Abstracts from the Medical Research Symposium for Students and Foundation Doctors 21 November 2018
Total Page：16
File Type：pdf, Size：1020Kb
Abstracts from the Medical Research Symposium for Students and Foundation Doctors 21 November 2018 November 2018 This abstract book has been produced using author-supplied copy and no editing has been undertaken. No responsibility is assumed for any claims, instructions, methods or drug dosages included in the abstracts: it is recommended that these are verified independently. Undergraduate Prizes Best undergraduate oral presentation Comparing Outcomes of Stent Retriever Thrombectomy versus Direct Aspiration for the Endovascular Treatment of Acute Anterior Circulation Stroke SE Thompson, R Jones, K Nader Birmingham Medical School Introduction Endovascular therapy with a stent retriever has been shown to be superior to standard medical therapy in the treatment of acute ischaemic stroke and is recommended by the American Stroke Association. Direct aspiration thrombectomy is another commonly used method increasing in popularity with advances in catheter technology. Few studies have directly compared the efficacy of the two methods, with current evidence equivocal. This study compares the stent retriever and direct aspiration methods. Patients and methods 101 patients presenting to the Queen Elizabeth Hospital Birmingham between January 2013-November 2017 with anterior circulation ischaemic stroke, fulfilling the criteria for endovascular therapy, were retrospectively analysed. 45 patients underwent first-line stent retriever thrombectomy and in 56 patients, direct aspiration was the primary method. The primary outcome was successful revascularization (TICI 2b/3) and secondary outcomes included procedural and clinical measures. Results Successful revascularization was achieved more frequently when direct aspiration was the primary chosen method (91.1% vs. 57.8%, p=0.000) and was significantly more likely to be successful with a single pass (p=0.005). Direct aspiration procedure time was shorter (51 minutes, IQR 34-75) than stent retriever thrombectomy (72 minutes, IQR 58-99), despite more frequently needing rescue therapy (p=0.019). A favourable early neurological outcome was more frequently achieved in those undergoing direct aspiration (75.5% vs. 53.8%, p=0.033), although there were no significant differences in mortality (p=0.633). Conclusions First-line treatment with direct aspiration may be superior to stent retriever thrombectomy, offering potential clinical, procedural and cost benefits. To our knowledge, this is the first study at a UK centre of its kind. Best undergraduate poster Investigation of the microbial community associated with Mycobacterium abscessus infection – An emerging pathogen in Cystic Fibrosis. Sarah Higgi, Helen Gavillet, Aussami Abbas, Damien Rivett, Heather Green, Thomas Daniels, Christopher van der Gast Southampton Medical School Introduction Cystic fibrosis (CF) is a multi-systemic genetic disorder characterised by frequent pulmonary exacerbations. Exacerbations are typically associated with pathogens such as Pseudomonas aeruginosa, a known accelerator of lung function decline. Previous sequencing studies investigating the community structure of P. aeruginosa have demonstrated that it is a dominant community member and is highly resilient to antibiotics.1 In comparison, limited knowledge exists for pathogens such as Mycobacterium abscessus which has also been linked to accelerated lung function decline.2 The aim of this study was therefore to describe the community composition of M. abscessus, and retrospectively analyse the impacts of M. abscessus on lung function over a three-year study period. Patients and methods Sputum samples were collected from 44 people with CF – 23 chronic M. abscessus cases and 21 chronic P. aeruginosa controls. Clinical and demographic data was collated, and lung function analysis was conducted comparing lung function decline between the groups. Lung function decline was also analysed by sub-dividing cases based on the presence of nontuberculous mycobacterium pulmonary disease (NTM-PD). 16S rRNA sampling was utilised on the Illumina MiSeq platform, to sequence 60 DNA extracts (phenol/chloroform extraction), and an Operational Taxonomic Unit (OTU) table was generated allowing for compositional analysis. Results The presence of M. abscessus led to a significant decline in lung function in the cases (- 7.88%) compared to controls (+1.00%), (p=0.002) and a significant decrease was noted with the presence of NTM-PD (p=0.006). Significant compositional differences were seen between the two groups (p=0.0113, R=0.08015) with no significant difference seen in taxa diversity or richness. Conclusions The presence of M. abscessus leads to a unique bacterial community structure in the CF lung compared to P. aeruginosa colonised controls. Accelerated lung function shown in this study further highlights the clinical significance of this bacteria. This is the first study to find a significant association with NTM-PD, and the presence of compositional differences may indicate a need to re- evaluate current treatments. References 1. Stressmann FA, Rogers GB, van der Gast CJ, et al. Long-term cultivation-independent microbial diversity analysis demonstrates that bacterial communities infecting the adult cystic fibrosis lung show stability and resilience. Thorax 2012;67(10):867-73. 2. Floto RA, Olivier KN, Saiman L, et al. US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis. Thorax 2016;71 Suppl 1:i1-22. Commended undergraduate poster The positional variation of the median nerve: An ultrasound study Mr James Moorby, Mr Richard Pinder, Dr Reginald Edward, Dr Katherine Sanders Hull-York Medical School Introduction Near-nerve steroid injection is a common conservative treatment for carpal tunnel syndrome with varying rates of success. This is frequently performed using a ‘blind’ technique, referencing surface anatomical landmarks to estimate the position of the median nerve. The morphological variants of the median nerve have been described, however little study has been carried out investigating the positional variation of the nerve relative to the landmark tendons. This study aims to establish an accurate estimate of the positional variation of the median nerve relative to palmaris longus (PL) and flexor carpi radialis (FCR) within the general population, with variation in wrist width between individuals considered. Patients and methods Sixty wrists of thirty normal subjects were studied. Ultrasonography was performed at sites 0, 1 and 2cm proximal to the distal wrist crease. Measurements were taken of the position of the medial border of the median nerve relative to the medial borders of the PL and FCR musculotendinous units. Results There were statistically significant differences in the average distances from the median nerve to palmaris longus and flexor carpi radialis at each scanning site. Also, when patient’s wrist width was considered the significant differences persisted. The prevalence of PL agenesis in the sample was 21.7%. Mean measurements (in mm) of PL-MN at each scanning site were as follows: DWC +2= -5.09. DWC +1=-1.39. DWC=2.45. And the mean measurements for FCR-MN at each site were: DWC+2=2.24. DWC+1=6.40. DWC=10.82. Conclusions There is significant positional variation of the median nerve in the distal forearm which should be considered by clinicians when utilising blind techniques used for injection into the carpal tunnel. Without this, there may be an increased risk of nerve damage and reduction in efficacy. Despite this, using ultrasound guidance may further reduce the potential risks associated with blind techniques. Commended undergraduate poster Assessment of Retina and Choroid Using Optical Coherence Tomography in Health, Hypertension and Chronic Kidney Disease. Nikolaos Tzoumas, Tariq Farrah, Neeraj Dhaun The University of Edinburgh Introduction Using optical coherence tomography (OCT) we have previously demonstrated strong associations between chorioretinal thinning and degree of renal dysfunction and systemic inflammation, in patients at high cardiovascular disease risk. The progression of chorioretinal structural changes over time and in different patient subgroups remain unexplored. Patients and methods We used the SPECTRALIS-OCT machine to re-examine the retinal and retinal nerve fibre layer (RNFL) thickness, macular volume, and choroidal thickness of 28 subjects, a median of 43 months after their index scans. We recruited 11 patients with hypertension (clinic blood pressure ≥140/90 mmHg prior to treatment); 10 with pre-dialysis CKD (estimated glomerular filtration rate (eGFR) 8-125 ml/min/1.73m2); and 7 matched healthy controls. The same, masked investigator carried out each study. Results On follow-up, outer-temporal retinal thickness and macular volume were reduced in CKD (P <0.05), temporal-inferior RNFL thickness was reduced in CKD and hypertension (P <0.05), and choroidal thickness at location I was reduced in hypertension (P <0.01). Conclusions Increasing age is associated with chorioretinal thinning, which may be accelerated in CKD and hypertension. Larger studies evaluating these changes over longer periods of time are necessary to fully assess the extent of this impact. References 1. Balmforth C, van Bragt JJ, Ruijs T, Cameron JR, Kimmitt R, Moorhouse R, et al. Chorioretinal thinning in chronic kidney disease links to inflammation and endothelial dysfunction. JCI insight. 2016;1. 2. Go AS, Chertow GM, Fan D, McCulloch