24 results on '"Richard CS"'
Search Results
2. Interpretable many-class decoding for MEG
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Richard Csaky, Mats W.J. van Es, Oiwi Parker Jones, and Mark Woolrich
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MEG ,Neuroimaging ,Decoding ,Machine learning ,Permutation feature importance ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Multivariate pattern analysis (MVPA) of Magnetoencephalography (MEG) and Electroencephalography (EEG) data is a valuable tool for understanding how the brain represents and discriminates between different stimuli. Identifying the spatial and temporal signatures of stimuli is typically a crucial output of these analyses. Such analyses are mainly performed using linear, pairwise, sliding window decoding models. These allow for relative ease of interpretation, e.g. by estimating a time-course of decoding accuracy, but have limited decoding performance. On the other hand, full epoch multiclass decoding models, commonly used for brain–computer interface (BCI) applications, can provide better decoding performance. However interpretation methods for such models have been designed with a low number of classes in mind. In this paper, we propose an approach that combines a multiclass, full epoch decoding model with supervised dimensionality reduction, while still being able to reveal the contributions of spatiotemporal and spectral features using permutation feature importance. Crucially, we introduce a way of doing supervised dimensionality reduction of input features within a neural network optimised for the classification task, improving performance substantially. We demonstrate the approach on 3 different many-class task-MEG datasets using image presentations. Our results demonstrate that this approach consistently achieves higher accuracy than the peak accuracy of a sliding window decoder while estimating the relevant spatiotemporal features in the MEG signal.
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- 2023
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- View/download PDF
3. ICP-MS Method Validation for the Analysis of Trace Elements in Illicit Heroin
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Richard Cs Wong, Kar-Weng Chan, and Guan Huat Tan
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Illicit heroin ,Detection limit ,Reproducibility ,Chromatography ,Sample Weight ,Chemistry ,Biochemistry (medical) ,Clinical Biochemistry ,Analytical chemistry ,Repeatability ,Mass spectrometry ,Biochemistry ,Analytical Chemistry ,Electrochemistry ,Inductively coupled plasma mass spectrometry ,Spectroscopy - Abstract
The analysis of the trace elements present in the street doses of heroin has currently been undertaken with a dual aim: to estimate the elemental compositions and to cluster the case samples. Inductively coupled plasma-mass spectrometry was optimized to quantify 18 trace elements simultaneously. The method presented high repeatability and reproducibility for the target elements. The linear concentration ranges achieved linearity with r2 > 0.9975. The limits of detection (LOD) were sufficiently low for almost all the elements except for Ca (LOD = 100 ppb). The limit of quantification (LOQ) for each element was also found acceptable. All target elements show mean recoveries between 92%–108%. Other major findings of this study including intra-sample (RSD
- Published
- 2012
4. Qualitative Analysis of Illicit Heroin via Visual Examination for Forensic Intelligence
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Guan Huat Tan, Richard Cs Wong, and Kar-Weng Chan
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Illicit heroin ,business.industry ,Visual examination ,Qualitative property ,computer.software_genre ,Heroin ,Qualitative analysis ,mental disorders ,Medicine ,Artificial intelligence ,business ,computer ,Forensic intelligence ,Natural language processing ,medicine.drug - Abstract
The qualitative information derived from the physical characteristics associated with heroin seizures has never been given emphasis. This study seeks to make use of the qualitative data for forensic intelligence purposes. A photographic setup is introduced for preserving the original conditions of the samples. The technique was found to be simple and inexpensive; it is also useful for general heroin profiling. The textures of the heroin substances, wrapping styles observed from the drug packages and the sealing on the package were documented. Upon analyzing 311 heroin cases, it was found that most cases contained coarse structures of heroin which were packed in packages bearing one packer’s seal with rectangular seal-marks. Possible interpretations for the observed variables are also given in this paper.
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- 2012
5. ICP-MS Method Validation for the Analysis of Trace Elements in Illicit Heroin
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Chan, Kar-Weng, primary, Tan, Guan-Huat, additional, and Wong, Richard CS, additional
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- 2012
- Full Text
- View/download PDF
6. A Low-Power Highly Linear CMOS Transconductance Topology
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Zare-Hoseini, Hashem, primary, Kale, Izzet, additional, and Morling, Richard CS, additional
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- 2006
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7. Evidence-based surgery. Canadian Association of Geneal Surgeons Evidence Based Reviews in Surgery. 5. Need for preoperative radiation in rectal cancer.
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Richard CS, Phang PT, McLeod RS, and Canadian Association of General Surgeons Evidence Based Reviews in Surgery
- Abstract
Question: Does the addition of preoperative radiotherapy increase the benefit of total mesorectal excision for rectal cancer? Design: A randomized controlled trial. Setting: A multicentre setting, which included hospitals from The Netherlands, Sweden, Canada and other European locations. Patients: The study included 1861 patients who had histologically confirmed adenocarcinoma of the rectum without evidence of distant metastases and in whom the inferior margin of the tumour was located not farther that 15 cm from the anal verge and below the level of Sl-2. Intervention: Patients were randomly assigned to treatment with preoperative radiation (5 Gy on each of 5 d) followed by total mesorectal excision (n = 897) or to total mesorectal excision alone (n = 908). Main outcome measures: Two main outcomes were measured: overall survival rate and local recurrence. Results: The table shows the results at the 2-year follow-up. Conclusion: Preoperative radiotherapy (short course) with total mesorectal excision significantly decreases the local recurrence rate compared with surgery alone at a median follow-up of 2 years. [ABSTRACT FROM AUTHOR]
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- 2003
8. Diverticulitis: A Review of Current and Emerging Practice-Changing Evidence.
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Wu S, Al Khaldi M, Richard CS, and Dagbert F
- Abstract
Acute diverticulitis represents a common colorectal emergency seen in the Western world. Over time, management of this condition has evolved. This review aims to highlight recent evidence and update current recommendations. Notable evidence has emerged in certain aspects of diverticulitis. This includes disease pathogenesis, as emerging data suggest a potentially greater role for the microbiome and genetic predisposition than previously thought. Acute management has also seen major shifts, where traditional antibiotic treatment may no longer be necessary for acute uncomplicated diverticulitis. Following successful medical management of acute diverticulitis, indications for elective sigmoidectomy have decreased. The benefit of emergency surgery remains for peritonitis, sepsis, obstruction, and acute diverticulitis in certain immunocompromised patients. Routine colonoscopy, once recommended after all acute diverticulitis episodes, has been shown to be beneficial for cancer exclusion in a distinct patient population. Despite advances in research, certain entities remain poorly understood, such as smoldering diverticulitis and symptomatic uncomplicated diverticular disease. As research in the field expands, paradigm shifts will shape our understanding of diverticulitis, influencing how clinicians approach management and educate patients., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)
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- 2023
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9. 2023 Canadian Surgery Forum: Sept. 20-23, 2023.
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Brière R, Émond M, Benhamed A, Blanchard PG, Drolet S, Habashi R, Golbon B, Shellenberger J, Pasternak J, Merchant S, Shellenberger J, La J, Sawhney M, Brogly S, Cadili L, Horkoff M, Ainslie S, Demetrick J, Chai B, Wiseman K, Hwang H, Alhumoud Z, Salem A, Lau R, Aw K, Nessim C, Gawad N, Alibhai K, Towaij C, Doan D, Raîche I, Valji R, Turner S, Balmes PN, Hwang H, Hameed SM, Tan JGK, Wijesuriya R, Tan JGK, Hew NLC, Wijesuriya R, Lund M, Hawel J, Gregor J, Leslie K, Lenet T, McIsaac D, Hallet J, Jerath A, Lalu M, Nicholls S, Presseau J, Tinmouth A, Verret M, Wherrett C, Fergusson D, Martel G, Sharma S, McKechnie T, Talwar G, Patel J, Heimann L, Doumouras A, Hong D, Eskicioglu C, Wang C, Guo M, Huang L, Sun S, Davis N, Wang J, Skulsky S, Sikora L, Raîche I, Son HJ, Gee D, Gomez D, Jung J, Selvam R, Seguin N, Zhang L, Lacaille-Ranger A, Sikora L, McIsaac D, Moloo H, Follett A, Holly, Organ M, Pace D, Balvardi S, Kaneva P, Semsar-Kazerooni K, Mueller C, Vassiliou M, Al Mahroos M, Fiore JF Jr, Schwartzman K, Feldman L, Guo M, Karimuddin A, Liu GP, Crump T, Sutherland J, Hickey K, Bonisteel EM, Umali J, Dogar I, Warden G, Boone D, Mathieson A, Hogan M, Pace D, Seguin N, Moloo H, Li Y, Best G, Leong R, Wiseman S, Alaoui AA, Hajjar R, Wassef E, Metellus DS, Dagbert F, Loungnarath R, Ratelle R, Schwenter F, Debroux É, Wassef R, Gagnon-Konamna M, Pomp A, Richard CS, Sebajang H, Alaoui AA, Hajjar R, Dagbert F, Loungnarath R, Sebajang H, Ratelle R, Schwenter F, Debroux É, Wassef R, Gagnon-Konamna M, Pomp A, Santos MM, Richard CS, Shi G, Leung R, Lim C, Knowles S, Parmar S, Wang C, Debru E, Mohamed F, Anakin M, Lee Y, Samarasinghe Y, Khamar J, Petrisor B, McKechnie T, Eskicioglu C, Yang I, Mughal HN, Bhugio M, Gok MA, Khan UA, Fernandes AR, Spence R, Porter G, Hoogerboord CM, Neumann K, Pillar M, Guo M, Manhas N, Melck A, Kazi T, McKechnie T, Jessani G, Heimann L, Lee Y, Hong D, Eskicioglu C, McKechnie T, Tessier L, Archer V, Park L, Cohen D, Parpia S, Bhandari M, Dionne J, Eskicioglu C, Bolin S, Afford R, Armstrong M, Karimuddin A, Leung R, Shi G, Lim C, Grant A, Van Koughnett JA, Knowles S, Clement E, Lange C, Roshan A, Karimuddin A, Scott T, Nadeau K, Macmillan J, Wilson J, Deschenes M, Nurullah A, Cahill C, Chen VH, Patterson KM, Wiseman SM, Wen B, Bhudial J, Barton A, Lie J, Park CM, Yang L, Gouskova N, Kim DH, Afford R, Bolin S, Morris-Janzen D, McLellan A, Karimuddin A, Archer V, Cloutier Z, Berg A, McKechnie T, Wiercioch W, Eskicioglu C, Labonté J, Bisson P, Bégin A, Cheng-Oviedo SG, Collin Y, Fernandes AR, Hossain I, Ellsmere J, El-Kefraoui C, Do U, Miller A, Kouyoumdjian A, Cui D, Khorasani E, Landry T, Amar-Zifkin A, Lee L, Feldman L, Fiore J, Au TM, Oppenheimer M, Logsetty S, AlShammari R, AlAbri M, Karimuddin A, Brown C, Raval MJ, Phang PT, Bird S, Baig Z, Abu-Omar N, Gill D, Suresh S, Ginther N, Karpinski M, Ghuman A, Malik PRA, Alibhai K, Zabolotniuk T, Raîche I, Gawad N, Mashal S, Boulanger N, Watt L, Razek T, Fata P, Grushka J, Wong EG, Hossain I, Landry M, Mackey S, Fairbridge N, Greene A, Borgoankar M, Kim C, DeCarvalho D, Pace D, Wigen R, Walser E, Davidson J, Dorward M, Muszynski L, Dann C, Seemann N, Lam J, Harding K, Lowik AJ, Guinard C, Wiseman S, Ma O, Mocanu V, Lin A, Karmali S, Bigam D, Harding K, Greaves G, Parker B, Nguyen V, Ahmed A, Yee B, Perren J, Norman M, Grey M, Perini R, Jowhari F, Bak A, Drung J, Allen L, Wiseman D, Moffat B, Lee JKH, McGuire C, Raîche I, Tudorache M, Gawad N, Park LJ, Borges FK, Nenshi R, Jacka M, Heels-Ansdell D, Simunovic M, Bogach J, Serrano PE, Thabane L, Devereaux PJ, Farooq S, Lester E, Kung J, Bradley N, Best G, Ahn S, Zhang L, Prince N, Cheng-Boivin O, Seguin N, Wang H, Quartermain L, Tan S, Shamess J, Simard M, Vigil H, Raîche I, Hanna M, Moloo H, Azam R, Ko G, Zhu M, Raveendran Y, Lam C, Tang J, Bajwa A, Englesakis M, Reel E, Cleland J, Snell L, Lorello G, Cil T, Ahn HS, Dube C, McIsaac D, Smith D, Leclerc A, Shamess J, Rostom A, Calo N, Thavorn K, Moloo H, Laplante S, Liu L, Khan N, Okrainec A, Ma O, Lin A, Mocanu V, Karmali S, Bigam D, Bruyninx G, Georgescu I, Khokhotva V, Talwar G, Sharma S, McKechnie T, Yang S, Khamar J, Hong D, Doumouras A, Eskicioglu C, Spoyalo K, Rebello TA, Chhipi-Shrestha G, Mayson K, Sadiq R, Hewage K, MacNeill A, Muncner S, Li MY, Mihajlovic I, Dykstra M, Snelgrove R, Wang H, Schweitzer C, Wiseman SM, Garcha I, Jogiat U, Baracos V, Turner SR, Eurich D, Filafilo H, Rouhi A, Bédard A, Bédard ELR, Patel YS, Alaichi JA, Agzarian J, Hanna WC, Patel YS, Alaichi JA, Provost E, Shayegan B, Adili A, Hanna WC, Mistry N, Gatti AA, Patel YS, Farrokhyar F, Xie F, Hanna WC, Sullivan KA, Farrokhyar F, Patel YS, Liberman M, Turner SR, Gonzalez AV, Nayak R, Yasufuku K, Hanna WC, Mistry N, Gatti AA, Patel YS, Cross S, Farrokhyar F, Xie F, Hanna WC, Haché PL, Galvaing G, Simard S, Grégoire J, Bussières J, Lacasse Y, Sassi S, Champagne C, Laliberté AS, Jeong JY, Jogiat U, Wilson H, Bédard A, Blakely P, Dang J, Sun W, Karmali S, Bédard ELR, Wong C, Hakim SY, Azizi S, El-Menyar A, Rizoli S, Al-Thani H, Fernandes AR, French D, Li C, Ellsmere J, Gossen S, French D, Bailey J, Tibbo P, Crocker C, Bondzi-Simpson A, Ribeiro T, Kidane B, Ko M, Coburn N, Kulkarni G, Hallet J, Ramzee AF, Afifi I, Alani M, El-Menyar A, Rizoli S, Al-Thani H, Chughtai T, Huo B, Manos D, Xu Z, Kontouli KM, Chun S, Fris J, Wallace AMR, French DG, Giffin C, Liberman M, Dayan G, Laliberté AS, Yasufuku K, Farivar A, Kidane B, Weessies C, Robinson M, Bednarek L, Buduhan G, Liu R, Tan L, Srinathan SK, Kidane B, Nasralla A, Safieddine N, Gazala S, Simone C, Ahmadi N, Hilzenrat R, Blitz M, Deen S, Humer M, Jugnauth A, Buduhan G, Kerr L, Sun S, Browne I, Patel Y, Hanna W, Loshusan B, Shamsil A, Naish MD, Qiabi M, Nayak R, Patel R, Malthaner R, Pooja P, Roberto R, Greg H, Daniel F, Huynh C, Sharma S, Vieira A, Jain F, Lee Y, Mousa-Doust D, Costa J, Mezei M, Chapman K, Briemberg H, Jack K, Grant K, Choi J, Yee J, McGuire AL, Abdul SA, Khazoom F, Aw K, Lau R, Gilbert S, Sundaresan S, Jones D, Seely AJE, Villeneuve PJ, Maziak DE, Pigeon CA, Frigault J, Drolet S, Roy ÈM, Bujold-Pitre K, Courval V, Tessier L, McKechnie T, Lee Y, Park L, Gangam N, Eskicioglu C, Cloutier Z, McKechnie T (McMaster University), Archer V, Park L, Lee J, Patel A, Hong D, Eskicioglu C, Ichhpuniani S, McKechnie T, Elder G, Chen A, Logie K, Doumouras A, Hong D, Benko R, Eskicioglu C, Castelo M, Paszat L, Hansen B, Scheer A, Faught N, Nguyen L, Baxter N, Sharma S, McKechnie T, Khamar J, Wu K, Eskicioglu C, McKechnie T, Khamar J, Lee Y, Tessier L, Passos E, Doumouras A, Hong D, Eskicioglu C, McKechnie T, Khamar J, Sachdeva A, Lee Y, Hong D, Eskicioglu C, Fei LYN, Caycedo A, Patel S, Popa T, Boudreau L, Grin A, Wang T, Lie J, Karimuddin A, Brown C, Phang T, Raval M, Ghuman A, Candy S, Nanda K, Li C, Snelgrove R, Dykstra M, Kroeker K, Wang H, Roy H, Helewa RM, Johnson G, Singh H, Hyun E, Moffatt D, Vergis A, Balmes P, Phang T, Guo M, Liu J, Roy H, Webber S, Shariff F, Helewa RM, Hochman D, Park J, Johnson G, Hyun E, Robitaille S, Wang A, Maalouf M, Alali N, Elhaj H, Liberman S, Charlebois P, Stein B, Feldman L, Fiore JF Jr, Lee L, Hu R, Lacaille-Ranger A, Ahn S, Tudorache M, Moloo H, Williams L, Raîche I, Musselman R, Lemke M, Allen L, Samarasinghe N, Vogt K, Brackstone M, Zwiep T, Clement E, Lange C, Alam A, Ghuman A, Karimuddin A, Phang T, Raval M, Brown C, Clement E, Liu J, Ghuman A, Karimuddin A, Phang T, Raval M, Brown C, Mughal HN, Gok MA, Khan UA, Mughal HN, Gok MA, Khan UA, Mughal HN, Gok MA, Khan UA, Mughal HN, Gok MA, Khan UA, James N, Zwiep T, Van Koughnett JA, Laczko D, McKechnie T, Yang S, Wu K, Sharma S, Lee Y, Park L, Doumouras A, Hong D, Parpia S, Bhandari M, Eskicioglu C, McKechnie T, Tessier L, Lee S, Kazi T, Sritharan P, Lee Y, Doumouras A, Hong D, Eskicioglu C, McKechnie T, Lee Y, Hong D, Dionne J, Doumouras A, Parpia S, Bhandari M, Eskicioglu C, Hershorn O, Ghuman A, Karimuddin A, Brown C, Raval M, Phang PT, Chen A, Boutros M, Caminsky N, Dumitra T, Faris-Sabboobeh S, Demian M, Rigas G, Monton O, Smith A, Moon J, Demian M, Garfinkle R, Vasilevsky CA, Rajabiyazdi F, Boutros M, Courage E, LeBlanc D, Benesch M, Hickey K, Hartwig K, Armstrong C, Engelbrecht R, Fagan M, Borgaonkar M, Pace D, Shanahan J, Moon J, Salama E, Wang A, Arsenault M, Leon N, Loiselle C, Rajabiyazdi F, Boutros M, Brennan K, Rai M, Farooq A, McClintock C, Kong W, Patel S, Boukhili N, Caminsky N, Faris-Sabboobeh S, Demian M, Boutros M, Paradis T, Robitaille S, Dumitra T, Liberman AS, Charlebois P, Stein B, Fiore JF Jr, Feldman LS, Lee L, Zwiep T, Abner D, Alam T, Beyer E, Evans M, Hill M, Johnston D, Lohnes K, Menard S, Pitcher N, Sair K, Smith B, Yarjau B, LeBlanc K, Samarasinghe N, Karimuddin AA, Brown CJ, Phang PT, Raval MJ, MacDonell K, Ghuman A, Harvey A, Phang PT, Karimuddin A, Brown CJ, Raval MJ, Ghuman A, Hershorn O, Ghuman A, Karimuddin A, Raval M, Phang PT, Brown C, Logie K, Mckechnie T, Lee Y, Hong D, Eskicioglu C, Matta M, Baker L, Hopkins J, Rochon R, Buie D, MacLean A, Ghuman A, Park J, Karimuddin AA, Phang PT, Raval MJ, Brown CJ, Farooq A, Ghuman A, Patel S, Macdonald H, Karimuddin A, Raval M, Phang PT, Brown C, Wiseman V, Brennan K, Patel S, Farooq A, Merchant S, Kong W, McClintock C, Booth C, Hann T, Ricci A, Patel S, Brennan K, Wiseman V, McClintock C, Kong W, Farooq A, Kakkar R, Hershorn O, Raval M, Phang PT, Karimuddin A, Ghuman A, Brown C, Wiseman V, Farooq A, Patel S, Hajjar R, Gonzalez E, Fragoso G, Oliero M, Alaoui AA, Rendos HV, Djediai S, Cuisiniere T, Laplante P, Gerkins C, Ajayi AS, Diop K, Taleb N, Thérien S, Schampaert F, Alratrout H, Dagbert F, Loungnarath R, Sebajang H, Schwenter F, Wassef R, Ratelle R, Debroux É, Cailhier JF, Routy B, Annabi B, Brereton NJB, Richard C, Santos MM, Gimon T, MacRae H, de Buck van Overstraeten A, Brar M, Chadi S, Kennedy E, Baker L, Hopkins J, Rochon R, Buie D, MacLean A, Park LJ, Archer V, McKechnie T, Lee Y, McIsaac D, Rashanov P, Eskicioglu C, Moloo H, Devereaux PJ, Alsayari R, McKechnie T, Ichhpuniani S, Lee Y, Eskicioglu C, Hajjar R, Oliero M, Fragoso G, Ajayi AS, Alaoui AA, Rendos HV, Calvé A, Cuisinière T, Gerkins C, Thérien S, Taleb N, Dagbert F, Sebajang H, Loungnarath R, Schwenter F, Ratelle R, Wassef R, Debroux E, Richard C, Santos MM, Kennedy E, Simunovic M, Schmocker S, Brown C, MacLean A, Liberman S, Drolet S, Neumann K, Stotland P, Jhaveri K, Kirsch R, Alnajem H, Alibrahim H, Giundi C, Chen A, Rigas G, Munir H, Safar A, Sabboobeh S, Holland J, Boutros M, Kennedy E, Richard C, Simunovic M, Schmocker S, Brown C, MacLean A, Liberman S, Drolet S, Neumann K, Stotland P, Jhaveri K, Kirsch R, Bruyninx G, Gill D, Alsayari R, McKechnie T, Lee Y, Hong D, Eskicioglu C, Zhang L, Abtahi S, Chhor A, Best G, Raîche I, Musselman R, Williams L, Moloo H, Caminsky NG, Moon JJ, Marinescu D, Pang A, Vasilevsky CA, Boutros M, Al-Abri M, Gee E, Karimuddin A, Phang PT, Brown C, Raval M, Ghuman A, Morena N, Ben-Zvi L, Hayman V, Hou M (University of Calgary), Nguyen D, Rentschler CA, Meguerditchian AN, Mir Z, Fei L, McKeown S, Dinchong R, Cofie N, Dalgarno N, Cheifetz R, Merchant S, Jaffer A, Cullinane C, Feeney G, Jalali A, Merrigan A, Baban C, Buckley J, Tormey S, Benesch M, Wu R, Takabe K, Benesch M, O'Brien S, Kazazian K, Abdalaty AH, Brezden C, Burkes R, Chen E, Govindarajan A, Jang R, Kennedy E, Lukovic J, Mesci A, Quereshy F, Swallow C, Chadi S, Habashi R, Pasternak J, Marini W, Zheng W, Murakami K, Ohashi P, Reedijk M, Hu R, Ivankovic V, Han L, Gresham L, Mallick R, Auer R, Ribeiro T, Bondzi-Simpson A, Coburn N, Hallet J, Cil T, Fontebasso A, Lee A, Bernard-Bedard E, Wong B, Li H, Grose E, Brandts-Longtin O, Aw K, Lau R, Abed A, Stevenson J, Sheikh R, Chen R, Johnson-Obaseki S, Nessim C, Hennessey RL, Meneghetti AT, Bildersheim M, Bouchard-Fortier A, Nelson G, Mack L, Ghasemi F, Naeini MM, Parsyan A, Kaur Y, Covelli A, Quereshy F, Elimova E, Panov E, Lukovic J, Brierley J, Burnett B, Swallow C, Eom A, Kirkwood D, Hodgson N, Doumouras A, Bogach J, Whelan T, Levine M, Parvez E, Ng D, Kazazian K, Lee K, Lu YQ, Kim DK, Magalhaes M, Grigor E, Arnaout A, Zhang J, Yee EK, Hallet J, Look Hong NJ, Nguyen L, Coburn N, Wright FC, Gandhi S, Jerzak KJ, Eisen A, Roberts A, Ben Lustig D, Quan ML, Phan T, Bouchard-Fortier A, Cao J, Bayley C, Watanabe A, Yao S, Prisman E, Groot G, Mitmaker E, Walker R, Wu J, Pasternak J, Lai CK, Eskander A, Wasserman J, Mercier F, Roth K, Gill S, Villamil C, Goldstein D, Munro V, Pathak A (University of Manitoba), Lee D, Nguyen A, Wiseman S, Rajendran L, Claasen M, Ivanics T, Selzner N, McGilvray I, Cattral M, Ghanekar A, Moulton CA, Reichman T, Shwaartz C, Metser U, Burkes R, Winter E, Gallinger S, Sapisochin G, Glinka J, Waugh E, Leslie K, Skaro A, Tang E, Glinka J, Charbonneau J, Brind'Amour A, Turgeon AF, O'Connor S, Couture T, Wang Y, Yoshino O, Driedger M, Beckman M, Vrochides D, Martinie J, Alabduljabbar A, Aali M, Lightfoot C, Gala-Lopez B, Labelle M, D'Aragon F, Collin Y, Hirpara D, Irish J, Rashid M, Martin T, Zhu A, McKnight L, Hunter A, Jayaraman S, Wei A, Coburn N, Wright F, Mallette K, Elnahas A, Alkhamesi N, Schlachta C, Hawel J, Tang E, Punnen S, Zhong J, Yang Y, Streith L, Yu J, Chung S, Kim P, Chartier-Plante S, Segedi M, Bleszynski M, White M, Tsang ME, Jayaraman S, Lam-Tin-Cheung K, Jayaraman S, Tsang M, Greene B, Pouramin P, Allen S, Evan Nelson D, Walsh M, Côté J, Rebolledo R, Borie M, Menaouar A, Landry C, Plasse M, Létourneau R, Dagenais M, Rong Z, Roy A, Beaudry-Simoneau E, Vandenbroucke-Menu F, Lapointe R, Ferraro P, Sarkissian S, Noiseux N, Turcotte S, Haddad Y, Bernard A, Lafortune C, Brassard N, Roy A, Perreault C, Mayer G, Marcinkiewicz M, Mbikay M, Chrétien M, Turcotte S, Waugh E, Sinclair L, Glinka J, Shin E, Engelage C, Tang E, Skaro A, Muaddi H, Flemming J, Hansen B, Dawson L, O'Kane G, Feld J, Sapisochin G, Zhu A, Jayaraman S, Cleary S, Hamel A, Pigeon CA, Marcoux C, Ngo TP, Deshaies I, Mansouri S, Amhis N, Léveillé M, Lawson C, Achard C, Ilkow C, Collin Y, Tai LH, Park L, Griffiths C, D'Souza D, Rodriguez F, McKechnie T, Serrano PE, Hennessey RL, Yang Y, Meneghetti AT, Panton ONM, Chiu CJ, Henao O, Netto FS, Mainprize M, Hennessey RL, Chiu CJ, Hennessey RL, Chiu CJ, Jatana S, Verhoeff K, Mocanu V, Jogiat U, Birch D, Karmali S, Switzer N, Hetherington A, Verhoeff K, Mocanu V, Birch D, Karmali S, Switzer N, Safar A, Al-Ghaithi N, Vourtzoumis P, Demyttenaere S, Court O, Andalib A, Wilson H, Verhoeff K, Dang J, Kung J, Switzer N, Birch D, Madsen K, Karmali S, Mocanu V, Wu T, He W, Vergis A, Hardy K, Zmudzinski M, Daenick F, Linton J, Zmudzinski M, Fowler-Woods M, He W, Fowler-Woods A, Shingoose G, Vergis A, Hardy K, Lee Y, Doumouras A, Molnar A, Nguyen F, Hong D, Schneider R, Fecso AB, Sharma P, Maeda A, Jackson T, Okrainec A, McLean C, Mocanu V, Birch D, Karmali S, Switzer N, MacVicar S, Dang J, Mocanu V, Verhoeff K, Jogiat U, Karmali S, Birch D, Switzer N, McLennan S, Verhoeff K, Purich K, Dang J, Kung J, Mocanu V, McLennan S, Verhoeff K, Mocanu V, Jogiat U, Birch DW, Karmali S, Switzer NJ, Jeffery L, Hwang H, Ryley A, Schellenberg M, Owattanapanich N, Emigh B, Nichols C, Dilday J, Ugarte C, Onogawa A, Matsushima K, Martin MJ, Inaba K, Schellenberg M, Emigh B, Nichols C, Dilday J, Ugarte C, Onogawa A, Shapiro D, Im D, Inaba K, Schellenberg M, Owattanapanich N, Ugarte C, Lam L, Martin MJ, Inaba K, Rezende-Neto J, Patel S, Zhang L, Mir Z, Lemke M, Leeper W, Allen L, Walser E, Vogt K, Ribeiro T, Bateni S, Bondzi-Simpson A, Coburn N, Hallet J, Barabash V, Barr A, Chan W, Hakim SY, El-Menyar A, Rizoli S, Al-Thani H, Mughal HN, Bhugio M, Gok MA, Khan UA, Warraich A, Gillman L, Ziesmann M, Momic J, Yassin N, Kim M, Makish A, Walser E, Smith S, Ball I, Moffat B, Parry N, Vogt K, Lee A, Kroeker J, Evans D, Fansia N, Notik C, Wong EG, Coyle G, Seben D, Smith J, Tanenbaum B, Freedman C, Nathens A, Fowler R, Patel P, Elrick T, Ewing M, Di Marco S, Razek T, Grushka J, Wong EG, Park LJ, Borges FK, Nenshi R, Serrano PE, Engels P, Vogt K, Di Sante E, Vincent J, Tsiplova K, Devereaux PJ, Talwar G, Dionne J, McKechnie T, Lee Y, Kazi T, El-Sayes A, Bogach J, Hong D, Eskicioglu C, Connell M, Klooster A, Beck J, Verhoeff K, Strickland M, Anantha R, Groszman L, Caminsky NG, Watt L, Boulanger N, Razek T, Grushka J, Di Marco S, Wong EG, Livergant R, McDonald B, Binda C, Luthra S, Ebert N, Falk R, and Joos E
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- 2023
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10. Prevalence of pks + bacteria and enterotoxigenic Bacteroides fragilis in patients with colorectal cancer.
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Oliero M, Hajjar R, Cuisiniere T, Fragoso G, Calvé A, Dagbert F, Loungnarath R, Sebajang H, Schwenter F, Wassef R, Ratelle R, De Broux É, Richard CS, and Santos MM
- Abstract
Background: Colorectal cancer (CRC) is the third most diagnosed cancer and the second most common cause of cancer deaths worldwide. CRC patients present with an increase in pathogens in their gut microbiota, such as polyketide synthase-positive bacteria (pks +) and enterotoxigenic Bacteroides fragilis (ETBF). The pks + Escherichia coli promotes carcinogenesis and facilitates CRC progression through the production of colibactin, a genotoxin that induces double-strand DNA breaks (DSBs). ETBF is a procarcinogenic bacterium producing the B. fragilis toxin (bft) that promotes colorectal carcinogenesis by modulating the mucosal immune response and inducing epithelial cell changes., Methods: Fecal samples were collected from healthy controls (N = 62) and CRC patients (N = 94) from the province of Québec (Canada), and a bacterial DNA extraction was performed. Fecal DNA samples were then examined for the presence of the pks island gene and bft using conventional qualitative PCR., Results: We found that a high proportion of healthy controls are colonized by pks + bacteria (42%) and that these levels were similar in CRC patients (46%). bft was detected in 21% of healthy controls and 32% of CRC patients, while double colonization by both pks + bacteria and ETBF occurred in 8% of the healthy controls and 13% of the CRC patients. Most importantly, we found that early-onset CRC (< 50 years) patients were significantly less colonized with pks + bacteria (20%) compared to late-onset CRC patients (52%)., Conclusions: Healthy controls had similar levels of pks + bacteria and ETBF colonization as CRC patients, and their elevated levels may place both groups at greater risk of developing CRC. Colonization with pks + bacteria was less prevalent in early-compared to late-onset CRC., (© 2022. The Author(s).)
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- 2022
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11. Restorative Proctocolectomy for Ulcerative Colitis: Different Strategies for Different Situations.
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Dagbert F and Richard CS
- Subjects
- Humans, Postoperative Complications, Colitis, Ulcerative surgery, Proctocolectomy, Restorative adverse effects
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- 2022
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12. Improvement of colonic healing and surgical recovery with perioperative supplementation of inulin and galacto-oligosaccharides.
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Hajjar R, Oliero M, Cuisiniere T, Fragoso G, Calvé A, Djediai S, Annabi B, Richard CS, and Santos MM
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- Animals, Dietary Supplements, Disease Models, Animal, Female, Mice, Mice, Inbred C57BL, Perioperative Period, Postoperative Complications prevention & control, Treatment Outcome, Wound Healing, Anastomotic Leak prevention & control, Colonic Diseases surgery, Fatty Acids, Volatile administration & dosage, Inulin administration & dosage
- Abstract
Background and Aims: Anastomotic leak (AL) is a major complication in colorectal surgery. Recent evidence suggests that the gut microbiota may affect healing and may cause or prevent AL. Butyrate is a beneficial short-chain fatty acid (SCFA) that is produced as a result of bacterial fermentation of dietary oligosaccharides and has been described as beneficial in the maintenance of colonic health. To assess the impact of oligosaccharides on colonic anastomotic healing in mice, we propose to modulate the microbiota with oligosaccharides to increase butyrate production via enhancement of butyrate-producing bacteria and, consequently, improve anastomotic healing in mice., Methods: Animal experiments were conducted in mice that were subjected to diets supplemented with inulin, galacto-oligosaccharides (GOS) or cellulose, as a control, for two weeks before undergoing a surgical colonic anastomosis. Macroscopic and histological assessment of the anastomosis was performed. Extent of epithelial proliferation was assessed by Ki-67 immunohistochemistry. Gelatin zymography was used to evaluate the extent of matrix metalloproteinase (MMP) hydrolytic activity., Results: Inulin and GOS diets were associated with increased butyrate production and better anastomotic healing. Histological analysis revealed an enhanced mucosal continuity, and this was associated with an increased re-epithelialization of the wound as determined by increased epithelial proliferation. Collagen concentration in peri-anastomotic tissue was higher with inulin and GOS diets and MMP activity, a marker of collagen degradation, was lower with both oligosaccharides. Inulin and GOS diets were further associated with lower bacterial translocation., Conclusions: Dietary supplementation with inulin and GOS may improve anastomotic healing and reinforce the gut barrier in mice., Competing Interests: Conflicts of interest The authors have no conflicts of interest to disclose., (Copyright © 2021 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)
- Published
- 2021
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13. The role of butyrate in surgical and oncological outcomes in colorectal cancer.
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Hajjar R, Richard CS, and Santos MM
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- Cell Movement, Cell Proliferation, Colon metabolism, Colon microbiology, Colon pathology, Colorectal Neoplasms pathology, Energy Metabolism, Epithelial Cells microbiology, Epithelial Cells pathology, Humans, Neoplasm Invasiveness, Permeability, Wound Healing, Bacteria metabolism, Butyrates metabolism, Colon surgery, Colorectal Neoplasms metabolism, Epithelial Cells metabolism, Gastrointestinal Microbiome
- Abstract
Butyrate is a short-chain fatty acid produced by colonic gut bacteria as a result of fermentation of dietary fibers. In the colon, butyrate is a major energy substrate and contributes to the nutritional support and proliferation of a healthy mucosa. It also promotes the intestinal barrier function by enhancing mucus production and tight junctions. In addition to its pro-proliferative effect in healthy colonocytes, butyrate inhibits the proliferation of cancer cells. The antineoplastic effect of butyrate is associated with the inhibitory effect of butyrate on histone deacetylase (HDAC) enzymes, which promote carcinogenesis. Due to the metabolic shift of cancer cells toward glycolysis, unused butyrate accumulates and inhibits procarcinogenic HDACs. In addition, recent studies suggest that butyrate may improve the healing of colonic tissue after surgery in animal models, specifically at the site of reconnection of colonic ends, anastomosis, after surgical resection. Here, we review current evidence on the impact of butyrate on epithelial integrity and colorectal cancer and present current knowledge on data that support its potential applications in surgical practice.
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- 2021
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14. High-grade neuroendocrine small-cell carcinoma of the anal canal: Long-term remission with chemoradiotherapy.
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Hajjar R, Richard CS, Aubin F, Campeau MP, Soucy G, and Broux É
- Abstract
Primary small-cell carcinoma of the anal canal is an exceedingly rare tumor with a poor prognosis even when aggressive therapy is initiated. We present the case of a 53-year-old male patient who presented with chronic anal pain. Examination under general anesthesia revealed the presence of a mass in the anal canal. A biopsy was performed, and histopathological examination showed a high-grade neuroendocrine small-cell carcinoma. Assessment with endoscopic ultrasound showed an invasion of the internal anal sphincter. The patient was treated with a chemoradiotherapy (CRT) regimen consisting of cisplatin and etoposide, combined to radiotherapy. The patient achieved long-term remission with CRT. This is one of the first reports in the literature of a case of a high-grade neuroendocrine small-cell carcinoma of the anal canal where long-term remission was achieved with non-surgical management of a tumor invading the anal sphincter. This favorable evolution with CRT suggests that remission could still be achieved with anal small-cell carcinomas. More cases are however required to validate this approach., Relevance for Patients: This case presentation suggests that long-term remission can still be achieved using CRT and without an extensive surgical resection in patients with small-cell carcinoma of the anal canal., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright: © Whioce Publishing Pte. Ltd.)
- Published
- 2021
15. Current evidence on the relation between gut microbiota and intestinal anastomotic leak in colorectal surgery.
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Hajjar R, Santos MM, Dagbert F, and Richard CS
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- Anastomotic Leak physiopathology, Animals, Humans, Intestinal Diseases physiopathology, Risk Factors, Wound Healing, Anastomotic Leak etiology, Colectomy adverse effects, Gastrointestinal Microbiome physiology, Intestinal Diseases microbiology, Intestinal Diseases surgery, Proctectomy adverse effects
- Abstract
Background: Anastomotic leak (AL) is a major complication in colorectal surgery. It worsens morbidity, mortality and oncological outcomes in colorectal cancer. Some evidence suggests a potential effect of the intestinal microbiome on wound healing. This review aims to provide a comprehensive review on historical and current evidence regarding the relation between the gastrointestinal microbiota and AL in colorectal surgery, and the potential microbiota-modifying effect of some perioperative commonly used measures., Data Sources: A comprehensive search was conducted in Pubmed, Medline and Embase for historical and current clinical and animal studies addressing perioperative intestinal microbiota evaluation, intestinal healing and AL., Conclusions: Evidence on microbes' role in AL is mainly derived from animal experiments. The microbiota's composition and implications are poorly understood in surgical patients. Elaborate microbiota sequencing is required in colorectal surgery to identify potentially beneficial microbial profiles that could lead to specific perioperative microbiome-altering measures and improve surgical and oncological outcomes., (Copyright © 2019 Elsevier Inc. All rights reserved.)
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- 2019
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16. Canadian Association of General Surgeons Evidence Based Reviews in Surgery. 5. Need for preoperative radiation in rectal cancer. Preoperative radiotherapy combined with total mesorectal excision for resectable rectal cancer.
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Richard CS, Phang PT, and McLeod RS
- Published
- 2003
17. Canadian Association of General Surgeons Evidence Based Reviews in surgery. 4. Decision analysis of total thyroidectomy versus thyroid lobectomy in low-risk, differentiated thyroid cancer.
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Richard CS, Nason RW, and McLeod RS
- Published
- 2002
18. Pregnancy, delivery, and pouch function after ileal pouch-anal anastomosis for ulcerative colitis.
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Ravid A, Richard CS, Spencer LM, O'Connor BI, Kennedy ED, MacRae HM, Cohen Z, and McLeod RS
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- Adult, Defecation, Fecal Incontinence, Female, Humans, Middle Aged, Pregnancy, Retrospective Studies, Colitis, Ulcerative surgery, Colonic Pouches, Delivery, Obstetric, Pregnancy Outcome
- Abstract
Purpose: This study was designed to evaluate the pregnancies, method of delivery, and functional results of females with chronic ulcerative colitis who have an ileal pouch-anal anastomosis., Methods: A mailed questionnaire was sent to all females with an ileal pouch-anal anastomosis for chronic ulcerative colitis. Information on the pregnancy, method of delivery, and outcome was collected. Those females who had a successful pregnancy and delivery were contacted by telephone to clarify results and determine pouch functional results. Other clinical information was obtained from the Mount Sinai Hospital Inflammatory Bowel Disease database., Results: Thirty-eight subjects had 67 pregnancies. Of these, 29 subjects had 49 deliveries. There were 25 vaginal deliveries and 24 cesarean sections. There were two pouch-related complications during the pregnancies and four pouch-related complications postpartum. All were treated nonoperatively. Stool frequency and day and night incontinence were increased during pregnancy in most subjects, but after delivery, prepregnancy function was restored in 24 (83 percent) of them. Five subjects (17 percent) had some degree of permanent deterioration in pouch function. Of these, three had vaginal deliveries, and two had cesarean sections. Multiple births and birth weight were not found to adversely affect subsequent pouch function., Conclusion: Pregnancy is safe in females with ileal pouch-anal anastomosis. Functional results are altered almost exclusively during the third trimester, but pouch function promptly returns to prepregnancy status in most females. A small proportion of females have long-term disturbances in function, but these are not related to the method of delivery. Thus, the method of delivery should be dictated by obstetric considerations.
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- 2002
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19. Quality of life is excellent after a pelvic pouch for colitis-associated neoplasia.
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Thompson-Fawcett MW, Richard CS, O'Connor BI, Cohen Z, and McLeod RS
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- Carcinoma etiology, Carcinoma pathology, Colitis, Ulcerative pathology, Colonic Neoplasms etiology, Colonic Neoplasms pathology, Female, Humans, Male, Middle Aged, Patient Satisfaction, Surveys and Questionnaires, Carcinoma surgery, Colitis, Ulcerative complications, Colonic Neoplasms surgery, Proctocolectomy, Restorative psychology, Quality of Life
- Abstract
Purpose: Despite high patient satisfaction with a pelvic pouch, patients experience some bowel dysfunction. Patients whose indication for surgery is neoplasia may have near-normal preoperative bowel function. We hypothesized that these patients would be less accepting of a poorer functional status after surgery, reflected in a poorer measure of quality of life., Method: Sixteen patients who had dysplasia or cancer as the primary indication for surgery were compared with a matched control group whose indication for surgery was failed medical therapy. Quality of life was assessed using one disease-specific instrument, the Inflammatory Bowel Disease Questionnaire, two generic quality-of-life instruments, the Sickness Impact Profile and the Short Form 36, and two utility assessments., Results: The groups were well matched with no significant differences in functional outcome. Quality-of-life scores were high in both groups and there were no significant differences in overall quality of life between the two groups using all five instruments. There was evidence of a response shift phenomenon in the failed medical therapy control group., Conclusion: Quality of life of patients who have a pelvic pouch for colitis-associated neoplasia is excellent and the same as that of patients who have a pouch for failure of medical therapy.
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- 2000
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20. Internal sphincterotomy is superior to topical nitroglycerin in the treatment of chronic anal fissure: results of a randomized, controlled trial by the Canadian Colorectal Surgical Trials Group.
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Richard CS, Gregoire R, Plewes EA, Silverman R, Burul C, Buie D, Reznick R, Ross T, Burnstein M, O'Connor BI, Mukraj D, and McLeod RS
- Subjects
- Administration, Topical, Adult, Aged, Female, Fissure in Ano pathology, Humans, Male, Middle Aged, Nitroglycerin administration & dosage, Treatment Outcome, Vasodilator Agents administration & dosage, Anal Canal surgery, Fissure in Ano drug therapy, Fissure in Ano surgery, Nitroglycerin therapeutic use, Vasodilator Agents therapeutic use
- Abstract
Purpose: This was a multicenter, randomized, controlled trial to compare the effectiveness of topical nitroglycerin with internal sphincterotomy in the treatment of chronic anal fissure., Methods: Patients with symptomatic chronic anal fissures were randomly assigned to 0.25 percent nitroglycerin tid or internal sphincterotomy. Both groups received stool softeners and fiber supplements and were assessed at six weeks and six months., Results: Ninety patients were accrued, but 8 were excluded from the analysis because they refused internal sphincterotomy after randomization (6), the fissure healed before surgery (1), or a fissure was not observed at surgery (1). There were 38 patients in the internal sphincterotomy group (22 males; mean age, 40.3 years) and 44 patients in the nitroglycerin group (15 males; mean age, 38.7 years). At six weeks 34 patients (89.5 percent) in the internal sphincterotomy group compared with 13 patients (29.5 percent) in the nitroglycerin group had complete healing of the fissure (P = 5x10(-8)). Five of the 13 patients in the nitroglycerin group relapsed, whereas none in the internal sphincterotomy group did. At six months fissures in 35 (92.1 percent) patients in the internal sphincterotomy group compared with 12 (27.2 percent) patients in the nitroglycerin group had healed (P = 3x10(-9)). One (2.6 percent) patient in the internal sphincterotomy group required further surgery for a superficial fistula compared with 20 (45.4 percent) patients in the nitroglycerin group who required an internal sphincterotomy (P = 9x10(-6)). Eleven (28.9 percent) patients in the internal sphincterotomy group developed side effects compared with 37 (84 percent) patients in the nitroglycerin group (P<0.0001). Nine (20.5 percent) patients discontinued the nitroglycerin because of headaches (8) or a severe syncopal attack (1)., Conclusions: Internal sphincterotomy is superior to topical nitroglycerin 0.25 percent in the treatment of chronic anal fissure, with a high rate of healing, few side effects, and low risk of early incontinence. Thus, internal sphincterotomy remains the treatment of choice for chronic anal fissure.
- Published
- 2000
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21. Bowel resection for intestinal endometriosis.
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Urbach DR, Reedijk M, Richard CS, Lie KI, and Ross TM
- Subjects
- Adult, Colon, Sigmoid pathology, Colon, Sigmoid surgery, Endometriosis diagnosis, Endometriosis pathology, Female, Follow-Up Studies, Humans, Hysterectomy, Ovariectomy, Rectal Diseases diagnosis, Rectal Diseases pathology, Rectum pathology, Rectum surgery, Retrospective Studies, Sigmoid Diseases diagnosis, Sigmoid Diseases pathology, Endometriosis surgery, Rectal Diseases surgery, Sigmoid Diseases surgery
- Abstract
Purpose: The study contained herein was undertaken to evaluate which factors predict a good outcome following intestinal resection for endometriosis., Methods: A retrospective analysis of all patients undergoing bowel resection for severe (American Fertility Society Stage IV) endometriosis at one institution between the years 1992 and 1996 was conducted using systematic chart review and follow-up by telephone interview., Results: Twenty-nine patients were identified within the study period. The most frequent symptoms were pelvic pain, abdominal pain, rectal pain, and dysmenorrhea. Nearly all patients (93 percent) underwent low anterior resection of the rectum and distal sigmoid. Other intestinal procedures were appendectomy, terminal ileal resection, cecectomy, and sigmoid resection. Thirty-four percent of patients had simultaneous total abdominal hysterectomy and bilateral salpingooophorectomy. Complete follow-up was obtained on 26 patients (90 percent; mean follow-up 22.6 (range, 8-63) months). All patients (100 percent) reported subjective improvement. Forty-six percent of patients were "cured" according to the prospectively applied definition (resolution of symptoms without need for further medical or surgical therapy). The only variable analyzed that was associated with "cure" was concomitant total abdominal hysterectomy and bilateral salpingooophorectomy (odds ratio, 12; 95 percent confidence interval, 1.8-81.7). This association remained significant after correcting for age and the presence of gastrointestinal symptoms., Conclusion: Intestinal resection can be performed safely in most women with severe endometriosis and bowel involvement, although many of these patients experience persistent or recurrent symptoms. Total abdominal hysterectomy and bilateral salpingooophorectomy at the time of bowel resection correlates with improved outcome.
- Published
- 1998
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22. Outcome of the pelvic pouch procedure in patients with prior perianal disease.
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Richard CS, Cohen Z, Stern HS, and McLeod RS
- Subjects
- Adult, Colitis complications, Colitis diagnosis, Crohn Disease diagnosis, Crohn Disease etiology, Diagnosis, Differential, Female, Humans, Male, Prospective Studies, Rectovaginal Fistula diagnosis, Rectovaginal Fistula etiology, Treatment Outcome, Anus Diseases etiology, Colitis surgery, Proctocolectomy, Restorative adverse effects
- Abstract
Purpose: There is concern that patients with presumed ulcerative colitis and significant perianal disease may in fact have Crohn's disease. Moreover, prior perianal disease may be an independent factor for poor outcome of the pelvic pouch. The aim of this study was to evaluate the effect of prior perianal disease on pelvic pouch outcome., Methods: Between 1982 and 1994, 52 of 753 patients (6.9 percent) who had a pelvic pouch procedure were prospectively identified as having perianal disease. Outcome of the pelvic pouch of these 52 patients (Group I) were compared with the outcome of 701 pelvic pouch patients with no prior perianal disease (Group II). The perianal diseases identified in Group I were fissure-in-ano (17), perianal abscesses (13), fistula-in-ano (7), rectovaginal fistula (3), and significant hemorrhoids/skin tags (25). Eleven patients (21 percent) had more than one type of perianal disease. Twenty-seven patients (52 percent) required a total of 33 perianal operations for the different anal pathologies., Results: Both groups were comparable for the following characteristics: age at time of pelvic pouch procedure, pathology (ulcerative colitis or indeterminate colitis), design of pouch, and type of ileoanal anastomosis (handsewn or stapled). An ileoanal anastomosis leak developed in 21 percent of patients (n = 11) in Group I vs. 11.4 percent (n = 80) in Group II (P < 0.05). Perianal postoperative complications occurred in 11.5 percent of patients (n = 6) in Group I vs. 1.7 percent (n = 12) in Group II (P < 0.05). Total pouch failure rate was not significantly different between the two groups (11.5 vs. 7.6 percent; P > 0.05). Crohn's disease was subsequently diagnosed in 1.9 vs. 2.7 percent (P > 0.05). Subgroup analysis of Group I patients showed no significant difference in outcome according to type of perianal lesion or a history of perianal surgery., Conclusion: Prior perianal disease significantly increases the risk of developing an ileoanal anastomotic leak and postoperative perianal complications. However, a pelvic pouch procedure may be an acceptable surgical alternative for selected ulcerative colitis patients with prior perianal disease because the overall pouch failure rate is not significantly increased.
- Published
- 1997
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23. Follow-up of patients after resection for colorectal cancer: a position paper of the Canadian Society of Surgical Oncology and the Canadian Society of Colon and Rectal Surgeons.
- Author
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Richard CS and McLeod RS
- Subjects
- Canada, Colorectal Surgery, Evidence-Based Medicine, Follow-Up Studies, Humans, Medical Oncology, Randomized Controlled Trials as Topic, Societies, Medical, Colorectal Neoplasms surgery
- Published
- 1997
24. Sulindac for periampullary polyps in FAP patients.
- Author
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Richard CS, Berk T, Bapat BV, Haber G, Cohen Z, and Gallinger S
- Subjects
- Adenoma complications, Adenoma pathology, Adenomatous Polyposis Coli complications, Adult, Aged, Anti-Inflammatory Agents, Non-Steroidal administration & dosage, Duodenal Neoplasms complications, Duodenal Neoplasms pathology, Endoscopy, Gastrointestinal, Female, Humans, Intestinal Polyps complications, Intestinal Polyps pathology, Male, Middle Aged, Prospective Studies, Sulindac administration & dosage, Treatment Outcome, Adenoma drug therapy, Adenomatous Polyposis Coli surgery, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Duodenal Neoplasms drug therapy, Intestinal Polyps drug therapy, Sulindac therapeutic use
- Abstract
Background: Gastro-duodenal polyps develop in up to 90% of familial adenomatous polyposis (FAP) patients and periampullary carcinoma is one of the most common extra-colonic malignancies in this syndrome. Periampullary adenomas have been shown to be precursor lesions to periampullary carcinoma. Sulindac, a non-steroidal anti-inflammatory drug, has been reported to cause regression of rectal polyps in FAP patients, however its role in periampullary polyp regression is unclear., Methods: In May 1993, a prospective study was begun to evaluate the role of sulindac in prevention of polyp recurrence after resection of large (> 1 cm) duodenal polyps in FAP patients. Eight patients, mean age 50 years (range 35 to 65), with documented large periampullary polyps were placed on sulindac 150 mg twice daily. Prior to enrollment, all patients had their large polyps removed from the periampullary region by interventional endoscopy or by surgery. All patients had multiple small residual duodenal polyps. Follow-up was performed by one experienced endoscopist with a side-viewing video endoscope. Endoscopy was performed 6 monthly. Median follow-up time was 17.5 months (range 10 to 24 months)., Results: In 3 patients, sulindac was discontinued due to side effects: abdominal cramps (n = 2) and upper G-I bleeding (n = 1). None of the patients had regression of small periampullary polyps. In addition, one patient developed an invasive periampullary carcinoma while on sulindac and 3 patients developed large recurrent periampullary polyps requiring further treatment., Summary: In our experience, sulindac is of no significant benefit for the control of periampullary polyps in FAP. Effective medical treatment of these polyps is still lacking.
- Published
- 1997
- Full Text
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