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.

Automatic conformal prescription of very selective saturation bands for in vivo 1H-MRSI of the prostate.

An important step in the implementation of three-dimensional in vivo proton magnetic resonance spectroscopic imaging ((1)H-MRSI) of the prostate is the placement of spatial saturation pulses around the region of interest (ROI) for the removal of unwanted contaminating signals from peripheral tissue. The present study demonstrates the use of a technique called conformal voxel magnetic resonance spectroscopy (CV-MRS). This method automates the placement, orientation, timing and flip angle of very selective saturation (VSS) pulses around an irregularly-shaped, user-defined ROI. The method employs a user adjustable number of automatically positioned VSS pulses (20 used in the present study) which null the signal from periprostatic lipids while closely conforming the shape of the excitation voxel to the shape of the prostate. A standard endorectal coil in combination with a torso-phased array coil was used for all in vivo prostate studies. Three-dimensional in vivo prostate (1)H-MRSI data were obtained using the proposed semi-automated CV-MRS technique, and compared with a standard point resolved spectroscopy (PRESS) technique at TE = 130 ms using manual placement of saturation pulses. The in vivo prostate (1)H-MRSI data collected from 12 healthy subjects using the CV-MRS method showed significantly reduced lipid contamination throughout the prostate, and reduced baseline distortions. On average there was a 50 ± 17% (range 12% - 68%) reduction in lipids throughout the prostate. A voxel-by-voxel benchmark test of over 850 voxels showed that there were 63% more peaks fitted using the LCModel when using a Cramer-Rao Lower Bound (CRLB) cut-off of 40% when using the optimized conformal voxel technique in comparison to the manual placement approach. The evaluation of this CV-MRS technique has demonstrated the potential for easy automation of the graphical prescription of saturation bands for use in (1)H-MRSI.

Comparison of brain MR images at 1.5T using BLADE and rectilinear techniques for patients who move during data acquisition.

BACKGROUND AND PURPOSE: MR imaging of moving patients can be challenging and motion correction techniques have been proposed though some have associated new artifacts. The objective of this study was to semiquantitatively compare brain MR images of moving patients obtained at 1.5T by using partially radial and rectilinear acquisition techniques. MATERIALS AND METHODS: FLAIR, T2-, T1-, and contrast-enhanced T1-weighted image sets of 25 patients (14-94 years) obtained by using BLADE (like PROPELLER, a partially radial acquisition) and rectilinear techniques in the same imaging session were compared by 2 neuroradiologists in terms of extent of the motion artifact, image quality, and lesion visibility. ICC between opinions of the evaluators was calculated. RESULTS: Of the total of 70 image sets, the motion artifact was small in the partially radial images in 43 and in the rectilinear images in 13, and the opinions of the evaluators were discordant in the remaining 14 sets (ICC = 0.63, P < .05). The quality of partially radial images was higher for 36 sets versus 9 rectilinear sets, with disagreement between the 2 evaluators in the remaining 25 (ICC = 0.15, P < .05). Pathologic lesions were better characterized on 37 sets of partially radial images versus 13 sets of rectilinear images, and opinions of the evaluators differed in 20 sets (ICC = 0.90, P < .05). The neuroradiologists deemed 4 sets of rectilinear images nondiagnostic compared with only 1 set of radial images. CONCLUSIONS: The data demonstrate that our application of BLADE sequences reduces the extent of motion artifacts in brain images of moving patients, improving image quality and lesion characterization.

Evaluation of image quality of a 32-channel versus a 12-channel head coil at 1.5T for MR imaging of the brain.

BACKGROUND AND PURPOSE: Multichannel phased-array head coils are undergoing exponential escalation of coil element numbers. While previous technical studies have found gains in SNR and spatial resolution with the addition of element coils, it remains to be determined how these gains affect clinical reading. The purpose of this clinical study was to determine if the SNR and spatial resolution characteristics of a 32-channel head coil result in improvements in perceived image quality and lesion evaluation. MATERIALS AND METHODS: Twenty-one patients underwent MR imaging of the brain at 1.5T sequentially with both a 12-channel and a 32-channel receive-only phased-array head coil. Axial T2WIs, T1WIs, FLAIR images, and DWIs were acquired. Anonymized images were compared side-by-side and by sequence for image quality, lesion evaluation, and artifacts by 3 neuroradiologists. Results of the comparison were analyzed for the preference for a specific head coil. RESULTS: FLAIR and DWI images acquired with the 32-channel coil showed significant improvement in image quality in several parameters. T2WIs also improved significantly with acquisition by the 32-channel coil, while T1WIs improved in a limited number of parameters. While lesion evaluation also improved with acquisition of images by the 32-channel coil, there was no apparent improvement in diagnostic quality. There was no difference in artifacts between the 2 coils. CONCLUSIONS: Improvements in SNR and spatial resolution attributed to image acquisition with a 32-channel head coil are paralleled by perceived improvements in image quality.

Toxic impacts of cypermethrin on behavior and histology of certain tissues of albino rats.

In the present investigation, the behavioral, morphological, and histopathological effects of cypermethrin, a widely used synthetic pyrethroid insecticide, was ascertained in male and female albino rats (Rattus norvegicus). Cypermethrin administered at repeated oral doses of 5 and 20 mg/kg/day for 30 days produced varying degree of mild to moderate toxic symptoms and behavioral changes in both male and female rats. The lower dose produced very mild toxicosis characterized by intermittent diarrhea, decreased feed intake, and thick eye discharge, whereas higher dose displayed mild to moderate toxicosis with diarrhea, decreased feed intake, loss of body weight, dyspnoea, ataxia, eye discharge, and salivation. Two female and one male albino rats died between 23 to 28 days after displaying signs of incoordination and tremors. Repeated oral doses of cypermethrin for 30 days enhanced the relative weight of liver and heart, but significantly decreased that of brain, kidneys, and testes. Microscopically, cypermethrin produced neuronal degeneration and increase in glial cells in brain, and disorganization of hepatic laminae, increase in sinusoid, and necrosis of hepatocytes in liver. Section of kidney displayed hemorrhage and sloughing off renal epithelial cell in the convoluted tubules, shrinkage of glomeruli, and necrosis of renal tubules. Repeated administration of cypermethrin also produced hemorrhages within myocardium, disruption of branching structure, and loss of striation of cardiac tissue; thickening of alveolar septa in lungs, partial to extensive loss of various stages of spermatogenesis in testes, and loss of follicular cells and oocytes in ovaries. The study suggested that repeated oral exposure of cypermethrin has considerable harmful effects on body organs in R. norvegicus.

Association of marital status with access to renal transplantation.

In this report we evaluated the association of marital status with access to renal transplantation. We analyzed data from the USRDS. In patients with ESRD aged ≥ 27 (mean age of first marriage in the US), we analyzed the association of marital status with two outcomes: (1) likelihood of being placed on the waiting list for renal transplantation or first transplant, (2) likelihood of receiving kidney transplant in patients already listed. We analyzed marital status as a categorical variable: (1) not married (including never been married and widowed); (2) divorced or separated; and (3) currently married. Subgroups based on age, race, sex, donor type and diabetic status were also analyzed. After adjustments for the included independent variables and compared to individuals never married or widowed, those who were divorced/separated (HR 1.55, p < 0.001) and currently married (HR 1.54, p < 0.001) had a higher likelihood of being placed on the transplant waiting list. Once listed, married individuals had higher chances of getting transplanted as well (HR 1.28, p = 0.033). This trend was consistent in most of the subgroups studied. We demonstrated that being married is associated with better access to renal transplantation compared to those who were never married/widowed.

Advances in volume monitoring in dialysis patients.

Estimating volume status in patients on chronic dialysis is of great clinical value. Both hypervolemia and hypovolemia are associated with serious short term and long term complications, and volume status is often difficult to assess due to multiple factors affecting intravascular and extravascular volume compartments, as well as variability between patients in baseline blood pressures and physical exams. Traditional methods such as estimated dry weight (EDW) and physical exams are often not accurate because of the subjective nature of these indicators and variability between patients' baselines. This can lead to inaccurate volume status estimation and the associated complications. Furthermore, the concept of estimated dry weight is often defined based on measurements of blood pressure which may not accurately reflect volume status. In this review we describe several methods of measuring volume status in dialysis patients that may be more accurate than traditional measurements of blood pressure and dry weight estimation. These methods include dilutional techniques, imaging of vascular structures, use of biomarkers, bioimpedance analysis and online monitoring of biochemical variables during dialysis itself. We also discuss the clinical applicability and comparisons between these methods including the benefits and drawbacks of these methods and areas for future research.