported in the literature. After discussion in the head and neck and urology multi-disciplinary teams meeting, the patient was offered trans-oral robotic-assisted surgery (TORS) for local control and prevention of progression of a fungating oropharyngeal mass. TORS partial pharyngectomy and left buccal artery myomucosal flap reconstruction were successfully carried out, with preservation of some swallow function.

Intraparotid lymph node metastasis from a nasal septal carcinoma: an unusual source of the unknown primary.

Metastatic disease to the parotid lymph nodes typically occurs secondary to head and neck and cutaneous squamous cell carcinomas (SCC). Nasal septal SCC is an exceedingly rare primary cancer that rarely spreads to regional lymph nodes. A 39-year-old man presented with left-sided cervical lymphadenopathy and nasal polyposis. Initial assessment suggested that he may have a head and neck SCC of unknown origin with nodal deposits in close proximity to the parotid gland. Cross-sectional imaging did not reveal the primary source. After further review of imaging and examination under anaesthetic, the primary SCC was found on the left nasal septum. The patient ultimately required a type 1 craniofacial resection and adjuvant chemoradiotherapy to treat the disease. Thorough investigation of the 'unknown primary' SCC including cross-sectional imaging and endoscopic examination is essential for the diagnosis of rare and unusual primary SCCs. Nasal septal SCC can be successfully managed with combined modality treatment in the form of surgical resection and chemoradiotherapy.

Novel Energy Devices in Head and Neck Robotic Surgery - A Narrative Review.

The advent of trans-oral robotic surgery (TORS) has facilitated removal of tumors previously deemed unresectable, by providing access to the deep structures of the head and neck. Despite this, the wider dissemination of TORS has been restricted due to issues with line of access, as the da Vinci robot was never designed with head and neck surgery in mind. Flexible instruments and novel energy delivery devices offer great potential in overcoming some of the existing challenges surrounding TORS. This review aimed to summarize the existing literature surrounding energy delivery in TORS and highlight areas of future innovation. MEDLINE was searched for studies relating to energy delivery in TORS in November 2019. The existing literature surrounding monopolar and bipolar electrocautery, LASER (CO2, Tm:YAG and blue LASER), Ligasure and Harmonic was reviewed. Additionally, the latest iteration of the da Vinci; the SP, and the FLEX robot were evaluated as novel methods of energy delivery in TORS. Overall, these novel energy devices and robotic systems are predicted to further improve energy delivery to the head and neck. The use of flexible LASER in particular is well substantiated in the literature. This has the potential to achieve treatment de-escalation, based on the excellent outcomes demonstrated for disease-free margins and post-operative morbidity.

Transoral Robotic Surgery for Oropharyngeal Squamous Cell Carcinoma: Improving Function While Maintaining Oncologic Outcome.

The improved survival in patients with HPV-positive (human papilloma virus) oropharyngeal squamous cell carcinoma as compared with HPV-negative disease calls for treatment that preserves quality of life, particularly a functional swallow. There are several trials currently assessing treatment de-escalation in terms of less invasive transoral robotic surgery, reduced-dose radiotherapy, and omission of chemotherapy in this disease cohort. It is important for head and neck oncology surgeons to stay abreast of developments in this area to offer their patients the most up-to-date treatment and consider recruiting patients to trials at their institutions. For this purpose, we provide a summary of current trials and associated challenges in managing a disease with fast-evolving treatment algorithms.

Specialty Showcase Days: Can Specialist Careers Workshops Improve The Consideration Of ENT For Medical Students?

OBJECTIVE: We hypothesize that poor consideration of specialist surgery is due to a lack of exposure to information about careers and practice itself. Ear, Nose, and Throat (ENT) surgery is given little weight in medical school curricula, despite ENT problems being extremely common. Our objective is to assess whether a specialty showcase day was sufficient to boost informed consideration of this career. DESIGN: We designed a half-day course involving an interactive careers workshop exploring ENT as a specialty choice, alongside simulation stations of commonly presenting ENT problems led by ENT doctors. We used pre- and post-course evaluation sheets to explore factors that encourage and discourage students from surgical careers and perceptions of ENT. SETTING: A large proportion of UK medical schools do not offer ENT placements, and of those that do, nearly half are not compulsory. This leaves students unaware of ENT as a career option and unclear about what an ENT career comprises. Our half-day course took place in the simulation suite at St Mary's Hospital, London. PARTICIPANTS: Medical students were mainly in their third year of study and had aspirations towards a variety of surgical and non-surgical careers, with a minority aspiring towards ENT before the course. RESULTS: Our results demonstrate that all students found the session useful and had a much better understanding of ENT practice, with almost all students leaving more likely to consider a career in ENT. CONCLUSION: We would like to repeat this session in different student year groups and compare their perceptions with our results. We find our results a good case for including informative careers workshops as part of medical school teaching. We pose that interactive workshops exploring specialist surgical careers are a valid way to enable students in making informed career decisions - particularly in specialties that are under-represented at medical school.

'Choose and Book' in ENT: the GP perspective.

OBJECTIVES: 'Choose and Book' is a UK government initiative devised to allow a greater freedom of choice for National Health Service patients. The system is designed to give patients a choice of hospitals and appointment times, as well as giving their general practitioner (GP) more responsibility for appropriate prioritization. We set out to determine the attitudes of UK GPs to the new Choose and Book project and to assess the impact that these changes are likely to have on ENT practice. DESIGN: Postal questionnaire survey. METHODS: Five hundred GPs were sent a questionnaire about the planned Choose and Book referral project. RESULTS: Three hundred and eighty GPs (76 per cent) replied to the questionnaire after reminders were sent. Most were aware of the project and had been sent information about it. Of those who had heard of it, 61.5 per cent did not think it was a good thing. Most stated that both they and their patients were satisfied with current prioritization practices. Many GPs would be willing to delegate responsibility for prioritization to non-clinical staff. Important time and responsibility issues were identified. CONCLUSIONS: The majority of GPs were not in favour of Choose and Book. Many cited difficulties with time constraints and an inflexible system as factors that made Choose and Book unacceptable.

Construct validity of cadaveric temporal bones for training and assessment in mastoidectomy.

OBJECTIVE: To determine the construct validity of cadaveric temporal bones in mastoidectomy training. STUDY DESIGN: A prospective observational study. METHODS: Trainees from the North London otolaryngology training program performed step-wise modified radical mastoidectomy on cadaveric temporal bones under faculty supervision. Performance was assessed using a validated mastoidectomy assessment tool. A longitudinal assessment of nine trainees was also carried out over two sessions separated by 12 months. The main outcomes measures were task-specific (TS) and global skills (GS). RESULTS: Twenty-six intermediate and eight novice trainees participated and were assessed by a minimum of two assessors each. Intermediate trainees performed significantly better than novices in TS and GS (P < 0.001). Performance correlated well with training level using Spearman rank correlation coefficient (r(s)) (TS r(s) 0.265 and GS r(s) 0.503). The number of otological procedures performed, and in particular mastoidectomies, correlated well with performance (TS r(s) 0.327 and GS r(s) 0.528). Longitudinal assessment showed significant improvement with iteration (TS P = 0.008 and GS P = 0.008). Attending otological courses also improved performance significantly (TS r(s) 0.345 and GS r(s) 0.469). CONCLUSIONS: The cadaveric temporal bone demonstrated construct validity and can be used to detect progress in performance of otolaryngology trainees. This is a keystone in moving toward a competency-based training system. LEVEL OF EVIDENCE: N/A.

Construct validity of the ovine model in endoscopic sinus surgery training.

OBJECTIVES/HYPOTHESIS: To demonstrate construct validity of the ovine model as a tool for training in endoscopic sinus surgery (ESS). STUDY DESIGN: Prospective, cross-sectional evaluation study. METHODS: Over 18 consecutive months, trainees and experts were evaluated in their ability to perform a range of tasks (based on previous face validation and descriptive studies conducted by the same group) relating to ESS on the sheep-head model. Anonymized randomized video recordings of the above were assessed by two independent and blinded assessors. A validated assessment tool utilizing a five-point Likert scale was employed. Construct validity was calculated by comparing scores across training levels and experts using mean and interquartile range of global and task-specific scores. Subgroup analysis of the intermediate group ascertained previous experience. Nonparametric descriptive statistics were used, and analysis was carried out using SPSS version 21 (IBM, Armonk, NY). RESULTS: Reliability of the assessment tool was confirmed. The model discriminated well between different levels of expertise in global and task-specific scores. A positive correlation was noted between year in training and both global and task-specific scores (P < .001). Experience of the intermediate group was variable, and the number of ESS procedures performed under supervision had the highest impact on performance. CONCLUSIONS: This study describes an alternative model for ESS training and assessment. It is also the first to demonstrate construct validity of the sheep-head model for ESS training.