Frances Tse
McMaster University
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Featured researches published by Frances Tse.
Gastrointestinal Endoscopy | 2008
Frances Tse; Louis Liu; Alan N. Barkun; David Armstrong; Paul Moayyedi
BACKGROUND EUS has been proposed as a less invasive means of diagnosing choledocholithiasis and may eliminate the need for ERCP and its associated risks. The literature pertaining to EUS for the diagnosis of choledocholithiasis reports widely varying sensitivities and specificities. OBJECTIVE To more precisely estimate the diagnostic accuracy of EUS in suspected choledocholithiasis. DESIGN MEDLINE and EMBASE databases were used to identify prospective cohort studies in which the results of EUS were compared with the results of an acceptable criterion standard, including ERCP, intraoperative cholangiography, or surgical exploration. Two independent reviewers extracted standardized data and assessed trial quality. A random effects model was used to estimate the sensitivity, specificity, likelihood, and diagnostic odds ratio (DOR), and a summary receiver operating characteristic curve was constructed. All predefined potential sources of heterogeneity were explored by subgroup analysis and meta-regression. PATIENTS A total of 2673 patients with suspected choledocholithiasis were reported in 27 studies that satisfied the inclusion criteria. RESULTS EUS had a high overall pooled sensitivity of 0.94 (95% CI, 0.93-0.96), a specificity of 0.95 (95% CI, 0.94-0.96), and an area under the curve of 0.98. Three variables appeared to yield a higher DOR: a higher disease prevalence, an adequate time interval between index test and criterion standards, and the presence of verification bias. LIMITATIONS Misclassification of patients by imperfect criterion standards could potentially underestimate the performance of an EUS. CONCLUSIONS An EUS is a noninvasive test, with excellent overall sensitivity and specificity for diagnosing choledocholithiasis. An EUS should, therefore, be used to select patients for a therapeutic ERCP to minimize the risk of complications associated with unnecessary diagnostic ERCP.
Gastroenterology | 2016
Geoffrey C. Nguyen; Cynthia H. Seow; Cynthia Maxwell; V Huang; Yvette Leung; Jennifer Jones; Grigorios I. Leontiadis; Frances Tse; Uma Mahadevan; C. Janneke van der Woude; Alain Bitton; Brian Bressler; Sharyle Fowler; John K. Marshall; Carrie Palatnick; Anna Pupco; Joel Ray; Laura E. Targownik; Janneke van der Woude; William G. Paterson
BACKGROUND & AIMS The management of inflammatory bowel disease (IBD) poses a particular challenge during pregnancy because the health of both the mother and the fetus must be considered. METHODS A systematic literature search identified studies on the management of IBD during pregnancy. The quality of evidence and strength of recommendations were rated using the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach. RESULTS Consensus was reached on 29 of the 30 recommendations considered. Preconception counseling and access to specialist care are paramount in optimizing disease management. In general, women on 5-ASA, thiopurine, or anti-tumor necrosis factor (TNF) monotherapy for maintenance should continue therapy throughout pregnancy. Discontinuation of anti-TNF therapy or switching from combination therapy to monotherapy may be considered in very select low-risk patients. Women who have a mild to moderate disease flare while on optimized 5-ASA or thiopurine therapy should be managed with systemic corticosteroid or anti-TNF therapy, and those with a corticosteroid-resistant flare should start anti-TNF therapy. Endoscopy or urgent surgery should not be delayed during pregnancy if indicated. Decisions regarding cesarean delivery should be based on obstetric considerations and not the diagnosis of IBD alone, with the exception of women with active perianal Crohns disease. With the exception of methotrexate, the use of medications for IBD should not influence the decision to breast-feed and vice versa. Live vaccinations are not recommended within the first 6 months of life in the offspring of women who were on anti-TNF therapy during pregnancy. CONCLUSIONS Optimal management of IBD before and during pregnancy is essential to achieving favorable maternal and neonatal outcomes.
Sensors | 2009
Munir M. El-Desouki; M. Jamal Deen; Qiyin Fang; Louis W. C. Liu; Frances Tse; David Armstrong
Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4∼5 μm) due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps).
The American Journal of Gastroenterology | 2014
Rebecca Anglin; Yuhong Yuan; Paul Moayyedi; Frances Tse; David Armstrong; Grigorios I. Leontiadis
OBJECTIVES:There is emerging concern that selective serotonin reuptake inhibitors (SSRIs) may be associated with an increased risk of upper gastrointestinal (GI) bleeding, and that this risk may be further increased by concurrent use of nonsteroidal anti-inflammatory (NSAID) medications. Previous reviews of a relatively small number of studies have reported a substantial risk of upper GI bleeding with SSRIs; however, more recent studies have produced variable results. The objective of this study was to obtain a more precise estimate of the risk of upper GI bleeding with SSRIs, with or without concurrent NSAID use.METHODS:MEDLINE, EMBASE, PsycINFO, the Cochrane central register of controlled trials (through April 2013), and US and European conference proceedings were searched. Controlled trials, cohort, case–control, and cross-sectional studies that reported the incidence of upper GI bleeding in adults on SSRIs with or without concurrent NSAID use, compared with placebo or no treatment were included. Data were extracted independently by two authors. Dichotomous data were pooled to obtain odds ratio (OR) of the risk of upper GI bleeding with SSRIs +/− NSAID, with a 95% confidence interval (CI). The main outcome and measure of the study was the risk of upper GI bleeding with SSRIs compared with placebo or no treatment.RESULTS:Fifteen case–control studies (including 393,268 participants) and four cohort studies were included in the analysis. There was an increased risk of upper GI bleeding with SSRI medications in the case–control studies (OR=1.66, 95% CI=1.44,1.92) and cohort studies (OR=1.68, 95% CI=1.13,2.50). The number needed to harm for upper GI bleeding with SSRI treatment in a low-risk population was 3,177, and in a high-risk population it was 881. The risk of upper GI bleeding was further increased with the use of both SSRI and NSAID medications (OR=4.25, 95% CI=2.82,6.42).CONCLUSIONS:SSRI medications are associated with a modest increase in the risk of upper GI bleeding, which is lower than has previously been estimated. This risk is significantly elevated when SSRI medications are used in combination with NSAIDs, and physicians prescribing these medications together should exercise caution and discuss this risk with patients.
Hpb | 2006
Frances Tse; Jeffrey Barkun; Joseph Romagnuolo; Gad Friedman; Jeffrey D. Bornstein; Alan N. Barkun
Evaluation of suspected biliary tract obstruction is a common clinical problem. Clinical data such as history, physical examination, and laboratory tests can accurately identify up to 90% of patients whose jaundice is caused by extrahepatic obstruction. However, complete assessment of extrahepatic obstruction often requires the use of various imaging modalities to confirm the presence, level, and cause of obstruction, and to aid in treatment plan. In the present summary, the literature on competing technologies including endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiopancreatography (PTC), endoscopic ultrasound (EUS), intraductal ultrasonography (IDUS), magnetic resonance cholangiopancreatography (MRCP), helical CT (hCT) and helical CT cholangiography (hCTC) with regards to diagnostic performance characteristics, technical success, safety, and cost-effectiveness is reviewed. Patients with obstructive jaundice secondary to choledocholithiasis or pancreaticobiliary malignancies are the primary focus of this review. Algorithms for the management of suspected obstructive jaundice are put forward based on current evidence. Published data suggest an increasing role for EUS and other noninvasive imaging techniques such as MRCP, and hCT following an initial transabdominal ultrasound in the assessment of patients with suspected biliary obstruction to select candidates for surgery or therapeutic ERCP. The management of patients with a suspected pancreaticobiliary condition ultimately is dependent on local expertise, availability, cost, and the multidisciplinary collaboration between radiologists, surgeons, and gastroenterologists.
Gastroenterology | 2017
Robert Enns; Lawrence Hookey; David Armstrong; Charles N. Bernstein; Steven J. Heitman; Christopher W. Teshima; Grigorios I. Leontiadis; Frances Tse; Daniel C. Sadowski
BACKGROUND & AIMS Video capsule endoscopy (CE) provides a noninvasive option to assess the small intestine, but its use with respect to endoscopic procedures and cross-sectional imaging varies widely. The aim of this consensus was to provide guidance on the appropriate use of CE in clinical practice. METHODS A systematic literature search identified studies on the use of CE in patients with Crohns disease, celiac disease, gastrointestinal bleeding, and anemia. The quality of evidence and strength of recommendations were rated using the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. RESULTS The consensus includes 21 statements focused on the use of small-bowel CE and colon capsule endoscopy. CE was recommended for patients with suspected, known, or relapsed Crohns disease when ileocolonoscopy and imaging studies were negative if it was imperative to know whether active Crohns disease was present in the small bowel. It was not recommended in patients with chronic abdominal pain or diarrhea, in whom there was no evidence of abnormal biomarkers typically associated with Crohns disease. CE was recommended to assess patients with celiac disease who have unexplained symptoms despite appropriate treatment, but not to make the diagnosis. In patients with overt gastrointestinal bleeding, and negative findings on esophagogastroduodenoscopy and colonoscopy, CE should be performed as soon as possible. CE was recommended only in selected patients with unexplained, mild, chronic iron-deficiency anemia. CE was suggested for surveillance in patients with polyposis syndromes or other small-bowel cancers, who required small-bowel studies. Colon capsule endoscopy should not be substituted routinely for colonoscopy. Patients should be made aware of the potential risks of CE including a failed procedure, capsule retention, or a missed lesion. Finally, standardized criteria for training and reporting in CE should be defined. CONCLUSIONS CE generally should be considered a complementary test in patients with gastrointestinal bleeding, Crohns disease, or celiac disease, who have had negative or inconclusive endoscopic or imaging studies.
Endoscopy | 2016
Frances Tse; Yuhong Yuan; Paul Moayyedi; Grigorios I. Leontiadis; Alan N. Barkun
Background and study aims Difficult cannulation is a risk factor for pancreatitis following endoscopic retrograde cholangiopancreatography (ERCP). The double-guidewire technique (DGT) may improve cannulation success and reduce the risk of post-ERCP pancreatitis (PEP) in patients with difficult cannulation. This systematic review compared the DGT with persistent conventional cannulation or other advanced techniques in patients with difficult cannulation. Patients and Methods CENTRAL, MEDLINE, EMBASE, and CINAHL databases and DDW and UEGW abstracts up to March 2016 were searched for randomized controlled trials (RCTs) comparing DGT with persistent conventional cannulation or other advanced techniques (precut, pancreatic duct [PD] stenting). The primary outcome was PEP. Secondary outcomes included severity of PEP, successful cannulation of the common bile duct (CBD) with the randomized technique, overall CBD cannulation success, and ERCP-related complications. Results 7 RCTs (577 patients) were included. Use of the DGT significantly increased PEP compared to other endoscopic techniques (risk ratio [RR] 1.98, 95 % confidence interval [95 %CI] 1.14 - 3.42). There was no significant difference in CBD cannulation success with the randomized technique (RR 1.04, 95 %CI 0.87 - 1.24) or in overall cannulation success (RR 1.04, 95 %CI 0.91 - 1.18) between DGT and other techniques. There was also no significant difference in the risk of other ERCP-related complications (bleeding, perforation, cholangitis, and mortality). The results were robust in sensitivity analyses. Conclusions In patients with difficult cannulation, sole use of the DGT appears to increase the risk of PEP without any superiority in achieving biliary cannulation compared to other techniques. PD stenting may reduce the risk of PEP when the DGT is used. The influence of co-intervention in the form of per-procedural nonsteroidal anti-inflammatory drug (NSAID) administration is unclear.
Canadian Journal of Gastroenterology & Hepatology | 2013
Resheed Alkhiari; Deepti Jacob; Zain Kassam; Osama Abu Zaghlan; Frances Tse
1Department of Medicine, McMaster University, Hamilton, Ontario; 2Department of Medicine, University of Calgary, Calgary, Alberta; 3Division of Gastroenterology, McMaster University, Hamilton, Ontario; 4Harvard School of Public Health, Harvard University, Boston, Massachusetts, USA Correspondence: Dr Frances Tse, Division of Gastroenterology, McMaster University, Room 2F53, 1200 Main Street West, Hamilton, Ontario L8N 3Z5. Telephone 905-521-2100 ext 76733, fax 905-523-6048, e-mail [email protected] Received for publication April 21, 2013. Accepted May 12, 2013 Case presentation A 53-year-old man admitted for stem cell transplantation in the context of acute myeloid leukemia was referred for gastric content leakage from a persistent gastrocutaneous fistula. A percutaneous endoscopic gastrostomy (PEG) tube had been placed for four months due to suboptimal nutrition. The PEG tube was subsequently removed due to improvement in caloric intake and nutritional status. Unfortunately, drainage of gastric contents (approximately 250 mL/day) from the gastrocutaneous fistula after removal of the PEG tube persisted. This led to peristomal skin maceration and breakdown resulting in local cutaneous bleeding from the PEG tube site. Despite conservative management with bowel rest, proton pump inhibitor therapy, wound care and parenteral nutrition, drainage and bleeding from the gastrocutaneous fistula site persisted. The remainder of his medical history was noncontributory. Physical examination using subjective global assessment revealed a hemodynamically stable man with adequate nutritional status, without any examination or laboratory contraindications to endoscopy. Informed consent was obtained to proceed with an attempt to close the gastrocutaneous fistula via endoscopic hemoclips before considering surgical closure. During endoscopy, the opening of the fistula was identified in the antrum (Figure 1). Single-modality therapy was used and three hemoclips were placed in an attempt to close the fistula site (Figure 2). A stoma bag was placed over the pre-existing fistula site; no air leakage was observed at the time of endoscopy. The fistula tract closed within 24 h after the procedure with no further leakage noted. The patient was closely followed over the ensuing week. Daily clinical assessments were conducted and no evidence of gastric content was noted at the previous fistula site. The patient was kept nil per os for three days and proton pump inhibitor therapy was continued. His diet was then advanced. The lack of gastric output from the fistula tract postendoclip placement, even after the initiation of oral feeds, confirmed the successful outcome of the procedure (Figure 3).
Canadian Journal of Gastroenterology & Hepatology | 2016
Nauzer Forbes; Mohan Cooray; Raed Al-Dabbagh; Yuhong Yuan; Frances Tse; Louis Liu; Ted Xenodemetropoulos
Background. In 2012, Health Canada released a warning regarding domperidone use, based on associations with life-threatening arrhythmias and death. Objective. This study aimed to compare the appropriateness of domperidone prescribing patterns before the advisory to those afterward. Methods. Two retrospective reviews were conducted for patients prescribed domperidone during quarters in 2005 and 2012. Outcomes included appropriateness of indication, dosing regimens, monitoring of electrolytes, baseline electrocardiogram performance and characteristics, presence of left ventricular dysfunction, and coprescription of QT-prolonging medications. Univariable and multivariable logistic regression analyses were performed. p values < 0.05 were considered significant. Results. 290 and 287 patients were analyzed in 2005 and 2012, respectively. Domperidone initiation in hospital decreased from 2005 to 2012 (71.4% versus 39.4%, p < 0.0001) as did prescriptions for nonapproved indications (84.8% versus 58.2%, p < 0.0001). In-hospital initiation predicted prescription for nonapproved indications (OR = 7.01, 95% CI 4.52–10.87, p < 0.0001). Use of domperidone as the sole GI drug predicted nonapproved indications (OR = 2.51, 95% CI 1.38–4.55, p = 0.002). Conclusions. The advisory was associated with more appropriate domperidone initiation and compliance with recommended dosages. Our study suggests the need for increased awareness of the dosing and monitoring of domperidone to ensure patient safety.
Journal of the Canadian Association of Gastroenterology | 2018
Louis W C Liu; Christopher N. Andrews; David Armstrong; Nicholas Diamant; Nasir Jaffer; Adriana Lazarescu; Marilyn Li; Rosemary Martino; William G. Paterson; Grigorios I. Leontiadis; Frances Tse
Abstract Background and aims Our aim is to review the literature and provide guidelines for the assessment of uninvestigated dysphagia. Methods A systematic literature search identified studies on dysphagia. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Statements were discussed and revised via small group meetings, teleconferences, and a web-based platform until consensus was reached by the full group. Results The consensus includes 13 statements focused on the role of strategies for the assessment of esophageal dysphagia. In patients presenting with dysphagia, oropharyngeal dysphagia should be identified promptly because of the risk of aspiration. For patients with esophageal dysphagia, history can be used to help differentiate structural from motility disorders and to elicit alarm features. An empiric trial of proton pump inhibitor therapy should be limited to four weeks in patients with esophageal dysphagia who have reflux symptoms and no additional alarm features. For patients with persistent dysphagia, endoscopy, including esophageal biopsy, was recommended over barium esophagram for the assessment of structural and mucosal esophageal disease. Barium esophagram may be useful when the availability of endoscopy is limited. Esophageal manometry was recommended for diagnosis of esophageal motility disorders, and high-resolution was recommended over conventional manometry. Conclusions Once oropharyngeal dysphagia is ruled out, patients with symptoms of esophageal dysphagia should be assessed by history and physical examination, followed by endoscopy to identify structural and inflammatory lesions. If these are ruled out, then manometry is recommended for the diagnosis of esophageal dysmotility.