0794 Reduction in Restless Legs Syndrome Symptoms with Non-Invasive Peripheral Nerve Stimulation

Introduction

Restless Legs Syndrome (RLS) is a sensorimotor neurological condition characterized by an uncontrollable urge to move the legs that interferes with falling and staying asleep. For the over 5 million Americans with clinically significant RLS, these symptoms occur multiple nights per week, significantly impair quality of life, increase the prevalence of depression and anxiety, and increase suicide risk. FDA-approved medications for RLS are associated with progressively worsening RLS symptoms and numerous adverse events, whereas existing medical device treatments have limited efficacy.

Methods

We evaluated a novel neurostimulation intervention for RLS developed by Noctrix Health; electrical stimulation was applied non-invasively and bilaterally to the peroneal nerve of patients with moderate-to-severe primary RLS. Stimulation parameters were engineered to maximize therapeutic efficacy while minimizing interference with sleep. To assess the therapeutic efficacy of this technique, we conducted a multi-site randomized patient-blinded crossover trial comparing active neurostimulation treatment to a sham device. Following a lab visit for calibration, optimization, and training, each patient was instructed to self-administer each treatment - active and sham - for 14 consecutive nights at home.

Results

Active neurostimulation treatment resulted in a clinically significant reduction in RLS severity of 4.2 points on the International RLS Rating Scale (IRLS) relative to sham (P<0.01), comparable to FDA-approved medications. Moreover, 79% of patients demonstrated a clinically significant improvement on the Clinical Global Impressions-Improvement scale (CGI-I) compared to 7% for sham (P<0.01).

Conclusion

To our knowledge, this is the first sham-controlled study demonstrating a clinically significant reduction in RLS severity resulting from a non-pharmacological intervention. This therapeutic effect was sustained over 2-weeks of in-home patient-administered usage, indicating consistent efficacy. A medical device based on this technology could be a promising alternative or complement to medications.

Support

Funding was provided by Noctrix Health, Inc.

Neuroenhancement in surgeons: benefits, risks and ethical dilemmas

Background

Surgeons traditionally aim to reduce mistakes in healthcare through repeated training and advancement of surgical technology. Recently, performance-enhancing interventions such as neurostimulation are emerging which may offset errors in surgical practice.

Methods

Use of transcranial direct-current stimulation (tDCS), a novel neuroenhancement technique that has been applied to surgeons to improve surgical technical performance, was reviewed. Evidence supporting tDCS improvements in motor and cognitive performance outside of the field of surgery was assessed and correlated with emerging research investigating tDCS in the surgical setting and potential applications to wider aspects of healthcare. Ethical considerations and future implications of using tDCS in surgical training and perioperatively are also discussed.

Results

Outside of surgery, tDCS studies demonstrate improved motor performance with regards to reaction time, task completion, strength and fatigue, while also suggesting enhanced cognitive function through multitasking, vigilance and attention assessments. In surgery, current research has demonstrated improved performance in open knot-tying, laparoscopic and robotic skills while also offsetting subjective temporal demands. However, a number of ethical issues arise from the potential application of tDCS in surgery in the form of safety, coercion, distributive justice and fairness, all of which must be considered prior to implementation.

Conclusion

Neuroenhancement may improve motor and cognitive skills in healthcare professions with impact on patient safety. Implementation will require accurate protocols and regulations to balance benefits with the associated ethical dilemmas, and to direct safe use for clinicians and patients.

Differential expression of caveolin-1 during pathogenesis of combined pulmonary fibrosis and emphysema: Effect of phosphodiesterase-5 inhibitor

INTRODUCTION

Combined pulmonary fibrosis and emphysema (CPFE) is a relatively new entity within the spectrum of cigarette smoke induced lung disorders. Currently there is no consensus about its treatment. We hypothesized that caveolin-1 critically determines the parenchymal and vascular remodeling leading to the development of CPFE. We assessed the effect of therapeutic targeting of caveolin-1 in mesenchymal and endothelial cells by the phosphodiesterase-5 inhibitor, sildenafil.

METHODS

Male Wistar rats (n = 168) were exposed to; room air (control); bleomycin (7 U/kg), bleomycin+sildenafil (50 mg/kg/day P.O.), cigarette smoke (CS) (4 Gold Flake 69 mm/day), CS + sildenafil, CS + bleomycin, CS + bleomycin+sildenafil. Animals were euthanized at 8, 9, 11, 12 weeks and lung histopathological changes, collagen deposition, ROS, Xanthine oxidase, caveolin-1 determined.

RESULTS

Cigarette smoke causes progressive ROS accumulation, caveolin-1 up-regulation in alveolar epithelial cells, alveolar macrophages, peribronchiolar fibroblasts, endothelial and vascular smooth muscle cells, interstitial inflammation and emphysema. Sildenafil reduces oxidative stress, parenchymal caveolin-1 and attenuates emphysema caused by CS. Bleomycin increases lung ROS and downregulates caveolin-1 leading to fibroblast proliferation and fibrosis. Combined cigarette smoke and bleomycin exposure, results in differential caveolin-1 expression and heterogeneous parenchymal remodeling with alternating areas of emphysema and fibrosis. Increased caveolin-1 induces premature senescence of lung fibroblasts and emphysema. Decreased caveolin-1 is associated with propagation of EMT and fibrosis. Sildenafil attenuates the parenchymal remodeling however it is not effective in reducing VSMC hypertrophy in combined group.

CONCLUSION

CPFE is characterized by heterogenous parenchymal remodeling and differential caveolin-1 expression. Sildenafil therapy attenuates parenchymal pathologies in CPFE. Additional therapy is however needed for attenuating VSMC remodeling.

A26 PEDIATRIC-ONSET INFLAMMATORY BOWEL DISEASE INCREASES THE RISK OF VENOUS THROMBOEMBOLISM: A CANGIEC POPULATION-BASED STUDY

Background

Inflammatory bowel disease (IBD) increases the risk of venous thromboembolism (VTE) in patients of all ages but the risk of VTE among Canadian children with IBD has not previously been investigated.

Aims

Report the incidence of VTE and subtypes pulmonary embolism (PE) and deep vein thrombosis (DVT) in children with and without IBD.

Methods

Children diagnosed with IBD <16y were identified from health administrative data in Ontario (2002–2014), Alberta (2007–2015), and Nova Scotia (2002–2012) using validated algorithms and matched by age and sex to children without IBD (1:5 ratio). Validated ICD-10 codes identified hospitalizations for incident VTE (DVT, PE, and sinovenous thrombosis). Province-specific 5-year cumulative incidence per 1000 person-years (PY) of VTEs were pooled using fixed-effects generalized linear mixed models with a Freeman-Tukey double arcsine transformation. Incidence rate ratios (IRR) within 5 years of diagnosis were pooled using fixed-effects generalized linear mixed models to compare children with and without IBD, and children with Crohn’s disease (CD) and ulcerative colitis (UC).

Results

3127 children with IBD (1826 CD; 1045 UC) were matched to 15,635 children without IBD. The cumulative incidence of VTE within 5 years of IBD diagnosis was 2.8 (95% CI 2.1–3.8) per 1000 PYs compared to 0.13 (95% CI 0.07–0.24) per 1000 PYs in children without IBD (Table). The 5-year cumulative incidences of VTE, DVT, and PE were significantly higher in children with IBD than in children without IBD (VTE: IRR 21.44, 95% CI 10.73–42.82; DVT: IRR 25.15, 95% CI 11.12–56.89; PE: IRR 4.01, 95% CI 1.22–13.18). Compared to UC patients, children with CD were at lower risk of VTE (IRR 0.53, 95% CI 0.29–0.96) and numerically, but not statistically, lower risk of DVT (IRR 0.59, 95% CI 0.30–1.14).

Conclusions

Although VTEs are relatively rare among children with IBD, these children are at much greater risk than children without IBD. Gastroenterologists caring for these patients should be cognizant of VTE risk and provide appropriate prophylaxis to those at high risk of VTE.

Funding Agencies

CCC

A169 DEVELOPMENT OF A DECISION TOOL TO IMPROVE UTILISATION OF RECOMMENDED SURVEILLANCE INTERVALS FOR INDIVIDUALS WITH COLORECTAL POLYPS: A FOCUS GROUP ANALYSIS

Background

Several studies have demonstrated a high utilization of colonoscopy at shorter and longer time intervals than guideline recommendations. Innovative methods are required to increase adherence to recommended timing.

Aims

1) Explore current approaches used by endoscopist (EPs) and primary care providers (PCPs) to determine and communicate colonoscopy surveillance intervals (SI) between EPs, PCPs, and patients.

2) Obtain feedback for refining a decision tool to facilitate recommended SI.

3) Determine participant agreement of recommended SIs with current guidelines.

Methods

We conducted 4 focus groups (FGs); 3 FGs included EPs (n=12) and EPs in training (n=6); 1 FG included PCPs (n=4). FG questions explored use of guidelines, communication and follow-up practices with PCPs, EPs and patients, and challenges to follow-up.

Participants were also asked for feedback about a prototype polyp SI decision tool that was developed using an algorithm synthesizing current Canadian Association of Gastroenterology, US Multisociety Task Force, and expert panel guidelines on SI. FGs were audio-recorded and transcribed for qualitative content analysis. FGs were analysed separately, then compared for similarities and differences. Finally, participants individually made interval recommendations for 7 common endoscopy scenarios. Responses were analyzed for agreement with the guidelines used to develop the decision tool.

Results

EPs reported not routinely referring to guidelines and were confident in their memory of the intervals although some reported checking occasionally. Many indicated they may use the tool in a web based or mobile application for more complicated scenarios, although some would never use it. Concerns regarding the tool included being up to date with research evidence and having required data to input on hand. PCPs reported the tool may be useful as a communication aid to involve patients in decision making. A challenge noted in all FGs was role confusion regarding communicating, tracking, and scheduling patients’ future procedures on time.

Analysis of EPs (n=9) responses to the 7 scenarios showed that percent agreement with guidelines was low: 44% scored below 50% correct. Participants with the highest agreement scored 6/7; responses with the lowest agreement scored 0/7. The most common score was 3/7.

Conclusions

EPs appeared to be overconfident in their recommendations, but many were open to trying a website or mobile application decision tool to make evidence-based colonoscopy SI recommendations. Understanding, among PCPs and EPs, regarding responsibility for communicating results and scheduling follow-up surveillance for patients was inconsistent. Participant feedback informed development of a mobile application that is currently being pilot tested.

Funding Agencies

Research Manitoba

A2 THE BOWEL CLEANSING NATIONAL INITIATIVE (BCLEAN): PREDICTORS OF INADEQUATE BOWEL PREPARATION

Background

Adequate bowel cleansing before colonoscopy is, in theory, a simple concept but the high rate of inadequate or incomplete bowel cleanliness and its consequences have been the subject of many studies, guidelines, and meta- analyses. The complexity resides in all the pre-endoscopic factors surrounding preparation intake that may? influence quality of the bowel preparation.

Aims

To identify preendoscopic variables associated with inadequate bowel preparation

Methods

In this randomized trial conducted in adult outpatients in 10 Canadian hospitals, all early morning (AM) colonoscopies were scheduled between 7h30AM and 10h30AM and patients were randomized to PEG low volume or high- volume split-dose or high- volume day before. Later colonoscopies (PM) were scheduled between 10h30AM and 16h30PM and patients were randomized to PEG low-volume or high- volume split-dose or low- volume same day. A secondary random allocation assigned patients to a clear fluid or low residue diet. Inadequate bowel preparation was identified on the Boston Bowel Preparation Scale with a total score <6 with any of the 3 colonic segments subscores <2). All preendoscopic variables such as patients related factors, diet and type of bowel preparation were evaluated between groups with chi-square, Fisher’s exact or t-test where appropriate. All variables found to be significantly associated with a clean preparation on univariable analysis at the P=0.15 level were used to construct a multivariable model. Because of stratified randomization by time with possible resulting differing confounders, AM and PM patients were analysed separately.

Results

Over 29 months, 1726 patients were stratified in the AM group and 1750 patients in the PM group. 16.9% had inadequate bowel preparation in the AM group and 9.8% in the PM group. Pre-endoscopic variables associated with an inadequate bowel cleanliness in AM colonoscopy were a non screening indication (OR 1.36, 95%CI 1.04–1.78), a Charlson score>0 (OR 1.36, 95% 1.03–1.80) and a low residue diet (OR 1.53, 95%CI 1.17–2.01). Amongst PM colonoscopies, variables associated with an inadequate bowel cleanliness were increased age (OR 1.03, 95% 1.01–1.04), a non screening indication (OR 1.90 95%CI 1.35–2.70); a Charlson score>0 (OR 1.63, 95%CI 1.15–2.32), and a low residue diet (OR 1.41, 95%CI 1.01; 1.98).

Conclusions

In this large randomized trial, amongst patients undergoing an AM colonoscopy, pre- endoscopic factors associated with an inadequate bowel preparation were a non screening indication, comorbidities and a low residue diet. Amongst PM colonoscopy patients, in addition to these variables, an increased age was also associated with an inadequate bowel preparation.

Funding Agencies

received arm-length funding from Pendopharm Inc.

A81 POST COLONOSCOPY COLORECTAL CANCERS IN MANITOBA: A POPULATION-BASED ANALYSIS

Background

Recent consensus guidelines from the World Endoscopy Organization (WEO) recommend all jurisdictions report unadjusted rates of post colonoscopy (PC) colorectal cancers (CRC). Until recently, prior reports have mostly focused on PC-CRC in the CRC screening age groups.

Aims

We evaluated the rate and predictors of PC-CRC in the adult population for the province of Manitoba from 1990 to 2016.

Methods

Individuals 18+ years at CRC diagnosis were identified from the Manitoba Cancer Registry. Colonoscopies in the 3 years preceding CRC diagnosis were identified via linkage to Manitoba Health (MH) physicians billing claims. CRCs were classified, based on WEO recommendations, as: (1) detected CRC (colonoscopy up to 6 months before CRC diagnosis) and (2) PC-CRC-3y (colonoscopy 6–36 months before CRC diagnosis). Generalized linear models with generalized estimating equations (to adjust for clustering within endoscopy physicians) were used to test for differences in rates over 3-time intervals (1990/91 – 1999/00; 2000/01 - 2009/10; 2010/11 – Dec 31 2016), provincial region of performance of colonoscopy and identify other associations from the MH data.

Results

Overall, 10.5% of the 16,639 CRCs diagnosed in the study period and with colonoscopy in the preceding 3 years were PC-CRC-3y. CRCs diagnosed between April 2000 and March 2010 were more likely to be PC-CRC-3y than those diagnosed between April 2010 and December 2016 (odds ratio [OR] 1.18; 95% confidence interval [CI]: 1.03–1.37). Female sex (OR for male: 0.86; 95% CI: 0.77–0.94), IBD diagnosis (OR 3.04; 95% CI: 2.56–4.52), prior CRC (OR 5.41; 95% CI: 4.61–6.34), prior colonoscopy (OR 2.10; 95% CI 1.88–2.36), diverticulosis (OR 2.39; 95% CI: 2.16–2.6), colonoscopy by GP (OR: 1.62; 95% CI 1.16–2.26 vs. surgeons) were associated with increased odds of PC-CRC-3y. There were no regional differences, and no effect of colonoscopy volume or age greater than 75 (or lower than 50).

Conclusions

In Manitoba, the PC-CRC-3y rate decreased slightly in recent years. The study results of large number of PC-CRC-3y along with only a slight decrease in rates over the years, support calls for root cause analysis to evaluate individual cases of PC-CRC. An initial focus could be the groups with increased risk of PC-CRC.

Funding Agencies

Manitoba Health

A246 POPULATION WIDE STUDY OF THE EPIDEMIOLOGY AND OUTCOMES OF ANTI-TNF DOSE AUGMENTATION IN INFLAMMATORY BOWEL DISEASE

Background

Inflammatory bowel disease (IBD) patients who experience loss of response to anti-tumor necrosis factor (anti-TNF) therapy are often treated with augmented doses of anti-TNF to recapture response. Despite this, factors associated with dose augmentation and treatment outcomes following dose augmentation remain largely undefined.

Aims

To examine the epidemiology of anti-TNF dose augmentation and determine the associated treatment outcomes among a province-wide cohort of anti-TNF treated IBD subjects.

Methods

The University of Manitoba Inflammatory Bowel Disease Epidemiological Database was used to identify patients receiving infliximab or adalimumab maintenance therapy for IBD in the Canadian province of Manitoba. Anti-TNF dose augmentation was defined as a ≥50% increase in anti-TNF dose or a shortening of dosing interval to ≤42 days for infliximab or ≤10 days for adalimumab. Anti-TNF failure was defined as corticosteroid use, IBD-related hospitalization, resective IBD surgery, or change in anti-TNF agent. Competing risks regression using a proportional subhazards model was used to determine the associations between dose augmentation, anti-TNF failure, anti-TNF discontinuation and a number of patient, disease, and treatment factors.

Results

871 persons (624 Crohn’s disease (CD), 247 ulcerative colitis (UC)) using anti-TNF maintenance therapy were identified. Cumulative incidence of dose augmentation among continued users was 25.7% at 90 days, 52.3% at 1 year, and 72.8% at 5 years. Anti-TNF failure occurred in 261 of 575 dose augmented subjects, with corticosteroid use the most common failure-defining event. Failure of standard dose anti-TNF in the 90 days preceding dose augmentation was strongly associated with failure of dose augmentation (HR 2.98 (2.27–3.93); p<0.0001). Persons with CD were less likely to receive corticosteroids but more likely to switch anti-TNF agents than persons with UC.

Conclusions

Rates of adverse IBD outcomes remain high after dose augmentation, particularly when dose augmentation is undertaken shortly after (or in response to) one of these adverse events. Our data suggest that dose augmentation may not be as effective as uncontrolled observational studies have indicated.

Funding Agencies

None

A24 RATE OF GASTROINTESTINAL ENDOSCOPY USE AND CONCOMITTANT ANESHESIOLOGY ASSISTANCE AND PREDICTORS OF ANESTHESIOLOGY ASSISTANCE: A POPULATION-BASED ANALYSIS

Background

There are limited Canadian data on time trends of gastrointestinal endoscopy (GIE) use and concomitant anesthesiology assistance.

Aims

To test the time trends and variations in concomitant anesthesiology assistance during GIE in the central Canadian province of Manitoba.

Methods

Physicians claims reimbursement data from the provincial health ministry were used to ascertain upper & lower GIE procedures and anesthesiology assistance annually from 1984 to 2016. The annual provincial population was determined from health insurance registration files. Generalized linear models with generalized estimating equations were used to test the linear trend over time and differences amongst age groups, health regions and income quintiles. Logistic regression analysis with generalized estimating equations was used to assess predictors of anesthesiology use.

Results

410, 685 individuals had at least one procedure in the observation period. Approximately half of the procedures were performed outside the recommended CRC screening age group of 50–74 years, with 38% among those less than 50 years. The average annual rate of increase was 4.6% (95% CI 4.4–4.8%). The rate of increase stabilized among the > 75 years group over the last 5 years of the study. There were marked regional variation in GIE procedures, with the smallest increase in Winnipeg region (the largest urban region):2.9% (95%CI: 2.5–3.3) vs. 5.2% (95%CI: 4.8–5.6) in Southern Health; RR: 2.2(figure 1 A). There were no differences in GIE rates by income quintile. Similar patterns were seen in analysis stratified by upper and lower GIE. Concomitant anesthesiology use ranged from 1% in Winnipeg region to 80% in the southern rural region (figure 1B). In the logistic regression analysis, independent predictors of concomitant anesthesiology use in rural regions included younger age, female sex, lower income quintile, and higher comorbidities of patients, GP endoscopist, region of physician practice, and lower volume endoscopy physician.

Conclusions

Marked regional variations in GIE use and concomitant anesthesiology use were observed in a universal health care system. Efforts to standardize care are needed to reduce variations.

Funding Agencies

Manitoba Health

A64 HOSPITALIZATION IN INFLAMMATORY BOWEL DISEASE: A POPULATION-BASED COMPARISON OF DEFINITIONS

Background

Most administrative studies of hospitalization in inflammatory bowel disease (IBD) use two definitions: IBD in any diagnostic position (IBD-ANY), and IBD as the most responsible diagnostic (IBD-MRD). There is a third less commonly used definition: total hospitalization; this definition captures all hospitalizations of prevalent IBD patients and therefore it can give a more realistic picture of the burden of IBD.

Aims

To compare differing definitions (total, IBD-ANY, and IBD-MRD) of hospitalizations.

Methods

A previously defined population-based IBD prevalent cohort for Alberta (n=30,698) was used to pull all hospital admissions from the Discharge Administrative Database (DAD; 2002–2015). Three hospitalization definitions were used: i. Total (all hospitalizations of prevalent cohort independent of presence of code for IBD); ii. IBD-ANY (code for IBD [K50.x; K51.x] contained in any diagnosis field); and, iii. IBD-MRD (most responsible diagnosis was IBD). Age- and sex- standardized rates (2015 Canadian population) were calculated using the prevalent population. Log-linear regression was performed to calculate Average Annual Percentage Change (AAPC) with associated 95% confidence intervals (CI) of each type of hospitalization. We assessed the top five most common most-responsible diagnosis codes for hospitalizations that were contained in the total hospitalizations but not an IBD-ANY hospitalization.

Results

From 2002 to 2015, 63.5% of IBD prevalent patients in AB had ≥1 hospitalization; 44.2% had ≥1 IBD-ANY hospitalization; 28.6% had ≥1 IBD-MRD hospitalization; and, 40.6% had a hospitalization that did not contain a code for IBD. All hospitalization rates decreased significantly over time. Of the top five most common most responsible diagnosis, contained in admissions that were not IBD-ANY, three were gastroenterological: i. K52.9 (non-infective gastroenteritis); ii. A09.9 (diarrhea and gastroenteritis of presumed infectious origin); and, iii. Z43.2 (attention to ileostomy).

Conclusions

Total hospitalizations is an important measure to report since accounting for all hospitalizations of IBD patients is necessary in order to allocate healthcare resources appropriately. To be able to ensure these patients receive the care they need we need to be able to accurately assess the true burden of IBD.

Funding Agencies

CIHR

A172 EXPERIENCE AND PERCEPTIONS OF SIMETHICONE USE DURING COLONOSCOPY: A SURVEY OF NORTH AMERICAN ENDOSCOPISTS

Background

Simethicone is an anti-foaming agent which can be used to decrease the surface tension of air bubbles and improve visualization of colonic mucosa during colonoscopy. Recent studies have found that residual simethicone persists in endoscopes despite reprocessing and disinfection and promotes persistent moisture in endoscope channels. Simethicone residues can theoretically contribute to biofilm formation by providing nutritional milieu for microbial growth, which could increase the risk of transmission of infections among patients. Endoscopists’ perceptions on simethicone use and potential benefits are unknown, and this study aims to start filling this gap.

Aims

To assess experience and perceptions of simethicone use during colonoscopy in North America.

Methods

A REDCap® survey was distributed via email to members of various national professional associations and personal contacts of the study authors. Once the survey is complete, logistic regression analysis will be performed to assess univariate and multivariate associations of simethicone use. Preliminary data are reported in this abstract.

Results

47 practicing endoscopists have responded so far, of which 31 (64%) are surgeons and 16 are gastroenterologists (34%). The participants had been in practice for a median of eight years (range 1 – 34 years) and performed a median of ten colonoscopies per week. All 47 endoscopists practiced in Canada, with representation from seven provinces. Two endoscopists (4%) ask patients to use simethicone orally as part of their bowel preparation. During outpatient colonoscopy, 22 endoscopists (47%) never use simethicone, 19 endoscopists (40%) use simethicone less than 50% of the time, and six endoscopists (13%) use simethicone more than 50% of the time. Endoscopists were divided as to whether certain bowel preparations influenced their use of simethicone (agree or strongly agree 9, 19%; neutral 29, 62%; disagree or strongly disagree 9, 19%), that simethicone use could contribute to the transmission of pathogens through endoscopes (agree or strongly agree 6, 13%; neutral 34, 72%; disagree or strongly disagree 7, 15%), or that simethicone use increases their adenoma detection rate (agree or strongly agree 18, 38%; neutral 21, 45%; disagree or strongly disagree 8, 17%).

Conclusions

Of the current respondents of this survey, just over half (53%) of endoscopists report using simethicone during outpatient colonoscopies. Most reported simethicone use was via the water pump or instrument channel; oral simethicone use maybe minimal. Current respondents were divided in their perception that type of bowel preparation influences their use of simethicone or that simethicone use could contribute to the transmission of pathogens. Many endoscopists believed simethicone use could increase their adenoma detection rate.

Funding Agencies

None

Proteasomal adaptations underlying carfilzomib-resistance in human bone marrow plasma cells

Donor-specific antibodies (DSAs) have a deleterious effect on allografts and remain a major immunologic barrier in transplantation. Current therapies to eliminate DSAs are ineffective in highly HLA-sensitized patients. Proteasome inhibitors have been employed as a strategy to target bone marrow plasma cells (BMPCs), the source of long-term antibody production; however, their efficacy has been limited by poorly defined drug-resistance mechanisms. Here, we performed transcriptomic profiling of CD138⁺ BMPCs that survived in vivo desensitization therapy with the proteasome inhibitor carfilzomib to identify mechanisms of drug resistance. The results revealed a genomic signature that included increased expression of the immunoproteasome, a highly specialized proteasomal variant. Western blotting and functional studies demonstrated that catalytically active immunoproteasomes and the immunoproteasome activator PA28 were upregulated in carfilzomib-resistant BMPCs. Carfilzomib-resistant BMPCs displayed reduced sensitivity to the proteasome inhibitors carfilzomib, bortezomib, and ixazomib, but enhanced sensitivity to an immunoproteasome-specific inhibitor ONX-0914. Finally, in vitro carfilzomib treatment of BMPCs from HLA-sensitized patients increased levels of the immunoproteasome β5i (PSMB8) catalytic subunit suggesting that carfilzomib therapy directly induces an adaptive immunoproteasome response. Taken together, our results indicate that carfilzomib induces structural changes in proteasomes and immunoproteasome formation.

P1731 Multiple floating thrombi in aortic arch leading to acute stroke: A case report and systematic review of literature

Introduction

Around 10-15% of acute cerebrovascular events occur in young adults with age less than 40 years. Trans-oesophageal echocardiogram (TOE) is routinely performed to rule out any cardio-embolic source in patients with ischemic stroke. TOE has shown to significantly change management strategy in up to 16.7% of stroke cases. We report a rare case of recurrent stroke in a young female who was found to have multiple mobile thrombi in aortic arch on TOE. We also report systematic review of literature of similar cases to highlight the management strategies.

Case Presentation

A 38-year-old female presented with one-week history of right upper and lower extremity paresthesia along with headache. Physical examination was unremarkable for any focal neurological deficits at time of initial evaluation. She had pertinent history of acute stroke two years ago associated with non-occlusive left common carotid artery thrombus for which she was previously on anticoagulation with rivaroxaban. The anticoagulation, however, was stopped five months ago after repeat imaging revealed complete resolution of thrombus. Electrocardiogram showed normal sinus rhythm without any other significant abnormality. CT head showed no acute bleeding or infarct. MRI brain showed scattered infarcts in right cerebral hemisphere and left cerebellar hemisphere. CT angiography of head and neck showed multiple small nodular and linear pedunculated thrombi in distal arch of aorta (see Figure 2). TOE was then performed which confirmed two pedunculated and mobile echogenic masses, largest measuring 0.9 x 0.6 cm, in the distal aortic arch (see Figure 1). TOE did not show intracardiac source of embolism. Laboratory testing for thrombophilia was negative for Factor V and Prothrombin gene mutation and heterozygous positive for Methylenetetrahydrofolate reductase (MTHFR)-677T gene. She was also found to have elevated homocysteine levels. She was restarted on anticoagulation with rivaroxaban.

Discussion and Conclusion

Young patients with stroke should undergo detailed investigation to rule out hypercoagulable pathology and cardiovascular embolic source. This should also include multimodality imaging including TOE in the selected patients. During TOE examination, a particular attention should be paid for evaluation of aortic source of thombo-embolism. Our patient was heterozygous for MTHFR-66T gene which is associated with decreassed activity of MTHFR by 35 % with elevated homocysteine levels. Treatment of floating aortic thrombus is still controversial. Anticoagulation is suggested as primary modality by multiple authors who reported complete resolution of thrombus. Other option includes surgical thrombectomy. Our patient was treated with anticoagulation alone due to hypercoagulable state and small size of thrombi.

Abstract P1731 Figure.

Suboptimal Adherence in Clinical Practice to Guidelines Recommendation to Screen for Lynch Syndrome

BACKGROUND

Identification of Lynch syndrome (LS) followed by annual/biannual surveillance colonoscopy markedly reduces the risk of developing new colorectal cancer (CRC) among those with LS.

AIMS

(1) To determine the current practice of identifying LS in the USA and Canada, and current surveillance and management practices for those diagnosed with LS; (2) to determine whether variances in current practice are physician/region dependent or influenced by ease of access to specialist clinics.

METHODS

An online survey request was sent to practicing gastroenterologists through the Canadian Association of Gastroenterology and the American College of Gastroenterology. Fisher's exact tests were performed to determine the factors associated with screening for LS and separately for follow-up, surveillance, and management.

RESULTS

A total of 249 participants were recruited, of which 237 were gastroenterologists and included in the analysis. Less than one-third of practicing gastroenterologists indicated that their CRC patients were undergoing screening tests to identify LS. While 42% (65/153) of participants from the USA stated that their patients were undergoing universal LS screening (i.e., among all diagnosed with CRC), only 12% (6/49) of participants from Canada reported this practice (p < 0.001). There was no difference in reported practice between the physicians that do and do not have access to hereditary clinics (35% vs. 34% testing; p = 0.54). Appropriate surveillance interval to look for CRC in patients with LS was recommended by most.

CONCLUSION

This survey suggests there is a significant difference in practice between Canada and the USA in regard to identification of LS, with suboptimal practice throughout North America.

Positron emission tomography/computed tomography guided percutaneous biopsies of Ga-68 avid lesions using an automated robotic arm

PURPOSE

The purpose of this prospective study was to evaluate the feasibility of positron emission tomography/computed tomography (PET/CT)-guided biopsy of Ga-68 avid lesions using an automated robotic arm and determine the diagnostic yield of this technique.

MATERIAL AND METHODS

Patients who underwent Ga-68 labelled tracers imaging followed by PET/CT-guided biopsies of tracer-avid lesions were prospectively included. Biopsies were performed using a dedicated automated-robotic-arm assisted PET/CT-guided biopsy device on the same-day of diagnostic PET/CT-imaging. The tissue samples were retrieved after confirming the position of needle-tip in the target lesion. Procedure-related complications and radiation exposure of the interventionist were recorded. Histopathological reports were reviewed for diagnostic yield.

RESULTS

A total of 25 patients (19 men, six women) with a mean age of 50.8±17.3 (SD) years (range: 17-83 years) were included. The biopsies were performed after PET/CT using Ga-68 DOTANOC (n=16) or Ga-68 PSMA (n=8) and Ga-68 chemokine-analogue (n=1). The biopsy samples were obtained from the liver (n=9), bone (n=8), lymph-nodes (n=3), lung (n=1), pancreas (n=1), anterior mediastinal lesion (n=1), peritoneal-deposit (n=1) and thigh-lesion (n=1). No immediate or delayed procedure-related complications were documented in any patient. PET/CT-guided molecular sampling was technically successful in all the patients. Histopathology revealed malignancies in all the biopsied specimens without the need for repeat sampling or further invasive-diagnostic workup, with a diagnostic yield of 100%. The estimated absorbed-radiation dose was 566.7μSv/year for the interventionist.

CONCLUSION

PET/CT-guided molecular biopsy using Ga-68 labelled radiotracers is feasible and can be performed safely and accurately with a high-diagnostic yield. It is helpful in accurately staging the disease when tracer-avid isolated distant lesion evident on imaging and highly practical in patients with previous inconclusive sampling.

Role of computed tomography in prediction of gastrointestinal fistula in patients with acute pancreatitis

AIM

To identify computed tomography (CT) features that predict gastrointestinal fistula (GIF) in patients with acute pancreatitis (AP).

METHODS

This retrospective study comprised consecutive patients with AP and GIF from June 2017 to June 2018. The diagnosis of GIF was based on upper gastrointestinal endoscopy, colonoscopy or surgery. A cohort of 19 matched patients from a prospective database of AP served as control group. Measures of severity, and clinical outcome were evaluated. CT parameters were compared between the groups to assess the features that could predict the development of GIF.

RESULTS

There was no difference between the two groups in terms of disease etiology, severity, drainage, and mortality. On univariate analysis, the CT features that were found to be significantly different between the two groups were the presence of bowel wall thickening (P=0.005), maximum thickness of the bowel wall (P=0.007), presence of air foci in extra pancreatic necrosis/ collection (P=0.013), discontinuity of the bowel wall (P=0.046) and the displacement/ compression of bowel by fluid collection (P=0.014). On multivariate analysis, all the above-mentioned CT findings except discontinuity of bowel wall were found to be statistically significant.

CONCLUSION

CT is helpful in predicting GIF in patients with AP.

Controlled intramolecular H-transfer in malonaldehyde in the electronic ground state mediated through the conical intersection of 1nπ* and 1ππ* excited electronic states

We report photo-isomerization of malonaldehyde in its electronic ground state (S0), mediated by coupled 1nπ*(S1)-1ππ*(S2) excited electronic states, accomplished with the aid of optimally designed ultraviolet (UV)-laser pulses. In particular, control of H-transfer from a configuration predominantly located in the left well (say, reactant) to that in the right well (say, product) of the electronic ground S0 potential energy surface is achieved by a pump-dump mechanism including the nonadiabatic interactions between the excited S1 and S2 states. An interplay between the nonadiabatic coupling due to the conical intersection of the S1 and S2 states and the laser-molecule interaction is found to be imprinted in the time-dependent electronic population. The latter is also examined by employing optimal fields of varying intensities and frequencies of the UV laser pulses. For the purpose of the present study, we constructed a three-state and two-mode coupled diabatic Hamiltonian with the help of adiabatic electronic energies and transition dipole moments calculated by ab initio quantum chemistry methods. The electronic diabatic model is developed using the calculated adiabatic energies of the two excited electronic states (S1 and S2) in order to carry out the dynamics study. The optimal fields for achieving the controlled isomerization are designed within the framework of optimal control theory employing the optimization technique of a multitarget functional using the genetic algorithm. The laser-driven dynamics of the system is treated by numerically solving the time-dependent Schrödinger equation within the dipole approximation. A time-averaged yield of the target product of ∼40% is achieved in the present treatment of dynamics with optimal laser pulses.

Impact of severe hypoglycaemia on psychological outcomes in adults with Type 2 diabetes: a systematic review

AIM

Hypoglycaemia affects many people with Type 2 diabetes using insulin and other glucose-lowering therapies. This systematic review examined the impact of severe hypoglycaemia (episodes requiring external assistance) on psychological outcomes (e.g. emotional well-being, health status and quality of life) in adults with Type 2 diabetes.

METHODS

MEDLINE Complete, PsycINFO and CINAHL databases were searched for peer-reviewed empirical studies, published in English, reporting the occurrence and severity of hypoglycaemia and its relationship with patient-reported outcomes (PROs) in adults with Type 2 diabetes. Data were extracted from published reports and analysed.

RESULTS

Of 3756 potentially relevant abstracts, 29 studies met the inclusion criteria. Most reported cross-sectional data and sample sizes varied widely (N = 71 to 17 563). Although definitions of mild and severe hypoglycaemia were largely consistent between studies, additional non-standard categorizations (e.g. moderate, very severe) were apparent and recall periods varied. Overall, severe hypoglycaemia was associated with increased fear of hypoglycaemia and decreased emotional well-being, health status and diabetes-specific quality of life. Effect sizes show that the association with fear of hypoglycaemia was stronger than with general health status.

CONCLUSIONS

Notwithstanding the limitations of the empirical studies, these findings indicate that severe hypoglycaemia in adults with Type 2 diabetes (insulin- and non-insulin-treated) is associated with impaired psychological outcomes. Healthcare professionals should address the psychological impact of severe hypoglycaemia during clinical consultations, to support individuals to minimize exposure to, and the psychological consequences of, severe hypoglycaemia.