Clinical Focus

  • General Surgery
  • Surgical Procedures, Minimally Invasive
  • Gastrointestinal Surgery, Endoscopic
  • Bariatric Surgery
  • Single Incision Laparoscopic Surgery
  • Gastric Bypass
  • Esophageal Reflux
  • Esophageal Achalasia
  • Sleeve Gastrectomy
  • Hernias, Paraesophageal Hiatal
  • Abdominal Hernias
  • Splenectomies
  • Gastric Pacemaker for Gastroparesis
  • Trauma Surgery

Academic Appointments

Administrative Appointments

  • Medical Director, Program Transform, Stanford Hospital and Clinics (2014 - Present)
  • Director, Surgical Education Fellowship, Stanford Department of Surgery (2011 - Present)
  • Director, Stanford Surgery ACS Education Institute/Goodman Simulation Center, Stanford Department of Surgery (2011 - Present)
  • Director, Core Clerkship in Surgery, Stanford School of Medicine (2011 - Present)
  • Associate Program Director, Stanford Surgery Residency (2011 - Present)
  • Assistant Dean for Clerkship Education, Stanford School of Medicine (2015 - Present)

Honors & Awards

  • Surgical Socrates Award, Department of Surgery Indiana University Medical Center Indianapolis, Indiana (2002)
  • Meritorious Service Medal, United States Air Force (2003)
  • Special Recognition for Teaching, Department of Surgery at University of Nevada School of Medicine, Las Vegas, Nevada (2005)
  • Faculty Teaching Award, Department of Surgery at University of Nevada School of Medicine, Las Vegas, Nevada (2006)
  • Poster of Distinction, SAGES Annual Meeting at Las Vegas, Nevada (2007)
  • John Austin Collins, MD Memorial Teaching Award, Department of Surgery, Stanford School of Medicine (2010)
  • John Austin Collins, MD Memorial Teaching Award, Department of Surgery, Stanford School of Medicine (2012)
  • Henry J. Kaiser Family Foundation Teaching Award for Clerkship Instruction, Stanford School of Medicine (2014)
  • Award for Excellence in the Promotion of the Learning Environment and Student Wellness, Stanford School of Medicine (2014)

Boards, Advisory Committees, Professional Organizations

  • Curriculum Committee Member, American College of Surgeons Education Institutes (ACS-EI) (2012 - Present)

Professional Education

  • Residency:Indiana University Medical Center GME Verifications (2002) IN
  • Fellowship:Stanford University Medical Center (2007) CA
  • Internship:Loyola University Medical Center (1996) IL
  • Medical Education:Loyola Univ Of Chicago Stritch (1995) IL
  • Board Certification: General Surgery, American Board of Surgery (2003)
  • BS, University of CA, San Diego, Bio-Engineering (1990)

Community and International Work

  • Healthy Options for Prevention and Education, Las Vegas, Nevada


    Childhood Obesity Prevention

    Partnering Organization(s)

    University of Nevada School of Medicine

    Populations Served

    Economically Disadvantaged/Hispanic

    Ongoing Project


    Opportunities for Student Involvement


Research & Scholarship

Current Research and Scholarly Interests

We live in an exciting time of new techniques in minimal surgical access. These techniques are being practiced in basic as well as more advanced general surgical and bariatric procedures. Controlled studies of outcomes comparing standard approaches to these newer ones are the only way to validate these evolving and more cosmetically pleasing techniques.

The education of surgeons has been changing from a mentorship skills acquisition model towards a simulation first approach. The variety of methods to convey medical knowledge and technical prowess must be honed to provide the future surgeons with the most effective education in a world with more time constraints. Studies that explore new ways to improve standard education of surgical residents as well as novel approaches to teaching technical, team dynamics, and crisis management skills are essential toward the goal of producing a caring and skilled physician.

The educational environment for medical students and residents has changed. Because of this, a more comprehensive and systematic inter-disciplinary approach is essential to adapt to the learning styles of modern trainees. Programs of education must be innovative in scope and practice. Evaluation of novel programs qualitatively and quantitatively ensure these robust curricula accomplish the task of conveying knowledge and skills efficiently.

Teamwork and communication remain important, yet under emphasized, concepts in our complex clinical practices. Superior patient care as shown by improved outcomes are the result of interdisciplinary team training. Promoting this behavioral culture in large tertiary institutions require new educational methods. Simulation training, as part of a comprehensive large scale blended learning model cross disciplines can yield improved patient care outcomes. Studies to prove this are necessary in program implementation through maintenance.


2015-16 Courses

Stanford Advisees


All Publications

  • Mesenteric defect closure in laparoscopic Roux-en-Y gastric bypass: a randomized controlled trial. Surgical endoscopy Rosas, U., Ahmed, S., Leva, N., Garg, T., Rivas, H., Lau, J., Russo, M., Morton, J. M. 2015; 29 (9): 2486-2490


    Internal herniation is a potential complication following laparoscopic Roux-en-Y gastric bypass (LRYGB). Previous studies have shown that closure of mesenteric defects after LRYGB may reduce the incidence of internal herniation. However, controversy remains as to whether mesenteric defect closure is necessary to decrease the incidence of internal hernias after LRYGB. This study aims to determine if jejeunal mesenteric defect closure reduces incidence of internal hernias and other complications in patients undergoing LRYGB.105 patients undergoing laparoscopic antecolic RYGB were randomized into two groups: closed mesenteric defect (n = 50) or open mesenteric defect (n = 55). Complication rates were obtained from the medical record. Patients were followed up to 3 years post-operatively. Patients also completed the gastrointestinal quality of life index (GI QoL) pre-operatively and 12 months post-operatively. Outcome measures included: incidence of internal hernias, complications, readmissions, reoperations, GI QoL scores, and percent excess weight loss (%EWL).Pre-operatively, there were no significant differences between the two groups. The closed group had a longer operative time (closed-153 min, open-138 min, p = 0.073). There was one internal hernia in the open group. There was no significant difference at 12 months for decrease in BMI (closed-15.9, open-16.3 kg/m(2), p = 0.288) or %EWL (closed-75.3 %, open-69.0 %, p = 0.134). There was no significant difference between the groups in incidence of internal hernias and general complications post-operatively. Both groups showed significantly improved GI QoL index scores from baseline to 12 months post-surgery, but there were no significant differences at 12 months between groups in total GI QoL (closed-108, open-112, p = 0.440).In this study, closure or non-closure of the jejeunal mesenteric defect following LRYGB appears to result in equivalent internal hernia and complication rates. High index of suspicion should be maintained whenever internal hernia is expected after LRYGB.

    View details for DOI 10.1007/s00464-014-3970-3

    View details for PubMedID 25480607

  • Mesenteric defect closure in laparoscopic Roux-en-Y gastric bypass: a randomized controlled trial SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Rosas, U., Ahmed, S., Leva, N., Garg, T., Rivas, H., Lau, J., Russo, M., Morton, J. M. 2015; 29 (9): 2486-2490
  • Validity evidence for Surgical Improvement of Clinical Knowledge Ops: a novel gaming platform to assess surgical decision making AMERICAN JOURNAL OF SURGERY Lin, D. T., Park, J., Liebert, C. A., Lau, J. N. 2015; 209 (1): 79-85


    Current surgical education curricula focus mainly on the acquisition of technical skill rather than clinical and operative judgment. SICKO (Surgical Improvement of Clinical Knowledge Ops) is a novel gaming platform developed to address this critical need. A pilot study was performed to collect validity evidence for SICKO as an assessment for surgical decision making.Forty-nine subjects stratified into 4 levels of expertise were recruited to play SICKO. Later, players were surveyed regarding the realism of the gaming platform as well as the clinical competencies required of them while playing SICKO.Each group of increasing expertise outperformed the less experienced groups. Mean total game scores for the novice, junior resident, senior resident, and expert groups were 5,461, 8,519, 11,404, and 13,913, respectively (P = .001). Survey results revealed high scores for realism and content.SICKO holds the potential to be not only an engaging and immersive educational tool, but also a valid assessment in the armamentarium of surgical educators.

    View details for DOI 10.1016/j.amjsurg.2014.08.033

    View details for Web of Science ID 000346121100013

  • What is the future of training in surgery? Needs assessment of national stakeholders SURGERY Kim, S., Dunkin, B. J., Paige, J. T., Eggerstedt, J. M., Nicholas, C., Vassilliou, M. C., Spight, D. H., Pliego, J. F., Rush, R. M., Lau, J. N., Carpenter, R. O., Scott, D. J. 2014; 156 (3): 707-717


    The Curriculum Committee of the American College of Surgeons-Accredited Educational Institutes conducted a need assessment to (1) identify gaps between ideal and actual practices in areas of surgical care, (2) explore educational solutions for addressing these gaps, and (3) shape a vision to advance the future of training in surgery.National stakeholders were recruited from the committee members' professional network and interviewed via telephone. Interview questions targeted areas for improving surgical patient care, optimal educational solutions for training in surgery including simulation roles, and entities that should primarily bear training costs. We performed an iterative, qualitative analysis including member checking to identify key themes.Twenty-two interviewees included state/national board representatives, risk managers, multispecialty faculty/program directors, nurses, trainees, an industry representative, and a patient. Surgeons' communication with patients, families, and team members was raised consistently by stakeholders as a way to establish clear expectations regarding pre-, peri-, and postoperative care. Other comments highlighted the surgeon's development and demonstration and maintenance of cognitive and technical skills, including surgical judgment. Stakeholders also reiterated the critical need for surgeons to engage in on-going self-assessment and professional development to identify and remediate recognized limitations. Recommended learning modalities for meeting surgeons' needs included active learning (deliberate practice, diverse patient experiences), experiential learning (simulation), and peer and mentored learning (preceptorship).This first formal needs assessment of education for surgeons points to opportunities for educational programs in patient-centered communication, learning models that match preferences of new generations of trainees, and training in interprofessional/interdisciplinary team communication and teamwork.

    View details for DOI 10.1016/j.surg.2014.04.047

    View details for Web of Science ID 000341228200028

    View details for PubMedID 25175505

  • PREDICT: Instituting an Educational Time Out in the Operating Room. Journal of graduate medical education Yang, R. L., Esquivel, M., Erdrich, J., Lau, J., Melcher, M. L., Wapnir, I. L. 2014; 6 (2): 382-383

    View details for DOI 10.4300/JGME-D-14-00086.1

    View details for PubMedID 24949168

  • Comparison of robotic and laparoendoscopic single-site surgery systems in a suturing and knot tying task SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Eisenberg, D., Vidovszky, T. J., Lau, J., Guiroy, B., Rivas, H. 2013; 27 (9): 3182-3186


    BACKGROUND: Laparoendoscopic single-site (LESS) surgery has been established for various procedures. Shortcomings of LESS surgery include loss of triangulation, instrument collisions, and poor ergonomics, making advanced laparoscopic tasks especially challenging. We compared a LESS system with a robotic single-site surgery platform in performance of a suturing and knot-tying task under clinically simulated conditions. METHODS: Each of five volunteer minimally invasive surgeons was tasked with suturing a 5 cm longitudinal enterotomy in porcine small intestine with square knots at either end, using a laparoendoscopic or da Vinci robotic single-site surgery platform, within a 20 min time limit. A saline leak test was then performed. Each surgeon performed the task twice using each system. The time to completion of the task and presence of a leak were noted. Fisher's exact test was used to compare the overall completion rate within the defined time limit, and a Wilcoxon rank test was used to compare the specific times to complete the task. A p value of <0.05 was considered significant. RESULTS: All surgeons were able to complete the task on the first try within 20 min using the robot system; 60 % of surgeons were able to complete it after two attempts using the LESS surgery system. Time to completion using the robot system was significantly shorter than the time using the standard LESS system (p < 0.0001). There were no leaks after closure with the robot system; the leak rate following the standard LESS system was 90 %. CONCLUSIONS: Surgeons demonstrated significantly better suturing and knot-tying capabilities using the robot single-site system compared to a standard LESS system. The robotic system has the potential to expand single-site surgery to more complex tasks.

    View details for DOI 10.1007/s00464-013-2874-y

    View details for Web of Science ID 000323621500016

    View details for PubMedID 23443484

  • The assessment of emotional intelligence among candidates interviewing for general surgery residency. Journal of surgical education Lin, D. T., Kannappan, A., Lau, J. N. 2013; 70 (4): 514-521


    There is an increasing demand for physicians to possess strong personal and social qualities embodied in the concept of emotional intelligence (EI). However, the residency selection process emphasizes mainly academic accomplishments. In this system, the faculty interview is the primary means of evaluating the nontangible, nonacademic attributes of a candidate.To determine whether the impressions derived from faculty interviews correlate with an applicant's actual EI as measured by a validated objective instrument.Participating applicants interviewing for a surgical residency position at Stanford completed an EI inventory Trait Emotional Intelligence Questionnaire (TEIQue). Faculty estimated the EI of the applicants they interviewed using a corresponding 360° evaluation form. Multivariate linear regression was performed to identify demographic and academic factors predictive of EI. Applicant TEIQue scores and faculty 360° impressions were correlated using Pearson coefficients.Mean EI of the cohort was higher than that of the average population (5.43 vs 4.89, p<0.001). Age was the only demographic variable that significantly informed EI (B = 0.07, p = 0.005). Among the academic factors considered, United States Medical Licensing Examination Step 1 score was a slight negative predictor of EI (B =-0.007, p = 0.04). Applicant global EI scores did not correlate with faculty impressions of overall EI (r = 0.27, p = 0.06). Of the 4 domains that comprise global EI, sociability and emotionality demonstrated a moderate correlation between applicant and faculty scores (r = 0.31, p = 0.03 and r = 0.27, p = 0.05, respectively). None of the fifteen individual facets of EI demonstrated any correlation between applicant and faculty ratings (r =-0.12 to 0.26, p = 0.06-0.91). No association was found between applicant TEIQue and traditional faculty interview evaluations (r = 0.18, p = 0.19).Applicant EI correlated poorly with academic parameters and was not accurately assessed by faculty interviews. Methods that better capture this dimension should be incorporated into the residency selection process.

    View details for DOI 10.1016/j.jsurg.2013.03.010

    View details for PubMedID 23725940

  • Hemobilia from Transjugular Liver Biopsy Resulting in Gallbladder Rupture DIGESTIVE DISEASES AND SCIENCES Plerhoples, T. A., Lau, J. N. 2013; 58 (3): 630-633
  • Recurrent abdominal liposarcoma: Analysis of 19 cases and prognostic factors. World journal of gastroenterology : WJG Lu, W., Lau, J., Xu, M. D., Zhang, Y., Jiang, Y., Tong, H. X., Zhu, J., Lu, W. Q., Qin, X. Y. 2013; 19 (25): 4045-52


    To evaluate the clinical outcome of re-operation for recurrent abdominal liposarcoma following multidisciplinary team cooperation.Nineteen consecutive patients who had recurrent abdominal liposarcoma underwent re-operation by the retroperitoneal sarcoma team at our institution from May 2009 to January 2012. Patient demographic and clinical data were reviewed retrospectively. Multidisciplinary team discussions were held prior to treatment, and re-operation was deemed the best treatment. The categories of the extent of resection were as follows: gross total resection (GTR), palliative resection and partial resection. Surgical techniques were divided into discrete lesion resection and combined contiguous multivisceral resection (CMR). Tumor size was determined as the largest diameter of the specimen. Patients were followed up at approximately 3-monthly intervals. For survival analysis, a univariate analysis was performed using the Kaplan-Meier method, and a multivariate analysis was performed using the Cox proportional hazards model.Nineteen patients with recurrent abdominal liposarcoma (RAL) underwent 32 re-operations at our institute. A total of 51 operations were reviewed with a total follow-up time ranging from 4 to 120 (47.4 ± 34.2) mo. The GTR rate in the CMR group was higher than that in the non-CMR group (P = 0.034). CMR was positively correlated with intra-operative bleeding (correlation coefficient = 0.514, P = 0.010). Six cases with severe postoperative complications were recorded. Patients with tumor sizes greater than 20 cm carried a significant risk of profuse intra-operative bleeding (P = 0.009). The ratio of a highly malignant subtype (dedifferentiated or pleomorphic) in recurrent cases was higher compared to primary cases (P = 0.027). Both single-factor survival using the Kaplan-Meier model and multivariate analysis using the Cox proportional hazards model showed that overall survival was correlated with resection extent and pathological subtype (P < 0.001 and P = 0.02), however, relapse-free interval (RFI) was only correlated with resection extent (P = 0.002).Close follow-up should be conducted in patients with RAL. Early re-operation for relapse is preferred and gross resection most likely prolongs the RFI.

    View details for PubMedID 23840151

  • The Effect of Positive and Negative Verbal Feedback on Surgical Skills Performance and Motivation JOURNAL OF SURGICAL EDUCATION Kannappan, A., Yip, D. T., Lodhia, N. A., Morton, J., Lau, J. N. 2012; 69 (6): 798-801


    There is considerable effort and time invested in providing feedback to medical students and residents during their time in training. However, little effort has been made to measure the effects of positive and negative verbal feedback on skills performance and motivation to learn and practice. To probe these questions, first-year medical students (n = 25) were recruited to perform a peg transfer task on Fundamentals of Laparoscopic Surgery box trainers. Time to completion and number of errors were recorded. The students were then randomized to receive either positive or negative verbal feedback from an expert in the field of laparoscopic surgery. After this delivery of feedback, the students repeated the peg transfer task. Differences in performance pre- and post-feedback and also between the groups who received positive feedback (PF) vs negative feedback (NF) were analyzed. A survey was then completed by all the participants. Baseline task times were similar between groups (PF 209.3 seconds; NF 203 seconds, p = 0.58). The PF group averaged 1.83 first-time errors while the NF group 1 (p = 0.84). Post-feedback task times were significantly decreased for both groups (PF 159.75 seconds, p = 0.05; NF 132.08 seconds, p = 0.002). While the NF group demonstrated a greater improvement in mean time than the PF group, this was not statistically significant. Both groups also made fewer errors (PF 0.33 errors, p = 0.04; NF 0.38 errors, p = 0.23). When surveyed about their responses to standardized feedback scenarios, the students stated that both positive and negative verbal feedback could be potent stimulants for improved performance and motivation. Further research is required to better understand the effects of feedback on learner motivation and the interpersonal dynamic between mentors and their trainees.

    View details for DOI 10.1016/j.jsurg.2012.05.012

    View details for Web of Science ID 000311024100021

    View details for PubMedID 23111049

  • Potential Nutritional Conflicts in Bariatric and Renal Transplant Patients OBESITY SURGERY Lightner, A. L., Lau, J., Obayashi, P., Birge, K., Melcher, M. L. 2011; 21 (12): 1965-1970


    An increasing number of morbidly obese patients with end stage renal disease (ESRD) are sequentially undergoing bariatric surgery followed by renal transplantation. Discrepancies between the nutritional recommendations for obesity and chronic kidney disease (CKD) are often confusing for the obese patient in renal failure. However, when recommendations are structured according to stage and treatment of disease, a consistent plan can be clearly communicated to the patient. Therefore, to optimize patient and graft outcomes we present nutritional recommendations tailored to three patient populations: obese patients with ESRD, patients post Roux-en-Y gastric bypass (RYGBP) with ESRD, and patients post RYGBP and post renal transplantation.

    View details for DOI 10.1007/s11695-011-0423-0

    View details for Web of Science ID 000297201700023

    View details for PubMedID 21526378

  • Another Use of the Mobile Device: Warm-up for Laparoscopic Surgery JOURNAL OF SURGICAL RESEARCH Plerhoples, T. A., Zak, Y., Hernandez-Boussard, T., Lau, J. 2011; 170 (2): 185-188


    An important facet of laparoscopic surgery is its psychomotor component. As this aspect of surgery gains attention, lessons from other psychomotor-intense fields such as athletics have led to an investigation of the benefits of "warming up" prior to entering the operating room. Practical implementation of established methods of warm-up is hampered by a reliance on special equipment and instrumentations that are not readily available. In light of emerging evidence of translatability between video-game play and operative performance, we sought to find if laparoscopic task performance improved after warming up on a mobile device balance game.Laparoscopic novices were randomized into either the intervention group (n = 20) or the control group (n = 20). The intervention group played a mobile device balance game for 10 min while the control group did no warm-up whatsoever. Assessment was performed using two tasks on the ProMIS laparoscopic simulation system: "object positioning" (where small beads are transferred between four cups) and "tissue manipulation" (where pieces of plastic are stretched over pegs). Metrics measured were time to task completion, path length, smoothness, hand dominance, and errors.The intervention group made fewer errors: object positioning task 0.20 versus 0.70, P = 0.01, tissue manipulation task 0.15 versus 0.55, P = 0.05, total errors 0.35 versus 1.25, P = 0.002. The two groups performed similarly on the other metrics.Warm-up using a mobile device balance game decreases errors on basic tasks performed on a laparoscopic surgery simulator, suggesting a practical way to warm-up prior to cases in the operating room.

    View details for DOI 10.1016/j.jss.2011.03.015

    View details for Web of Science ID 000295128600013

    View details for PubMedID 21529831

  • The role of functional endoscopic sinus surgery in asthmatic patients JOURNAL OF OTOLARYNGOLOGY Park, A. H., Lau, J., Stankiewicz, J., Chow, J. 1998; 27 (5): 275-280


    This study was conducted to determine the efficacy of FESS (functional endoscopic sinus surgery) on sinus and asthma symptoms.Seventy-nine patients with asthma and medically unresponsive sinusitis were evaluated. Maximal medical therapy was attempted to relieve both sinus and asthma symptoms. The surgical procedures involved standard FESS techniques. Fifty-six percent of patients had undergone a sinus procedure prior to the FESS. Nasal polyposis was noted in 73% of the group. The majority of patients had pansinusitis.Eighty-six percent of patients stated that FESS improved their sinusitis. Nine of 11 sinus symptoms recorded preoperatively diminished significantly (p < .05) following surgery. Eighty percent of patients noted improvement of their asthma following FESS. The factors associated with treatment failure and the unique characteristics of this disease process were evaluated.FESS is a viable option in the treatment of asthma when medical therapy fails.

    View details for Web of Science ID 000076536200006

    View details for PubMedID 9800626