Dr. Nassar is a board certified General Surgeon in both the USA and Canada. Dr. Nassar has five years of clinical experience in tertiary care referral academic health-centres in Canada prior to joining Stanford University in surgery, trauma and critical care. His clinical interests are emergency and elective surgery in addition to trauma and critical care medicine. He is also a skilled endoscopist performing both upper and lower gastrointestinal endoscopy. His research interests are varied and include the development of assessment tools for trainees, burnout among physicians and other healthcare professionals. In addition he is especially interested in training trainees in simulation based medical education with a focus on perioperative inter-professional collaboration and patient safety. He is a true clinician educator and is a certified simulation educator as well as an ATLS course director. Dr. Nassar has also earned an MSc degree in Health Science Education from McMaster University, Canada.

Clinical Focus

  • General Surgery
  • Acute Care Surgery
  • Trauma
  • Critical Care
  • Hernia
  • Abdominal wall reconstruction
  • EGD and Colonoscopy

Academic Appointments

Administrative Appointments

  • Program Director, Surgical Critical Care fellowship, Stanford University (2019 - Present)
  • Director, Surgery Coaching Program, Stanford Healthcare (2019 - Present)
  • Unit Medical Director, Trauma K7 ward, Stanford Healthcare (2019 - Present)
  • Associate Program Director, Surgical Critical Care, Stanford University (2018 - 2019)

Honors & Awards

  • Staff Award for Outstanding Contribution as Relationship-centered Communication Leader, Stanford Healthcare (2019)

Professional Education

  • Fellowship:McMaster University Michael G DeGroote School of Medicine Registrar (2012) Canada
  • Residency:McMaster University Michael G DeGroote School of Medicine Registrar (2011) Canada
  • Board Certification: General Surgery, American Board of Surgery (2011)
  • MSc, McMaster University, Hamilton, ON, Canada, Health Science Education (2015)
  • Board Certification: Critical Care Medicine, Royal College of Physicians and Surgeons of Canada (2012)
  • Board Certification, American Board of Surgery, General Surgery (2011)
  • Board Certification: General Surgery, Royal College of Physicians and Surgeons of Canada (2011)
  • O-IMG Clerkship, McMaster University, Hamilton, ON, Canada, Clerkship Undergraduate program (2006)
  • Medical Education:University of Al-Mustansiriyah College of Medicine (1995) Iraq


All Publications

  • Bedside Optic Nerve Ultrasonography for Diagnosing Increased Intracranial Pressure: A Systematic Review and Meta-analysis. Annals of internal medicine Koziarz, A., Sne, N., Kegel, F., Nath, S., Badhiwala, J. H., Nassiri, F., Mansouri, A., Yang, K., Zhou, Q., Rice, T., Faidi, S., Passos, E., Healey, A., Banfield, L., Mensour, M., Kirkpatrick, A. W., Nassar, A., Fehlings, M. G., Hawryluk, G. W., Almenawer, S. A. 2019


    Background: Optic nerve ultrasonography (optic nerve sheath diameter sonography) has been proposed as a noninvasive, quick method for diagnosing increased intracranial pressure.Purpose: To examine the accuracy of optic nerve ultrasonography for diagnosing increased intracranial pressure in children and adults.Data Sources: 13 databases from inception through May 2019, reference lists, and meeting proceedings.Study Selection: Prospective optic nerve ultrasonography diagnostic accuracy studies, published in any language, involving any age group or reference standard.Data Extraction: 3 reviewers independently abstracted data and performed quality assessment.Data Synthesis: Of 71 eligible studies involving 4551 patients, 61 included adults, and 35 were rated as having low risk of bias. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of optic nerve ultrasonography in patients with traumatic brain injury were 97% (95% CI, 92% to 99%), 86% (CI, 74% to 93%), 6.93 (CI, 3.55 to 13.54), and 0.04 (CI, 0.02 to 0.10), respectively. Respective estimates in patients with nontraumatic brain injury were 92% (CI, 86% to 96%), 86% (CI, 77% to 92%), 6.39 (CI, 3.77 to 10.84), and 0.09 (CI, 0.05 to 0.17). Accuracy estimates were similar among studies stratified by patient age, operator specialty and training level, reference standard, sonographer blinding status, and cutoff value. The optimal cutoff for optic nerve sheath dilatation on ultrasonography was 5.0 mm.Limitation: Small studies, imprecise summary estimates, possible publication bias, and no evaluation of effect on clinical outcomes.Conclusion: Optic nerve ultrasonography can help diagnose increased intracranial pressure. A normal sheath diameter measurement has high sensitivity and a low negative likelihood ratio that may rule out increased intracranial pressure, whereas an elevated measurement, characterized by a high specificity and positive likelihood ratio, may indicate increased intracranial pressure and the need for additional confirmatory tests.Primary Funding Source: None. (PROSPERO: CRD42017055485).

    View details for DOI 10.7326/M19-0812

    View details for PubMedID 31739316

  • Motivators and Stressors for Canadian Research Coordinators in Critical Care: The MOTIVATE Survey. American journal of critical care : an official publication, American Association of Critical-Care Nurses McDonald, E., Zytaruk, N., Heels-Ansdell, D., Smith, O., Borges, D., Hand, L., Clarke, F., Nassar, A., Bennardo, M., Cook, D., Canadian Critical Care Research Coordinators Group 2020; 29 (1): 41?48


    BACKGROUND: Critical care research coordinators implement study protocols in intensive care units, yet little is known about their experiences.OBJECTIVE: To identify the responsibilities, stressors, motivators, and job satisfaction of critical care research coordinators in Canada.METHODS: Responses to a self-administered survey were collected in order to identify and understand factors that motivate and stress research coordinators and enhance their job satisfaction. Items were generated in 5 domains (demographics, job responsibilities, stressors, motivators, and satisfaction). Face validity pretesting was conducted and clinical sensibility was evaluated. Items were rated on 5-point Likert scales. Descriptive analyses were used to report results.RESULTS: The response rate was 78% (66 of 85). Most critical care research coordinators (71%) were employed full time; they were engaged in 9 studies (7 academic, 2 industry); and 49% were nurses. Of 30 work responsibilities, the most frequently cited were submitting ethics applications (89%), performing data entry (89%), and attending meetings (87%). Highest-rated stressors were unrealistic workload and weekend/holiday screening; highest-rated motivators were a positive work environment and team spirit. Overall, 26% were "very satisfied" and 53% were "satisfied" with their jobs.CONCLUSIONS: Critical care research coordinators in Canada indicate that, despite significant work responsibilities, they are satisfied with their jobs thanks to positive work environments and team spirit.

    View details for DOI 10.4037/ajcc2020627

    View details for PubMedID 31968081

  • Academic Clinicians' Workload Challenges and Burnout Analysis CUREUS Nassar, A. K., Waheed, A., Tuma, F. 2019; 11 (11)
  • Developing an Inpatient Relationship-Centered Communication Curriculum for Surgical Teams: Pilot Study Nassar, A., Weimer-Elder, B., Kline, M., Minthorn, C., Staudenmayer, K. L., Yang, R., Spain, D. A., Maggio, P., Korndorffer, J. R., Johnson, T. ELSEVIER SCIENCE INC. 2019: E48
  • Academic Clinicians' Workload Challenges and Burnout Analysis. Cureus Nassar, A. K., Waheed, A., Tuma, F. 2019; 11 (11): e6108


    Academic clinicians have high expectations to meet in their academic institutions. Accomplishments are to be expected in multiple domains for their positions' sustainability and promotions. In addition to excelling in their clinical practice, they are expected to maintain productive scholarly activities and meet the required educational and administrative responsibilities. Striking a balance between clinical, educational, research, and administrative duties is highly challenging and could lead to emotional exhaustion and burnout. Lately, the ever-growing patient population, competitive academic environment, and resident work hour restrictions have led to increased strain and demand on academic physicians and predisposing them to burnout. Despite the numerous studies looking at burnout in various professions, fewer studies have looked at burnout, specifically in clinical faculty members. Little is known about academic job satisfaction, stress, and rates of burnout, or how these factors affect scholarly success and productivity. Clinician faculty educators may be at significant risk of burnout. There is some evidence that clinically burned-out faculty had less confidence in their teaching skills and had fewer life-long learning habits. These results suggest that burnout may influence not only the quality of care but also the quality of training provided to others.

    View details for DOI 10.7759/cureus.6108

    View details for PubMedID 31886048

    View details for PubMedCentralID PMC6901369

  • The MacTRAUMA TTL Assessment Tool: Developing a Novel Tool for Assessing Performance of Trauma Trainees: Initial Reliability Testing Journal of Surgical Education Nassar, A., Coates , A., Tuma, F., Farrokhyar, F., Reid, S. 2016
  • Burnout Among Academic Surgeons Canadian Surgery Forum Nassar, A. K., Reid, S., Kahnamoui, K., McConnell, M. 2015: S177

    View details for DOI 10.1503/cjs.008615

  • A novel use of high fidelity simulation to test inter-rater reliability of a TTL assessment tool Simulation Summit Reid, S., Coates, A., Nassar, A., Farrokhyar, F., Tuma, F., Bhandari, M., Faidi, S. Royal College of Physicians and Surgeons of Canada. 2014: 56
  • BURNOUT AMONG CRITICAL CARE WORKERS Canadian Critical Care Forum Nassar, A., Meade, M., Reid, S., Kahnamoui, K., Karachi, T., Sawchuk, C., Cook, D. Canadian Critical Care Forum. 2014
  • MOTIVATORS AND STRESSORS FOR CANADIAN RESEARCH COORDINATORS IN CRITICAL CARE: THE MOTIVATE SURVEY Canadian Critical Care Forum McDonald, E., Zytaruk, N., Borges, D., Bennardo, M., Clarke, F., Heels-Ansdell, D., Hand, L., Meade, M., Nassar, A., Cook, D. Canadian Critical Care Forum. 2014
  • Developing a tool to evaluate trauma team leader performance: initial reliability testing. The Trauma Association of Canada Annual Scientific Meeting Reid, S., Coates, A., Nassar, A., Farrokhyar, F., Tuma, F., Faidi, S. 2014: S76
  • The mactrauma TTL assessment tool: developing a novel tool for assessing performance of trauma trainees Trauma Association of Canada Reid, S., Coates, C., Nassar, A., Tuma, F., Farrokhyar, F., Faidi, S. 2013: S13
  • The Effect of General Surgery Clerkship Rotation on the Attitude of Medical Students Towards General Surgery as a Future Career JOURNAL OF SURGICAL EDUCATION Al-Heeti, K. N., Nassar, A. K., DeCorby, K., Winch, J., Reid, S. 2012; 69 (4): 544-549


    Literature suggests declining interest in General Surgery (GS) and other surgical specialties, with fewer Canadian medical residency applicants identifying a surgical specialty as their first choice. Although perceptions of surgical careers may begin before enrollment in clerkship, clerkship itself provides the most concentrated environment for perceptions to evolve. Most students develop perceptions about specialties during their clinical clerkships. This study examines the immediate impact of GS clerkship on student attitudes toward GS as a career, and on preferences towards GS compared with other specialties.A pre-post design involved 61 McMaster clinical clerks. Two instruments were used to collect data from students over the course of clerkship (2008-2009). Paired comparison (PC) compared ranking of career choices before and after clerkship. Semantic differential (SD) measured attitudes toward GS and variables that may have affected attitudes before and after clerkship. Analyses used SPSS 16.0 (SPSS Inc., Chicago, IL).Clerks ranked preferences for GS changed substantially after clerkship, moving from the 10th to the 5th position compared with other specialties. Ranks of surgical subspecialties also changed, though GS demonstrated the largest improvement. SD results were consistent with PC, showing improved attitudes after rotation, with differences both statistically and practically significant (t = 3.81, p < 0.000, effect size = 0.23). Results indicated that attitudes toward all areas related to GS clerkship (attending physicians, surgical residents, ward nurses, scrub nurses, workload, knowledge achieved, technical skills acquired) improved significantly except attitude toward technical skills acquired.Clinical clerkship at McMaster was a positive experience and significantly enhanced preferences towards GS and attitudes towards GS as a career. Medical schools should foster positive interaction between clinical clerks and staff (including attending surgeons and nurses), ensure that teaching hospital staff provide a positive experience for clerks, and should provide opportunities to learn basic technical skills during GS clerkship.

    View details for DOI 10.1016/j.jsurg.2012.04.005

    View details for Web of Science ID 000305366200018

    View details for PubMedID 22677595

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