Safety of day-case endoscopic sinus surgery in England: An observational study using an administrative dataset.

INTRODUCTION: As elective surgical services recover from the COVID-19 pandemic a movement towards day-case surgery may reduce waiting lists. However, evidence is needed to show that day-case surgery is safe for endoscopic sinus surgery (ESS). The aim of this study was to investigate the safety of day-case ESS in England. DESIGN: Secondary analysis of administrative data. METHODS: We extracted data from the Hospital Episodes Statistics database for the 5 years from 1 April 2014 to 31 March 2019. Patients undergoing elective ESS procedures aged ≥17 years were included. Exclusion criteria included malignant neoplasm, complex systemic disease and trans-sphenoidal pituitary surgery. The primary outcome was readmission within 30 days post-discharge. Multilevel, multivariable logistic regression modelling was used to compare outcomes for those operated on as day-cases and those with an overnight stay after adjusting for demographic, frailty, comorbidity and procedural covariates. RESULTS: Data were available for 49 223 patients operated on across 129 NHS hospital trusts. In trusts operating on more than 50 patients in the study period, rates of day-case surgery varied from 20.6% to 100%. Nationally, rates of day-case surgery increased from 64.0% in the financial year 2014/2015 to 78.7% in 2018/2019. Day-case patients had lower rates of 30-day emergency readmission (odds ratio 0.71, 95% confidence interval 0.62 to 0.81). Outcomes for patients operated on in trusts with ≥80% day-case rates compared with patients operated on in trusts with <50% rates of day-case surgery were similar. CONCLUSIONS: Our data support the view that ESS can safely be performed as day-case surgery in most cases, although it will not be suitable for all patients. There appears to be scope to increase rates of day-case ESS in some hospital trusts in England.

The synapse in traumatic brain injury.

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide and is a risk factor for dementia later in life. Research into the pathophysiology of TBI has focused on the impact of injury on the neuron. However, recent advances have shown that TBI has a major impact on synapse structure and function through a combination of the immediate mechanical insult and the ensuing secondary injury processes, leading to synapse loss. In this review, we highlight the role of the synapse in TBI pathophysiology with a focus on the confluence of multiple secondary injury processes including excitotoxicity, inflammation and oxidative stress. The primary insult triggers a cascade of events in each of these secondary processes and we discuss the complex interplay that occurs at the synapse. We also examine how the synapse is impacted by traumatic axonal injury and the role it may play in the spread of tau after TBI. We propose that astrocytes play a crucial role by mediating both synapse loss and recovery. Finally, we highlight recent developments in the field including synapse molecular imaging, fluid biomarkers and therapeutics. In particular, we discuss advances in our understanding of synapse diversity and suggest that the new technology of synaptome mapping may prove useful in identifying synapses that are vulnerable or resistant to TBI.

A retrospective study on long-term efficacy of intranasal lysine-aspirin in controlling NSAID-exacerbated respiratory disease.

PURPOSE: Aspirin treatment after desensitization (ATAD) represents an effective therapeutic option suitable for NSAID-exacerbated respiratory disease (N-ERD) patients with recalcitrant disease. Intranasal administration of lysine-aspirin (LAS) has been suggested as a safer and faster route than oral ATAD but evidence for its use is less strong. We investigated nasal LAS therapy long-term efficacy based on objective outcomes, smell function, polyp recurrence and need for surgery or rescue therapy. Clinical biomarkers predicting response to intranasal LAS, long-term side effects and consequences of discontinuing treatment have been evaluated. METHODS: A retrospective analysis of a database of 60 N-ERD patients seen between 2012 and 2020 was performed in March 2021. They were followed up at 3-months, 1-, 2- and 3-years with upper and lower airway functions assessed at each follow-up. RESULTS: Higher nasal airflow and smell scores were found at each follow-up in patients taking LAS (p < 0.001 and p = 0.048 respectively). No influence of LAS on pulmonary function measurements was observed. Patient on intranasal LAS showed a lower rate of revision sinus surgery when compared to those who discontinued the treatment (p < 0.001). None of the variables studied was found to influence LAS treatment response. CONCLUSION: Our study demonstrates the clinical effectiveness of long-term intranasal LAS in the management of N-ERD in terms of improved nasal airflow and olfaction and a reduced need for revision sinus surgery. Intranasal LAS is safe, being associated with a lower rate of side effects when compared to oral ATAD. However, discontinuation of the treatment at any stage is associated with a loss of clinical benefit.

The Role of Social Media in Improving Patient Recruitment for Research Studies on Persistent Post-Infectious Olfactory Dysfunction.

Background and Objectives: Since the COVID-19 pandemic, the number of cases of post-infectious olfactory dysfunction (PIOD) has substantially increased. Despite a good recovery rate, olfactory dysfunction (OD) becomes persistent in up to 15% of cases and further research is needed to find new treatment modalities for those patients who have not improved on currently available treatments. Social media has emerged as a potential avenue for patient recruitment, but its role in recruiting patients with smell dysfunction remains unexplored. We conducted a survey using the AbScent Facebook page to evaluate the feasibility of using this platform for future studies on smell dysfunction. Materials and Methods: Between 26 October and 4 November 2021, we conducted an online survey to evaluate propensity of patients with PIOD who would be willing to participate in research studies on smell dysfunction. Results: Sixty-five subjects were surveyed with a response rate of 90.7%. The median visual analogue scale (VAS) for sense of smell was 0 at infection and 2 at survey completion. The median length of OD was 1.6 years, and the main cause of OD was SARS-CoV-2 (57.6%). Parosmia was reported in 41 subjects (69.5%) whilst phantosmia in 22 (37.3%). The median length of olfactory training (OT) was 6 months but subjectively effective in 15 subjects (25.4%). Twenty-seven subjects (45.8%) tried other medications to improve olfaction, but only 6 participants (22.2%) reported an improvement. All subjects expressed their propensity to participate in future studies with most of them (38; 64.4%) willing to be enrolled either in medical and surgical studies or to be part of a randomised study design (11; 18.6%). Conclusions: Using the AbScent Facebook platform we successfully selected a population of subjects with persistent and severe OD that have failed to improve on available treatments and are willing to participate in further clinical trials.

Characteristics of taste dysfunction in COVID-19 subjects coming from two different countries.

Taste dysfunction (TD) has been recognised, together with olfactory dysfunction, as a key presenting symptom of COVID-19. The capability to recognise flavours, flavour intensities and aroma characteristics can be highly variable within the same population, as well as potentially diverse between culturally different populations. The aims of this study are to evaluate whether a difference in the types of TD presentation amongst COVID-19 positive subjects can be demonstrated and whether a difference exists between populations of different cultures.

The Evidence Base for the Benefits of Functional Septorhinoplasty and its Future Post COVID-19.

Ever since the introduction of the concept of Procedures of Limited Clinical Value (PoLCV), procedures such as functional septorhinoplasty have been subject to additional funding restrictions within the British National Health Service. Recent publications have suggested that 10% of Clinical Commissioning Groups in the United Kingdom no longer fund septorhinoplasty surgery irrespective of the indications, including congenital malformations or post-trauma, and despite the strong evidence available in the literature in treating a range of health conditions. Thus, inequity exists across the country. At present functional septorhinoplasty surgery is frequently but incorrectly grouped together with aesthetic rhinoplasty, both of which are deemed to be cosmetic interventions. Moreover, as we exit the peak of the current coronavirus disease 2019 (COVID-19) pandemic, procedures deemed to be of lower clinical priority will potentially be at risk throughout Europe. The purpose of this review is twofold; the first is to put forward the evidence to commissioners in favor of functional septorhinoplasty surgery on patient well-being and mental health; the second is to demonstrate why functional septorhinoplasty surgery is a distinct procedure from aesthetic rhinoplasty and why it ought not to be classified as a procedure of limited clinical value.

Olfactory and Gustatory Function before and after Laparoscopic Sleeve Gastrectomy.

Background and Objectives: Bariatric surgery is the gold standard for the treatment of morbid obesity, and current evidence suggests that patients undergoing surgery can show changes in their sense of taste and smell. However, no definitive conclusions can be drawn given the heterogeneity of the studies and the contrasting results reported in the literature. Materials and Methods: We enrolled 18 obese patients undergoing laparoscopic sleeve gastrectomy (LSG) and 15 obese controls. At baseline (T0) and 6 months after enrollment/surgery (T1), both groups underwent Sniffin' Sticks and whole mouth test. Post-operative qualitative taste variations were also analyzed and SNOT-22, VAS for taste and smell, and MMSE were administered. Results: An improvement in the olfactory threshold was observed in the treatment group (p = 0.03) at 6 months. At multivariate analysis, the olfactory threshold differences observed correlated with MMSE (p = 0.03) and T0 gustatory identification (p = 0.01). No changes in sense of taste were observed between the two groups at 6 months, even though nine subjects in the treatment group reported a worsening of taste. This negatively correlated with age (p < 0.001), but a positive marginal correlation was observed with the olfactory threshold difference between T0 and T1 (p = 0.06). Conclusions: Olfaction can improve after LSG, and this seems to be the consequence of an improved olfactory threshold. Although we did not observe any change in gustatory identification, food's pleasantness worsened after bariatric surgery.

Draf III frontal sinus surgery for the treatment of Pott's puffy tumour in adults: our case series and a review of frontal sinus anatomy risk factors.

PURPOSE: We present our case series of four adult patients with Pott's puffy tumour (PPT), successfully treated with Draf III over a mean period of 11 months. A critical review of the literature is also provided. METHODS: A retrospective review of patients undergoing Draf III for PPT from January 2018 to January 2019 was performed. RESULTS: Four consecutive male patients ranging from 26 to 62 years, with a mean age of 49.5 ± 16.3 years, undergoing Draf III for Pott's puffy tumour were included. Two patients had a Kuhn type IV frontal cell narrowing the frontonasal pathway and presented without previous sinus surgery, whereas the other two had previous sinus surgery. The success rate of the operation was 100% with an average length of follow-up of 11 months (range 5-18). CONCLUSION: In our experience, the Draf III procedure is a highly effective treatment of PPT. In particular, we have demonstrated it to be very effective in accessing highly positioned Kuhn type IV cells.

Nasal reconstructive surgery for vasculitis affecting the nose: our two-centre international experience.

PURPOSE: To recommend an international multidisciplinary medical and surgical algorithm of treatment in nasal vasculitis, which will create a more streamlined approach. METHODS: A two-centre, international retrospective analysis of granulomatosis with polyangiitis (GPA) and levamisole-associated vasculitis (LAV) cases presenting between 2005 and 2019 was carried out. Demographic data, and surgical and medical treatment were recorded. Patients' signs and symptoms were analysed, and recommended treatment strategies outlined with key surgical procedures described. RESULTS: Forty-one GPA patients and 11 LAV patients were included in the study with a mean age of 38.6 and 38.8 years, respectively. A stepwise surgical management approach with reconstructive options is described and includes: (1) examination under general anaesthesia, biopsy, and insertion of silastic nasal splints; (2) septal perforation repair (with caution); (3) mild-to-moderate saddle nose reconstruction with costal cartilage; (4) severe saddle nose reconstruction with osseocartilaginous rib grafts; (5) soft-tissue reconstruction techniques. CONCLUSIONS: The management of nasal vasculitis is a particular challenge in facial plastic surgery. It requires a close collaborative approach with a physician skilled in the medical management of vasculitis. Surgery must be planned judiciously, with realistic patient expectations and only after a sustained period of remission. For more severe saddle deformities, the modified osseocartilaginous Andrews technique gives excellent long-term results.

A national survey of clinical practice of surveillance for post-traumatic brain injury hypopituitarism in the United Kingdom and Ireland.

Background: Traumatic brain injury (TBI) is the most common cause of death and disability in young adults in industrialised countries. Post-TBI hypopituitarism (PTHP) is thought to occur in one-third of patients, however the natural history and predictive factors are not fully understood and as such guidelines for surveillance vary. The aim of this study was to assess the variations in current surveillance practices across the Neurosurgery Centres within the United Kingdom.Methods: A questionnaire was developed following discussions with an expert panel and distributed to members of the Society of British Neurosurgeons (SBNS), by email and printed copy, to survey surveillance practices for PTHP. The questionnaire primarily aimed to determine how commonly screening was performed and the clinical parameters used to guide these surveillance practices.Results: There were 45 responders representing Neurosurgery units in regions of England, Scotland and Ireland. The majority of participants (86.7%) considered PTHP to be a problem but only 25% (11/45) routinely screened for PTHP. There was wide variation in the criteria used to determine which patients were screened.Conclusions: Our survey suggests that few Neurosurgeons routinely screen for PTHP and those that do use a wide variation of clinical parameters to guide surveillance practice. A UK-wide prospective cohort study may help identify patients at risk of developing PTHP.

A pilot study to determine the effects of nasal co-phenylcaine on drug-induced sleep endoscopy.

PURPOSE: The use of nasal decongestant and nasal anaesthesia is currently not recommended during drug-induced sleep endoscopy (DISE) according to the European position paper. The evaluation of the effects of nasal decongestant/anaesthesia on DISE has not been performed before and our aim is to perform a pilot study to determine whether nasal decongestants/anaesthesia affects DISE outcomes. METHODS: 27 patients undergoing DISE for OSA or for simple snoring were included. On each patient, DISE was performed twice, before and approximately 10 min after the administration of two puffs of co-phenylcaine nasal spray (lidocaine hydrochloride 5%, phenylephrine 0.5%, and benzalkonium chloride 0.01%) into each nostril. A nasal peak inspiratory flow was used for the objective assessment of nasal airway obstruction. During the first and the second DISE the loudness of the snoring was also recorded. RESULTS: Change in DISE total grading after nasal spray administration was not statistically significant. For the same grading, changes in percentage of contribution to collapse were not statistically significant. Sex, AHI, BMI, tonsils grade, presence of rhinitis, turbinate hypertrophy, nasal septal deviation, or nasal peak inspiratory flow limitation had no influence on the effect of nasal spray. Co-phenylcaine did not significantly influence the loudness of snoring. CONCLUSIONS: Our pilot study supports the use of co-phenylcaine nasal spray during DISE and the positive effects of the nasal spray do not influence the grading outcome. Importantly, the decongestant enhances the nasal assessment during DISE and potentially aids in the diagnosis of nasal obstruction while the nasal anaesthetic component may be beneficial by reducing nasal discomfort during DISE and thereby helping to reduce the total dose of intravenous anaesthetic administered. However, further studies on a larger population are needed to confirm our results.

Investigating the nasal cycle using unilateral peak nasal inspiratory flow and acoustic rhinometry minimal cross-sectional area measurements.

OBJECTIVE: To plot the nasal cycle using unilateral peak nasal inspiratory flow (UPNIF) and unilateral minimal cross-sectional area (UMCA) readings demonstrating a linear relationship in normal nasal function. Additionally, to determine how this changes in abnormal nasal function. DESIGN: A cross-sectional study measuring UPNIF and UMCA in controls demonstrating normal nasal function and in patients with nasal obstruction. SETTING: Royal National Throat Nose and Ear Hospital, London. PARTICIPANTS: A total of 39 participants, 26 controls and 13 patients, were recruited. Controls exhibited normal nasal function with SNOT-22 <5. Patients nasal obstruction symptoms secondary to inflammation or structural abnormality with SNOT-22 >9. MAIN OUTCOME MEASURES AND RESULTS: Airflow rates and resistance values were derived from UPNIF and UMCA measurements respectively based on Poiseuille's laws. Ratios between right and left UPNIF and UMCA values were taken to adjust for confounding factors. The relationship of 1/Resistance Ratio and Airflow Rate Ratio demonstrated a linear of direct proportionality of strong correlation and statistical significance (correlation coefficient = 0.76, P « 0.01). This suggests that data points from controls with a normal nasal cycle lie closely along the regressed line, whilst those lying significantly away were shown to belong to patients with nasal dysfunction. Olfactory dysfunction appears to be a sensitive discriminator in predicting this. CONCLUSION: This study demonstrates the directly proportional relationship of 1/Resistance Ratio and Airflow Rate Ratio in normal nasal function. Furthermore, nasal pathology can be predicted if data points lie significantly outside these normal limits. Further studies are needed to validate exact normal and abnormal thresholds.

Hypothermia for Intracranial Hypertension after Traumatic Brain Injury.

BACKGROUND: In patients with traumatic brain injury, hypothermia can reduce intracranial hypertension. The benefit of hypothermia on functional outcome is unclear. METHODS: We randomly assigned adults with an intracranial pressure of more than 20 mm Hg despite stage 1 treatments (including mechanical ventilation and sedation management) to standard care (control group) or hypothermia (32 to 35°C) plus standard care. In the control group, stage 2 treatments (e.g., osmotherapy) were added as needed to control intracranial pressure. In the hypothermia group, stage 2 treatments were added only if hypothermia failed to control intracranial pressure. In both groups, stage 3 treatments (barbiturates and decompressive craniectomy) were used if all stage 2 treatments failed to control intracranial pressure. The primary outcome was the score on the Extended Glasgow Outcome Scale (GOS-E; range, 1 to 8, with lower scores indicating a worse functional outcome) at 6 months. The treatment effect was estimated with ordinal logistic regression adjusted for prespecified prognostic factors and expressed as a common odds ratio (with an odds ratio <1.0 favoring hypothermia). RESULTS: We enrolled 387 patients at 47 centers in 18 countries from November 2009 through October 2014, at which time recruitment was suspended owing to safety concerns. Stage 3 treatments were required to control intracranial pressure in 54% of the patients in the control group and in 44% of the patients in the hypothermia group. The adjusted common odds ratio for the GOS-E score was 1.53 (95% confidence interval, 1.02 to 2.30; P=0.04), indicating a worse outcome in the hypothermia group than in the control group. A favorable outcome (GOS-E score of 5 to 8, indicating moderate disability or good recovery) occurred in 26% of the patients in the hypothermia group and in 37% of the patients in the control group (P=0.03). CONCLUSIONS: In patients with an intracranial pressure of more than 20 mm Hg after traumatic brain injury, therapeutic hypothermia plus standard care to reduce intracranial pressure did not result in outcomes better than those with standard care alone. (Funded by the National Institute for Health Research Health Technology Assessment program; Current Controlled Trials number, ISRCTN34555414.).

Temperature Variability in a Modern Targeted Temperature Management Trial.

OBJECTIVES: The Eurotherm3235 trial showed that therapeutic hypothermia was deleterious in patients with raised intracranial pressure following traumatic brain injury. We sought to ascertain if increased temperature variability within the first 48 hours, or for 7 days post randomization, were modifiable risk factors associated with poorer outcome. DESIGN: Eurotherm3235 was a multicenter randomized controlled trial. Patients were randomized to receive either therapeutic hypothermia in addition to standard care or the later only. Mean moving range (mr) was used to stratify subjects into tertiles by the variability present in their core temperature within the first 48 hours post randomization and within 7 days post randomization. The primary outcome measure was a collapsed Glasgow Outcome Scale-Extended at 6 months post randomization. The temperature variability effect was estimated with ordinal logistic regression adjusted for baseline covariates and treatment effect. SETTING: Forty-seven critical care units in 18 countries. PATIENTS: Patients enrolled in the Eurotherm3235 trial to either therapeutic hypothermia or control treatments only. MEASUREMENTS AND MAIN RESULTS: Three hundred eighty-six patients were included in our study. High level of temperature variability during the first 48 hours was associated with poorer collapsed Glasgow Outcome Scale-Extended. This effect remained statistically significant when only the control arm of the study was analyzed. No statistically significant effect was seen within the first 48 hours in the hypothermia group or within 7 days in either group. CONCLUSIONS: When targeting normothermia, temperature variability may be a statistically significant variable in an ordinal analysis adjusted for baseline covariates.

Revisited: A Systematic Review of Therapeutic Hypothermia for Adult Patients Following Traumatic Brain Injury.

OBJECTIVES: Therapeutic hypothermia has been of topical interest for many years and with the publication of two international, multicenter randomized controlled trials, the evidence base now needs updating. The aim of this systematic review of randomized controlled trials is to assess the efficacy of therapeutic hypothermia in adult traumatic brain injury focusing on mortality, poor outcomes, and new pneumonia. DATA SOURCES: The following databases were searched from January 1, 2011, to January 26, 2018: Cochrane Central Register of Controlled Trial, MEDLINE, PubMed, and EMBASE. STUDY SELECTION: Only foreign articles published in the English language were included. Only articles that were randomized controlled trials investigating adult traumatic brain injury sustained following an acute, closed head injury were included. Two authors independently assessed at each stage. DATA EXTRACTION: Quality was assessed using the Cochrane Collaboration's tool for assessing the risk of bias. All extracted data were combined using the Mantel-Haenszel estimator for pooled risk ratio with 95% CIs. p value of less than 0.05 was considered statistically significant. All statistical analyses were conducted using RevMan 5 (Cochrane Collaboration, Version 5.3, Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014). DATA SYNTHESIS: Twenty-two studies with 2,346 patients are included. Randomized controlled trials with a low risk of bias show significantly more mortality in the therapeutic hypothermia group (risk ratio, 1.37; 95% CI, 1.04-1.79; p = 0.02), whereas randomized controlled trials with a high risk of bias show the opposite with a higher mortality in the control group (risk ratio, 0.70; 95% CI, 0.60-0.82; p < 0.00001). CONCLUSIONS: Overall, this review is in-keeping with the conclusions published by the most recent randomized controlled trials. High-quality studies show no significant difference in mortality, poor outcomes, or new pneumonia. In addition, this review shows a place for fever control in the management of traumatic brain injury.

Cerebral Concussion Primes the Lungs for Subsequent Neutrophil-Mediated Injury.

OBJECTIVES: Mild traumatic brain injury in the form of concussion is extremely common, and the potential effects on pulmonary priming have been underestimated. The aim of this study was to characterize the pulmonary response following mild traumatic brain injury and assess the pulmonary susceptibility to lung injury after a subsequent innocuous pulmonary insult. DESIGN: Experimental in vivo study. SETTING: University research laboratory. SUBJECTS: Male CD1 mice. INTERVENTIONS: We developed a model of concussive traumatic brain injury in mice followed by pulmonary acid microaspiration. To assess the dependent role of neutrophils in mediating pulmonary injury, we specifically depleted neutrophils. MEASUREMENTS AND MAIN RESULTS: Lateral fluid percussion to the brain resulted in neuronal damage and neutrophil infiltration as well as extensive pulmonary interstitial neutrophil accumulation but no alveolar injury. Following subsequent innocuous acid microaspiration, augmented alveolar neutrophil influx led to the development of pulmonary hemorrhage that was reduced following neutrophil depletion. CONCLUSIONS: This model shows for the first time that innocuous acid microaspiration is sufficient to induce neutrophil-mediated lung injury following mild concussion and that the extracranial effects of mild traumatic brain injury have been underestimated.

Mortality Risk Stratification After Traumatic Brain Injury and Hazard of Death With Titrated Hypothermia in the Eurotherm3235Trial.

OBJECTIVES: Hypothermia reduces intracranial hypertension in patients with traumatic brain injury but was associated with harm in the Eurotherm3235Trial. We stratified trial patients by International Mission for Prognosis and Analysis of Clinical Trials in [Traumatic Brain Injury] (IMPACT) extended model sum scores to determine where the balance of risks lay with the intervention. DESIGN: The Eurotherm3235Trial was a randomized controlled trial, with standardized and blinded outcome assessment. Patients in the trial were split into risk tertiles by IMPACT extended model sum scores. A proportional hazard analysis for death between randomization and 6 months was performed by intervention and IMPACT extended model sum scores tertiles in both the intention-to-treat and the per-protocol populations of the Eurotherm3235Trial. SETTING: Forty-seven neurologic critical care units in 18 countries. PATIENTS: Adult traumatic brain injury patients admitted to intensive care who had suffered a primary, closed traumatic brain injury; increased intracranial pressure; an initial head injury less than 10 days earlier; a core temperature at least 36°C; and an abnormal brain CT. INTERVENTION: Titrated Hypothermia in the range 32-35°C as the primary intervention to reduce raised intracranial pressure. MEASUREMENTS AND MAIN RESULTS: Three hundred eighty-six patients were available for analysis in the intention-to-treat and 257 in the per-protocol population. The proportional hazard analysis (intention-to-treat and per-protocol populations) showed that the treatment effect behaves similarly across all risk stratums. However, there is a trend that indicates that patients in the low-risk group could be at greater risk of suffering harm due to hypothermia. CONCLUSIONS: Hypothermia as a first line measure to reduce intracranial pressure to less than 20 mm Hg is harmful in patients with a lower severity of injury and no clear benefit exists in patients with more severe injuries.

Safety of human olfactory mucosal biopsy for the purpose of olfactory ensheathing cell harvest and nerve repair: a prospective controlled study in patients undergoing endoscopic sinus surgery.

BACKGROUND: Nasal olfactory mucosa is an accessible source of olfactory ensheathing cells for spinal cord regeneration. However, safety of the biopsy technique and the effects on sense of smell and nasal function have not been robustly assessed in the form of a prospective controlled study. METHODOLOGY: National Health Service ethical approval was granted for this study of 131 patients. The primary outcome measure was olfactory function and the secondary outcomes included postoperative complication rates as well as the SNOT 22, NOSE scale scores and surgeon reported (Lund-Kennedy score) nasal function outcomes. RESULTS: 65 patients underwent functional endoscopic sinus surgery (FESS) and superior turbinate biopsy, and 66 patients underwent FESS only as the control group. There was no significant difference in complication rates between the two groups. All Olfactory function outcomes were unaffected following olfactory biopsy. We demonstrated that the patients quality of life and nasal patency as well as surgeon reported outcome measurements remain unaffected following olfactory harvesting. CONCLUSIONS: We have uniquely provided level 2a evidence for the safety of endoscopic biopsy of olfactory mucosa, which does not affect nasal function or the sense of smell compared to standard FESS without biopsy.