.............Collins Day 2026.............

         SUBMIT REVIEW

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Session Podium 1: 0800–0810 - Dr. Ahmed Shoeib (PGY3) - Outcomes and cost analysis of varicocele embolization for male factor infertility: a single Canadian institution’s experience.

Presenter: Dr. Ahmed Shoeib

Shoeib A, Roberts M, Witherspoon L

Division of Urology

Quality Improvement

ABSTRACT  

Introduction:To evaluate clinical outcomes of varicocele embolization and assess its cost-effectiveness compared to microsurgical varicocelectomy using institutional data and literature-based benchmarks. Methods: A retrospective cohort study of adult men undergoing varicocele embolization at a single center (2019–2025) was performed. Pre- and post-procedure semen parameters were compared. Pregnancy outcomes were recorded. A micro-cost analysis incorporating equipment and operative time was conducted. Outcomes of microsurgical varicocelectomy were derived from contemporary literature for comparison. Results: 22 patients underwent embolization (mean age 34.0±6.5 years), with predominantly left-sided (81.8%) and grade 3 (59.1%) varicoceles. Significant improvements were observed in sperm concentration (11.97 to 25.20 million/mL, p=0.009), motility (17.91% to 26.52%, p=0.026), and total motile sperm count (4.29 to 20.82 million, p<0.001). At a mean follow-up of 22.2 months, spontaneous pregnancy occurred in 25.0% of couples, with additional pregnancies via IUI (5.0%) and IVF (45.0%) . These findings are consistent with contemporary literature demonstrating no significant difference in pregnancy rates between both procedures (22–48%), including prospective data showing comparable outcomes (36% vs 33%, p>0.05). Cost analysis demonstrated a lower total procedural cost for embolization ($2,766.26) compared to surgery ($3,024.50), driven by significantly shorter operative time (~30 vs ~110 minutes), despite higher equipment costs. Conclusions: Varicocele embolization yields significant improvements in semen parameters and achieves pregnancy outcomes comparable to microsurgical varicocelectomy. Despite higher material costs, embolization is more cost-effective due to reduced operative time. This analysis also does not account for additional economic advantages of embolization, including reduced postoperative pain, lower complication rates, and faster recovery, which further enhance its value. Taken together, embolization represents a high-value, minimally invasive alternative and should be considered the preferred first-line intervention in appropriately selected patients.

SUBMIT REVIEW

Session Podium 1: 0810–0820 - Dr. Hodan Mohamud (PGY1) - Radon Exposure and Risk of Genitourinary Malignancies: An Analysis of Administrative Health Data

Presenter: Dr. Hodan Mohamud

Mohamud H, Breau R, Lavallée L, Witherspoon L

Division of Urology

Clinical Research

Introduction: Radon is a naturally occurring radioactive noble gas and a major source of environmental background radiation. While its causal link to lung cancer is well established, its role in other malignancies remains poorly understood. Limited data, methodological inconsistencies, and confounding variables have prevented definitive conclusions. This study investigated the association between residential radon exposure and genitourinary malignancies, including bladder, renal, adrenal, and testicular cancers, using a large dataset. Methods: This retrospective cohort study utilized Epic's Cosmos database, a de-identified electronic health record platform representing approximately 150 million patients across the United States. Socioeconomic variables were collected and incorporated. Patients were stratified into low (<2 pCi/L), intermediate (2–4 pCi/L), and high risk (>4 pCi/L) radon exposure categories. Results: Over 150 million adult patients were analyzed between March 2023 and March 2026, of whom 57,756,626 (38.4%) were low risk, 48,011,173 (31.9%) intermediate, and 44,630,133 (29.7%) high risk. Overall genitourinary cancer rates per 100,000 were 2,320, 2,459, and 2,538 across low, intermediate, and high risk groups respectively. Bladder cancer rates were 141, 155, and 167, while renal cancer rates were 337, 341, and 350 per 100,000. A stepwise increase in malignancy rates was observed with greater radon exposure across all cancer types. Conclusion: This large cohort study demonstrates a consistent dose-dependent association between residential radon exposure and genitourinary malignancy rates, suggesting radon may contribute to risk of genitourinary malignancy beyond its known pulmonary effects. These findings highlight the need for prospective research and evidence-based radon screening and mitigation policies.  

SUBMIT REVIEW

Session Podium 1: 0820–0830 - Dr. Dexter Choi (PGY3) - Evaluating Surgical Residents’ Clinical Decision-Making: A Multi-Institutional Study using MyOnCall Pages (Educational)

Presenter: Dr. Dexter Choi

Choi D, Alibhai K, Gawad N, Raîche I, Wood J. T

Division of General Surgery

Educational Research

ABSTRACT  

Background: Clinical decision-making (CDM) is a core competency in surgical training, yet existing assessment tools often fail to distinguish knowledge deficits from CDM errors. MyOnCall (MOC) Pages, previously piloted and supported by preliminary validity evidence, use paired knowledge and triage questions within simulated on-call scenarios to differentiate knowledge gaps from errors in CDM. This study extends prior work by collecting validity evidence and evaluating educational value across Surgical Foundations programs. Methods: Residents from four Canadian Surgical Foundations programs completed MOC Pages consisting of case-based ‘pages’, each including a knowledge question and a triage CDM question, requiring learners to determine the urgency of response  to an on-call scenario. Questions were developed by content experts and mapped to Surgical Foundations Entrustable Professional Activities to support content validity. Descriptive statistics, reliability, and between-program comparisons were performed. Residents also completed a post-assessment survey evaluating perceived educational value. Results: Eight-one residents participated (86% completion). Mean knowledge score was 75.1% (SD 9.2). Safe triage responses predominated (82.6%, SD 10.9) with fewer overly cautious (10.1%, SD = 8.8) and unsafe responses (2.4%, SD = 3.7). Internal consistency was acceptable (Cronbach’s α = 0.75 knowledge; α = 0.83 triage), and test-retest reliability was moderate (r = 0.45-0.48, p < 0.01). Between-program differences in knowledge were statistically significant (F(3,72) = 6.72, p < 0.001) but small in magnitude on post-hoc analyses. Survey responses demonstrated high perceived clarity (M = 4/5), realism (M = 4.05/5), and overall satisfaction (3.84/5). Conclusion: MOC Pages demonstrated acceptable reliability and perceived educational value for assessing CDM in surgical trainees through case-based triage decisions. By distinguishing knowledge from judgment and identifying both unsafe and overly cautious decision patterns, the tool may be used as a scalable formative assessment to characterize trainee decision-making profiles and support competency-based surgical training.

SUBMIT REVIEW

Session Podium 1: 0830–0840 - Dr. Mohamad Bakhaidar (Fellow) - Development and Prospective Validation of a Porcine Simulation Model for Training in Unilateral Biportal Endoscopic Lumbar Decompression

Presenter: Dr. Mohamad Bakhaidar

Bakhaidar M, Alfawaz T, Coyle M, Nassek H, Perez Rodriguez Garcia G, Phan P, Tsai E

Division of Neurosurgery

Educational Research

Background: Unilateral biportal endoscopic (UBE) spine surgery has emerged as a minimally invasive alternative, offering improved recovery profiles but with a steep learning curve and limited access to structured training. Existing educational pathways, including cadaveric courses, are constrained by cost and availability. There remains a need for accessible, validated simulation models to facilitate skill acquisition in UBE techniques. Objective: To develop and validate a porcine lumbar spine model for simulation-based training in UBE surgery and to assess its educational effectiveness using established simulation validity frameworks. Methods: A prospective educational study was conducted at the University of Ottawa Skills and Simulation Centre between October 2025 and February 2026. Thirty-three participants, including junior and senior residents, fellows, and staff surgeons, completed a structured simulation curriculum consisting of pre-briefing, baseline assessment, instructional training, and post-training evaluation. Participants performed three standardized tasks assessing triangulation, anatomical identification, and drilling techniques. Performance was evaluated using a 7-point OSATS-based global rating scale and task completion times. Face, content, and construct validity were assessed through participant surveys and performance comparisons across experience levels. Results: The porcine model demonstrated strong face and content validity, with median Likert scores of 6–7 across all domains. Construct validity was confirmed, with senior participants outperforming juniors in multiple performance domains and demonstrating greater procedural efficiency (p ≤ 0.032). Following training, significant improvements were observed across all tasks, including increased performance scores and reduced task completion times (all p < 0.001). Junior participants exhibited greater relative improvement compared to senior trainees. Regression analysis identified training level as an independent predictor of baseline performance and training-associated gains. Conclusion: This porcine simulation model represents a valid and effective platform for training in UBE lumbar decompression. It offers a practical, accessible alternative to cadaveric training and may facilitate structured skill development, potentially accelerating the learning curve in endoscopic spine surgery.

SUBMIT REVIEW

Session Podium 1: 0840–0850 - Dr. Stephanie Antoniades (Fellow) - The Use of Indwelling vs Intermittent Catheterization in Hip Fracture Patients – a Pilot Feasibility Randomized Control Study

Presenter: Dr. Stephanie Antoniades

Antoniades S, Grammatopoulos G, Lalonde KA, Liew A, Meulenkamp B, Papp S, Wilkin G

Division of Orthopedic Surgery

Clinical Research

Introduction: Hip fractures are associated with significant morbidity and mortality. Complications such as urinary tract infections (UTIs) and postoperative urinary retention (POUR) are common in this population. Current protocols at most institutions do not recommend the use of an indwelling catheter during a hip fracture admission to avoid these complications. However, research has shown that most hospitals deviate from this protocol. We believe that a short period use of an indwelling catheter may lead to reduced discomfort, improved patient satisfaction without an increased risk of a UTI. The primary aim is to assess feasibility, recruitment and retention rates of hip fracture patients randomized to either indwelling or intermittent catheterization. The secondary aim is to compare the rates of UTI, POUR and patient satisfaction in both groups. Methods: One twenty hip fracture patients who presented to a single tertiary hospital between March 2023 to January 2026 were randomized into 2 groups; indwelling catheterization (N=60) and intermittent catheterization (N=60). Feasibility was assessed by a predetermined recruitment rate and retention rate. UTI and POUR rates were collected from medical and nursing records. Patient satisfaction was reported via a patient experience questionnaire. Results: We screened 946 patients, of whom 826 (87%) were excluded and 120 (13%) were randomly assigned to either the indwelling or intermittent group. Our accrual rate was 3.4 patients/month. Our retention rate was 97.5%. POUR developed in 16.6% of patients in both groups and UTI presented in 11.7% in the intermittent group and 15% in the indwelling group. Patients were more satisfied and comfortable in the indwelling group (median 2, IQR 1-5). Conclusion: In this feasibility study, recruitment took longer than expected despite our high retention rate. Further adaptations are required to warrant a successful multi-center trial. In addition, an indwelling catheter at admission with early removal following surgery seems to reduce patient discomfort and improve patient satisfaction, without a much higher risk of a UTI or POUR.

SUBMIT REVIEW

Session Podium 1: 0850–0900 - Dr. Alveena Ahmed (PGY2) - Efficacy of Spinal Cord Ischemia Prevention with Temporary Aneurysm Sac Perfusion vs. Segmental Artery Embolization in Endovascular Repair of Thoracoabdominal Aortic Aneurysms: A Systematic Review and Meta-Analysis 

Presenter: Dr. Alveena Ahmed

Ahmed A, Elzawy G, Kirkham A, Nagpal S, Roberts D

Division of Vascular Surgery

Clinical Research

Background: Spinal cord ischemia (SCI) remains a major complication of thoracoabdominal aortic aneurysm (TAAA). Temporary aneurysm sac perfusion (TASP) and minimally invasive segmental artery coil embolization (MISACE) have emerged as strategies for spinal cord “priming.” This study aims to synthesize available evidence and compare their effectiveness in preventing SCI in completely endovascular TAAA repair. Methods: PubMed, EMBASE, and Google Scholar were searched for studies published over the past 20 years. Observational studies evaluating TASP or MISACE were screened using predefined criteria, then data extraction performed in duplicate. A random-effects meta-analysis is planned to estimate pooled rates of SCI, permanent SCI, 30-day mortality, and interval rupture, along with secondary outcomes including technical success and major morbidity. Subgroup analysis and meta-regression will follow. Results: Of 437 screened studies, 23 met inclusion criteria (6 MISACE, 17 TASP), encompassing 198 MISACE and 2,897 TASP patients. In the TASP group, rates of SCI, permanent SCI, 30-day mortality, and interval rupture were 7.1% (IQR 5.5), 4% (IQR 4.6), 12% (IQR 13), and 2% (IQR 3), respectively. Corresponding MISACE rates were 5.6% (IQR 4), 5% (IQR 3.1), 17% (IQR 10), and 1.5% (IQR 2). Major morbidity from malperfusion and perioperative complications occurred in 5.6% (IQR 10.2) and 17.2% (IQR 12) of TASP patients vs. 7.1% (IQR 8.2) and 11.2% (IQR 7.6) in MISACE patients. Both techniques demonstrated high technical success. Quantitative data synthesis to estimate summary incidence of the aforementioned outcomes, subgroup analysis and meta-regression based on key anatomic, operative and demographic parameters will follow. Conclusion: TASP and MISACE have high rates of technical success and have comparable SCI outcomes following TAAA repair based on our preliminary analysis. Meta-analysis and meta-regression will follow for presentation to substantiate these results and offer more robust comparison.

SUBMIT REVIEW

Session Electronic Posters 1A: 0915–0918 - Dr. Salah Hammouche (Fellow) - PEEK-Based Hip Replacement: The Most Comprehensive Biomedical Assessment to Date

Presenter: Dr. Salah Hammouche

Hammouche S

Division of Orthopedic Surgery

Clinical Research

Introduction: Poly-ether-ether-ketone (PEEK)-based materials are emerging as promising alternatives to traditional polyethylene for total hip arthroplasty, offering favorable mechanical properties and biocompatibility. This study presents a comprehensive preclinical tribological assessment of unfilled PEEK and carbon fiber–reinforced PEEK (CFR-PEEK) as acetabular bearing surfaces, compared to cross-linked polyethylene (XLPE). Methods: A multi-modal experimental approach was employed, including pin-on-plate (POP) testing and hip simulator analysis. Key outcomes included wear factors, friction coefficients, surface roughness, and detailed characterization of wear particles—focusing on their morphology, size distribution, and geometry. Testing was conducted under varying contact pressures and used clinically relevant counterfaces, such as high-carbon cobalt-chromium (HCCoCr) and Biolox Delta ceramic. Results: showed that unfilled PEEK had inferior wear performance, with wear factors up to five times higher than XLPE. In contrast, CFR-PEEK demonstrated low wear rates, comparable to or better than XLPE, especially when paired with ceramic counterfaces. Surface analysis indicated significant roughening of HCCoCr following articulation, whereas ceramic surfaces remained largely unaffected. Notably, CFR-PEEK generated fewer submicron wear particles than XLPE and shifted toward larger particle sizes under microseparation conditions. Despite favorable wear characteristics, both PEEK-based materials exhibited consistently higher friction coefficients—two to three times greater than XLPE—regardless of counterface material or contact pressure. Hip simulator testing confirmed minimal volumetric wear and structural degradation for CFR-PEEK components, although carbon fiber pull-out was observed. Conclusion: CFR-PEEK paired with ceramic counterfaces shows promise as a low-wear bearing combination for hip arthroplasty. However, further investigation is necessary to understand the clinical implications of increased friction and the potential biological reactivity of wear debris before clinical adoption.

SUBMIT REVIEW

Session Electronic Posters 1A: 0918–0921 - Dr. Kala Hickey (PGY7) - A Meta-Analysis of Sodium Thiosulfate for the Prevention of Cisplatin-Induced Nephrotoxicity during HIPEC

Presenter: Dr. Kala Hickey

Hickey K, Aggarwal I, Apte S, Dingley B, Farag N, Sachdeva K

Division of General Surgical Oncology

Clinical Research

Background: CRS-HIPEC improves oncologic outcomes in select patients with peritoneal surface malignancies. Nephrotoxicity is a dose-limiting complication of platinum-based HIPEC. Sodium thiosulfate (STS) has been investigated as a nephroprotective agent. To our knowledge, this is the first systematic review and meta-analysis summarizing its impact.  Methods: A systemic search was performed using the Medline, Embase and Cochrane Library databases for studies evaluating nephroprotective agents used during surgeries where platinum-based HIPEC was performed. Any study from database inception to August 2025 was included. The primary outcome was post-operative acute kidney injury (AKI) using any definition. The systematic review protocol was published on PROSPERO (CRD420251141717).  Results: Of 252 records screened, 23 studies were included. Seven comparative studies with STS versus no STS were identified. Cisplatin dosing was 50–100 mg/m² over 60–90 minutes. STS was associated with substantially lower odds of AKI (random-effects OR 0.08, 95% CI [0.04–0.16]; p<0.001). In 10 single-arm studies in which all patients received STS, the pooled incidence of AKI was 0.11 (95% CI 0.06–0.18; p=0.043), using a random-effects model. Six studies included other nephroprotective agents with heterogeneous effect. Across studies using STS, only one patient who received high dose Cisplatin (350 mg/ m²) required dialysis, one study reported prolonged length of ICU stay for patients receiving STS, and no patients progressed to chronic kidney disease (CKD). STS was overall well tolerated, with transient hyponatremia as the main reported biochemical disruption. Conclusion: In comparative studies, STS was associated with significantly lower odds of AKI in patients undergoing platinum-based HIPEC and is overall safe to use. Evidence for other nephroprotective agents was limited and inconclusive. This systematic review and meta-analysis supports the use of STS as a nephroprotective agent during platinum-based HIPEC.   

SUBMIT REVIEW

Session Electronic Posters 1A: 0921–0924 - Dr. Kikachukwu Otiono (PGY3) - Safety of testosterone replacement therapy in critically ill tracheostomized and failed to wean patients

Presenter: Dr. Kikachukwu Otiono

Otiono K, Meggison H, Ross A, Shoeib A, Witherspoon L

Division of Urology

Clinical Research

Introduction: Testosterone deficiency is common in chronic critical illness and may impair ventilator weaning. Select intensive care unit (ICU) patients with failure to wean are initiated on testosterone replacement therapy (TRT) at our centre, though safety data remain limited. This study evaluated mortality, venous thromboembolism (VTE), and myocardial infarction (MI) following TRT in tracheostomized ICU patients, comparing observed mortality with APACHE II-predicated mortality using the standardized mortality ratio (SMR). Methods: A retrospective cohort (2019–2024) across two campuses of a single academic centre included adults admitted to the ICU who underwent tracheostomy and subsequently received TRT initiated by the ICU team. Outcomes at 30, 60, and 90 days following TRT initiation were assessed. SMR with 95% Byar confidence intervals (CI) was calculated using APACHE II-derived expected mortality. Results: 117 patients were included (65% male; mean age 65 years; mean ICU stay 46 days; mean APACHE II score 20.4). Mean total testosterone increased from 3.4 ± 6.9 nmol/L to 12.1 ± 11.4 nmol/L at 30 days in males (n = 21; p < 0.001). In females, levels increased from 0.37 ± 0.55 nmol/L (n = 12) to 1.69 ± 1.26 nmol/L (n = 9; p = 0.004). Hematocrit decreased from 0.358 ± 0.091 L/L to 0.313 ± 0.058 L/L at 90 days (ΔHCT = −0.046 ± 0.097). Mortality at 30, 60, and 90 days was 23.9% (95% CI 17.1–32.4), 29.1% (21.6–37.8), and 30.8% (23.1–39.6), respectively. VTE occurred in 12.8% (7.9–20.1) at 30/60 days and 13.7% (8.6–21.1) at 90 days; MI occurred in 4.3% (1.8–9.6) across all timepoints. Observed versus expected 90-day deaths (36 vs. 39.4) yielded an SMR of 0.91 (95% CI 0.68–1.24), indicating no excess mortality. Conclusions: In tracheostomized, critically ill patients, TRT was not associated with increased mortality, VTE, or MI within 90 days. Mortality aligned with APACHE-predicted risk (SMR ≈ 1), and hematocrit did not increase. VTE and MI rates were comparable to published ICU benchmarks (~10% and ~24% respectively). These findings support the short-term safety of TRT in this population and justify further investigation of its role in ventilator weaning and recovery.  

SUBMIT REVIEW

Session Electronic Posters 1A: 0924–0927 - Dr. Emma Higgins (PGY2) - Vascular Resection and Reconstruction During Pelvic Oncologic Surgery: A Systematic Review of Surgical and Oncologic Outcomes 

Presenter: Dr. Emma Higgins

Higgins E, Apte S, Farag N, Hickey K

Division of General Surgery

Clinical Research

Introduction: Complete surgical resection is the primary objective in managing locally advanced pelvic malignancies. Achieving R0 resection may require en bloc resection of major vessels, with possible reconstruction. The impact of vascular resection and reconstruction on oncologic outcomes and perioperative morbidity is unclear. This review aims to characterize outcomes for patients undergoing vascular reconstruction during curative intent pelvic sidewall surgery for locally advanced pelvic malignancy. Methods: A search of Embase, MEDLINE, Web of Science, and CINAHL identified studies reporting outcomes of adult patients undergoing surgery for gynecologic, colorectal, and soft tissue pelvic malignancies. Studies including major vessel resection with vascular reconstruction were included and compared to cohorts undergoing resection without reconstruction. Two reviewers independently screened, with discrepancies resolved by a third reviewer. The primary outcome was margin status. Secondary outcomes included vascular complications, major postoperative complications, and disease free/overall survival. The protocol was registered with PROSPERO CRD42021293929. Results: Of 1,175 records screened, 16 studies met inclusion criteria, comprising 542 patients, with 65% undergoing vascular reconstruction. Nine studies reported margin outcomes. R0 resection was achieved in 71%, while 29% had R1/R2 resection. A total of 85 vascular complications were reported, with 17.7% requiring reintervention. Complication rates varied due to heterogeneity in tumor types, surgical approaches, and reconstruction techniques. Conclusion: Vascular resection and reconstruction is a feasible strategy to achieve R0 resection in certain patients with locally advanced pelvic malignancies, possibly expanding eligibility for curative-intent surgery.  The risk of complications and reintervention highlights the importance of careful patient selection, preoperative counselling and shared decision-making.  Further prospective comparative studies of larger populations with standardized reporting are required to define patient selection criteria, quality of life outcomes and optimize oncologic outcomes.

SUBMIT REVIEW

Session Electronic Posters 1A: 0927–0930 - Dr. Catherine McGuire (PGY1) - Systematic Review and Meta-Analysis of the Outcomes of MSI-High Colorectal Cancer Liver Metastases Following Immunotherapy

Presenter: Dr. Catherine McGuire

McGuire C, Farag N, Higgins E, Martel G, Shorr R, Zabbal A,

Division of General Surgery

Clinical Research

Introduction: Immunotherapy has demonstrated efficacy in microsatellite instability-high (MSIH) colorectal cancer. However, the role of immune checkpoint inhibitors (ICI) in relation to surgery for colorectal liver metastases (CRLM) remains unclear. This systematic review and meta-analysis aims to evaluate outcomes in MSI-H CRLM patients treated with ICI to better define the role of liver resection in the immunotherapy era. Methods: This study followed PRISMA-P 2015 guidelines. A systematic search of Medline, Embase, Cochrane Library, and Web of Science was conducted for studies published between January 2013 and January 2026. Inclusion criteria were MSI-H colorectal cancer with liver metastases treated with ICI. Exclusion criteria included absence of ICI therapy, non-CRLM, nonoriginal research or MSS-only cohorts. Two reviewers independently screened studies, with discrepancies resolved by consensus. Primary outcomes were clinical and pathologic complete response (pCR). Meta-analysis was performed using a random-effects model. Heterogeneity was assessed using χ² and I² statistics, and risk of bias was evaluated using ROBINS-I and Cochrane RoB v2. Results: Of 4,299 studies screened, 366 underwent full-text review and 187 were included. PD-1 inhibitors were used in 90% of studies, most commonly pembrolizumab (55%). Radiologic response was observed in 17/33 (51.5%) patients. Among those who underwent metastasectomy, 19/26 (73.1%) had pCR, all following PD-1 therapy. Grade ≥3 adverse events were uncommon (5.5%). Conclusions: Evidence remains limited on the outcomes following ICI in MSI-H CRLM with no randomized trials. Radiologic response underestimates pathologic response, suggesting a potential role for confirming tumour viability prior to liver resection in MSI-H CRLM.

 SUBMIT REVIEW

Session Electronic Posters 1A: 0930–0933 - Dr. Lubina Nayak (PGY4) - Partial Adrenalectomy in Functional Tumors: An Underused Approach or a High-Risk Strategy?

Presenter: Dr. Lubina Nayak

Nayak L, Hakala A, Mohamud H, Rowe N

Division of General Surgery

Clinical Research

Background: Laparoscopic surgery requires dexterity, coordination, and fine motor skills. Traditional laparoscopic skill assessment has relied on human evaluators, which is both labor-intensive and subject to bias. Artificial intelligence (AI) offers objective, automated feedback for laparoscopic training, however its reliability and integration into surgical education remains unclear. This study aims to review recent developments in AI applications for laparoscopic skill assessment in surgical education and identifies areas for future research. Methods: MEDLINE, EMBASE, and Web of Science databases were searched for studies evaluating AI-based laparoscopic skill assessment involving medical students, surgical residents, and/or fellows published from 2015 to 2024. All original research referencing “artificial intelligence” or “virtual reality” or “computer simulation” and “laparoscopy” and “medical education” or “assessment” were included. Data were qualitatively analyzed and synthesized according to the PRISMA scoping review guidelines. Results: 1973 abstracts were reviewed, and 30 studies were included. Studies were classified as comparing AI systems against validated scoring methods by human raters (n = 12) and AI tools for distinguishing operator skill level (n = 18). The most common skills assessed by AI platforms were laparoscopic peg transfer (n = 9), suturing (n = 7), knot tying (n = 6), or pattern cutting (n = 6). AI models demonstrated strong correlation and agreement with manual scoring by human assessors on standardized assessment tools. AI skill assessment via real-time data capture and video analysis demonstrated moderate-to-high accuracy in distinguishing between novice and expert surgeons. Conclusion: AI-based technologies offer an objective alternative to manual assessment by accurately classifying operator skill level and providing reliable automated scoring for various laparoscopic tasks. Real-time AI feedback may accelerate skill acquisition, reduce human bias, and improve training efficiency. Further research with standardized AI assessment metrics and randomized trials is needed for validation prior to implementation in surgical education.  

SUBMIT REVIEW

Session Electronic Posters 1B: 0915–0918 - Dr. Ryan Sandarage (PGY4) - Patient and Tissue Factors Associated with Growth of Adult Human Spinal Cord Stem/Progenitor Cells

Presenter: Dr. Ryan Sandarage

Sandarage R.V, Galuta A, Jagadeesan S.K., Tsai E.C, Wai E

Division of Neurosurgery

Translational Research

Introduction: Adult human spinal cord stem/progenitor cells are of growing interest for spinal cord repair and regenerative medicine, but little is known about why these cells grow more successfully in some patients than others. A better understanding of the factors associated with cell growth may improve how human spinal cord tissue is studied and how future therapies are developed. Methods: Stem/progenitor cells were cultured from 42 spinal cord tissue samples obtained from 27 adult organ donors. Growth characteristics, including proliferation rate and doubling time, were assessed and compared according to donor age, sex, spinal cord region (thoracic, lumbar, conus), neurological conditions, and substance use history. Cell multipotency was confirmed by immunocytochemistry. A multivariable linear regression model was then developed to determine how well donor and tissue factors could predict cell growth, with performance assessed using cross-validation and an independent validation cohort. Results: Cell growth decreased with increasing donor age and was lower in donors with neurological conditions or substance use histories. Cells derived from the conus region demonstrated greater proliferative capacity than those from thoracic or lumbar regions. A model incorporating donor and tissue characteristics predicted cell growth with strong accuracy and performed well in an independent validation cohort. Conclusions: Growth of adult human spinal cord stem/progenitor cells varies according to both patient characteristics and the anatomical region of the spinal cord sampled. These findings improve our understanding of variability in human spinal cord cell biology and may help guide tissue selection, experimental design, and future development of regenerative strategies for spinal cord injury.

SUBMIT REVIEW

Session Electronic Posters 1B: 0918–0921 - Dr. Catherine Binda (PGY2) - General surgery resident knowledge, and training needs and implementation readiness for opportunistic salpingectomy: A cross-sectional needs assessment

Presenter: Dr. Catherine Binda

Binda C, Jarrer A, Koloszvari N

Division of General Surgery

Translational Research

Background: Opportunistic salpingectomy (OS), salpingectomy at the time of unrelated abdominal surgery, is an effective ovarian cancer primary prevention strategy endorsed by gynaecologic societies. National knowledge translation efforts promote general surgeons’ adoption of OS. Studies have explored surgeons’ perspective on OS implementation, but none have specifically assessed trainees’ knowledge gaps, training needs, or implementation readiness. Methods: A survey was distributed to all general surgery residents in a Canadian training program (Feb2026). The survey assessed OS familiarity, clinical exposure, barriers and facilitators, and preferred educational approaches. Descriptive statistics summarize responses. Results: Nineteen (65.5%) of 29 eligible residents responded. Most (73.7%) reported only partial familiarity with OS. One (5.3%) had performed OS, and 4 (21.1%) had observed OS. Despite limited exposure, most (68.4%) planned to offer OS in their future practice and believed OS should be included in residency training. The leading barriers were indication, risk, and technique knowledge gaps. Principal concerns included discomfort recognizing abnormal pathology (94.7%), limited access to training (78.9%), and lack of technical competency (73.7%). Medico-legal concerns about fertility or ovarian failure were reported by 63.2% and 68.4%, respectively. Cancer risk reduction (89.5%) and society guidelines (89.5%) were the strongest motivators. Residents desired intra-operative exposure (100%), video-based learning (84.2%), and clinical decision-support tools (84.2%) to learn OS. Conclusion: General surgery residents report strong interest in OS but face a significant knowledge-to-practice gap. Our findings will inform a needs-driven quality improvement initiative incorporating OS into our general surgery residency training program.

SUBMIT REVIEW

Session Electronic Posters 1B: 0921–0924 - Dr. Dexter Choi (PGY3) - Operative Debriefing for Surgical Education: A Scoping Review of Current Practices and Outcomes

Presenter: Dr. Dexter Choi

Choi D, Gawad N, Hamidi D, Raîche I, Wood T. J.

Division of General Surgery

Educational Research

Background: Surgical training requires concurrent development of technical and non-technical skills (NTS) including decision-making, conflict resolution, and leadership. Operative debriefing, a structured reflective discussion to review cases, supports learning across both domains. While debriefing frameworks are established in simulation and other clinical contexts, debriefing practices in surgery remain poorly characterized. This scoping review examines the structure and impact of operative debriefing. Methods: This review followed the Arksey and O’Malley framework with Levac et al. enhancements and is reported in accordance with PRISMA-ScR. PubMed, Embase, Web of Science, and ERIC were searched for studies published since 1980. Two reviewers independently screened titles, abstracts, and full texts. Studies describing operative debriefing in clinical or simulation settings were included. Data were extracted on study characteristics and debriefing features. Quantitative findings were summarized descriptively. Qualitative data were synthesized thematically to characterize outcomes, barriers, and facilitators. Results: Of 3,211 studies screened, 345 underwent full-text review, and 35 were included. Quantitative outcomes were heterogeneous and included technical performance measures (n=13), NTS assessments (n=7), debriefing quality (n=5), and participant perceptions through surveys (n=18). Six qualitative themes were identified: (1) structured, goal-oriented approaches improve debriefing quality; (2) bidirectional dialogue promotes learner engagement, feedback receptivity, and self-assessment; (3) effective NTS debriefing requires explicit frameworks; (4) gaps in structure and depth exist between ideal and real-world debriefing; (5) barriers include time constraints and limited debriefing culture; and (6) facilitator training improves debriefing quality. Conclusion: Operative debriefing is inconsistently implemented with misalignment between recommended and actual practices. Effective debriefs are structured, bidirectional, address NTS, and involve trained facilitators. Future work should focus on better integrating structured approaches in operative workflows.

SUBMIT REVIEW

Session Electronic Posters 1B: 0924–0927 - Dr. George Elzawy (PGY2) - Safety of Intentional Celiac Artery Coverage During Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-Analysis of Prognostic Studies

Presenter: Dr. George Elzawy

Elzawy G, Ahmed A, Kirkham A, Roberts D. J.

Division of Vascular Surgery

Clinical Research

Background: Thoracic endovascular aortic repair (TEVAR) is the preferred treatment for a range of aortic pathologies. Up to 15% of these procedures require celiac artery (CA) coverage. We conducted a systematic review and meta-analysis (SRMA) to determine the safety of intentional CA coverage during TEVAR. Methods: We searched MEDLINE and EMBASE for studies evaluating outcomes of TEVAR with intentional CA coverage for aneurysm, dissection, or trauma. The primary outcome was visceral ischemia. Secondary outcomes included 30-day and 1-year mortality, spinal cord ischemia (SCI), and endoleaks. We also conducted stratified meta-analyses and meta-regressions to determine whether outcomes were predicted by aortic pathology, patient age, aortic rupture, procedural urgency, and graft-to-superior mesenteric artery (SMA)) distance. Results: Among 332 studies identified, we included 20 studies (n=550 total patients) in the systematic review. To assess safety of CA coverage, included studies used preoperative CT angiography w (100%), diagnostic angiography (94%), and balloon occlusion (50%). The weighted-mean graft-to-SMA distance was 16.7 ± 8.5 mm. The pooled incidence of visceral ischemia was 3% (95% CI=1-6%), of 30-day mortality was 5% (95% CI=3–8%), of 1-year mortality was 15% (95% CI=8–23%), and of SCI was 3% (95% CI=1–6%). The incidence of endoleak and type II CA-related endoleak were 17% (95% CI=9–26%) and 6% (0–18%), respectively. Stratified meta-analyses suggested that the incidence of type II CA endoleak was significantly higher among patients with aneurysmal versus dissection/other aortic pathology (p=0.03). Meta-regression analyses suggested no significant differences in the incidence of adverse outcomes based on patient age, urgent/ruptured presentation, and mean graft-to-SMA distance. Conclusion: Intentional CA coverage during TEVAR is associated with a low risk of mortality and ischemic complications. Those undergoing this procedure for thoracic aortic aneurysms had a lower 1-year mortality and type II endoleak than aortic dissection.

SUBMIT REVIEW

 Session Electronic Posters 1B: 0927–0930 - Kwadjo Nyarko (Medical Student) - Patient Perspectives and Outcomes of Same-Day Discharge after Hepatectomy Pilot Program (SDDHep): A Mixed Methods Analysis

Presenter: Kwadjo Nyarko

Nyarko K, Abou-Khalil J, Aggarwal I, Balaa F, Berten K, Gilbert R,  Martel G

Division of General Surgery

Quality Improvement

Background: Advances in minimally invasive surgery and virtual recovery programs (VRAS) have supported the implementation of a Same-Day Discharge after Hepatectomy Pilot Program (SDDHep) at a tertiary hepatobiliary centre. Same-day discharge (SDD) after hepatectomy has not been adopted widely, and patient perspectives are not well characterized. This study aims to (1) evaluate program safety and efficacy relative to a historical cohort and (2) qualitatively evaluate patient perspectives. Methods: Quantitative data were collected from retrospective chart review and hospital analytics. Study outcomes, including SDD, length of stay (LOS), and 30-day readmission, were compared between SDDHep and historical cohorts. Within the SDDHep cohort, barriers to SDD and VRAS pain scores were assessed. The qualitative component is a thematic analysis of semi-structured interviews designed to explore patients' perceptions of the overall experience, program efficacy, and discharge readiness. Results: This study included patients who underwent robotic or laparoscopic hepatectomy between June 1, 2019 and March 24, 2026. A total of 217 patients were included in the study, with 27 in the SDD cohort. The SDD cohort had a significantly shorter median LOS than the control cohort (1 [0–1] vs. 2 [1–4] days; p < 0.001) and had a significantly higher percentage of same-day discharges (48.15% vs. 7.37%, p < 0.001). Five patients participated in semi-structured interviews, thematic analysis identified four key themes: 1) Perceived readiness for discharge, highlighting the variety of sentiments and contributing factors; 2) Safety and reassurance through remote monitoring, capturing its impact on confidence in recovery progression; 3) Perceived reduction in prolonged hospitalization, with patients viewing early discharge as effective and resource-efficient; and 4) Ongoing support needs after discharge, reflecting the importance of access to people and resources during recovery. All interviewed patients expressed satisfaction with the program. Conclusion: The preliminary insights from the SDDHep pilot demonstrate decreases in LOS and improved SDD likelihood. Patients found the program effective, safe, and supportive, and the findings support further expansion and evaluation of the program. 

SUBMIT REVIEW

Session Electronic Posters 1B: 0930–0933 - Dr. Ian Diffey (PGY2) - Artificial Intelligence Generated Operative Planning in Primary Aesthetic Rhinoplasty: A Proof-of-Concept Study

Presenter: Dr. Ian Diffey

Diffey, I, Peters D, Roumeliotis G

Division of Plastic Surgery

Clinical Research

Background: Operative planning in aesthetic rhinoplasty requires detailed deformity analysis and selection of appropriate surgical maneuvers. The ability of artificial intelligence (AI) systems to generate structured operative plans and simulate postoperative outcomes from preoperative images remains incompletely defined. Methods: This study represents an initial proof-of-concept  within a comparative case-based validation framework. Published cases of primary aesthetic rhinoplasty were identified from recent literature in Plastic and Reconstructive Surgery and affiliated journals. Included cases demonstrated standardized preoperative and postoperative photographs and clearly described operative plans. For each case, preoperative photographs were provided to an AI system without additional contextual input. The model was prompted to generate a structured operative plan including deformity analysis, surgical approach, operative maneuvers, and functional considerations, as well as an illustrative postoperative simulation. AI-generated plans were compared qualitatively with published operative descriptions, focusing on deformity recognition, operative strategy, and safety. Planned future phases of the study will include comparison between baseline and literature-informed AI conditions, blinded expert evaluation, and assessment of educational utility. Results: Two cases of primary aesthetic rhinoplasty were analyzed. Across both cases, the AI system accurately identified key deformities, including dorsal hump deformity, middle vault widening, and bulbous, under-rotated nasal tips. The AI consistently proposed appropriate operative strategies, including open rhinoplasty, dorsal hump reduction, osteotomies, and tip refinement. Structural support was incorporated in both cases, and functional considerations such as preservation of the internal nasal valve were addressed. High concordance with published operative plans was observed in deformity recognition and overall surgical approach. In one case, the AI-selected use of a columellar strut graft differed from the septal extension graft described in the source publication, representing variation in technique despite alignment in surgical objectives. No anatomically inappropriate or potentially harmful operative maneuvers were identified. AI-generated postoperative simulations demonstrated qualitative improvement consistent with published outcomes. Conclusions: In this proof of concept analysis, AI-generated operative planning from preoperative rhinoplasty images demonstrated high concordance with expert-derived surgical strategies and acceptable safety. These findings support the feasibility of AI-assisted surgical planning. Ongoing work will evaluate the impact of structured surgical knowledge on AI performance and its potential role in surgical education.

SUBMIT REVIEW

Session Podium 2: 0950–1000 - Dr. Salah Hammouche (Fellow) - Demographic and Surgical Correlates of Low Mental-Health Scores in Patients with Periprosthetic Joint Infection: A Prospective Observational Study

Presenter: Dr. Salah Hammouche

Hammouche S, Costa S, Henke Tarnow S, Grammatopoulos G, Abdelbary H, Beaulé P, Pontefract A, Poulin P, Garceau S

Division of Orthopedic Surgery

Clinical Research

Purpose: Periprosthetic joint infection (PJI) significantly impacts patients both physically and psychologically. Given the scarcity of mental-health resources, identifying those at greatest risk is vital for directing effective psychological care. This study examines demographic and surgical factors associated with low mental-health status to facilitate risk stratification and targeted support during PJI management. Methods: A prospective observational study was conducted at a tertiary referral center specializing in PJI. Adults undergoing surgical treatment for hip or knee PJI between November 2023 and August 2024 were assessed at three points: admission (T0), post-operative day five (T5d), and late follow-up (3–6 months, T3–6m). Assessments included the Patient Health Questionnaire-4 (PHQ-4), Demoralization Scale-II (DS-II), PROMIS Global Health, and EQ-5D-5L. Low mental health was defined as PHQ-4 ≥ 6 or DS-II ≥ 40.3. Demographic and clinical variables—age, sex, BMI, ASA class, infection chronicity, joint, procedure type, and length of stay—were analyzed using multivariate statistical methods (p < 0.05). Results: A total of 120 patients were enrolled (mean age 69 ± 10.8 years; mean BMI 31.6 ± 8.2). At baseline, 47% met criteria for low mental health. Compared to the normal/moderate group, individuals with low mental health were more often female (58% vs 32%, p = 0.04), had higher BMI (33.8 ± 9.4 vs 29.8 ± 7.2 kg/m², p = 0.03), exhibited greater medical complexity (ASA IV 31% vs 26%), and experienced more chronic infections (62% vs 44%). Hip PJI was slightly more frequent among those with low mental health (63% vs 52%), and their mean length of stay was longer (34.1 vs 25.2 days, p = 0.04). Across the cohort, PHQ-4 and DS-II scores improved from T0/T5d to T3–6m (p < 0.01), but patients with low baseline mental health continued to show poorer scores at final follow-up. Conclusion: Nearly half of PJI patients presented with significant psychological distress, which persisted among high-risk groups. Low mental-health status was associated with female sex, higher BMI, chronic infection, and greater comorbidity. Additionally, lower preoperative mental-health scores and longer hospital stays predicted poorer postoperative outcomes. Focusing psychological support on these high-risk subgroups may improve recovery and optimize the allocation of limited mental-health resources within PJI care pathways. 

SUBMIT REVIEW

Session Podium 2: 1000–1010 - Dr. Lubina Nayak (PGY4) - A Randomized Controlled Trial of Tranexamic Acid During Radical Cystectomy: The Long-term Oncologic Safety of a Lysine Analogue

Presenter: Dr. Lubina Nayak

Nayak L, Alam A, Breau R, Bryson G, Cagiannos I, Devereau PJ, Fergusson D, Flaman A, Houston B, Izawa J, Kanji S, Kassouf W, Kulkarni G, Lavallée L, Mallick R, Martel G, McIsaac D, Morash C, Rendon R, Saad F, Shayegan B, Tikkanen K, Turgeon A, Zarychanski R

Division of General Surgery

Clinical Research

Introduction: Tranexamic acid (TXA) is increasingly used during cancer surgery to reduce blood loss and transfusion. Preclinical studies suggest TXA may increase the probability of cancer recurrence by preventing breakdown of fibrin complexes that may protect circulating tumour cells from immune destruction. Tranexamic Acid during Cystectomy Trial (TACT) was a randomized, double-blind, placebo-controlled trial designed to evaluate the effect of perioperative TXA on transfusion rates, and this long term follow up evaluates if TXA impacts the risk of cancer recurrence. Methods: TACT was a multicenter trial conducted in 10 academic centers including patients who were planned to undergo radical cystectomy for the treatment of bladder cancer. Patients were randomized to receive a 10mg/kg loading dose of intravenous TXA, followed by a 5mg/kg/hour maintenance infusion during surgery in the intervention arm. In the control arm, patients received indistinguishable matching placebo. TACT-SAFETY is a long-term secondary analysis evaluating cancer recurrence (local or distant metastases), cancer-related death, and death from any cause. Results: Of 344 patients analysed for the primary outcome, 299 (TXA: n=150; placebo: n=149) were evaluated for cancer recurrence and were analyzed using an intention-to-treat approach. Median follow-up was 5.6 years (IQR 4.4-7.4 years). There were no clinically significant differences in baseline clinical, operative, and pathological characteristics. Recurrence occurred in 112 patients (TXA: n=48; placebo: n=64). TXA did not significantly affect the risk of recurrence (HR 0.72; 95%CI 0.49-1.05). Following recurrence, both groups received similar intensity of post-recurrence treatments. Of 125 patients that died, 90 patients died from metastatic bladder cancer. Cancer specific death (HR 0.79; 95%CI 0.52-1.19) or death from any cause (HR 0.83; 95%CI 0.58-1.18) did not differ between groups. Conclusions: TXA did not increase risk of cancer recurrence or death. This is the first study to evaluate long-term cancer outcomes in patients treated with TXA.   

SUBMIT REVIEW

Session Podium 2: 1010–1020 - Dr. Johann Licht (PGY1) - Abdominal Aortic Aneurysms in Ontario: Trends in Incidence, Treatment, and Outcomes

Presenter: Dr. Johann-Christoph Licht

Licht J-C, Brogly S, Brown P, Shellenberger J, Yacob M, Zelt D

Division of Vascular Surgery

Clinical Research

 
Background: Contemporary Canadian data on abdominal aortic aneurysm (AAA) epidemiology and management are limited. We evaluated trends in incidence, treatment, and outcomes of stable (sAAA) and ruptured AAA (rAAA) in Ontario over the past decade. Methods: We performed a population-based retrospective cohort study of patients ≥40 years with incident AAA identified from administrative databases in Ontario (2012–2023). sAAA and rAAA were defined using ICD-10 codes. Monthly age- and sex-standardized incidence rates were analyzed using autoregressive integrated moving average models, incorporating three population-level events: 2018 Canadian screening recommendations, COVID-19 onset (2020), and 2021 Canadian Society of Vascular Surgery guidelines. Treatment modality (endovascular aortic repair [EVAR] vs. open surgical repair [OSR]) and 30-day and 1-year mortality were assessed. Results: A total of 24,619 patients were included. AAA incidence declined over time for both sAAA and rAAA. A transient increase in sAAA incidence followed the 2018 screening recommendations, while COVID-19 was associated with a brief decline in diagnoses. No sustained effect of the 2021 guidelines was observed. Operative management decreased overall. For rAAA, EVAR use increased (10.2% to 18%) while OSR declined (40.8% to 31.3%); approximately 50% remained untreated. For sAAA, unrepaired aneurysms increased (28.2% to 42.7%), with stable EVAR use and declining OSR. Thirty-day and 1-year mortality after rAAA remained high but stable (54.7% and 61.7%). EVAR was associated with improved short-term outcomes versus OSR. In contrast, sAAA postoperative mortality increased modestly (30-day: 5% to 6.5%; 1-year: 14% to 16.5%). Unrepaired AAAs demonstrated high mortality. Conclusion: This study shows that incidence of AAA in Ontario is gradually declining in both stable and ruptured aneurysm over time, with increasing EVAR use and decreasing OSR, and a growing proportion of patients who do not undergo intervention. Mortality trends suggest improved short-term outcomes with EVAR, while unrepaired aneurysms continue to be associated with high mortality, highlighting important areas for ongoing evaluation.

SUBMIT REVIEW

Session Podium 2: 1020–1030 - Dr. Victoria Ivankovic (PGY3) - Tranexamic Acid in Cancer Surgery: A Systematic Evidence Map of Clinical and Preclinical Studies

Presenter: Dr. Victoria Ivankovic

Ivankovic V, Fergusson D, Martel G, Schulz A, Shorr R

Division of General Surgery

Clinical Research

Introduction: 

Tranexamic acid (TXA) is widely used to reduce blood loss and transfusion in major surgery. Its safety in oncologic surgery remains uncertain, with theoretical risks of venous thromboembolism (VTE) and tumor progression. We conducted a systematic analytic review of clinical and laboratory evidence evaluating TXA in cancer surgery or cancer models. Methods: We searched MEDLINE, Embase, CENTRAL, and Web of Science to May 2025. Screening and extraction were performed in duplicate using Covidence. From 2590 unique citations screened, 116 full texts were assessed and 48 studies met criteria. Eligible studies evaluated TXA or epsilon-aminocaproic acid (EACA) and reported transfusion, VTE, or oncologic outcomes in cancer populations or models. Findings were summarized narratively. Results: Forty-eight studies were included: 30 clinical and 18 laboratory. Among clinical studies reporting transfusion outcomes, most retrospective and single-center series demonstrated reduced transfusion with TXA. However, contemporary multicenter randomized trials did not reduce transfusion compared with control, suggesting any benefit is not consistent under modern care. Across studies assessing VTE, postoperative DVT/PE rates were typically 0-3% and did not differ between TXA and controls. Only a small number of clinical studies examined cancer outcomes directly, none showing harm, but all were underpowered for recurrence or survival. Laboratory studies yielded mixed results: some reported enhanced invasion or migration at supratherapeutic concentrations, others showed neutral or protective effects. Conclusions: TXA’s clinical effect on transfusion in cancer surgery is inconsistent, and contemporary randomized trials have not shown a transfusion reduction. Available data do not indicate increased VTE risk, and clinical signals of oncologic harm are absent but imprecise. Cancer-specific randomized trials powered for recurrence and survival endpoints are needed to define long-term safety and to clarify whether any indirect effects via transfusion exposure influence oncologic outcomes.

SUBMIT REVIEW

Session Podium 2: 1030–1040 - Dr. Adolfo Lopez Rios (PGY3) - Postoperative Complications and Patient-Reported Outcomes in Oncoplastic Surgery with Simultaneous Symmetry Procedures.

Presenter: Dr. Adolfo Lopez Rios

Lopez Rios A, Dozois A, Zhang J,

Division of Plastic Surgery

Clinical Research

Introduction: Breast cancer is one of the most prevalent cancers worldwide, and treatment often includes oncoplastic surgery. Certain conditions can lead to complications following this surgery. Purpose: This study aims to analyze the incidence of complications and their associated factors in women diagnosed with breast cancer who underwent oncoplastic surgery combined with symmetry-restoring procedures. Methods: A retrospective cohort study was conducted, which included a population of women diagnosed with breast cancer over the past 10 years who received oncoplastic surgery at the Ottawa Hospital in Canada. A database was created to collect information on demographic and clinical variables, procedure-related factors, complications, and patient-reported outcomes using the BREAST-Q questionnaire. Data analysis was conducted using a multivariate method in SPSS. Results: A total of 850 records were analyzed for women who underwent oncoplastic surgery involving symmetry-restoring procedures. The mean age of the participants was 53.5 years (SD 11.2 years), with ages ranging from 22 to 92 years. Fifty percent of the women had a BMI of 26 or higher. The mean follow-up period was 551 days. Among the participants, 44% had stage 2 breast cancer, 79% underwent mastectomy, and of those, 38% had reconstruction using an implant. Additionally, 26% underwent reduction surgery to restore symmetry. The overall complication rate was 42.6%. Among the women who experienced complications, 84% had minor complications, with skin necrosis (10.7%) and fat necrosis (10.6%) being the most common. The most frequently occurring major complication was chronic pain, affecting 2.9% of patients. The average psychosocial well-being score improved from 65.8 before surgery to 73.2 three months after surgery and 74.5 twelve months after surgery. Breast satisfaction scores also improved but slightly decreased at the one-year mark: 56.7 before the procedure, 66 three months after, and 65 twelve months after. Preliminary multivariate analysis indicated an association between smoking status (p = 0.005) and the type of surgery (p = 0.003) with the occurrence of complications following oncoplastic surgery. Conclusions: The most common surgical procedure performed was mastectomy with implant-based reconstruction, with breast reduction being the most frequently performed symmetry-restoring procedure. Although complications occurred in nearly half of the women who underwent surgery, most were classified as minor, suggesting that oncoplastic surgery is safe, feasible, and yields favourable outcomes for patients.  

 SUBMIT REVIEW

Session Podium 2: 1040–1050 - Dr. Kala Hickey (PGY7) - Nephroprotection with Sodium Thiosulfate Inhibits the Anticancer Efficacy of Cisplatin-HIPEC for Peritoneal Surface Malignancies

Presenter: Dr. Kala Hickey

Hickey K, Baratti D, Beretta F, Battistessa D, Deraco M, Gariboldi M, Gualio M, Kusamura S, Varinelli L, Venturelli E

Division of General Surgical Oncology

Translational Research

Introduction: Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) provides survival benefit for select patients with peritoneal surface malignancies (PSM). Cisplatin is frequently used in HIPEC protocols due to its synergistic cytotoxic effect with hyperthermia. However, cisplatin-associated nephrotoxicity remains a significant dose-limiting factor with acute and chronic renal failure occurring in up to 18.6% and 7.0% of cases respectively. Various nephroprotective agents have been investigated as adjuncts to mitigate cisplatin-related renal injury. Sodium thiosulfate (STS) is currently favored as a nephroprotective agent during platinum-based HIPEC and has been included in several HIPEC protocols, though there is no randomized data confirming its efficacy. Additionally, concerns exist that STS may inhibit cisplatin cytotoxicity. This study aims to explore whether and at what extent the presence of STS nephroprotection neutralizes cisplatin’s cytotoxic activity in the treatment of PSM. Methods: To evaluate the inhibitory effect of STS on cisplatin, we used a Patient-Derived Organoid (PDO) model developed from colorectal peritoneal metastases (PM) sensitive to HIPEC treatment with cisplatin and mitomycin C (MMC). The PDO line was treated with cisplatin alone or in combination with MMC and with STS at sublethal concentrations. Assessment of anti-tumor therapeutic efficacy was measured by PDO viability (percentage of live PDOs) following treatment with STS. Results: Results confirm a significant dose-dependent inhibitory effect of STS on cisplatin anti-tumor effect of up to 35% when administered both alone and together with MMC. Conclusion: These results suggest that STS does in fact impair the cytotoxic activity of cisplatin in a PDO model, confirming a reduction of cisplatin-HIPEC anti-tumor efficacy when used in combination with the nephroprotective agent. Further research is required to determine whether alternative agents may provide similar nephroprotection without compromising oncologic impact. These results will inform recommendations to enhance the safety and efficacy of cisplatin-HIPEC. 

SUBMIT REVIEW

Session Electronic Posters 2A: 1300–1303- Dr. Abeline Watkins (PGY2) - Aortic Root Abscess in Infective Endocarditis: Prognostic Impact and Outcomes of Patch Repair

Presenter: Dr. Abeline Watkins

Watkins A, Kang N, Dean M, Auclair F, Boodhwani M, Lau L, Messika-Zeitoun D, Toeg H, Voisine P, Rubens F

Division of Cardiac Surgery

Clinical Research

Background: Infective endocarditis (IE) remains a major cause of morbidity and mortality in adults, with aortic root abscess raising perioperative mortality to nearly 25%. While abscess formation is an established indication for urgent surgery, its independent prognostic significance is uncertain. Surgical repair of root abscesses also remains a topic of debate, with guidelines recommending extensive debridement while emerging evidence suggests patch repair offers comparable perioperative outcomes. Given these discrepancies, further investigation is warranted to clarify surgical strategy for managing root abscesses in aortic valve (AV) IE. Methods: We completed a retrospective study of all patients at our institution who were surgically treated for AV IE from 2019 to 2024. We compared outcomes in patients with and without root abscess, and for those with abscesses, we compared patch repair to extended repair (abscess resection with reconstruction or root replacement). The primary outcome was major adverse cardiac and cerebrovascular events (MACCE) – a composite of all-cause death, heart failure (HF). Results: There were 158 patients (83 with root abscess, 68 without) identified as having surgically repaired AV IE. Root abscesses were associated with increased MACCE (adjusted HR 2.72, 95% CI 1.29-5.75, p=0.009) and HF readmission (sub-HR 3.62, 95% CI 1.24–10.58, p=0.019) independent of preop clinical status. In the abscess group, patch repair was associated with significantly decreased MACCE (adjusted HR 0.32, 95%CI 0.14-0.70, p=0.005) and all-cause mortality (p=0.004) as well as decreased 30-day mortality (35% vs 13%, p=0.022) compared to extended repair, irrespective of abscess size. Conclusions: Aortic root abscess demonstrated independently increased MACCE and HF readmissions compared to AV IE without abscess, supporting early surgical intervention of AV endocarditis prior to root abscess formation to prevent the morbidity and mortality associated with disease progression. Treating root abscess with patch repair appears safe and may improve perioperative mortality and MACCE, making it a viable option compared to extended repair in eligible patients. 

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Session Electronic Posters 2A: 1303–1306- Dr. Raahulan Rathagirishnan (PGY3) - Use of Partially Injured Donors in Nerve Transfer Surgery: A Subgroup Analysis

Presenter: Dr. Raahulan Rathagirishnan

Rathagirishnan R, Boyd K, McIntyre M, Wolff G. K.

Division of Plastic Surgery

Clinical Research

Purpose: The standard of care for nerve transfer surgery is to utilize donor nerves with full strength and optimal function to maximize successful outcomes in peripheral nerve injuries. However, in significant brachial plexus injuries where suitable full-strength donors are limited, the exploration of partially injured donor nerves warrants investigation. This study evaluates the role and efficacy of these donors in nerve transfer surgeries, addressing the current literature gap regarding their potential contributions to functional recovery. Method: A cohort analysis was performed on all nerve transfers conducted at a single institution from 2011 to 2025. Donor nerves with a Medical Research Council (MRC) grade less than 5 and/or abnormal electromyography (EMG) results were analyzed. Primary outcomes included the number of patients achieving MRC strength grades of 3 or greater and 4 or greater, the number of patients with no change in MRC grade, and the average change in MRC grade. Secondary outcomes assessed complications and donor function morbidity. Results: Among 484 peripheral nerve surgeries, preliminary data from 2020 to 2025 identified 21 transfers using downgraded donor nerves. The mean patient age was 52.6 years, with 80.9% male. Notably, 65% achieved MRC grade 3 or greater strength, while 63 % reached MRC 4 or greater. 10.5% percent exhibited no change in MRC grade. The average change of MRC was 1.75. One patient experienced donor nerve morbidity, and one had a deterioration of their initial condition. Conclusions: Preliminary findings suggest that partially injured donor nerves may provide functional improvement when optimal donor options are limited, highlighting their potential role in complex brachial plexus injuries.  

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Session Electronic Posters 2A: 1306–1309- Daniel Kurtz (Medical Student) - Machine Learning Classification of Patients with Degenerative Cervical Myelopathy into Clinically Relevant Clusters and Development of an Adoptable Clinical Algorithm

Presenter: Daniel Kurtz

Kurtz D, Phan P, Sun, C

Division of Orthopedic Surgery

Clinical Research

Introduction: Degenerative cervical myelopathy (DCM) affects thousands of Canadians yearly, often requiring surgery to minimize disability and suffering. Surgery leads to improved functional status and patient satisfaction, but the absence of reliable predictive tools leads to uncertainty in clinical decision making. Methods: Data was extracted from an ongoing, prospective national DCM observational cohort study. Relevant patient-related, clinical, and radiological variables were selected based on literature. An unsupervised K-prototypes machine learning (ML) model clustered patients into clinically meaningful phenotypes. The optimal number of clusters was determined with the elbow and silhouette methods, followed by clinician validation. Outcome measures of interest were compared using the Kruskal Wallis and Mann-Witney U tests. A Classification and Regression Tree (CART) model was developed to adapt the clustering model into a predictive clinical algorithm. Results: A total of 774 patients met inclusion criteria, with 15 features utilized. Baseline clinical, demographic, and radiographic findings were used to classify patients into four different subgroups with distinct feature means and clinical prognoses. Despite baseline differences, all clusters reported similar satisfaction with surgery. The CART model was comprised of three levels with eight leaf nodes. Three features, Age, SF-12 Mental Component Score, and SF-12 Physical Component Score contributed to the CART model from 17 initial features. The CART model attained an AUC score of 0.93 and an accuracy of 81.8% on the testing dataset, with comparable accuracy for all classes. Conclusions: Four clinically relevant subgroups with unique patient profiles and distinguishable outcomes were identified in the DCM patient cohort using the K-prototypes model. The CART algorithm accurately predicted all four classes using only three pre-surgical features. This clustering approach, coupled with the CART clinical algorithm, would allow physicians to provide personalized, nuanced care based on patient risk criteria and improve expectation counselling. 

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Session Electronic Posters 2A: 1309–1312- Dr. Abdulaziz Al-Daqqaq (PGY1) - Quantifying limitations of the Tuohy-Borst ureteroscope adapter and exploration of alternatives: a single-centre, multi-arm study.

Presenter: Dr. Abdulaziz Al-Daqqaq

Al-Daqqaq A, Ahmad I,  Almuaiqel M, Carrillo B, Elnakoury F, Farcas M, Habib K, Hamzeh A, Lee J, Parkhomenko E, Shaikh S

Division of Urology

Clinical Research

Introduction: Ureteroscope adapters are essential in ureteroscopy (URS) for maintaining irrigation pressure and facilitating instrument passage. The Tuohy-Borst adapter (TBA), widely used in Canadian practice, has been associated with jet-leaks, fluid contamination, and instrument damage. We aimed to compare the mechanical performance and ergonomic characteristics of commonly used ureteroscope adapters. Methods: A benchtop comparative study was conducted on seven adapters, including adjustable (TBA, BPS-A) and self-sealing designs (Check-Flo, Urolok, KSES, CS-B612, CS-G7). Three custom testing systems evaluated: (1) maximum pressure tolerance, (2) fluid leak during simulated laser fibre manipulation, and (3) force required for instrument advancement and withdrawal. Tests were performed in triplicate. One-way ANOVA was used for comparisons (p<0.05). Results: All adjustable adapters (TBA, BPS-A) and select self-sealing adapters (Check-Flo, Urolok) withstood pressures up to 1500 mmHg without instruments in situ, while reusable valves leaked at approximately 200 mmHg. The TBA required the highest force for instrument advancement (52.16g) and withdrawal (54.12g) (p<0.001), and demonstrated greater leak (0.757g) compared to BPS-A (0.600g, p=0.002) and substantially more than self-sealing adapters (≤0.052g, p<0.001). Self-sealing adapters (Check-Flo, Urolok) exhibited the lowest resistance and leak. Conclusions: Significant variability exists among ureteroscope adapters in sealing performance and ergonomics. While adjustable adapters allow instrument fixation, they are associated with increased resistance and leakage. Self-sealing designs offer superior sealing and lower manipulation forces. These findings support tailored adapter selection based on procedural priorities and highlight opportunities for device optimization.  

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Session Electronic Posters 2A: 1312–1315- Dr. Nardin Farag (PGY3) - Hospital-Free Days as a Patient-Centered Outcome after Liver Resection for Colorectal Liver Metastases

Presenter: Dr. Nardine Farag

Farag N, Abou-Khalil J, Balaa F, Bertens K, Gilbert R, Ivankovic V, Le Phu Tucker C, Martel G, McGuire C, Ramsay T, Schulz A

Division of General Surgery

Clinical Research

Background: Traditional oncologic outcomes provide limited insight into patient experience following liver resection for colorectal liver metastases (CRLM). Hospital-free days (HFDs), integrating inpatient and outpatient encounters, may better quantify treatment burden. We evaluated HFDs as a patient-centered outcome. Methods: Adult patients undergoing liver resection for CRLM at a Canadian tertiary center (2009–2023) were included. HFDs were defined as days alive and out of hospital from surgery to progression or last follow-up. Healthcare interaction (HI), measured in days, included all inpatient admissions, emergency visits, and outpatient encounters, over defined follow-up period.  Multivariable negative binomial regression identified factors associated with HI (inverse of HFDs). Results: Among 461 patients (mean age 62.3 years), median follow-up was 65 months. Node-positive disease, tumor size ≥5 cm, and number of liver metastases were associated with worse PFS (median 10.2 months [IQR 4.7–29.3]). Preoperative chemotherapy, node-positive disease, and RAS-mutant status were associated with worse OS (p < 0.05). On multivariate analysis, preoperative chemotherapy (IRR 1.64, 95% CI 1.34–2.00; p < 0.001), node-positive disease (IRR 1.22, 95% CI 1.00–1.48; p = 0.046), and tumor size ≥5 cm (IRR 1.27, 95% CI 1.01–1.61; p = 0.043) were associated with increased HI, whereas metachronous disease ≥12 months was protective (IRR 0.46, 95% CI 0.37–0.57; p < 0.001). In synchronous disease, preoperative chemotherapy remained associated with increased HI (IRR 1.92, 95% CI 1.42–2.57; p < 0.001). Conclusion: HFDs identify clinically meaningful differences in treatment burden beyond survival and should complement traditional endpoints in CRLM research.

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Session Electronic Posters 2A: 1315–1318- Dr. Nardin Farag (PGY3) - Adverse Neurovascular Events Associated with Complex Pelvic Sidewall Surgery: Single-Centre Retrospective Observational Analysis

Presenter: Dr. Nardin Farag

Farag N, Apte S, Bilkhu A, Hickey K, Kabani H, Lavallée L, Nyarko K, Sinasac S

Division of General Surgery

Clinical Research

Background: Pelvic sidewall surgery (PSWS) for locally advanced pelvic malignancy is high-risk and technically challenging. Understanding its neurovascular complication profile is critical to balance oncologic benefit against long-term morbidity. This study quantifies and characterizes major postoperative neurovascular events in a Canadian tertiary center to inform surgical decision-making, prevention strategies, and patient counselling. Methods: Adult patients undergoing pelvic lymph node dissection alone (PLND) or curative-intent major PSWS (vascular/muscular resection or neural dissection) at The Ottawa Hospital (2022–2025) were reviewed. Predictors of 90-day neurovascular and overall complications were assessed. Results: Among 84 patients, 65 (77.4%) underwent PLND and 19 (22.6%) major PSWS. Mean age was 63.5 ± 11.7 years; 42 (50.0%) were male. Major PSWS was significantly more performed for tumor recurrence than PLND (47.4% vs 4.6%, p<0.001). On univariable analysis, major PSWS was associated with multispecialty involvement, any transfusion, estimated blood loss ≥500 cc, and longer operative time (p<0.001). Overall, 49/84 (58.3%) patients experienced complications; all major PSWS patients had ≥1 complication (Clavien–Dindo ≥1). Major complications (≥3a) occurred in 21/84 (25.0%). Neurovascular events occurred in 15/84 (17.9%): neuropathy (9), venous thromboembolism (4), acute limb ischemia (3), and major bleeding (3). Major PSWS had higher neurovascular (42.1% vs 10.8%, p=0.004) and major complication rates (57.9% vs 15.4%, p<0.001). Within 90 days, 19 patients required readmission and two died (disease progression and postoperative respiratory failure). Multivariable analysis was not feasible due to low event rates. Conclusion: Despite positive oncologic outcomes for well-selected patients, neurovascular complications are an important consideration of major PSWS. Targeted pathways for thromboprophylaxis and postoperative limb monitoring are critical and should be considered in this setting.

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Session Electronic Posters 2B: 1300–1303-  Dr. Mohamad Bakhaidar (Fellow) - Suture-Crossing Ossified Cephalohematoma: A Systematic Review of the Current Literature and Proposal of a New Classification Subtype

Presenter: Dr. Mohamad Bakhaidar

Bakhaidar M, Abdulraham S, Aljohani O, Babgi M, Bamsallm M, Haq H, Perez Rodriguez Garcia G

Division of Neurosurgery

Clinical Research

Background: Cephalohematoma is a subperiosteal hemorrhage of the skull typically confined by cranial suture lines. While most cases resolve spontaneously, persistent lesions may ossify, leading to cosmetic deformity and potential need for intervention. Existing classification systems, including the widely cited Wong classification, categorize ossified cephalohematomas (OC) based on inner table morphology but do not account for lesions that cross cranial sutures. This study aims to systematically review the literature on OC, characterize suture-crossing variants, and propose a modified classification system and management algorithm. Methods: A systematic review was conducted in accordance with PRISMA guidelines using PubMed, Scopus, Web of Science, Cochrane, and Google Scholar databases. Studies reporting ossified cephalohematoma were included. Data extraction included patient demographics, lesion characteristics, suture involvement, presence of craniosynostosis, management strategies, and outcomes. Cases were analyzed and categorized, with particular focus on lesions crossing cranial sutures. Results: A total of 33 studies comprising 90 patients (including the present case) were included. The mean age at presentation was 12 months, with the majority presenting in infancy. Suture-crossing OCs were identified in 13.3% of cases and were strongly associated with craniosynostosis, often requiring surgical intervention with suturectomy. Across the literature, surgical management was the most common approach, demonstrating high rates of deformity resolution. Conclusion: Suture-crossing ossified cephalohematomas represent a distinct clinical entity not captured in existing classification systems. We propose a third subtype to address this gap, which may carry unique associations with craniosynostosis and require tailored management strategies. Early recognition of this pattern is essential for appropriate surgical planning and improved clinical outcomes.

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Session Electronic Posters 2B: 1303–1306- Dr. Mohamad Bakhaidar (Fellow) - Biomechanical Analysis of Long-Segment Cervical Spine Stabilization: Finite Element Analysis of Pedicle, Pars, Translaminar and Hybrid Screw Fixation Models

Presenter: Dr. Mohamad Bakhaidar

Bakhaidar M, Devaraj K, Ghamasaee P, Harinathan B, Shabani S, Shahbandi A, Yassin Kassab A. M, Yoganandan N

Division of Neurosurgery

Clinical Research

Introduction: Screw placement in the C2 vertebra plays a pivotal role in providing a robust anchor point for cervical fusion. This study aimed to evaluate the biomechanical performance of pars, pedicle, and translaminar screw techniques, alongside various hybrid constructs using finite element (FE) analysis. Methods: A validated FE model of the C2-T1 vertebrae was employed, with lateral mass screws from C3 to C6, and a pedicle screw for T1 vertebra to simulate posterior cervical fusion. A physiological loading condition was simulated by applying a 2 Nm force across all scenarios. The range of motion (ROM) and rod stress were compared among pedicle, pars, and translaminar screw fixation. Additionally, the performance of various hybrid constructs was assessed. Results: In flexion, pars screws exhibited 38.5% increase in motion compared to pedicle screws and a 65.5% increase compared to translaminar screws. In extension, pars screws showed a 36.1% increase in motion versus pedicle screws and 72.9% versus translaminar screws. In lateral bending, translaminar screws presented a 8.9-fold greater motion compared to pedicle screws and nearly doubled the ROM in axial rotation. Translaminar screws exhibited an increase in rod stress (19%) compared to pedicle screws. Among the hybrid constructs, the bilateral pedicle-bilateral translaminar (BiPed-BiTrans) construct demonstrated the least ROM in flexion, rendering it the stiffest. In contrast, the unilateral pedicle-unilateral translaminar model exhibited the least stability in flexion, with 2.2 times greater ROM versus the Biped-BiTrans construct. Conclusion: Translaminar screws provided robust fixation in a C2-T1 construct during flexion and extension but were inferior to pars and pedicle screws in axial rotation and lateral bending and associated with greater rod stress. The Biped-BiTrans construct was the most rigid hybrid construct, demonstrating the smallest ROM in flexion.

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Session Electronic Posters 2B: 1306–1309- Dr. Hannah Koury (PGY4) - Incidence of delirium on an academic vascular surgery inpatient ward in Ontario, Canada: a retrospective cohort study

Presenter: Dr. Hannah Koury

Koury H F., Kubelik D, Roberts D, Thompson K

Division of Vascular Surgery

Quality Improvement

Introduction: Delirium is an acute, fluctuating disturbance in attention and cognition associated with significant morbidity and mortality. It is identified through validated tools like the Confusion Assessment Method (CAM). The incidence and outcomes of delirium in vascular surgery patients have not been studied. Methods: We conducted a retrospective cohort study of patients who screened and did not screen positive for delirium using the CAM after admission to the vascular surgery inpatient ward between June 1, 2024-June 29, 2025 at The Ottawa Hospital in Ottawa, Ontario. Primary outcomes were length of stay, in-hospital mortality, and discharge disposition.  Results: In total, 33 patients during the study period screened positive for delirium (cumulative incidence=8%). Most delirium developed postoperatively, with a median onset of 4 days after vascular surgery (IQR 3-6.5 days). Delirium was observed after a range of procedures, most commonly major amputation and infrainguinal bypass. Most patients rated 2/10 on a pain scale after screening positive for delirium (IQR 0-6.5). Duration of catheter use was on average 1 day in delirious patients (IQR 0-6 days). Median length of stay was significantly longer in patients who developed delirium (15.7 days [IQR 8.9-36.1 days] versus those that did not (9 days [IQR 4-20]; p = 0.0036). Those that developed delirium were also more likely to require discharge to an alternate location (43.5% vs 18%; p=0.042, OR=3.50, 95%. CI:1.17-10.48) and to die in-hospital (30.3% vs 2%; p = 0.0003, OR=21.7,95% CI: 2.62-180.1). Conclusions: Delirium is common among vascular surgery inpatients and associated with prolonged hospitalization, increased mortality, and higher likelihood of non-home discharge. These findings align with existing literature and establish baseline data to inform targeted quality improvement initiatives in this population.

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Session Electronic Posters 2B: 1309–1312- Dr. Ramana Trivedi (PGY5) - Cardiac Modulation of Neural Signals in the Subthalamic Nucleus

Presenter: Dr. Ramana Trivedi

Trivedi A, Pogosyan A, Tan H

Division of Neurosurgery

Clinical Research

Introduction: Neural stimulation is known to directly influence cardiac parameters; conversely, cardiac activity has also been shown to modulate neural activity. However, there is a dearth of subcortical recordings directly examining this phenomenon. Deep brain stimulation (DBS) may provide evidence in this area. In addition to delivering stimulation, DBS electrodes are used to record local field potentials. In this experiment, we seek to analyze cardiac modulation of neural signals recorded from the subthalamic nucleus (STN) in patients with Parkinson’s disease. Methods: Eligible patients underwent bilateral placement of STN DBS. Following placement, with the leads externalized, EEG and ECG leads were placed. Recordings were performed with patients at rest, with and without single stimulation pulses. Recordings involved rest recordings, as well as recordings with single and paired stimulation pulse delivery. This paradigm was carried out in the ON- and OFF- medication states. Results: Beta power was significantly modulated by time from QRS peak with a trough before the QRS and a peak afterwards. Additionally, there was a significantly greater difference between pre-QRS and post-QRS ERNA amplitudes in the OFF-condition as compared to the ON-condition. Finally, pre-stimulation beta power and ERNA amplitude demonstrated a negative correlation in the OFF-condition, and a positive correlation in the ON-condition. Conclusion: This study identified significant cardiac modulation of local neural signals in the STN, most notably ERNA and beta activity. This modulation was biphasic in nature and appeared broadly attenuated by the administration of medication. The exact mechanism underpinning this finding is unclear. Given the correlational nature of this data, any validation of the underlying mechanism will require further interventional experimental paradigms.

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Session Electronic Posters 2B: 1312–1315- Dr. Emili Gubskaya (PGY2) - The Impact of Exposure to Opioid Agonist Treatment on Depression and Anxiety Among People who use Drugs

Presenter: Dr. Emili Gubskaya

Gubskaya E, Choi J, Hayashi K, Kerr T, Milloy MJ, Thylmann G

Division of General Surgery

Clinical Research

Introduction: Opioid agonist treatment (OAT) is a key response to the North American opioid overdose epidemic. While people who use drugs (PWUD) are known to suffer from high rates of comorbid mental illness, the impact of OAT on mental health outcomes has not been well characterized. We sought to examine the impact of OAT on measures of depression and anxiety among PWUD. Methods: Data were derived from two longitudinal cohort studies of PWUD in Vancouver, Canada. The sample was restricted to individuals with at least three follow-up visits, a baseline depression score of >22 as measured by the Centre for Epidemiological Studies Depression Scale, and to those who were enrolled in OAT or reported at least weekly opioid use. The primary outcomes were clinically significant levels of depression and anxiety, as measured by the PROMIS scales. Multivariable generalized estimating equation (GEE) analyses were conducted to explore potential associations between enrollment in OAT, depression and anxiety. Results: Between December 1, 2016 and May 31, 2023, 910 PWUD were eligible for the study. In a multivariable analysis, while no association was found between OAT engagement and anxiety (Adjusted Odds Ratio [AOR] = 0.98, 95% Confidence Interval [CI]: (0.81 – 1.08), engagement in OAT was negatively associated with depression (AOR = 0.73, 95% CI: 0.62 – 0.86). Conclusion: In this longitudinal study engagement in OAT was associated with lower depression scores but had no association with anxiety. While the findings regarding depression are consistent with the known impacts of substance use treatment, future research should examine why anxiety measures did not improve, and strategies that can treat anxiety disorders in this population should be investigated.

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Session Podium 3: 1335–1345 - Dr. Yuan Qiu (PGY4) - Intra-institutional use of positive deviancy in surgical infections in isolated coronary bypass

Presenter: Dr. Yuan Qiu

Qiu Y, Dean M, Lajeunesse J, Taljaard M, Neilipovitz K, Charlebois A, Hogan C, Al-Atassi T, Boodhwani M, Guo M, Issa H, Lam BK, Masters R, Ruel M, Toeg H, Voisine P, Rubens F

Division of Cardiac Surgery

Quality Improvement

Introduction: Surgical site infections (SSIs) after cardiac surgery remain a significant cause of morbidity and mortality despite advances in perioperative care. Traditional quality improvement approaches focus on deficiencies rather than identifying practices from exceptional performers. This study aimed to use positive deviancy methodology was to identify surgeons with superior SSI rates following isolated coronary artery bypass grafting (CABG) and characterize their protective surgical practices. Methods: This retrospective analysis of prospective collected data included 3,087 patients undergoing isolated CABG at a single tertiary cardiac surgery center from Jan 2021–Mar 2025. Primary outcome was total sternal wound infection within 30 days. Risk-adjusted surgeon performance was evaluated using mixed-effects logistic regression. Positive deviants were defined as surgeons with observed-to-expected (O/E) ratios <1.0 with 95% confidence intervals (CIs) excluding unity. Surgical techniques were systematically reviewed through anonymized surveys. Results: A total of 3,087 consecutive patients undergoing isolated CABG were included, and total sternal wound infection occurred in 175 patients (5.7%). Nine surgeons were stratified to: better performers (O/E <1.0, n=5), worse performers (O/E ≥1.2, n=3), and average performers (O/E 1.0–1.19, n=1). One surgeon achieved statistically significant superior performance (O/E=0.590, 95% CI: 0.39–0.91), representing 41% fewer SSIs than expected across 543 cases. Wound irrigation at closure (100% vs. 0%), double skin preparation with chlorhexidine and providone (100% vs. 0%), superior Ioban adherence quality (5/5 vs. 3.7/5 vs. 3.2/5, p<0.001), and minimal cautery usage (1/5 vs. 3.2/5 vs. 3.5/5, p<0.001) were identified as protective techniques to minimize SSIs after isolated CABG. Conclusions: Positive deviancy methodology successfully identified four modifiable surgical practices associated with reduced total SSIs. These represent immediately implementable interventions for infection prevention in cardiac surgery. Future studies to validate these findings across multiple institutions and evaluate outcomes are needed.  

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Session Podium 3: 1345–1355 - Dr. Catherine Binda (PGY2) - Paediatric general surgery virtual versus in person clinical assessments: Patient satisfaction and the cost of accessing care

Presenter: Dr. Catherine Binda

Binda C, Eamer G, Wiebe M

Division of General Surgery

Quality Improvement

Background: Virtual care and telemedicine have become increasingly popular in the wake of the COVID-19 pandemic. We aim to compare patient satisfaction and costs incurred between in-person and virtual clinical encounters for patients presenting for consultation and follow-up of common paediatric surgical diseases at an academic centre with a broad catchment area.  Methods: Children and caregivers were invited to participate in an electronic survey capturing patient satisfaction using the Perceived Quality of Medical Care (PQMC) questionnaire and reported costs incurred during their encounter. Basic demographic data were extracted through chart review. Hourly wages were estimated using the median employment income for the nearest Census Metropolitan Areas reported by Statistics Canada. Descriptive statistics and comparative statistics, including Shapiro-Wilk normality tests and the Mann-Whitney U Test, were used to assess differences in patient satisfaction and total costs between virtual and in-person encounters. Results: Between July 2023 and December 2024, 18 children and 112 caregivers completed 65 surveys of in-person and 65 surveys of virtual clinical encounters. The Perceived Quality of Medical Care (PQMC) scores for the in-person (36.4; SD=5.6) and virtual groups (37.9; SD=5.6) were not statistically different (p=0.20). The total out-of-pocket cost of in-person ($239.72; SD=$527.42) and virtual ($73.64; SD=$126.55) clinical encounters were statistically different (p<0.05). Conclusion: Given we found no significant difference in patient satisfaction but did find a significant difference in the out-of-pocket costs associated with virtual and in-person clinical encounters, virtual encounters should continue to be offered to our paediatric surgical patients.

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Session Podium 3: 1355–1405 - Alexis Mah (Medical Student) - Comparing implant exchange and autologous conversion after immediate implant-based breast reconstruction: A retrospective cohort study

Presenter: Alexis Mah

Mah A, Diffey I, Ranjbar D, Zhang J

Division of Plastic Surgery

Clinical Research

Introduction: Immediate breast reconstruction contributes to comprehensive breast cancer care. Many patients who undergo implant-based breast reconstruction (IBR) will subsequently undergo revision, including implant exchange or autologous conversion to optimize breast stability and patient satisfaction. We aimed to compare complication rates, BREAST-Q scores, and decision-making factors for each revision type. Methods: We conducted a retrospective chart review comparing patients who underwent autologous revision versus implant exchange following immediate IBR at our centre from January 2011 to January 2026. Fisher’s exact and two-sided t-tests were used to compare categorical and continuous variables, respectively. Results: Compared to implant exchange patients (n=20), autologous revision patients (n=19) demonstrated no significant difference in overall complication rate (OR 1.66, 95% CI [0.40, 7.18]) (p=0.53), significantly higher contour deformity rates (OR 10.46, 95% CI [1.12, 523.51]) (p=0.02), greater satisfaction with surgeon (MD 25.57, 95% CI [0.83, 50.31]) (p=0.04), greater satisfaction with information at 3 months (MD 20.36, 95% CI [2.87, 37.85]) (p=0.03) and 12 months (MD 27.08, 95% CI [3.84, 50.32]) (p=0.03), and non-significant trends towards greater satisfaction with breasts (MD 22.49, 95% CI [-3.86, 48.84]) (p=0.09) and satisfaction with outcome (MD 28.55, 95% CI [-3.98, 61.08]) (p=0.08). Decision-making factors for autologous revision included desire to avoid capsular contracture, implant-associated pain and asymmetry. Decision-making factors for implant exchange were symmetry optimization, implant size change and poor candidacy for autologous conversion. Conclusions: We found differences in determinants and outcomes between revision procedures. Autologous revision patients often aimed to avoid implant-related complications. Aesthetic refinement and poor candidacy for autologous revision commonly influenced those who underwent implant exchange. Prospective studies can investigate these relationships to strengthen and improve clinical application of these results.

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Session Podium 3: 1405–1415 - Dr. Anood Alqaydi (PGY7) - Patterns and Variability in Perioperative Management of Esophageal Cancer Across High‑Volume Canadian Centers

Presenter: Dr. Anood Alqaydi

Alqaydi A, Jones D

Division of Thoracic Surgery

Quality Improvement

Background: Esophageal cancer remains a leading cause of cancer-related mortality worldwide, with rising incidence of adenocarcinoma in Western populations. For patients with locally advanced, non-metastatic disease, multimodal therapy including surgery is standard; however, perioperative management varies widely across institutions. Limited data exist describing national practice patterns within high-volume Canadian centers. Objectives: To characterize the commonality and variation in perioperative care pathways—including preoperative, intraoperative, and postoperative management among esophageal cancer surgeons across Canada, and to identify opportunities for standardization and quality improvement. Methods: We conducted a cross-sectional survey of thoracic surgeons involved in esophageal cancer care across 36 centers in 9 Canadian provinces. The questionnaire was focused on management of distal esophageal and gastroesophageal junction adenocarcinoma. Data collected include surgeon demographics, institutional characteristics, patient flow pathways, staging and treatment algorithms, operative techniques, and postoperative care practices. Comparative analyses will explore associations between practice patterns and variables such as surgeon experience, center volume, and practice type. Results: We anticipate identifying both substantial commonality in core perioperative practices and meaningful variation in key areas such as surgical approach, lymphadenectomy, perioperative optimization, and postoperative surveillance. These findings are expected to highlight gaps in standardization and inform priorities for future research. Conclusions: This national survey will provide the first comprehensive overview of perioperative esophageal cancer management across high-volume Canadian centers. By identifying areas of consensus and variation, this study aims to support the development of targeted quality improvement initiatives and inform future pragmatic clinical trials to optimize patient outcomes.

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Session Podium 3: 1415–1425 - Dr. Yaz Qaoud (PGY3) - The WASHOUT Study: Workup and Management of Patients with Emergency Hematuria Across the World

Presenter: Dr. Yaz Qaoud

Qaoud Y, Ahmayda A, Asif A, Bhatt R N, Byrnes K, Chow B, Cresswell J, Gallagher K, Green J,  Ippoliti S, Ireland A, Kasivisvanathan V, Kerdegari N, Khadhouri S,  Lavallée T. L, MacLennan G, Madhavan K, Mak Q, Nathan A, Nichols M, Ng A, Phonde A, Saemah P B, Varma R

Division of Urology

Clinical Research

Introduction: Gross hematuria accounts for 15% of urological emergency admissions, yet evidence-based management guidelines are lacking, resulting in wide variation in care. The WASHOUT study aimed to characterize international management practices and examine how variation in care may influence outcomes. Methods: A prospective international multicenter study including patients >16 years of age admitted with gross hematuria was initiated using the BURST collaborative model. Traumatic hematuria and admissions <24 hours in duration were excluded. The primary outcome was length of stay (LoS); secondary outcomes were mortality and readmission at 90 days. Analyses included covariate-adjusted Poisson regression for LoS and logistic regression for mortality and readmission. Results: 8,500 patients at 382 centers were included over one year. Median LoS was 4 days (IQR 2–8), 90-day mortality of 10.59% and readmission was 15%. At presentation, 5% of patients were hemodynamically unstable, 5% septic, 11% required high-dependency care, and 21% required transfusion. Conservative ward-based management was successful in 35% of cases. 53% of patients received imaging evaluation, and 35% received procedural intervention during admission. Median time to determine the cause of hematuria was 1 day (0–2) during admission and 21 days (10–41) for patients evaluated as outpatients. 25% of patients had malignancy,(12.5% pre-existing, 12.5% newly diagnosed), with an additional 5% diagnosed during follow-up. Urothelial carcinoma accounted for 77% of the malignancies identified during admission.Patients with >2 days to definitive management had a 5.6-day longer LoS, 2.5% greater probability of 90-day mortality, and 3.1% higher readmission risk. Frailty, sepsis, upper tract obstruction, lack of imaging, and underlying malignancy were also associated with longer LoS and higher mortality. Prior radiotherapy, antiplatelet or anticoagulant therapy, absence of prior hospital admissions, and longer initial hospital stays were associated with higher 90-day readmission rates. Conclusions: WASHOUT is the largest prospective international multicentre study of emergency hematuria admissions. Emergency hematuria is associated with substantial morbidity, high readmission rates, and a significant malignancy burden. Delays in imaging and definitive management were associated with worse outcomes, highlighting the need for standardized management guidelines.

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