A Metabolic Intravascular Platform to Study FDG Uptake in Vascular Injury.

PURPOSE: Metabolic alterations underlie many pathophysiological conditions, and their understanding is critical for the development of novel therapies. Although the assessment of metabolic changes in vivo has been historically challenging, recent developments in molecular imaging have allowed us to study novel metabolic research concepts directly in the living subject, bringing us closer to patients. However, in many instances, there is need for sensors that are in close proximity to the organ under investigation, for example to study vascular metabolism. METHODS: In this study, we developed and validated a metabolic detection platform directly in the living subject under an inflammatory condition. The signal collected by a scintillating fiber is amplified using a photomultiplier tube and decodified by an in-house tunable analysis platform. For in vivo testing, we based our experiments on the metabolic characteristics of macrophages, cells closely linked to inflammation and avid for glucose and its analog 18F-fluorodeoxyglucose (18F-FDG). The sensor was validated in New Zealand rabbits, in which inflammation was induced by either a) high cholesterol (HC) diet for 16 weeks or b) vascular balloon endothelial denudation followed by HC diet. RESULTS: There was no difference in weight, hemodynamics, blood pressure, or heart rate between the groups. Vascular inflammation was detected by the metabolic sensor (Inflammation: 0.60 ± 0.03 AU vs. control: 0.48 ± 0.03 AU, p = 0.01), even though no significant inflammation/atherosclerosis was detected by intravascular ultrasound, underscoring the high sensitivity of the system. These findings were confirmed by the presence of macrophages on ex vivo aortic tissue staining. CONCLUSION: In this study, we validated a tunable very sensitive metabolic sensor platform that can be used for the detection of vascular metabolism, such as inflammation. This sensor can be used not only for the detection of macrophage activity but, with alternative probes, it could allow the detection of other pathophysiological processes.

The management of laryngeal lipoid proteinosis.

BACKGROUND: Lipoid proteinosis is a rare autosomal recessive disorder caused by mutations in the extracellular matrix protein 1 gene. It is characterised by deposition of hyaline material in the skin and mucous membranes. This paper describes the management of two cases with laryngopharyngeal disease. METHODS: Two patients with a biopsy diagnosis of lipoid proteinosis were identified from the surgical pathology archive covering the period 2004-2016. Their notes were reviewed. RESULTS: An adult male and an adult female were identified. Both had dysphonia and laryngopharyngeal lesions. The patients underwent interval laser microlaryngoscopy to debulk disease but minimise mucosal injury and scarring, using a 'pepper pot' technique. Both had adequate symptom control. CONCLUSION: Lipoid proteinosis is a rare genetic condition, which typically presents in infancy with dysphonia and subsequent skin involvement. Two cases are presented to demonstrate that laryngotracheal symptoms can be controlled with interval laser debulking and the 'pepper pot' technique without causing stenosis.

Management of complex pediatric laryngotracheal stenosis with skin graft reconstruction.

OBJECTIVES: For pediatric patients with laryngotracheal stenosis, the ultimate goal is creation of a safe, functional airway. Unfortunately, wound healing in a hollow structure can complicate repair attempts, leading to restenosis. Herein, we present our experience using skin-grafting techniques in two complex pediatric laryngotracheal stenosis cases, leading to successful decannulation or speech production. METHODS: A chart review was performed examining the evaluation and management of two pediatric patients with laryngotracheal stenosis despite prior reconstructive attempts. Patient history, bronchoscopic evaluation, intra-operative technique, post-operative management, treatment outcomes, and complications were noted. Harvesting and preparation of the split-thickness skin grafts (STSG) proceeded in a similar manner for each case. Stenting material varied based on the clinical scenario. RESULTS: Using this technique, our patient with a Type 3 glottic web achieved substantial improvement in exercise tolerance, as well as vocal strength and quality. In addition, our aphonic patient could vocalize for the first time since her laryngotracheal injury. CONCLUSIONS: Temporary endoluminal stenting with skin graft lining can reproduce epithelial continuity and provide "biological inhibition" to enhance the wound healing process. When previous reconstructive efforts have failed, use of STSG can be considered in the management of complex pediatric laryngotracheal stenosis.

A Study of Clinical Coding Accuracy in Surgery: Implications for the Use of Administrative Big Data for Outcomes Management.

BACKGROUND: Clinical coding is the translation of clinical activity into a coded language. Coded data drive hospital reimbursement and are used for audit and research, and benchmarking and outcomes management purposes. METHODS: We undertook a 2-center audit of coding accuracy across surgery. Clinician-auditor multidisciplinary teams reviewed the coding of 30,127 patients and assessed accuracy at primary and secondary diagnosis and procedure levels, morbidity level, complications assignment, and financial variance. Postaudit data of a randomly selected sample of 400 cases were reaudited by an independent team. RESULTS: At least 1 coding change occurred in 15,402 patients (51%). There were 3911 (13%) and 3620 (12%) changes to primary diagnoses and procedures, respectively. In 5183 (17%) patients, the Health Resource Grouping changed, resulting in income variance of £3,974,544 (+6.2%). The morbidity level changed in 2116 (7%) patients (P < 0.001). The number of assigned complications rose from 2597 (8.6%) to 2979 (9.9%) (P < 0.001). Reaudit resulted in further primary diagnosis and procedure changes in 8.7% and 4.8% of patients, respectively. CONCLUSIONS: The coded data are a key engine for knowledge-driven health care provision. They are used, increasingly at individual surgeon level, to benchmark performance. Surgical clinical coding is prone to subjectivity, variability, and error (SVE). Having a specialty-by-specialty understanding of the nature and clinical significance of informatics variability and adopting strategies to reduce it, are necessary to allow accurate assumptions and informed decisions to be made concerning the scope and clinical applicability of administrative data in surgical outcomes improvement.

Impact of unilateral vocal fold mobility impairment on laryngopulmonary physiology.

OBJECTIVE: To examine the impact of unilateral vocal fold mobility impairment (UVFMI) on airway physiology. STUDY DESIGN: Cross-sectional observational study. PARTICIPANTS: There were 21 patients with UVFMI and 53 controls. MAIN OUTCOME MEASURES: All patients and patient controls underwent a maximum-effort flow-volume loop examination. Forced expiratory flow in one second (FEV1 ), forced expiratory volume (FVC), peak inspiratory flow rate and peak expiratory flow rate (PIFR and PEFR, respectively) and area under the inspiratory and expiratory flow-volume loops (AUCI nspiratory and AUCE xpiratory, respectively) were measured. The ratio of PEFR to PIFR and AUCE xpiratory to AUCI nspiratory was derived. RESULTS: There were 48 males and 26 females. Mean age at measurement was 39 ± 11 years. Patients and controls were matched for age, sex, height and weight. None of the expiratory variables were significantly different between the groups. PIFR was significantly lower in UVFMI patients compared with controls (3.4 ± 1.2 versus 5.3 ± 1.8; P < 0.0001), as was AUCI nspiratory (11.5 ± 6.3 versus 17.5 ± 8.5; P = 0.0002). PEFR/PIFR provided the best differentiation between patients with UVFMI and controls with an area under the Receiver Operating Characteristic (ROC) curve of 0.96 and at a threshold of 1.9, and PEFR/PIFR had sensitivity and specificity of 95.2% and 90.6%, respectively. CONCLUSIONS: Flow-volume loops are a non-invasive method of studying vocal abduction and could compliment voice assessment and laryngoscopy in UVFMI. With further research, they could provide an outcome measure for laryngeal rehabilitative procedures, and a shared physiological language for screening and surgical quality assurance.

Outcome of a multimodality approach to the management of idiopathic subglottic stenosis.

OBJECTIVES/HYPOTHESIS: To assess the results of treating idiopathic subglottic stenosis (ISS), determine predictors of treatment success and outcome, and better define roles and limitations of endoscopic and open surgery. STUDY DESIGN: Prospective observational study. METHODS: Fifty-four consecutive patients were treated between 2004 and 2012. Patient, stenosis and treatment details, complications, open surgery rates, and outcomes were recorded. Regression analyses were used to identify predictors of endoscopic treatment success; treatment frequency; and functional outcomes in airway, dyspnea, voice, and swallowing domains. RESULTS: All patients were female and mean age at diagnosis was 48 ± 12 years. Symptoms-to-diagnosis latency was 21 ± 20 months. There were 10 concomitant glottic and subglottic stenoses. Most lesions were Myer-Cotton grade 3 (48%). Overall, 78% of patients were managed endoscopically. Treatment included intralesional corticosteroids, laser surgery, balloon dilation, and temporary silastic stenting in selected cases. Annual intervention rate was 1.07 ± 0.79. Mean follow-up was 45 months. Factors associated with intervention frequency were stenosis location and severity. Twelve patients underwent anteroposterior laryngotracheal reconstruction with biological inhibition. This resulted in disease remission in all patients with subglottic stenosis, and in most patients with concomitant glottic and subglottic stenosis. Patients with total laryngotracheal stenosis required ongoing treatment for glottic disease. All patients maintained prosthesis-free airways, but in one patient this required a laryngectomy. Most patients achieved good functional outcomes. Stenosis location was the only independent predictor of dyspnea and voice outcomes. CONCLUSIONS: ISS can be effectively treated with endoscopic surgery or a bespoke open reconstructive procedure that does not compromise on female voice quality. LEVEL OF EVIDENCE: 4.

An audit of the nature and impact of clinical coding subjectivity variability and error in otolaryngology.

OBJECTIVES: To audit the accuracy of clinical coding in otolaryngology, assess the effectiveness of previously implemented interventions, and determine ways in which it can be further improved. DESIGN: Prospective clinician-auditor multidisciplinary audit of clinical coding accuracy. PARTICIPANTS: Elective and emergency ENT admissions and day-case activity. MAIN OUTCOME MEASURES: Concordance between initial coding and the clinician-auditor multi-disciplinary teams (MDT) coding in respect of primary and secondary diagnoses and procedures, health resource groupings health resource groupings (HRGs) and tariffs. RESULTS: The audit of 3131 randomly selected otolaryngology patients between 2010 and 2012 resulted in 420 instances of change to the primary diagnosis (13%) and 417 changes to the primary procedure (13%). In 1420 cases (44%), there was at least one change to the initial coding and 514 (16%) health resource groupings changed. There was an income variance of £343,169 or £109.46 per patient. The highest rates of health resource groupings change were observed in head and neck surgery and in particular skull-based surgery, laryngology and within that tracheostomy, and emergency admissions, and specially, epistaxis management. A randomly selected sample of 235 patients from the audit were subjected to a second audit by a second clinician-auditor multi-disciplinary team. There were 12 further health resource groupings changes (5%) and at least one further coding change occurred in 57 patients (24%). These changes were significantly lower than those observed in the pre-audit sample, but were also significantly greater than zero. Asking surgeons to 'code in theatre' and applying these codes without further quality assurance to activity resulted in an health resource groupings error rate of 45%. The full audit sample was regrouped under health resource groupings 3.5 and was compared with a previous audit of 1250 patients performed between 2007 and 2008. This comparison showed a reduction in the baseline rate of health resource groupings change from 16% during the first audit cycle to 9% in the current audit cycle (P < 0.001). CONCLUSIONS: Otolaryngology coding is complex and susceptible to subjectivity, variability and error. Coding variability can be improved, but not eliminated through regular education supported by an audit programme.

Validation of the Clinical COPD Questionnaire as a psychophysical outcome measure in adult laryngotracheal stenosis.

OBJECTIVES: To validate the Clinical Chronic Obstructive Pulmonary Disease Questionnaire (CCQ), a patient-administered instrument developed for bronchopulmonary disease as a disease-specific psychophysical outcome measure for adult laryngotracheal stenosis. DESIGN: Prospective observational study. SETTINGS: Tertiary/National referral airway reconstruction centre. PARTICIPANTS: Thirty-three tracheostomy-free patients undergoing endoscopic laryngotracheoplasty. MAIN OUTCOME MEASURES: CCQ and the Medical Research Council (MRC) Dyspnoea scale, a previously validated but more limited scale, were administered to patients 2 weeks before surgery, preoperatively, and 2 weeks after endoscopic laryngotracheoplasty. Pulmonary function was assessed preoperatively. Internal consistency was assessed with Cronbach alpha statistics and test-retest reliability was determined using intraclass correlation. Correlations between CCQ and MRC scale, and pulmonary function were used to assess convergent and divergent validity respectively. Instrument responsiveness was assessed by correlating total and domain-specific CCQ scores with anatomical disease severity and post-treatment effect size. RESULTS: There were 12 males and 21 females. Mean age was 44 +/- 15 years. Cronbach alpha coefficient and intraclass correlation coefficient were 0.88 and 0.95 respectively. Total and domain-specific CCQ scores significantly correlated with the MRC scores (P < 0.001) and significant correlations between CCQ and peak expiratory flow rate and FEV(1) were identified (P < 0.03). There were statistically significant changes in total and domain-specific CCQ scores when different stenosis severities were compared. Clinical COPD Questionnaire scores also changed significantly and congruently following surgery (P < 0.05 in both cases). DISCUSSION: Clinical COPD Questionnaire is a valid and sensitive instrument for assessing symptom severity and levels of function and well-being in adult patients with laryngotracheal stenosis and can be used as a patient-centred disease-specific outcome measure for this condition.

A multidisciplinary audit of clinical coding accuracy in otolaryngology: financial, managerial and clinical governance considerations under payment-by-results.

OBJECTIVES: To audit the accuracy of otolaryngology clinical coding and identify ways of improving it. DESIGN: Prospective multidisciplinary audit, using the 'national standard clinical coding audit' methodology supplemented by 'double-reading and arbitration'. SETTINGS: Teaching-hospital otolaryngology and clinical coding departments. PARTICIPANTS: Otolaryngology inpatient and day-surgery cases. MAIN OUTCOME MEASURES: Concordance between initial coding performed by a coder (first cycle) and final coding by a clinician-coder multidisciplinary team (MDT; second cycle) for primary and secondary diagnoses and procedures, and Health Resource Groupings (HRG) assignment. RESULTS: 1250 randomly-selected cases were studied. Coding errors occurred in 24.1% of cases (301/1250). The clinician-coder MDT reassigned 48 primary diagnoses and 186 primary procedures and identified a further 209 initially-missed secondary diagnoses and procedures. In 203 cases, patient's initial HRG changed. Incorrect coding caused an average revenue loss of 174.90 pounds per patient (14.7%) of which 60% of the total income variance was due to miscoding of a eight highly-complex head and neck cancer cases. The 'HRG drift' created the appearance of disproportionate resource utilisation when treating 'simple' cases. At our institution the total cost of maintaining a clinician-coder MDT was 4.8 times lower than the income regained through the double-reading process. CONCLUSIONS: This large audit of otolaryngology practice identifies a large degree of error in coding on discharge. This leads to significant loss of departmental revenue, and given that the same data is used for benchmarking and for making decisions about resource allocation, it distorts the picture of clinical practice. These can be rectified through implementing a cost-effective clinician-coder double-reading multidisciplinary team as part of a data-assurance clinical governance framework which we recommend should be established in hospitals.

Impact of oxygen concentration and laser power on occurrence of intraluminal fires during shared-airway surgery: an investigation.

OBJECTIVES: Airway fires pose a risk during laser microlaryngoscopy, and neurosurgical cotton patties, used to prevent tissue injury from stray laser beams, are a potential ignition source. Using a configuration approximating clinical practice, we experimentally assessed the relative impact of changing different 'fire triad' components on the occurrence of airway fires, in order to better inform patient care. METHODS: The relative effects of wet vs dry neurosurgical patties, oxygen concentration and laser power setting on the patty ignition time were studied in a cadaveric porcine model. Data were analysed using t-test and two-way analysis of variance. RESULTS: Dry patties ignited after 2.3 +/- 1.2 seconds (average +/- standard deviation) of continuous 5 W laser fire at 50 per cent oxygen concentration, compared with 63.9 +/- 27.8 seconds for wet patties under the same laser and oxygen settings (p < 0.0001). There was a statistically significant reduction in the time to patty ignition when laser power settings were increased from 5 to 7.5 W, but no further reductions occurred when the power was further increased to 10 W (p < 0.05; Tukey test for multiple comparisons; two-way analysis of variance). There was no significant reduction in the time to ignition between oxygen concentrations of 50 and 75 per cent, but the time to ignition fell significantly when the oxygen concentration was further increased to 100 per cent. CONCLUSION: We suggest that surgical patties should always be soaked and should be used for relatively short periods, in order to prevent drying. If at all possible clinically, prolonged laser use at high power settings and ventilation with 100 per cent oxygen should be avoided.

Physiological comparison of spontaneous and positive-pressure ventilation in laryngotracheal stenosis.

BACKGROUND: We compared spontaneous and positive-pressure ventilation in patients undergoing general anaesthesia for the treatment of extrathoracic, intralumenal laryngotracheal stenosis to assess the best method of ventilation in this patient group. METHODS: Records of 30 patients with laryngotracheal stenosis, but not with a tracheostomy, undergoing lumen-restoring surgery were prospectively reviewed. Awake spirometry and flow-volume loops were recorded before the procedure. Patients received i.v. anaesthesia induction, muscle paralysis, and positive-pressure ventilation through a laryngeal mask airway (LMA). Anaesthetized tidal volume (TV) and flow-volume loop measurements were obtained. RESULTS: We studied 19 males and 11 females [mean age 47 (SD 19) yr], ASA Grade III or IV, with lesions at 31 (10) mm below the vocal cords. Peak inspiratory flow (PIF) and peak expiratory flow (PEF) rates were 2.0 (1.2) litre s(-1) and 3.2 (1.7) litre s(-1) when awake. Tidal volumes were 657 (193) ml [9.2 (3.6) ml kg(-1)] and 586 (158) ml [8.3 (3.1) ml kg(-1)], respectively, when anaesthetized. There was a significant reduction in the PEF/PIF ratio, from a mean of 2.4 (1.3) awake to 1.0 (0.1) when anaesthetized (P<0.0001). A significant correlation was noted between awake PEF and anaesthetized expiratory TV (r=0.57; P<0.001) but not between awake PIF and anaesthetized inspiratory TV. DISCUSSION: Positive-pressure ventilation through an LMA is an effective method of ventilating patients with laryngotracheal stenosis. Spontaneous ventilation creates negative inspiratory intratracheal pressure that exacerbates an extrathoracic lesion, whereas positive-pressure ventilation generates positive intratracheal pressure that improves ventilation. This helps explain the apparent resolution of airway obstruction after positive-pressure ventilation.

Sensitivity and responsiveness of the Medical Research Council dyspnoea scale to the presence and treatment of adult laryngotracheal stenosis.

OBJECTIVES: To assess the sensitivity and responsiveness of the Medical Research Council (MRC) scale, a psychophysical dyspnoea assessment instrument to the presence and treatment of adult laryngotracheal stenosis. DESIGN: Prospective observational study. SETTINGS: Tertiary/National referral airway reconstruction centre. PARTICIPANTS: Fourty tracheostomy-free patients undergoing endoscopic airway examination/laryngotracheoplasty. MAIN OUTCOME MEASURES: Demographic and clinical information, obtained from patient records, lesion severity, which was recorded intraoperatively, standard spirometry, which was measured preoperatively, and the MRC dyspnoea scale, which was administered preoperatively and at the first outpatient visit 4-6 weeks later. RESULTS: There were 16 males and 24 females. Mean age at presentation was 44 +/- 14 years (+/- SD). Postintubation stenosis was the commonest aetiology (73%) followed by idiopathic subglottic stenosis and Wegener's Granulomatosis. Six patients were examined post-treatment and had minimal residual stenosis and the remaining patients had glottic stenosis (n = 11) or Myer-Cotton Grade I (n = 8), II (n = 7) or III (n = 8) tracheal stenoses. Pre-treatment MRC dyspnoea scores and the degree of change in the MRC score following treatment strongly correlated with pre-treatment stenosis severity (r = 0.75 and r = -0.71 respectively; P < .001). Moreover statistically significant correlations existed between preoperative peak expiratory flow and forced expiratory volume in 1 s and preoperative MRC dyspnoea scores (r = -0.34 and r = -0.35 respectively; P < 0.05). DISCUSSION: Exertional dyspnoea is the hallmark symptom of laryngotracheal stenosis and for many patients it is the primary cause of disability. These findings confirm that the MRC dyspnoea scale is an appropriate outcome instrument for assessing dyspnoea associated with this condition.

Results of endoscopic surgery and intralesional steroid therapy for airway compromise due to tracheobronchial Wegener's granulomatosis.

BACKGROUND: Upper airway compromise due to tracheobronchial stenosis commonly occurs in patients with Wegener's granulomatosis (WG). There is at present no consensus on the optimal management of this life threatening condition. OBJECTIVE: To assess the results of laryngo-tracheo-bronchoscopy, intralesional steroid therapy, laser surgery and dilatation in managing obstructive tracheobronchial WG. METHODS: Records of 18 previously untreated stridulous patients with obstructive tracheobronchial WG, treated between 2004 and 2006, were prospectively recorded on an airway database and retrospectively reviewed. Information about patient and lesion characteristics and treatment details were recorded. Treatment progress was illustrated using a timeline plot, and intervention-free intervals were calculated with actuarial analysis. RESULTS: There were nine males and the average age at presentation was 40 (16) years (range 13-74). There were 13 patients with tracheal and five with tracheal and bronchial lesions. The average tracheal lesion height was 8 (3) mm, located 23 (9) mm below the glottis. There were 1, 10 and 7 Myer-Cotton grade I, II and III lesions, respectively. Mean intervention-free interval following minimally invasive treatment was 26 (2.8) months. Following endobronchial therapy, the median intervention-free interval was 22 months (p>0.8 vs tracheal lesions). No patient required a tracheostomy or endoluminal stenting. CONCLUSIONS: Intralesional steroid therapy and conservative endoluminal surgery is an effective strategy for treating airway compromise due to active tracheal and bronchial WG, obviating the need for airway bypass or stenting. We recommend the combination of endotracheal dilatation, conservative laser surgery and steroid therapy as the standard of care for treating airway compromise due to obstructive tracheobronchial WG.

Results of endoscopic tracheoplasty for treating tracheostomy-related airway stenosis.

Post-tracheostomy 'lambdoid' deformity of the trachea is a specific and uncommon variant of adult post-intubation laryngotracheal stenosis, in which airway obstruction is caused by inward collapse of over-resected tracheal cartilage as a result of post-decannulation stomal contracture. We evaluated the results of endoscopic tracheoplasty as an alternative to open tracheal resection in 11 patients treated for this condition between 2004 and 2006. Patients were treated with endoscopic CO(2) laser resection, dilatation and endotracheal mitomycin C application. Suspension micro-laryngo-tracheoscopy and high-frequency supraglottic jet ventilation were used. Eleven patients with an average age of 56 years and lesion height and distance from glottis respectively of 11 +/- 5 mm and 35 +/- 12 mm were treated. The median number of treatments fell from four at the start of the series to two at the end (P = 0.08). The average follow-up was 17 +/- 8 months and all patients were cured with no cases of dysphagia or dysphonia. Almost all patients achieved and maintained a Medical Research Council Dyspnoea Scale of I or II. Endoscopic tracheoplasty is an effective treatment for this condition. It achieves a successful outcome while avoiding the operative risks, prolonged hospitalisation, and morbidity that is associated with tracheal resection. We recommend it as the standard of care for treating patients with this injury.