Richard Walker

University of Toronto

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Paul J. Karanicolas

Sunnybrook Health Science Centre

Emily Souder

University of Toronto

Avery B. Nathens

University of Toronto

Frances C. Wright

Sunnybrook Health Science Centre

Nicole J. Look Hong

University of Toronto

John Trachtenberg

University Health Network

Sean P. Cleary

University Health Network

May Lynn Quan

University of Calgary

Charles de Mestral

St. Michael's Hospital

Arash Azin

University of Toronto

Cooperative Institutions

Motion Control (United States)

250

University of Toronto

University Health Network

Princess Margaret Cancer Centre

Health Sciences Centre

Sunnybrook Health Science Centre

Consejo Superior de Investigaciones Científicas

Toronto General Hospital

Stanford University

National Institutes for Quantum and Radiological Science and Technology

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CSSO 2017 Annual Scientific Meeting Abstracts

Canadian Journal of Surgery (2017)

Janice Austin Natasha Klemm Emily Souder Tyler R. Chesney Das Anupam

# Diagnostic delays: A problem for young women with breast cancer? {#article-title-2} Breast cancer in young women is aggressive. Delays in diagnosis and treatment may contribute to the worse outcomes observed in the treatment of breast cancer in young women. The purpose of this study is to

10.1503/cjs.005717

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The effect of a simultaneous versus a staged resection of metastatic colorectal cancer on time to adjuvant chemotherapy

Journal of Surgical Oncology (2018)

Emily Souder Arash Azin Trevor Wood Dhruvin H. Hirpara Ahmad Elnahas

Patients with colorectal cancer with synchronous liver metastases may undergo a staged or a simultaneous resection. This study aimed to determine whether the time to adjuvant chemotherapy was delayed in patients undergoing a simultaneous resection.A retrospective cohort study was conducted between 2005 and 2016. The primary outcome was time to adjuvant chemotherapy. A multivariate linear regression was conducted to ascertain the adjusted effect of a simultaneous versus a staged approach on time to adjuvant chemotherapy.A total of 155 patients were included. A total of 127 patients underwent a staged resection, whereas 28 patients underwent a simultaneous resection. Age, sex, and American Society of Anesthesiologists class as well tumor, node, metastasis stage, tumor location, and number and size of metastases were not significantly different between the groups. The median time to adjuvant chemotherapy was 70 and 63 days for the staged and simultaneous groups, respectively (P = .27). Multivariate analysis did not demonstrate an increased propensity for prolonged time to chemotherapy after simultaneous resection (rate ratio: 0.97, 95% CI: 0.71-1.32, P = .84). There were no significant differences in the length of stay, complications, overall survival, and disease-free survival between the groups (P > .05).This study demonstrated that simultaneous resection does not result in significant delay of adjuvant chemotherapy compared with a staged approach.

Adjuvant Chemotherapy

10.1002/jso.25122

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Comparison of two novel staging systems with the TNM system in predicting stage III colon cancer survival

Journal of Surgical Oncology (2018)

Richard Walker Trevor Wood Emily Souder Michelle C. Cleghorn Manjula Maganti

Background and Objectives Adaptations of the TNM staging system that incorporate the Lymph Node Ratio (LNR) have been proposed for stage III colon cancer. This study compared the concordance of two novel staging systems and the TNM system with observed survival outcomes in stage III patients. Methods A review of patients who underwent surgery for stage III colon cancer between January 2002 and April 2015 at a tertiary care centre was performed. The Kaplan‐Meier method was used to estimate the 5‐year overall (OS) and disease free survival (DFS) rates, and the concordance probability was calculated to evaluate the discriminatory power of the staging systems. Results Two hundred and sixty‐one patients were identified. For TNM stages IIIA, IIIB, and IIIC, 5‐year OS was 83.4%, 67.6%, and 38.3%, respectively ( P < 0.001). All three staging systems were independently predictive of OS and DFS ( P < 0.001). However, the novel staging system by Sugimoto et al 18 was the most favourable prognostic tool, with a concordance of 0.646 for DFS and 0.659 for OS. Conclusions The novel staging system by Sugimoto et al 18 was superior to the TNM system. Incorporating LNR into staging models for node positive colon cancers may improve survival information available to patients and potentially aid treatment decisions.

Concordance

TNM staging system

10.1002/jso.25009

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G350(P) HASTE: Handover audit of safety, timeliness and efficiency

Archives of Disease in Childhood (2016)

Richard Walker Alexandra Battersby

Background and aims

Handover of patients between shifts is an important process, to ensure continuity of care and that important information is communicated to the appropriate personnel. It should be completed in a timely and efficient manner. Interruptions should only be for emergencies or essential clarification. In a large teaching hospital information regarding up to 80 patients needs to be communicated in a half an hour window every morning to a number of subspecialities. Late arrivals delay the start of this process and prolong the duration. Frequent interruptions may disrupt the process. We aimed to evaluate the start time, duration, personnel present and interruptions of morning handover in a tertiary centre.

Methods

10 days August to October 2015 were selected and analysed looking at start time and duration of handover, personnel present, whether or not safety briefing was performed and any late attendences, interruptions and non urgent phone calls. The standard was that the safety briefing should be completed 100% of the time and that handover should start on time and there should be no late arrivals.

Results

Handover on average started 5 min late each morning and 8/10 times the safety briefing was not performed. An average of 3 people were late to handover each morning and on average 2 non urgent phone calls were received each handover. Late attendance and interruptions positively correlated with length of handover with values of 0.48 and 0.45 respectively.

Conclusions

We concluded that there are too many interruptions which are frequently non urgent. Phone calls from nursing staff about routine tasks were frequent. The delay in starting handover and the duration impacted on the ability of teams to commence ward rounds in a timely manner. Following this audit, we have implemented a reminder about handover etiquette including 10 rules and have provided nursing staff with up to date information about handover timings and the appropriateness of phone calls. Following this intervention a re-audit is underway.

Attendance

10.1136/archdischild-2016-310863.340

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Effect of off-site transportation on detection of Neisseria gonorrhoeae in endocervical specimens.

PubMed (1996)

Peter C. Iwen Richard Walker Kathy Warren D M Kelly James Linder

To evaluate both the effect of off-site transportation on detection of Neisseria gonorrhoeae in cultured endocervical specimens and the impact of transportation on viability of N. gonorrhoeae by comparison of culture with a nucleic acid probe assay.Three endocervical swabs were randomly collected; one was tested on-site using a nucleic acid-based assay (PACE 2NG System, Gen-Probe, Inc, San Diego, Calif), one was tested off-site following inoculation to modified Thayer-Martin agar (Remel, Lenexa, Kan), and a third swab was tested on-site by culture isolation. A nucleic acid amplification assay of the original swab for PACE 2NG testing was used to resolve discrepancies.The emergency department of a university medical center.Four hundred two patients were evaluated. The test population consisted of both asymptomatic and symptomatic patients.Positivity for N. gonorrhoeae by one or more of the test procedures, with discrepancy analysis when warranted.Of 402 specimens evaluated, the sensitivities for on-site and off-site testing using culture isolation for N. gonorrhoeae were 88.9% and 77.8%, respectively, in a population prevalence of 6.7%. However, the sensitivity for on-site PACE 2NG testing for N. gonorrhoeae was 96.3%.A decrease in sensitivity between on-site and off-site culture was found, which suggested transportation may have an adverse effect on the detection of N gonorrhoeae. However, with the limited population and prevalence, the difference was not found to be statistically significant. Further studies indicated that the nucleic acid probe assay was significantly more sensitive (P = .05) when compared with off-site testing using a culture isolation method, demonstrating that viability is an important consideration. These results suggested that a molecular probe assay should be considered in testing specimens for N. gonorrhoeae, especially when the specimen is to be transported off-site.

Neisseria gonorrhoeae

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SINGLE DOSE ACTIVATED CHARCOAL FOR PRE-HOSPITAL USE, A FEASIBILITY STUDY BY SOUTH WESTERN AMBULANCE SERVICE NHS FOUNDATION TRUST

Emergency Medicine Journal (2015)

Richard Walker Sarah Black

In 2004 The National Institute for Health and Care Excellence (NICE) recommended in that ambulance services should carry Single Dose Activated Charcoal (SDAC) as an antidote to self-poisoning. A survey of ambulance services conducted a year later found a strong reluctance by services to carry the medication. As a result of a research project supporting the recommendation of NICE the South Western Ambulance Service conducted a six month trial of SDAC in two of its zones. A Patient Group Directive was produced and an education programme put in place. Patient Report Forms coded for overdose or where SDAC had been used were retrieved and examined for data. An on-line survey was completed by staff who had been involved in the trial. Paramedic crews attending cases of self-poisoning within one hour of ingestion offered SDAC to those patients. Of 69 occasions on which the medication was offered the uptake rate was 94%. 54% of administrations (n=38) were for hepatotoxic overdoses of paracetamol with a further 3 administrations for lethal doses of other types of drug. Crews used Toxbase on 13 occasions finding their advice extremely clear and helpful. This resulted in SDAC administration on all 13 occasions where crews were uncertain about its suitability on grounds of type of toxin ingested or because the one hour window had been exceeded.. Average time from ingestion to SDAC administration was 23 minutes and 26 seconds. Time on scene where SDAC was offered was 20 minutes and 24 seconds compared with 23 minutes and 26 seconds where SDAC was not offered. Vomiting post administration occurred in only 11% of cases and crews reported no problems encountered in managing patients. Concerns of ambulance services in 2005 of prolonged on-scene times, poor take-up and time required to clean ambulances appear unfounded.

Activated Charcoal

10.1136/emermed-2015-204880.9

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Call to Improve the Quality of Prediction Tools for Intrahepatic Cholangiocarcinoma Resection: A Critical Appraisal, Systematic Review, and External Validation Study

Annals of Surgery Open (2023)

Woo Jin Choi Richard Walker Luckshi Rajendran Owen Jones Annie Gravely

To conduct a systematic review, critical appraisal, and external validation of survival prediction tools for patients undergoing intrahepatic cholangiocarcinoma (iCCA) resection.Despite the development of several survival prediction tools in recent years for patients undergoing iCCA resections, there is a lack of critical appraisal and external validation of these models.We conducted a systematic review and critical appraisal of survival and recurrence prediction models for patients undergoing curative-intent iCCA resections. Studies were evaluated based on their model design, risk of bias, reporting, performance, and validation results. We identified the best model and externally validated it using our institution's data.This review included a total of 31 studies, consisting of 26 studies with original prediction tools and 5 studies that only conducted external validations. Among the 26, 54% of the studies conducted internal validations, 46% conducted external validations, and only 1 study scored a low risk of bias. Harrell's C-statistics ranged from 0.67 to 0.76 for internal validation and from 0.64 to 0.75 for external validation. Only 81% of the studies reported model calibration. Our external validation of the best model (Intrahepatic Cholangiocarcinoma [ICC]-Metroticket) estimated Harrell's and Uno's C-statistics of 0.67 (95% CI: 0.56-0.77) and Uno's time-dependent area under the receiver operating characteristic curve (AUC) of 0.71 (95% CI: 0.53-0.88), with a Brier score of 0.20 (95% CI: 0.15-0.26) and good calibration plots.Many prediction models have been published in recent years, but their quality remains poor, and minimal methodological quality improvement has been observed. The ICC-Metroticket was selected as the best model (Uno's time-dependent AUC of 0.71) for 5-year overall survival prediction in patients undergoing curative-intent iCCA resection.

Brier score

Critical appraisal

Intrahepatic Cholangiocarcinoma

10.1097/as9.0000000000000328

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Considering the cost of a simultaneous versus staged approach to resection of colorectal cancer with synchronous liver metastases in a publicly funded healthcare model

Journal of Surgical Oncology (2018)

Emily Souder Arash Azin Dhruvin H. Hirpara Richard Walker Sean P. Cleary

Background Simultaneous resection for colorectal cancer with synchronous liver metastases is an established alternative to a staged approach. This study aimed to compare these approaches with regards to economic parameters and short‐term outcomes. Methods A retrospective cohort analysis was conducted between 2005 and 2016. The primary outcome was cost per episode of care. Secondary measures included 30‐day clinical outcomes. A multivariate analysis was performed to determine the adjusted effect of a simultaneous surgical approach on total cost of care. Results Fifty‐three cases were identified; 27 in the staged approach, and 26 in the simultaneous group. Age ( P = 0.49), sex ( P = 0.20), BMI ( P = 0.74), and ASA class ( P = 0.44) were comparable between groups. Total cost ($20297 vs $27522), OR ($6830 vs $10376), PACU ($675 vs $1182), ward ($7586 vs $11603) and pharmacy costs ($728 vs $1075) were significantly less for the simultaneous group ( P < 0.05). The adjusted rate ratio for total cost of care in the staged group compared to simultaneous group was 1.51 (95%CI: 1.16‐1.97, P < 0.05). The groups had comparable Clavien‐Dindo scores ( P = 0.89), 30‐day readmissions ( P = 0.44), morbidity ( P = 0.50) and mortality ( P = 1.00). Conclusions Our study demonstrates that a simultaneous approach is associated with a significantly lower total cost while maintaining comparable short‐term outcomes.

10.1002/jso.25020

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Probiotic Microbes: The Scientific Basis

Richard Walker Merry Buckley

This report details how beneficial microbes could represent the future of medicine, with the potential to treat a variety of diseases in humans and animals from diarrhea and eczema to gum disease and autoimmune disorders.

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Hospital learning curves for robot-assisted surgeries: a population-based analysis

Surgical Endoscopy (2023)

Richard Walker Thérèse A. Stukel Charles de Mestral Avery B. Nathens Rodney H. Breau

Learning curve

Odds

10.1007/s00464-023-10625-6

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Citations (3)