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: American Board of Surgery, General Surgery (2011)
  • MSc, McMaster University, Hamilton, ON, Canada, Health Science Education (2015)
  • Board Certification: Royal College of Physicians and Surgeons of Canada, Critical Care Medicine (2012)
  • Board Certification, American Board of Surgery, General Surgery (2011)
  • Board Certification: Royal College of Physicians and Surgeons of Canada, General Surgery (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

  • Burnout among Academic Clinicians as It Correlates with Workload and Demographic Variables. Behavioral sciences (Basel, Switzerland) Nassar, A. K., Reid, S., Kahnamoui, K., Tuma, F., Waheed, A., McConnell, M. 2020; 10 (6)


    Burnout syndrome (BOS) in academic physicians is a psychological state resulting from prolonged exposure to job stressors. It leads to a decline in overall job performance, which could result in misjudgment and serious clinical errors. The current study identifies the prevalence, as well as the potential demographic and workload variables that contribute significantly to BOS in academic clinicians. We distributed a modified version of the Maslach Burnout Inventory (MBI) scale to the academic clinicians in our institution; 326/900 responded, with 56.21% male and 43.46% female. The MBI scale comprised of three dimensions of burnout: emotional exhaustion (EE), depersonalization (DP), and personal accomplishment (PA). Higher scores in EE and DP and lower scores in PA were associated with a higher risk for burnout. In considering the work-life of academic clinicians, this study used a modified version of the MBI to reflect three hypothesized sources of burnout: interactions with students/trainees, interactions with patients, and interactions with administration, as reflected in these three dimensions. Along both the EE and DP dimensions of the MBI, burnout was highest for interactions with administration (51% and 44.8%), moderate for interactions with patients (26.4% and 34.5%), and lowest for interactions with students (11.7% and 9.8%). The highest scores along the personal accomplishment component was found for interactions with students and patients (33.7% and 33.4%). Regression analyses identified several factors associated with higher scores on the EE and DP scales: younger age, surgical specialty, low academic rank, academic main practice, female gender, numerous night shifts, and living alone. Furthermore, higher patient volume contributed significantly to the increasing PA. This study suggests that administrative interaction contributes significantly to burnout amongst physicians, followed by patient care and trainees. Furthermore, surgeons, females, single, early career, and younger faculty staff members are at higher risk of suffering from burnout. Further studies are needed to characterize the nature of administrative interactions that contribute to burnout and to solidify other contributing variables.

    View details for DOI 10.3390/bs10060094

    View details for PubMedID 32471265

  • Mobile application-based guidelines to enhance patient care and provider education in trauma and acute care surgery. Trauma surgery & acute care open Hakes, N. A., Kethman, W. C., Spain, D., Nassar, A. K. 2020; 5 (1): e000479


    Providing up-to-date, universally accessible care guidelines and education within a quaternary care center is challenging. At our institution, trauma and acute care surgery guidelines have historically been published using a paper-based format. Mobile application-based guidelines were developed to address the shortcomings of paper-based guidelines.We assessed the utility, usability, and satisfaction of healthcare providers towards paper-based versus mobile application-based guidelines. A survey was administered to providers within the emergency department and intensive care unit.Fifty of 137 providers responded (36.5% response rate). Nearly half (47.4%, 9 of 19) of those who received a copy of the paper-based guidelines lost the guidelines at least once. Regarding usage of the mobile application-based guidelines, 92.6% (25 of 27) were aware of the application; 92.6% (25 of 27) considered the application comprehensive, 85.2% (23 of 27) thought the application was organized, and 66.7% (18 of 27) thought the application was easy to use. Additionally, 88.9% (24 of 27) found the application moderately, very, or extremely helpful and 85.2% (23 of 27) judged the application moderately, very, or extremely necessary. Overall, 88.9% (24 of 27) were satisfied with the application and indicated likeliness to recommend to a colleague. Seventeen of 27 (63.0%) agreed or strongly agreed that the application improved their provision of trauma and acute care.This survey demonstrates positive usability, utility, and satisfaction among trauma healthcare providers with the mobile application-based guidelines. Additionally, this quality improvement initiative highlights the importance of having comprehensive, organized, and easy-to-use trauma and acute care surgery guidelines and targeted educational materials available on demand. The successful transition from paper to mobile application-based guidelines serves as a model for other institutions to modernize and improve patient care and provider education.IV.

    View details for DOI 10.1136/tsaco-2020-000479

    View details for PubMedID 32760809

    View details for PubMedCentralID PMC7380731

  • 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

  • Enterocutaneous Fistula: A Simplified Clinical Approach CUREUS Tuma, F., Crespi, Z., Wolff, C. J., Daniel, D. T., Nassar, A. K. 2020; 12 (4)
  • Enterocutaneous Fistula: A Simplified Clinical Approach. Cureus Tuma, F., Crespi, Z., Wolff, C. J., Daniel, D. T., Nassar, A. K. 2020; 12 (4): e7789


    A "fistula" is an abnormal connection between two epithelial surfaces. Fistulae are named based on the two surfaces or lumens they connect to. Fistulae form due to loss of wall integrity from an underlying insult, leading to the penetrance of an adjacent organ or epithelized surface. Common causes of small bowel fistulae include sequelae of surgical intervention, foreign body, bowel diverticula, Crohn's disease, malignancy, radiation, and infection. A histopathological analysis displays acute and/or chronic inflammation due to the underlying pathology. A thorough history and physical examination are important components of patient evaluation. Generally, patients will present with non-specific constitutional symptoms in addition to local symptoms attributed to the fistula. In rare instances, symptoms may be severe and life-threatening. Initial laboratory workup includes complete blood count, comprehensive metabolic panel, and lactate level. Radiologic imaging is useful for definitive diagnosis and helps delineate anatomy. In practice, computed tomography (CT) is the initial imaging modality. The addition of intravenous or enteric contrast may be helpful in certain situations. Magnetic resonance imaging (MRI) may also be used in special circumstances. Invasive procedures, such as endoscopy, can assist in the evaluation of mucosal surfaces to diagnose pathology such as inflammatory processes. Appropriate management should include optimizing nutritional status, delineating fistulous tract anatomy, skincare, and managing the underlying disease. A non-operative approach is generally accepted as the initial approach especially in the acute/subacute setting. However, operative intervention is indicated in the setting of failed non-operative management. Successful management of small bowel fistulae requires a multidisciplinary team approach. To conclude, a small bowel fistula is a complex clinical disease, with surgical intervention being the most common cause in developed countries. The non-operative approach should be trialed before an operative approach is considered.

    View details for DOI 10.7759/cureus.7789

    View details for PubMedID 32461860

    View details for PubMedCentralID PMC7243661

  • Precautions for Operating Room Team Members during the COVID-19 Pandemic. Journal of the American College of Surgeons Forrester, J. D., Nassar, A. K., Maggio, P. M., Hawn, M. T. 2020


    The novel corona virus SARS-CoV-2 (COVID-19) can infect healthcare workers. We developed an institutional algorithm to protect operating room team members during the COVID-19 pandemic and rationally conserve personal protective equipment (PPE).An interventional platform (operating room, interventional suites, and endoscopy) PPE taskforce was convened by the hospital and medical school leadership and tasked with developing a common algorithm for PPE use, to be used throughout the interventional platform. In conjunction with our infection disease experts, we developed our guidelines based upon potential patterns of spread, risk of exposure and conservation of PPE.A decision tree algorithm describing our institutional guidelines for precautions for operating room team members was created. This algorithm is based on urgency of operation, anticipated viral burden at the surgical site, opportunity for a procedure to aerosolize virus, and likelihood a patient could be infected based on symptoms and testing.Despite COVID-19 being a new threat, we have shown that by developing an easy-to-follow decision tree algorithm for the interventional platform teams, we can ensure optimal healthcare worker safety.

    View details for DOI 10.1016/j.jamcollsurg.2020.03.030

    View details for PubMedID 32247836

  • 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

Footer Links:

Stanford Medicine Resources: