Bio

Clinical Focus


  • Surgery, Pediatric
  • Pediatric Surgery

Academic Appointments


Administrative Appointments


  • Emile Holman Professor and Chair, Stanford University School of Medicine - Department of Surgery (1999 - Present)
  • Susan B. Ford Surgeon in Chief, Lucile Packard Children's Hospital (2002 - Present)
  • Director, Surgical Innovation Program (2004 - Present)
  • Co-Director, Biodesign Program (2006 - Present)
  • Director, Stanford Education Institute/ Goodman Simulation Center (2007 - 2011)
  • Program Director, General Surgery Residency Training Program (2009 - 2011)

Honors & Awards


  • Fellow, American Institute for Medical and Biological Engineering (AIMBE) College of Fellows. (2014-present)
  • Outstanding Achievement in Medicine Award, Santa Clara Country Medical Association (2009)
  • Consultant - Mission reforme C.H.U., French Government (2009)
  • Proclamation of Thanks, LPCH Government Relations Department (2007)
  • Finalist: Franklin G. Ebaugh, Jr. Award, Stanford University School of Medicine (2007)
  • International Health Professional of the Year, International Biographical Center (2006)
  • The Henry J. Kaiser Family Foundation Award for Excellence in Clinical Teaching, Stanford University School of Medicine (2004)
  • Recognition of Service Excellence (ROSE), Lucile Packard Children's Hospital at Stanford (2004)
  • The John Austin Collins, MD Memorial Award-Outstanding Teaching and Dedication to Resident Teaching, Department of Surgery at Stanford University (2004)
  • America's Top Doctors, Castle Connolly Medical Ltd (2003-2009)
  • Best Doctors, San Francisco Magazine (2003-2005)
  • Best Doctors in America, Best Doctors Corporation (2002-2008)
  • Special Congressional Recognition, House of Representatives, USA (2003)
  • Alumnus of the Year, Marquette Medical Alumni Association - Medical College of Wisconsin (2003)
  • Computerworld Smithsonian Award - Information Technology and Innovation in Medicine, Penn State Department of Surgery (1999)
  • Computerworld Smithsonian Award - Robotically Assisted Microsurgery, Penn State Department of Surgery (1997)
  • Traveling Fellowship Award, James IV Association of Surgeons (1996)
  • The Thomas V.N. Ballantine Memorial Excellence in Surgical Education Award, Surgical Residents of the Milton S. Hershey Medical Center (1991)
  • Commencement Speaker, University of Wisconsin-Parkside (1991)
  • Distinguished Alumni Achievement Award, University of Wisconsin-Parkside (1991)
  • Chief Residents' Outstanding Teacher Award, Medical College of Virginia (1990)
  • "Outstanding Young Surgeon", VA Chapter American College of Surgeons (1989)
  • Fellowship, American College of Surgeons (1987-1989)
  • IA Bigger Medal "Outstanding Chief Resident", Medical College of Virginia (1983)
  • Resident Research Award, American Academy of Pediatrics Surgical Section (1981)
  • James Ewing Resident Research Award, Society of Surgical Oncology (1981)
  • Bigger-Lehman Resident Research Award, Virginia Surgical Society (1981)
  • David M. Hume Resident Research Award, Medical College of Virginia (1979)
  • "Outstanding Member 1977 Graduating Class", Medical College of Wisconsin (1977)
  • Millman Award, Medical College of Wisconsin (1977)

Professional Education


  • Residency:Medical College of Virginia (1983) VA
  • Board Certification: Pediatric Surgery, American Board of Surgery (1988)
  • Fellowship:UCSF Medical Center (1985) CA
  • Fellowship:Children's Hospital of Pittsburgh (1985) PA
  • Board Certification: General Surgery, American Board of Surgery (1984)
  • Internship:Medical College of Virginia (1978) VA
  • Medical Education:Medical College of Wisconsin (1977) WI
  • Fellowship, Univ. of CA, San Francisco, Fetal Surgery (1985)
  • Research Fellowship, Medical College of Virginia, Surgical Research (1980)
  • Resident, Children's Hospital, Pittsburgh, Pediatric Surgery (1985)
  • Chief Resident in Surgery, Medical College of Virginia, Surgery (1983)
  • Internship/Residency, Medical College of Virginia, Medicine (1982)
  • M.D., Medical College of Wisconsin, Medicine (1977)
  • B.S., University of Wisconsin-Parkside, Chemistry (1973)

Community and International Work


  • International Surgical Exchange

    Topic

    International surgical trainee travelling fellowship

    Partnering Organization(s)

    James IV Association

    Populations Served

    Worldwide

    Location

    International

    Ongoing Project

    Yes

    Opportunities for Student Involvement

    No

  • Mission réforme C.H.U., France

    Topic

    Healthcare reform

    Partnering Organization(s)

    Franch Government, IRCAD

    Populations Served

    Healthcare recipients

    Location

    International

    Ongoing Project

    Yes

    Opportunities for Student Involvement

    No

Research & Scholarship

Current Research and Scholarly Interests


Surgical Innovation, Simulation and Virtual Reality in Surgical Education, Fetal Healing-Cellular and Biochemical Mechanisms

Clinical Trials


  • Efficacy Study to Evaluate Laparoscopic Fascial Closure Device Recruiting

    During any minimally invasive surgery case, 5-25mm size incisions need to be made to gain access to the abdomen. One of the most difficult, time-consuming, and sometimes unreliable parts of the case is closing these incisions, especially in obese patients. This is mainly because these incisions are very small and the layer that needs to be closed (fascia) rests deep underneath the skin and fat tissue of the abdominal wall. Two of the investigators (CM and BS) have developed at Stanford an instrument that allows for an easier and more reliable closure of these wounds. The purpose of this study is to test this instrument in the closure of laparoscopic wounds in obese patients undergoing laparoscopic gastric bypass surgery.

    View full details

Teaching

2013-14 Courses


Graduate and Fellowship Programs


Publications

Journal Articles


  • Outcomes from a Postgraduate Biomedical Technology Innovation Training Program: The First 12 Years of Stanford Biodesign ANNALS OF BIOMEDICAL ENGINEERING Brinton, T. J., Kurihara, C. Q., Camarillo, D. B., Pietzsch, J. B., Gorodsky, J., Zenios, S. A., Doshi, R., Shen, C., Kumar, U. N., Mairal, A., Watkins, J., Popp, R. L., Wang, P. J., Makower, J., Krummel, T. M., Yock, P. G. 2013; 41 (9): 1803-1810

    Abstract

    The Stanford Biodesign Program began in 2001 with a mission of helping to train leaders in biomedical technology innovation. A key feature of the program is a full-time postgraduate fellowship where multidisciplinary teams undergo a process of sourcing clinical needs, inventing solutions and planning for implementation of a business strategy. The program places a priority on needs identification, a formal process of selecting, researching and characterizing needs before beginning the process of inventing. Fellows and students from the program have gone on to careers that emphasize technology innovation across industry and academia. Biodesign trainees have started 26 companies within the program that have raised over $200 million and led to the creation of over 500 new jobs. More importantly, although most of these technologies are still at a very early stage, several projects have received regulatory approval and so far more than 150,000 patients have been treated by technologies invented by our trainees. This paper reviews the initial outcomes of the program and discusses lessons learned and future directions in terms of training priorities.

    View details for DOI 10.1007/s10439-013-0761-2

    View details for Web of Science ID 000323736800002

    View details for PubMedID 23404074

  • Gastroenterology and Biodesign: Contributing to the Future of Our Specialty GASTROENTEROLOGY Nimgaonkar, A., Yock, P. G., Brinton, T. J., Krummel, T., Pasricha, P. J. 2013; 144 (2): 258-262

    View details for DOI 10.1053/j.gastro.2012.12.009

    View details for Web of Science ID 000314716300012

    View details for PubMedID 23246636

  • Symbiotic or Parasitic? A Review of the Literature on the Impact of Fellowships on Surgical Residents ANNALS OF SURGERY Plerhoples, T. A., Greco, R. S., Krummel, T. M., Melcher, M. L. 2012; 256 (6): 904-908

    Abstract

    We conducted a systematic review of published literature to gain a better understanding of the impact of advanced fellowships on surgical resident training and education.As fellowship opportunities rise, resident training may be adversely impacted.PubMed, MEDLINE, Scopus, BIOSIS, Web of Science, and a manual search of article bibliographies. Of the 139 citations identified through the initial electronic search and screened for possible inclusion, 23 articles were retained and accepted for this review. Data were extracted regarding surgical specialty, methodology, sample population, outcomes measured, and results.Eight studies retrospectively compared the eras before and after the introduction of a fellowship or trended data over time. Approximately half used data from a single institution, whereas the other half used some form of national data or survey. Only 3 studies used national case data. Fourteen studies looked at general surgery, 6 at obstetrics-gynecology, 2 at urology, and 1 at otolaryngology. Only one study concluded that fellowships have a generally positive impact on resident education, whereas 9 others found a negative impact. The remaining 13 studies found mixed results (n = 6) or minimal to no impact (n = 7).The overall impact of advanced surgical fellowships on surgical resident education and training remains unclear, as most studies rely on limited data of questionable generalizability. A careful study of the national database of surgery resident case logs is essential to better understand how early surgical specialization and fellowships will impact the future of general surgery education.

    View details for DOI 10.1097/SLA.0b013e318262edd5

    View details for Web of Science ID 000312261000012

    View details for PubMedID 22968071

  • Submucosal Endoscopic Myotomies for Esophageal Lengthening: A Novel Minimally Invasive Technique with Feasibility Study EUROPEAN JOURNAL OF PEDIATRIC SURGERY Wall, J., Perretta, S., Diana, M., Dhumane, P., Haro, J. A., Dallemagne, B., Becmeur, F., Krummel, T., Marescaux, J. 2012; 22 (3): 217-221

    Abstract

    Replacement conduits carry significant morbidity in long gap esophageal atresia. Surgical myotomies can lengthen the esophagus, but have not gained widespread adoption due to long-term dilatation. The aim of this study is to assess the feasibility of an emerging minimally invasive technique of submucosal endoscopic myotomy for esophageal lengthening.Bilateral submucosal lengthening endoscopic myotomies (BSLEM) were performed in three swine. Circular esophageal muscle fibers were selectively divided in a bilateral 3 cm longitudinal pattern. Ex-vivo tensile testing was performed on the BSLEM and compared with three circular myotomies, three spiral myotomies, and three controls.BSLEM was completed in all cases with one esophageal microperforation. The mean operating time was 38 minutes. Over physiologic force ranges of 0 to 100 g, the percentage esophageal elongation was significantly different among the four groups (p<0.05). Spiral myotomy enabled the maximal lengthening among the techniques. BSLEM enabled lengthening significantly greater than controls, but less than both types of surgical myotomy.BSELM is feasible and allows significant esophageal lengthening. Unlike surgical myotomies, BSELM enables selective division of circular fibers to potentially preserve perfusion near the anastomosis and prevent long-term dilatation. Studies are ongoing to characterize the ideal pattern of selective endoscopic myotomy and long-term effects.

    View details for DOI 10.1055/s-0032-1308711

    View details for Web of Science ID 000306110600008

    View details for PubMedID 22576306

  • Applying a Structured Innovation Process to Interventional Radiology: A Single-Center Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sista, A. K., Hwang, G. L., Hovsepian, D. M., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Yamada, K., Hong, R., Dhanani, R., Brinton, T. J., Krummel, T. M., Makower, J., Yock, P. G., Hofmann, L. V. 2012; 23 (4): 488-494

    Abstract

    To determine the feasibility and efficacy of applying an established innovation process to an active academic interventional radiology (IR) practice.The Stanford Biodesign Medical Technology Innovation Process was used as the innovation template. Over a 4-month period, seven IR faculty and four IR fellow physicians recorded observations. These observations were converted into need statements. One particular need relating to gastrostomy tubes was diligently screened and was the subject of a single formal brainstorming session.Investigators collected 82 observations, 34 by faculty and 48 by fellows. The categories that generated the most observations were enteral feeding (n = 9, 11%), biopsy (n = 8, 10%), chest tubes (n = 6, 7%), chemoembolization and radioembolization (n = 6, 7%), and biliary interventions (n = 5, 6%). The output from the screening on the gastrostomy tube need was a specification sheet that served as a guidance document for the subsequent brainstorming session. The brainstorming session produced 10 concepts under three separate categories.This formalized innovation process generated numerous observations and ultimately 10 concepts to potentially to solve a significant clinical need, suggesting that a structured process can help guide an IR practice interested in medical innovation.

    View details for DOI 10.1016/j.jvir.2011.12.029

    View details for Web of Science ID 000302396300009

    View details for PubMedID 22464713

  • The Goodman Simulation Center at Stanford JOURNAL OF SURGICAL EDUCATION Krummel, T., Feaster, S. J. 2011; 68 (1): 77-78

    View details for DOI 10.1016/j.jsurg.2010.05.024

    View details for Web of Science ID 000287424900016

    View details for PubMedID 21292221

  • Cost Consciousness and Medical Education NEW ENGLAND JOURNAL OF MEDICINE Rivas, H., Morton, J. M., Krummel, T. M. 2010; 363 (9): 888-889

    View details for Web of Science ID 000281196600019

    View details for PubMedID 20738193

  • Halsted-Holman vascular trauma legacy JOURNAL OF VASCULAR SURGERY Rich, N. M., Krummel, T. M., Burris, D. G. 2010; 52 (2): 508-511

    View details for DOI 10.1016/j.jvs.2010.01.093

    View details for Web of Science ID 000280455900043

    View details for PubMedID 20670783

  • A patient-centered, ethical approach to medical device innovation. The virtual mentor : VM Chao, K. Z., Riskin, D. J., Krummel, T. M. 2010; 12 (2): 91-95
  • Components of Critical Decision Making and ABSITE Assessment: Toward a More Comprehensive Evaluation. Journal of graduate medical education Krishnamurthy, S., Satish, U., Foster, T., Streufert, S., Dewan, M., Krummel, T. 2009; 1 (2): 273-277

    Abstract

    Accurate assessment of resident competency is a fundamental requisite to assure the training of physicians is adequate. In surgical disciplines, structured tests as well as ongoing evaluation by faculty are used for evaluating resident competency. Although structured tests evaluate content knowledge, faculty ratings are a better measure of how that knowledge is applied to real-world problems. In this study, we sought to explore the performance of surgical residents in a simulation exercise (strategic management simulations [SMS]) as an objective surrogate of real-world performance.Forty surgical residents participated in the SMS simulation that entailed decision making in a real-world-oriented task situation. The task requirements enable the assessment of decision making along several parameters of thinking under both crisis and noncrisis situations. Performance attributes include "simpler" measures of competency (activity level), intermediate categories (information management and emergency responses) to complex measures (breadth of approach and strategy). Scores obtained in the SMS were compared with the scores obtained on the American Board of Surgery In-Training Examination (ABSITE).The data were intercorrelated and subjected to a multiple regression analysis with ABSITE as the dependent variable and simulation scores as independent variables. Using a 1-tail test analysis, only 3 simulation variables correlated with performance on ABSITE at the .01 level (ie, basic activity, focused activity, task orientation). Other simulation variables showed no meaningful relationships to ABSITE scores at all.The more complex real-world-oriented decision-making parameters on SMS did not correlate with ABSITE scores. We believe that techniques such as the SMS, which focus on critical thinking, complement assessment of medical knowledge using ABSITE. The SMS technique provides an accurate measure of real-world performance and provides objective validation of faculty ratings.

    View details for DOI 10.4300/JGME-D-09-00034.1

    View details for PubMedID 21975992

  • NOTES and Other Emerging Trends in Gastrointestinal Endoscopy and Surgery: The Change That We Need and the Change That Is Real AMERICAN JOURNAL OF GASTROENTEROLOGY Pasricha, P. J., Krummel, T. M. 2009; 104 (10): 2384-2386

    Abstract

    In this inaugural year of a historic presidency, gastroenterologists and gastrointestinal surgeons may well want to turn their attention to more immediate transformative events that have the potential to revolutionize their own practice in the near future. The most visible and, perhaps, controversial of these is natural orifice transluminal endoscopic surgery (NOTES), but other equally important changes are emerging as investigators around the globe vie with one another in the demonstration of increasingly audacious procedures. As is to be expected, we are also already seeing a backlash from more conservative scholars attempting to temper what they believe to be the surgical equivalent of irrational exuberance. However, by far the most common attitude among gastroenterologists toward these changes is one of indifference. In this piece, we discuss the circumstances that led to the development of NOTES and other innovative procedures, the peril that lies in ignoring them, and the true promise that they hold for our specialties.

    View details for DOI 10.1038/ajg.2009.150

    View details for Web of Science ID 000270853300002

    View details for PubMedID 19806084

  • Inventing our future: training the next generation of surgeon innovators JOURNAL OF PEDIATRIC SURGERY Krummel, T. M. 2009; 44 (1): 21-35
  • Inside the operating room--balancing the risks and benefits of new surgical procedures: a collection of perspectives and panel discussion. Cleveland Clinic journal of medicine Cooper, J. D., Clayman, R. V., Krummel, T. M., Schauer, P. R., Thompson, C., Moreno, J. D. 2008; 75: S37-48

    View details for PubMedID 19024953

  • Responsible development and application of surgical innovations: a position statement of the Society of University Surgeons. Journal of the American College of Surgeons Biffl, W. L., Spain, D. A., Reitsma, A. M., Minter, R. M., Upperman, J., Wilson, M., Adams, R., Goldman, E. B., Angelos, P., Krummel, T., Greenfield, L. J. 2008; 206 (3): 1204-1209

    View details for DOI 10.1016/j.jamcollsurg.2008.02.011

    View details for PubMedID 18501819

  • Simulation-based endovascular skills assessment: The future of credentialing? JOURNAL OF VASCULAR SURGERY Tedesco, M. M., Pak, J. J., Harris, E. J., Krummel, T. M., Dalman, R. L., Lee, J. T. 2008; 47 (5): 1008-1014

    Abstract

    Simulator-based endovascular skills training measurably improves performance in catheter-based image-guided interventions. The purpose of this study was to determine whether structured global performance assessment during endovascular simulation correlated well with trainee-reported procedural skill and prior experience level.Fourth-year and fifth-year general surgery residents interviewing for vascular fellowship training provided detailed information regarding prior open vascular and endovascular operative experience. The pretest questionnaire responses were used to separate subjects into low (<20 cases) and moderate (20 to 100) endovascular experience groups. Subjects were then asked to perform a renal angioplasty/stent procedure on the Procedicus Vascular Intervention System Trainer (VIST) endovascular simulator (Mentice Corporation, Gothenburg, Sweden). The subjects' performance was supervised and evaluated by a blinded expert interventionalist using a structured global assessment scale based on angiography setup, target vessel catheterization, and the interventional procedure. Objective measures determined by the simulator were also collected for each subject. A postsimulation questionnaire was administered to determine the subjects' self-assessment of their performance.Seventeen surgical residents from 15 training programs completed questionnaires before and after the exercise and performed a renal angioplasty/stent procedure on the endovascular simulator. The beginner group (n = 8) reported prior experience of a median of eight endovascular cases (interquartile range [IQR], 6.5-17.8; range, 4-20), and intermediate group (n = 9) had previously completed a median of 42 cases (IQR, 31-44; range, 25-89, P = .01). The two groups had similar prior open vascular experience (79 cases vs 75, P = .60). The mean score on the structured global assessment scale for the low experience group was 2.68 of 5.0 possible compared with 3.60 for the intermediate group (P = .03). Scores for subcategories of the global assessment score for target vessel catheterization (P = .02) and the interventional procedure (P = .05) contributed more to the differentiation between the two experience groups. Total procedure time, fluoroscopy time, average contrast used, percentage of lesion covered by the stent, placement accuracy, residual stenosis rates, and number of cine loops utilized were similar between the two groups (P > .05).Structured endovascular skills assessment correlates well with prior procedural experience within a high-fidelity simulation environment. In addition to improving endovascular training, simulators may prove useful in determining procedural competency and credentialing standards for endovascular surgeons.

    View details for DOI 10.1016/j.jvs.2008.01.007

    View details for Web of Science ID 000255294700019

    View details for PubMedID 18372149

  • Intellectual property and royalty streams in academic departments: Myths and realities SURGERY Krummel, T. M., Shafi, B. M., Wall, J., Chandra, V., Mery, C., Gertner, M. 2008; 143 (2): 183-191

    View details for DOI 10.1016/j.surg.2007.11.011

    View details for Web of Science ID 000253172300009

    View details for PubMedID 18242333

  • Trauma training in simulation: Translating skills from SIM time to real time JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE Knudson, M. M., Khaw, L., Bullard, M. K., Dicker, R., Cohen, M. J., Staudenmayer, K., Sadjadi, J., Howard, S., Gaba, D., Krummel, T. 2008; 64 (2): 255-263

    Abstract

    : Training surgical residents to manage critically injured patients in a timely fashion presents a significant challenge. Simulation may have a role in this educational process, but only if it can be demonstrated that skills learned in a simulated environment translate into enhanced performance in real-life trauma situations.: A five-part, scenario-based trauma curriculum was developed specifically for this study. Midlevel surgical residents were randomized to receiving this curriculum in didactic lecture (LEC) fashion or with the use of a human performance simulator (HPS). A written learning objectives test was administered at the completion of the training. The first four major trauma resuscitations performed by each participating resident were captured on videotape in the emergency department and graded by two experienced judges blinded to the method of training. The assessment tool used by the judges included an evaluation of both initial trauma evaluation or treatment skills (part I) and crisis management skills (part II) as well as an overall score (poor/fail, adequate, or excellent).: The two groups of residents received almost identical scores on the posttraining written test. Average SIM and LEC scores for part I were also similar between the two groups. However, SIM-trained residents received higher overall scores and higher scores for part II crisis management skills compared with the LEC group, which was most evident in the scores received for the teamwork category (p = 0.04).: A trauma curriculum incorporating simulation shows promise in developing crisis management skills that are essential for evaluation of critically injured patients.

    View details for DOI 10.1097/TA.0b013e31816275b0

    View details for Web of Science ID 000253287100001

    View details for PubMedID 18301184

  • Responsible Development and Application of Surgical Innovations: A Position Statement of the Society of University Surgeons Journal of American College of Surgeons Biffl WL, Spain DA, Reitsma AM, Minter RM, Upperman J, Wilson M, Adams R, Goldman EB, Angelos P, Krummel TM, Greenfield LJ, The Society of University Surgeons Surgical Innovations Project Team 2008; 206 (6): 1204-1209
  • Innovative introduction to surgery in the preclinical years AMERICAN JOURNAL OF SURGERY Riboh, J., Curet, M., Krummel, T. 2007; 194 (2): 227-230

    Abstract

    Lack of exposure to surgery in the preclinical years of medical school contributes to students' negative opinions of the field and to low application rates to categorical surgical programs.Forty preclinical medical students attended a series of 16 seminars and practice sessions covering the gamut of surgical specialties and basic technical skills. Students were given a Likert format survey before and after taking the course.Students gave high ratings to course content (4.26/5) and lecturers (4.54/5). Students' confidence in their surgical skills doubled (1.45/5 to 3/5, P < .0001), and their perceived readiness for the surgical clerkship increased by 73% (1.63/5 to 2.82/5, P = .007).The preclinical years offer a promising venue for improving medical student interest and performance in surgery.

    View details for DOI 10.1016/j.amjsurg.2006.12.038

    View details for Web of Science ID 000248110900019

    View details for PubMedID 17618810

  • Keratinocytes modulate fetal and postnatal fibroblast transforming growth factor-beta and Smad expression in co-culture PLASTIC AND RECONSTRUCTIVE SURGERY Colwell, A. S., Yun, R., Krummel, T. M., Longaker, M. T., Lorenz, H. P. 2007; 119 (5): 1440-1445

    Abstract

    The mechanism of fetal scarless wound repair is poorly understood but is thought to involve unique characteristics and behavior patterns of the fetal dermal fibroblast. The authors hypothesized that keratinocytes may differentially modulate expression of key growth factors expressed during wound healing in fetal and postnatal fibroblasts.Murine E17 fetal (n = 12 animals) and newborn (n = 8 animals) fibroblasts were grown in isolation and co-culture with newborn keratinocytes (n = 12 animals). Quantitative real-time polymerase chain reaction was performed for transforming growth factor (TGF)-beta isoform, receptor, and signaling molecule (Smad) gene expression in each group under both conditions.At baseline, fetal fibroblasts have 1.8-fold greater TGF-beta3 expression than postnatal fibroblasts (p < 0.01). Keratinocytes induce a further increase of TGF-beta3 expression (p < 0.01) but decreased TGF-beta1, TGF-beta2, TGF-beta receptor (R)-I, and TGF-betaR-II expression in fetal fibroblasts. Keratinocytes also induce an increase in TGF-beta3 (p < 0.01) and a decrease TGF-beta2, TGF-betaR-I, and TGF-betaR-II expression in postnatal fibroblasts; however, TGF-beta1 expression is unchanged. Fetal fibroblasts have lower baseline expression of Smad3 and Smad4 than postnatal fibroblasts (p < 0.05). Keratinocytes decrease Smad3 and increase Smad7 expression in both fetal and postnatal fibroblasts (p < 0.01). In contrast, keratinocytes decrease Smad2 only in fetal fibroblasts (p < 0.05).Keratinocytes have an overall antifibrotic influence on both fetal and postnatal fibroblasts in co-culture conditions. These data further characterize intrinsic differences between fetal and postnatal fibroblasts.

    View details for DOI 10.1097/01.prs.0000256049.53562.39

    View details for Web of Science ID 000245711700007

    View details for PubMedID 17415238

  • Transforming growth factor-beta, smad, and collagen expression patterns in fetal and adult keratinocytes PLASTIC AND RECONSTRUCTIVE SURGERY Colwell, A. S., Faudoa, R., Krummel, T. M., Longaker, M. T., Lorenz, H. P. 2007; 119 (3): 852-857

    Abstract

    The transforming growth factor (TGF)-beta family regulates cellular proliferation, differentiation, and migration. To better define the influence of keratinocyte-derived TGF-beta during development and repair, the authors examined the TGF-beta isoform, receptor, signal messenger Smad, and collagen type I expression in fetal and postnatal keratinocytes.Sprague-Dawley rat keratinocytes were isolated in primary culture from fetal E17 (n = 6), newborn (n = 4), and 6-week-old adults (n = 4). Under serum-free conditions, quantitative polymerase chain reaction was performed for TGF-beta1, TGF-beta2, and TGF-beta3 ligands; TGF-beta receptor 1 (RI) and TGF-beta receptor 2 (RII); Smad4 and Smad7; and collagen type I expression.Total TGF-beta isoform expression increased 1.7-fold from E17 to newborn (p < 0.05) and adult (p < 0.01) ages. TGF-beta1 expression was 25-fold greater than TGF-beta2 and 10-fold greater than TGF-beta3 in fetal keratinocytes (p < 0.01 for each). The expression of TGF-beta1 was fivefold greater compared with TGF-beta2 and TGF-beta3 in newborn and adult keratinocytes (p < 0.01). TGF-beta-RI expression increased more than twofold (p < 0.01), whereas TGF-beta-RII expression increased by 25 percent (p < 0.01) from E17 to adult age. Smad4 increased more than twofold (p < 0.01), whereas Smad7 did not change appreciably. Collagen type I expression increased over 100-fold from E17 to adult (p < 0.005).The TGF-beta system and collagen type I have increased expression with increasing gestational age in keratinocytes. This suggests an increased profibrotic TGF-beta response and collagen type I production in keratinocytes during skin differentiation at ages associated with scarring.

    View details for DOI 10.1097/01.prs.0000255541.39993.66

    View details for Web of Science ID 000244438700011

    View details for PubMedID 17312487

  • IPEG panel on challenges of medical innovation: Case one JOURNAL OF LAPAROENDOSCOPIC & ADVANCED SURGICAL TECHNIQUES Krummel, T. M., Azizkhan, R., Holcomb, G. W., Winslade, W., Ziegler, M. M. 2007; 17 (1): 64-66

    View details for DOI 10.1089/lap.2006.9999

    View details for Web of Science ID 000245056900014

    View details for PubMedID 17362182

  • IPEG panel on challenges of medical innovation: Introduction JOURNAL OF LAPAROENDOSCOPIC & ADVANCED SURGICAL TECHNIQUES Krummel, T. M., Ziegler, M. M. 2006; 16 (6): 634-638

    View details for Web of Science ID 000243451900020

    View details for PubMedID 17243887

  • Inventing our future: training the next generation of surgeon innovators. Seminars in pediatric surgery Krummel, T. M., Gertner, M., Makower, J., Milroy, C., Gurtner, G., Woo, R., Riskin, D. J., Binyamin, G., Connor, J. A., Mery, C. M., Shafi, B. M., Yock, P. G. 2006; 15 (4): 309-318

    Abstract

    Current surgical care and technology has evolved over the centuries from the interplay between creative surgeons and new technologies. As both fields become more specialized, that interplay is threatened. A 2-year educational fellowship is described which teaches both the process and the discipline of medical/surgical device innovation. Multi-disciplinary teams (surgeons, engineers, business grads) are assembled to educate a generation of translators, who can bridge the gap between scientific and technologic advances and the needs of the physician and the patient.

    View details for PubMedID 17055962

  • Innovation in surgery - A historical perspective ANNALS OF SURGERY Riskin, D. J., T Longaker, M., Gertner, M., Krummel, T. M. 2006; 244 (5): 686-693

    Abstract

    To describe the field of surgical innovation from a historical perspective, applying new findings from research in technology innovation.While surgical innovation has a rich tradition, as a field of study it is embryonic. Only a handful of academic centers of surgical innovation exist, all of which have arisen within the last 5 years. To this point, the field has not been well defined, nor have future options to promote surgical innovation been thoroughly explored. It is clear that surgical innovation is fundamental to surgical progress and has significant health policy implications. A process of systematically evaluating and promoting innovation in surgery may be critical in the evolving practice of medicine.A review of the academic literature in technology innovation was undertaken. Articles and books were identified through technical, medical, and business sources. Luminaries in surgical innovation were interviewed to develop further relevance to surgical history. The concepts in technology innovation were then applied to innovation in surgery, using the historical example of surgical endoscopy as a representative area, which encompasses millennia of learning and spans multiple specialties of care.The history of surgery is comprised largely of individual, widely respected surgeon innovators. While respecting individual accomplishments, surgeons as a group have at times hindered critical innovation to the detriment of our profession and patients. As a clinical discipline, surgery relies on a tradition of research and attracting the brightest young minds. Innovation in surgery to date has been impressive, but inconsistently supported.A body of knowledge on technology innovation has been developed over the last decade but has largely not been applied to surgery. New surgical innovation centers are working to define the field and identify critical aspects of surgical innovation promotion. It is our responsibility as a profession to work to understand innovation in surgery, discover, translate, and commercialize advances to address major clinical problems, and to support the future of our profession consistently and rationally.

    View details for DOI 10.1097/01.sla.0000242706.91771.ce

    View details for Web of Science ID 000242278300012

    View details for PubMedID 17060760

  • What is surgery? Seminars in pediatric surgery Krummel, T. M. 2006; 15 (4): 237-241

    Abstract

    Progress in surgical science has been characterized by a continuous cycle of innovation from bedside to bench to bedside. Beginning 30,000 years ago with the first bone needles to surgical lasers and robotics of today, each quantum leap has resulted from the convergence of technical advances and creative surgeons, but always defined by an attitude of care toward the sick. One of the most innovative pediatric surgeons, Dr. Mark Ravitch, elucidated some simple yet profound principles in the precise answer to the question "What is Surgery?" This section outlines some simple concepts summarized as "Ravitch's Rules," which provide a useful framework for clarity in understanding the past and illuminating the road ahead. Surgeons must be thoughtful in how they define themselves and their craft, ignoring technological advances at their own peril.

    View details for PubMedID 17055953

  • The ethics of innovation in pediatric surgery. Seminars in pediatric surgery Riskin, D. J., Longaker, M. T., Krummel, T. M. 2006; 15 (4): 319-323

    Abstract

    Ethical issues in pediatric research have long been debated, and experimentation in pediatric surgery is under intense scrutiny. Extensive legislation and institutional systems that attempt to protect children while supporting necessary research are at times ineffective. Pediatric surgery has less funding and resources for innovation than fields with higher clinical volume. Not unlike pediatrics in general, innovation in pediatric surgery must be beyond criticism. And yet, for the sake of patients, innovation should not only be maintained, but must be encouraged.

    View details for PubMedID 17055963

  • Early-gestation fetal scarless wounds have less lysyl oxidase expression PLASTIC AND RECONSTRUCTIVE SURGERY Colwell, A. S., Krummel, T. M., Longaker, M. T., Lorenz, H. P. 2006; 118 (5): 1125-1129

    Abstract

    Lysyl oxidase cross-links collagen and elastin. Because cross-linking likely influences collagen architecture, the authors compared lysyl oxidase expression during scarless and scarring fetal dermal wound repair.Excisional dermal wounds were made on E17 (gestational day 16.5) and E19 (gestational day 18.5) mouse fetuses. Skin and wound RNA was collected at 8, 12, and 24 hours. Quantitative real-time polymerase chain reaction was performed for lysyl oxidase. The effect of transforming growth factor (TGF)-beta1 on lysyl oxidase expression in fetal fibroblasts was tested. Confluent primary fetal and postnatal fibroblast cultures were stimulated with TGF-beta1 for 24 hours, and lysyl oxidase expression was quantitated by performing real-time polymerase chain reaction. Lysyl oxidase expression was also quantitated in unwounded fetal skin to determine its expression profile during development.E17 and E19 fetal skin had approximately 2-fold greater lysyl oxidase expression than postnatal skin (p < 0.01), and fetal fibroblasts had greater baseline lysyl oxidase expression than postnatal fibroblasts. After TGF-beta1 stimulation, fetal and postnatal fibroblasts responded with increases in lysyl oxidase expression. In E17 early-gestation scarless fetal wounds, lysyl oxidase had small increases (<1.5-fold) in expression from 1 to 12 hours. In late-gestation E19 scarring fetal wounds, lysyl oxidase increased 1.8-fold at 8 hours and 2-fold at 12 hours, which was significantly greater than the changes observed in E17 scarless wounds (p < 0.01 for each).Lysyl oxidase has greater expression in E19 late-gestation wounds that heal with scar compared with E17 early-gestation scarless wounds. This suggests a role for lysyl oxidase in scar formation.

    View details for DOI 10.1097/01.prs.0000221056.27536.db

    View details for Web of Science ID 000241327600008

    View details for PubMedID 17016177

  • Fetal and adult fibroblasts have similar TGF-beta-mediated, Smad-dependent signaling pathways PLASTIC AND RECONSTRUCTIVE SURGERY Colwell, A. S., Krummel, T. M., Longaker, M. T., Lorenz, H. P. 2006; 117 (7): 2277-2283

    Abstract

    The scarless fetal skin-healing mechanism is mediated in part by the fibroblast and involves differential expression of transforming growth factor (TGF)-beta isoforms 1 and 3. The authors hypothesized that fetal and adult fibroblasts respond differently to TGF-beta isoform-specific stimulation, which may influence whether wounds scar. Connective tissue growth factor (CTGF), Smad3, and Smad7 are TGF-beta target genes. Expression of these targets was quantitated after TGF-beta1 and -beta3 stimulation of fetal and adult fibroblasts.Primary mouse fibroblast cultures at gestational day 16.5 (E17), 18.5 (E19), and 6 weeks (adult) were stimulated with TGF-beta1 or TGF-beta3. Quantitative polymerase chain reaction was performed for CTGF, Smad3, and Smad7 expression.CTGF was reduced four-fold in E17 and E19 compared with adult fibroblasts (p < 0.005). After TGF-beta1 stimulation, CTGF expression increased more than 60-fold in both E17 and E19 (p < 0.01), which was three-fold greater than that in adult fibroblasts (p < 0.005). TGF-beta3 induced more than 70-fold, 50-fold, and 20-fold increases in CTGF expression in E17, E19, and adult fibroblasts, respectively (p < 0.01 for each). Both TGF-beta1 and -beta3 decreased Smad3 expression and increased Smad7 expression in each fibroblast type, suggesting that intact TGF-beta-mediated signaling pathways were present.Fetal (E17 and E19) fibroblasts have lower CTGF expression compared with adult fibroblasts. However, fetal fibroblasts have larger increases in CTGF expression after TGF-beta1 or -beta3 stimulation. Fetal and adult mouse fibroblasts have similar TGF-beta1 and TGF-beta3 transcriptional regulation of Smad3 and Smad7. This suggests that scarless healing is likely not mediated by different Smad-dependent transcriptional responses to TGF-beta isoforms in the fetal E17 fibroblast.

    View details for DOI 10.1097/01.prs.0000224299.16523.76

    View details for Web of Science ID 000238431500026

    View details for PubMedID 16772929

  • An in vivo mouse excisional wound model of scarless healing PLASTIC AND RECONSTRUCTIVE SURGERY Colwell, A. S., Krummel, T. M., Longaker, M. T., Lorenz, H. P. 2006; 117 (7): 2292-2296

    Abstract

    The purpose of this study was to develop a reproducible murine model of fetal scarless wound healing.One-millimeter excisional wounds were made in fetal skin at gestational days 16.5 (E17) and 18.5 (E19) (term = day 21.5, or E22) and marked with India ink. Fetal mortality was less than 30 percent in E17 fetuses and 0 percent in E19 fetuses. Control postnatal 2-mm open wounds were made in 3-week-old mice.At 48 hours, E17 skin wounds had healed completely. E19 skin wounds also healed but were marked by skin irregularity at the wound site. Histologically, E17 wounds had fine reticular collagen architecture by trichrome staining and hair follicle regeneration. In contrast, E19 wounds healed with collagen deposition and scar formation and no hair follicle regeneration.The authors have developed a reliable mouse model of fetal scarless repair to help elucidate the mechanism of scarless wound healing to take advantage of genetically modified animals. The knowledge gained may be used to manipulate scarring in the adult to produce a more fetal-like wound.

    View details for DOI 10.1097/01.prs.0000219340.47232.eb

    View details for Web of Science ID 000238431500028

    View details for PubMedID 16772931

  • To simulate or not to simulate what is the question? ANNALS OF SURGERY Dutta, S., Gaba, D., Krummel, T. M. 2006; 243 (3): 301-303
  • Laparoscopic resection of type 1 choledochal cysts in pediatric patients SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES Le, D. M., Woo, R. K., Sylvester, K., Krummel, T. M., Albanese, C. T. 2006; 20 (2): 249-251

    Abstract

    Choledochal cyst resection and hepaticojejunostomy have historically been performed using an open technique. We describe here the largest single experience with this procedure using laparoscopic techniques in eight consecutive pediatric patients.There were six girls and two boys, of ages ranging from 3 months to 13 years. All had type I choledochal cysts. Three were asymptomatic, having been noted on prenatal ultrasonography. Five ports were utilized: one 5-mm telescope port at the umbilicus, two 3-mm operating ports on both sides of the umbilicus, one 5-mm left subcostal port for liver retraction, and one LLQ 5-mm assistant port.The median operating time was 155 min (range 110-250 min), with one conversion to an open procedure due to a high transection of the cyst leading to partial retraction of the left hepatic duct into the liver substance. Mean hospital stay was 3 days. At a mean follow-up of 18.8 months, all patients were anicteric and asymptomatic.Laparoscopic resection of choledochal cysts can be performed safely in pediatric patients with minimal morbidity and good long-term results.

    View details for DOI 10.1007/s00464-005-0151-4

    View details for Web of Science ID 000235059700014

    View details for PubMedID 16391960

  • Skin wounds in the MRL/MPJ mouse heal with scar WOUND REPAIR AND REGENERATION Colwell, A. S., Krummel, T. M., Kong, W., Longaker, M. T., Lorenz, H. P. 2006; 14 (1): 81-90

    Abstract

    Adult MRL/MpJ mice regenerate cartilage during repair of through-and-through ear punch wounds. However, the ability of this mouse strain to heal isolated cutaneous wounds by regeneration or with scar is unknown. The purpose of this study was to characterize the rate of reepithelialization and collagen architecture in dermal wounds from MRL/MpJ mice compared with C57bl/6 and Balb/c strains. Full-thickness incisional (5 mm) and excisional (2 mm diameter) skin wounds were made on the dorsum of 7-week-old MRL/MpJ, C57bl/6, and Balb/c mice. Ear punch wounds were made simultaneously on each animal. Reepithelialization was complete by 48 hours for incisional skin wounds in each strain. All excisional wounds showed incomplete reepithelialization at 24, 48, and 72 hours. At 14 days, all skin wounds had grossly healed. In contrast to the ear wounds made in C57bl/6 and Balb/c mice, MRL/MpJ ear wounds were completely healed by day 28. Dorsal skin wound sections at 14 and 28 days revealed dense collagen deposition and similar degrees of fibrosis between the three strains of mice. In conclusion, in contrast to wound healing in the ear, MRL/MpJ mouse dorsal cutaneous wounds heal similarly to C57bl/6 and Balb/c mice with dermal collagen deposition and scar formation.

    View details for DOI 10.1111/j.1743-6109.2005.00092.x

    View details for Web of Science ID 000235220000012

    View details for PubMedID 16476076

  • Simulation: a new frontier in surgical education. Advances in surgery Dutta, S., Krummel, T. M. 2006; 40: 249-263

    Abstract

    Simulation offers a new frontier in surgical education that promises to enhance the current approaches to training. It addresses the operational and fiscal realities of current healthcare deliveries while adhering to principles of educational psychology. Challenges for educators include systematic validation of simulation methods, attracting research funding agencies to support this cause, and development of appropriate funding mechanisms for the sometimes high facility and hardware costs. The greatest challenge, however, is instituting simulation into the minds of a surgical community that is already steeped in a long and entrenched tradition of Halstedian surgical training.

    View details for PubMedID 17163107

  • Portal vein thrombosis after laparoscopic splenectomy: an ongoing clinical challenge. JSLS : Journal of the Society of Laparoendoscopic Surgeons / Society of Laparoendoscopic Surgeons Miniati, D. N., Padidar, A. M., Kee, S. T., Krummel, T. M., Mallory, B. 2005; 9 (3): 335-338

    Abstract

    Portal vein thrombosis (PVT) following open splenectomy is a potentially lethal complication with an incidence of up to 6%. The objective of this report is to describe our management of a recent laparoscopic case, discuss current therapies, and consider antiplatelet therapy for prophylaxis.Medical records, laboratory studies, and imaging studies pertaining to a recent case of a laparoscopic splenectomy were examined. Current literature related to this topic was reviewed.A 16-year-old girl underwent laparoscopic splenectomy for idiopathic thrombocytopenic purpura. Her preoperative platelet count was 96K. She was discharged on postoperative day 1 after an uneventful operation including division of the splenic hilum with an endoscopic linear stapler. On postoperative day 20, she presented with a 5-day history of epigastric pain, nausea, and low-grade fevers without peritoneal signs. Her white blood cell count was 17.3; her platelets were 476K. Computed tomography demonstrated thrombosis of the splenic, superior mesenteric, and portal veins propagating into the liver. Heparinization was begun followed by an unsuccessful attempt at pharmacologic and mechanical thrombolysis by interventional radiology. Over the next 5 days, her pain resolved, she tolerated a full diet, was converted to oral anticoagulation and sent home. Follow-up radiographic studies demonstrated the development of venous collaterals and cavernous transformation of the portal vein.No standard therapy for PVT exists; several approaches have been described. These include systemic anticoagulation, systemic or regional medical thrombolysis, mechanical thrombolysis, and surgical thrombectomy. Unanswered questions exist about the most effective acute therapy, duration of anticoagulation, and the potential efficacy of routine prophylaxis with perioperative antiplatelet agents. PVT following splenectomy occurs with both the open and laparoscopic approach.

    View details for PubMedID 16121882

  • Stanford University School of Medicine ARCHIVES OF SURGERY Mark, J. B., Krummel, T. M. 2004; 139 (12): 1276-1277

    View details for Web of Science ID 000225506700001

    View details for PubMedID 15611449

  • Advanced technologies in plastic surgery: How new innovations can improve our training and practice PLASTIC AND RECONSTRUCTIVE SURGERY Grunwald, T., Krummel, T., Sherman, R. 2004; 114 (6): 1556-1567

    Abstract

    Over the last two decades, virtual reality, haptics, simulators, robotics, and other "advanced technologies" have emerged as important innovations in medical learning and practice. Reports on simulator applications in medicine now appear regularly in the medical, computer science, engineering, and popular literature. The goal of this article is to review the emerging intersection between advanced technologies and surgery and how new technology is being utilized in several surgical fields, particularly plastic surgery. The authors also discuss how plastic and reconstructive surgeons can benefit by working to further the development of multimedia and simulated environment technologies in surgical practice and training.

    View details for DOI 10.1097/01.PRS.0000138242.60324.1D

    View details for Web of Science ID 000224809700030

    View details for PubMedID 15509950

  • Robotic technology in surgery: past, present, and future AMERICAN JOURNAL OF SURGERY Camarillo, D. B., Krummel, T. M., Salisbury, J. K. 2004; 188 (4A): 2S-15S

    Abstract

    It has been nearly 20 years since the first appearance of robotics in the operating room. In that time, much progress has been made in integrating robotic technologies with surgical instrumentation, as evidenced by the many thousands of successful robot-assisted cases. However, to build on past success and to fully leverage the potential of surgical robotics in the future, it is essential to maximize a shared understanding and communication among surgeons, engineers, entrepreneurs, and healthcare administrators. This article provides an introduction to medical robotic technologies, develops a possible taxonomy, reviews the evolution of a surgical robot, and discusses future prospects for innovation. Robotic surgery has demonstrated some clear benefits. It remains to be seen where these benefits will outweigh the associated costs over the long term. In the future, surgical robots should be smaller, less expensive, easier to operate, and should seamlessly integrate emerging technologies from a number of different fields. Such advances will enable continued progress in surgical instrumentation and, ultimately, surgical care.

    View details for DOI 10.1016/j.amjsung.2004.08.025

    View details for Web of Science ID 000224479800003

    View details for PubMedID 15476646

  • Introduction: robotic surgery today and tomorrow AMERICAN JOURNAL OF SURGERY Chitwood, W. R., Krummel, T. M. 2004; 188 (4A): 1S-1S
  • Robot-assisted pediatric surgery AMERICAN JOURNAL OF SURGERY Woo, R., Le, D., Krummel, T. M., Albanese, C. 2004; 188 (4A): 27S-37S

    Abstract

    Computer-enhanced robotic surgical systems have been increasingly used to facilitate complex minimal access surgical procedures. In adult patients, such systems have been used to perform a wide variety of operations including coronary artery bypass grafting, mitral valve repair, Roux-en-Y gastric bypass, colon resection, nephrectomy, and radical prostatectomy. In the field of pediatric surgery, the experience with robotic surgical systems has been more limited. However, with improvements in robotic technology, interest and experience with robotic pediatric surgery have grown rapidly. The purpose of this article is to review the current experimental and clinical literature regarding the use of robotic surgical systems in the pediatric patient population.

    View details for DOI 10.1016/j.amjsurg.2004.08.017

    View details for Web of Science ID 000224479800006

    View details for PubMedID 15476649

  • Micro- and Nanoelectromechanical Systems in Medicine and Surgery Greco, R (Eds), Nanobiology: Nano Scale Fabrication of New Generation of Biomedical Devices, for publication in 2004 Gertner ME, Krummel TM 2004
  • Emergency medicine crisis resource management (EMCRM): Pilot study of a simulation-based crisis management course for emergency medicine ACADEMIC EMERGENCY MEDICINE Reznek, M., Smith-Coggins, R., Howard, S., Kiran, K., Harter, P., Sowb, Y., Gaba, D., Krummel, T. 2003; 10 (4): 386-389

    Abstract

    To determine participant perceptions of Emergency Medicine Crisis Resource Management (EMCRM), a simulation-based crisis management course for emergency medicine.EMCRM was created using Anesthesia Crisis Resource Management (ACRM) as a template. Thirteen residents participated in one of three pilot courses of EMCRM; following a didactic session on principles of human error and crisis management, the residents participated in simulated emergency department crisis scenarios and instructor-facilitated debriefing. The crisis simulations involved a computer-enhanced mannequin simulator and standardized patients. After finishing the course, study subjects completed a horizontal numerical scale survey (1 = worst rating to 5 = best rating) of their perceptions of EMCRM. Descriptive statistics were calculated to evaluate the data.The study subjects found EMCRM to be enjoyable (4.9 +/- 0.3) (mean +/- SD) and reported that the knowledge gained from the course would be helpful in their practices (4.5 +/- 0.6). The subjects believed that the simulation environment prompted realistic responses (4.6 +/- 0.8) and that the scenarios were highly believable (4.8 +/- 0.4). The participants reported that EMCRM was best suited for residents (4.9 +/- 0.3) but could also benefit students and attending physicians. The subjects believed that the course should be repeated every 8.2 +/- 3.3 months.The EMCRM participants rated the course very favorably and believed that the knowledge gained would be beneficial in their practices. The extremely positive response to EMCRM found in this pilot study suggests that this training modality may be valuable in training emergency medicine residents.

    View details for Web of Science ID 000181995500016

    View details for PubMedID 12670855

  • Virtual reality applied to procedural testing: The next era ANNALS OF SURGERY Bloom, M. B., Rawn, C. L., Salzberg, A. D., Krummel, T. M. 2003; 237 (3): 442-448

    Abstract

    To establish the construct validity of a virtual reality-based upper gastrointestinal endoscopy simulator as a tool for the skills training of residents.Previous studies have demonstrated the relevance of virtual reality training as an adjunct to traditional operating room learning for residents. The use of specific task trainers, which have the ability to objectively analyze and track user performance, has been shown to demonstrate improvements in performance over time. Using this off-line technology can lessen the financial and ethical concerns of using operative time to teach basic skills.Thirty-five residents and fellows from General Surgery and Gastrointestinal Medicine were recruited for this study. Their performance on virtual reality upper endoscopy tasks was analyzed by computer. Assessments were made on parameters such as time needed to finish the examination, completeness of the examination, and number of wall collisions. Subjective experiences were queried through questionnaires. Users were grouped according to their prior level of experience performing endoscopy.Construct validation of this simulator was demonstrated. Performance on visualization and biopsy tasks varied directly with the subjects' prior experience level. Subjective responses indicated that novice and intermediate users felt the simulation to be a useful experience, and that they would use the equipment in their off time if it were available.Virtual reality simulation may be a useful adjunct to traditional operating room experiences. Construct validity testing demonstrates the efficacy of this device. Similar objective methods of skills evaluation may be useful as part of a residency skills curriculum and as a means of procedural skills testing.

    View details for Web of Science ID 000185834100022

    View details for PubMedID 12616131

  • Current Problems in Surgical Addvanced Technology Current Problems in Surgery Salzberg D, Bloom M, Krummel TM 2003; 39 (8): 733-832
  • Evaluation of the educational effectiveness of a virtual reality intravenous insertion simulator ACADEMIC EMERGENCY MEDICINE Reznek, M. A., Rawn, C. L., Krummel, T. M. 2002; 9 (11): 1319-1325

    Abstract

    To evaluate construct and content validity as well as learners' perceptions of CathSim, a virtual reality intravenous (IV) insertion simulator.A prospective cohort study design was employed to determine construct validity, and a participant survey was used to ascertain content validity as well as user perceptions of CathSim. Forty-one attendings, residents, and medical students in emergency medicine and anesthesia attempted five simulated IV insertions on CathSim. Subject performances were scored by the computer, and subject perceptions of the simulator were measured using a Likert scale questionnaire (1 = worst rating; 5 = best rating). The subjects were divided into three groups (novices, intermediates, and experts) based on previous IV experience. To determine construct validity, performances of the three groups were compared using one-way analysis of variance (ANOVA). To determine content validity, the experts' perceptions of the simulator's realism and usefulness were assessed. Study subjects' perceptions of the simulator's ease of use and overall appeal were analyzed.The experts scored better than the others in five of nine scoring parameters (p < 0.05). The experts rated the realism of CathSim's four major simulation components at 3.85, 3.46, 3.69, and 3.46; the overall realism of CathSim at 2.93; and its utility for medical student training at 4.57. The simulator's ease of use was rated at 2.34 by all subjects. Novices reported a score of 4.59 regarding their likelihood to use the simulator.CathSim demonstrated construct validity in five of nine internal scoring parameters and was judged to be adequately realistic and highly useful for medical student training. Despite being difficult to learn to use, it remained appealing to the users, especially the novices.

    View details for Web of Science ID 000179203100038

    View details for PubMedID 12414488

  • Matrix metalloproteinases and the ontogeny of scarless repair: The other side of the wound healing balance PLASTIC AND RECONSTRUCTIVE SURGERY Peled, Z. M., Phelps, E. D., Updike, D. L., Chang, J., Krummel, T. M., Howard, E. W., Longaker, M. T. 2002; 110 (3): 801-811

    Abstract

    Early gestation mammalian fetuses possess the remarkable ability to heal cutaneous wounds in a scarless fashion. Over the past 20 years, scientists have been working to decipher the mechanisms underlying this phenomenon. Much of the research to date has focused on fetal correlates of adult wound healing that promote fibrosis and granulation tissue formation. It is important to remember, however, that wound repair consists of a balance between tissue synthesis, deposition, and degradation. Relatively little attention has been paid to this latter component of the fetal wound healing process. In this study, we examined the ontogeny of ten matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in nonwounded fetal rat skin and fibroblasts as a function of gestational age. We used a semiquantitative polymerase chain reaction protocol to analyze these important enzymes at time points that represent both the scarless and scar-forming periods of rat gestation. The enzymes evaluated were collagenase-1 (MMP-1), stromelysin-1 (MMP-3), gelatinase A (MMP-2), gelatinase B (MMP-9), membrane-type matrix metalloproteinases (MT-MMPs) 1, 2, and 3, and TIMPs 1, 2, and 3. Results demonstrated marked increases in gene expression for MMP-1, MMP-3 and MMP-9 that correlated with the onset of scar formation in nonwounded fetal skin. Similar results were noted in terms of MMP-9 gene expression in fetal fibroblasts. These results suggest that differences in the expression of these matrix metalloproteinases may have a role in the scarless wound healing phenotype observed early in fetal rat gestation. Furthermore, our data suggest that the differential expression of gelatinase B (MMP-9) may be mediated by the fetal fibroblasts themselves.

    View details for DOI 10.1097/01.PRS.0000019915.20203.EC

    View details for Web of Science ID 000177332700013

    View details for PubMedID 12172142

  • Advanced technology in surgery. Current problems in surgery Bloom, M. B., Salzberg, A. D., Krummel, T. M. 2002; 39 (8): 733-830

    View details for PubMedID 12374907

  • Microelectrical mechanical systems in surgery and medicine JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Salzberg, A. D., Bloom, M. B., Mourlas, N. J., Krummel, T. M. 2002; 194 (4): 463-476

    View details for Web of Science ID 000174710800009

    View details for PubMedID 11949752

  • Virtual reality and simulation: Training the future emergency physician ACADEMIC EMERGENCY MEDICINE Reznek, M., Harter, P., Krummel, T. 2002; 9 (1): 78-87

    Abstract

    The traditional system of clinical education in emergency medicine relies on practicing diagnostic, therapeutic, and procedural skills on live patients. The ethical, financial, and practical weaknesses of this system are well recognized, but the alternatives that have been explored to date have shown even greater flaws. However, ongoing progress in the area of virtual reality and computer-enhanced simulation is now providing educational applications that show tremendous promise in overcoming most of the deficiencies associated with live-patient training. It will be important for academic emergency physicians to become more involved with this technology to ensure that our educational system benefits optimally.

    View details for Web of Science ID 000173033300013

    View details for PubMedID 11772675

  • Wound Healing Zeigler M, Azizkhan R, Weber T (Eds): Pediatric Surgery Krummel TM, Bloom M, Krummel TM 2002
  • Fetal wound healing: Progress report and future directions SURGERY Longaker, N. T., Peled, Z. M., Chang, J., Krummel, T. M. 2001; 130 (5): 785-787

    View details for Web of Science ID 000172026000002

    View details for PubMedID 11685186

  • The surgical suite meets the new health economy JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS Canales, M. G., Macario, A., Krummel, T. 2001; 192 (6): 768-776

    View details for Web of Science ID 000169043500014

    View details for PubMedID 11400971

  • The future of medical education is no longer blood and guts, it is bits and bytes AMERICAN JOURNAL OF SURGERY Gorman, P. J., Meier, A. H., Rawn, C., Krummel, T. M. 2000; 180 (5): 353-356

    Abstract

    In the United States, medical care consumes approximately $1.2 trillion annually (14% of the gross domestic product) and involves 250,000 physicians, almost 1 million nurses, and countless other providers. While the Information Age has changed virtually every other facet of our life, the education of these healthcare professionals, both present and future, is largely mired in the 100-year-old apprenticeship model best exemplified by the phase "see one, do one, teach one." Continuing medical education is even less advanced. While the half-life of medical information is less than 5 years, the average physician practices 30 years and the average nurse 40 years. Moreover, as medical care has become increasingly complex, medical error has become a substantial problem. The current convulsive climate in academic health centers provides an opportunity to rethink the way medical education is delivered across a continuum of professional lifetimes. If this is well executed, it will truly make medical education better, safer, and cheaper, and provide real benefits to patient care, with instantaneous access to learning modules. At the Center for Advanced Technology in Surgery at Stanford we envision this future: within the next 10 years we will select, train, credential, remediate, and recredential physicians and surgeons using simulation, virtual reality, and Web-based electronic learning. Future physicians will be able to rehearse an operation on a projectable palpable hologram derived from patient-specific data, and deliver the data set of that operation with robotic assistance the next day.

    View details for Web of Science ID 000166008200008

    View details for PubMedID 11137686

  • Surgical Robotics In Harrison, M (ed): Fetal Therapy Bholat OS, Krummel TM 2000
  • Computer-assisted training and learning in surgery. Computer aided surgery Gorman, P. J., Meier, A. H., Krummel, T. M. 2000; 5 (2): 120-130

    Abstract

    The teaching and learning of surgery is a time-honored tradition based upon the "see one, do one, teach one" apprenticeship model. Recent improvement of this model has centered upon incremental change in skills teaching and testing and curricular development. Economic pressures have strained the resources of academic health centers and faculty responsible for teaching surgery, even as information technology has opened new avenues for obtaining and benefitting from relevant information. Combining the tools of simulation theory, virtual reality, and the principles of adult education offers new opportunities to optimize surgical education as we enter a more highly connected and interdependent era, where the boundaries between teacher and student blur as the modern surgeon truly becomes a lifelong learner.

    View details for PubMedID 10862134

  • A prototype haptic lumbar puncture simulator. Studies in health technology and informatics Gorman, P., Krummel, T., Webster, R., Smith, M., Hutchens, D. 2000; 70: 106-109

    Abstract

    Lumbar punctures (LP) are complex, precise procedures done to obtain cerebro-spinal fluid from a patient for diagnostic purposes. Incorrect techniques resulting from inadequate training or supervision can result in sub-optimal outcomes. As tactile feedback is crucial for a successful lumbar puncture, this procedure serves as an ideal candidate for the development of a haptic training simulator. The intent of this project is to engineer a force feedback LP simulator that provides a safe method of training students (medical students, residents, or trained physicians) for an actual LP procedure on a patient.

    View details for PubMedID 10977521

  • End user analysis of a force feedback virtual reality based surgical simulator. Studies in health technology and informatics Gorman, P. J., Lieser, J. D., Marshall, R. L., Krummel, T. M. 2000; 70: 102-105

    View details for PubMedID 10977520

  • Simulation and virtual reality in surgical education - Real or unreal? ARCHIVES OF SURGERY Gorman, P. J., Meier, A. H., Krummel, T. M. 1999; 134 (11): 1203-1208

    Abstract

    Rapid change is under way on several fronts in medicine and surgery. Advances in computing power have enabled continued growth in virtual reality, visualization, and simulation technologies. The ideal learning opportunities afforded by simulated and virtual environments have prompted their exploration as learning modalities for surgical education and training. Ongoing improvements in this technology suggest an important future role for virtual reality and simulation in surgical education and training.

    View details for Web of Science ID 000083520100006

    View details for PubMedID 10555634

Conference Proceedings


  • Trocar injuries in laparoscopic surgery Bhoyrul, S., Vierra, M. A., Nezhat, C. R., Krummel, T. M., Way, L. W. ELSEVIER SCIENCE INC. 2001: 677-683

    Abstract

    Disposable trocars with safety shields are widely used for laparoscopic access. The aim of this study was to analyze risk factors associated with injuries resulting from their use as reported to the Food and Drug Administration.Manufacturers are required to report medical device-related incidents to the Food and Drug Administration. We analyzed the 629 trocar injuries reported from 1993 through 1996.There were three types of injury: 408 injuries of major blood vessels, 182 other visceral injuries (mainly bowel injuries), and 30 abdominal wall hematomas. Of the 32 deaths, 26 (81%) resulted from vascular injuries and 6 (19%) resulted from bowel injuries. Eighty-seven percent of deaths from vascular injuries involved the use of disposable trocars with safety shields and 9% involved disposable trocars with a direct-viewing feature. The aorta (23%) and inferior vena cava (15%) were the vessels most commonly traumatized in the fatal vascular injuries. Ninety-one percent of bowel injuries involved trocars with safety shields and 7% involved direct-view trocars. The diagnosis of an enterotomy was delayed in 10% of cases, and the mortality rate in this group was 21%. In 41 cases (10%) the surgeon initially thought the trocar had malfunctioned, but in only 1 instance was malfunction subsequently found when the device was examined. The likelihood of injury was not related to any specific procedure or manufacturer.These data show that safety shields and direct-view trocars cannot prevent serious injuries. Retroperitoneal vascular injuries should be largely avoidable by following safe techniques. Bowel injuries often went unrecognized, in which case they were highly lethal. Device malfunction was rarely a cause of trocar injuries.

    View details for Web of Science ID 000169043500001

    View details for PubMedID 11400960

  • Virtual reality: Surgical application - Challenge for the new millennium Meier, A. H., Rawn, C. L., Krummel, T. M. ELSEVIER SCIENCE INC. 2001: 372-384

    View details for Web of Science ID 000167326600013

    View details for PubMedID 11245380

  • The effect of simulator use on learning and self-assessment: The case of Stanford University's E-Pelvis simulator Pugh, C. M., Srivastava, S., SHAVELSON, R., Walker, D., Cotner, T., Scarloss, B., Kuo, M., Rawn, C., Dev, P., Krummel, T. H., Heinrichs, L. H. I O S PRESS. 2001: 396-400

    View details for Web of Science ID 000169103300074

    View details for PubMedID 11317776

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