155 results on '"Krummel TM"'
Search Results
2. 140 Microarray Expression Analysis of Fetal Mouse Skin Development: Implications for Scarless Healing
- Author
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Yun, R, primary, Kong, W, additional, Faudoa, R, additional, Xia, W, additional, Krummel, TM, additional, Longaker, MT, additional, and Lorenz, HP, additional
- Published
- 2004
- Full Text
- View/download PDF
3. Evaluation of a vessel sealing system in a porcine model
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Turner, DJ, primary, De La Torre, RA, additional, Krummel, TM, additional, Denes, BS, additional, and Oelson, LSM, additional
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- 2003
- Full Text
- View/download PDF
4. Skin wounds in the MRL/MpJ mouse heal with scar [corrected] [published erratum appears in WOUND REPAIR REGENERATION 2007 Jan;15(1):163].
- Author
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Colwell AS, Krummel TM, Kong W, Longaker MT, and Lorenz HP
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- 2006
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5. Evaluation of the educational effectiveness of a virtual reality intravenous insertion simulator.
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Reznek MA, Rawn CL, and Krummel TM
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- 2002
6. Regulation of wound healing from a connective tissue perspective.
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Ehrlich HP and Krummel TM
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- 1996
7. Hyaluronic acid degradation products induce neovascularization and fibroplasia in fetal rabbit wounds.
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Mast BA, Frantz FW, Diegelmann RF, Krummel TM, and Cohen IK
- Published
- 1995
8. Cost consciousness and medical education.
- Author
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Rivas H, Morton JM, Krummel TM, Rivas, Homero, Morton, John M, and Krummel, Thomas M
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- 2010
- Full Text
- View/download PDF
9. Presidential Forum.
- Author
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Ellison EC, Ponsky JL, Harrison MR, McGrath MH, Angelos P, and Krummel TM
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- General Surgery education, General Surgery ethics, Humans, Surgical Procedures, Operative education, Surgical Procedures, Operative ethics, Therapies, Investigational ethics, United States, General Surgery methods, Surgical Procedures, Operative methods, Therapies, Investigational methods
- Published
- 2019
- Full Text
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10. The Rise of Wearable Technology in Health Care.
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Krummel TM
- Subjects
- Delivery of Health Care, Humans, Length of Stay, Self Care, Walking, Wearable Electronic Devices
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- 2019
- Full Text
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11. Preparation for the Diversity of 21st Century Surgical Leadership Opportunities Demands Diverse Opportunities for "Professional Development".
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Melcher ML, Greco RS, Krummel TM, Morris AM, and Hawn MT
- Subjects
- Humans, Professional Competence, Leadership, Surgeons
- Published
- 2018
- Full Text
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12. Three-dimensionally printed surface features to anchor endoluminal spring for distraction enterogenesis.
- Author
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Huynh N, Dubrovsky G, Rouch JD, Scott A, Chiang E, Nguyen T, Wu BM, Shekherdimian S, Krummel TM, and Dunn JCY
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- Animals, Female, Swine, Swine, Miniature, Fecal Incontinence diagnostic imaging, Fecal Incontinence surgery, Implants, Experimental, Intestines diagnostic imaging, Intestines surgery
- Abstract
Spring-mediated distraction enterogenesis has been studied as a novel treatment for short bowel syndrome (SBS). Previous approaches are limited by multiple surgeries to restore intestinal continuity. Purely endoluminal devices require a period of intestinal attachment for enterogenesis. The purpose of this study is to modify the device to prevent premature spring migration in a porcine model. Two models were created in juvenile mini-Yucatan pigs for the placement of three-dimensionally printed springs. (1) Two Roux-en-y jejunojenostomies with two Roux limbs were made. A spring with bidirectional hooked surface features was placed in one Roux limb and a spring with smooth surface was placed in the other Roux limb. (2) The in-continuity model had both hooked and smooth surface springs placed directly in intestinal continuity. Spring location was evaluated by weekly radiographs, and the intestine was retrieved after 2 to 4 weeks. Springs with smooth surfaces migrated between 1 to 3 weeks after placement in both porcine models. Springs with bidirectional hooked surface features were anchored to the intestine for up to 4 weeks without migration. Histologically, the jejunal architecture showed significantly increased crypt depth and muscularis thickness compared to normal jejunum. Bidirectional features printed on springs prevented the premature migration of endoluminal springs. These novel spring anchors allowed for their endoluminal placement without any sutures. This approach may lead to the endoscopic placement of the device for patients with SBS., Competing Interests: This study was partly funded by Sun West Company. There are no patents, products in development or marketed products to declare. This does not alter our adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.
- Published
- 2018
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13. Innovation within a university setting.
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Wynne EK and Krummel TM
- Subjects
- Humans, Academic Medical Centers, Diffusion of Innovation, Inventions, Organizational Innovation, Specialties, Surgical education
- Abstract
Elisabeth K. Wynne, MD, completed her undergraduate degree in bioengineering and is currently a surgical resident in training at the University of Washington. From 2014-2016, she served as a Biodesign Fellow at Stanford University. She plans to pursue a career of innovation as an academic surgeon. Thomas M. Krummel, MD, is the Emile Holman Professor and Chair Emeritus of the Department of Surgery at Stanford University School of Medicine. Throughout his career, Dr Krummel has been a pioneer and an innovator. For >12 years, he has partnered with Dr Paul Yock to co-direct the Stanford Biodesign program, which is designed to teach innovation at the emerging frontiers of engineering and biomedical sciences. Dr Krummel is Chairman of the Fogarty Institute for Innovation Board of Directors, and President of the International Scientific Committee at Institut de Recherche contre les Cancers de l'Appareil Digestif - IRCAD at the University of Strasbourg and is a frequent consultant to the medical device industry., (Copyright © 2016 Elsevier Inc. All rights reserved.)
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- 2016
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14. Try again. Fail again. Fail better.
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Krummel TM
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- 2015
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15. Forecasting innovation in surgery.
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Krummel TM
- Subjects
- Humans, Diffusion of Innovation, Surgical Procedures, Operative trends
- Published
- 2014
- Full Text
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16. Surgical safety checklists in ontario, Canada.
- Author
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Weiser TG and Krummel TM
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- Female, Humans, Male, Checklist, Hospitals standards, Patient Safety, Postoperative Complications mortality, Surgical Procedures, Operative mortality
- Published
- 2014
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17. Firearms, children, and health care professionals.
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Nance ML, Oldham KT, and Krummel TM
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- Child, Firearms legislation & jurisprudence, Health Policy trends, Humans, Pediatrics trends, Societies, Medical trends, United States, Wounds, Gunshot epidemiology, Wounds, Gunshot prevention & control, Firearms standards, Health Personnel standards, Pediatrics standards, Societies, Medical standards
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- 2014
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18. Firearm injuries and children: a policy statement of the American Pediatric Surgical Association.
- Author
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Nance ML, Krummel TM, and Oldham KT
- Subjects
- Child, Firearms, Humans, United States, Pediatrics, Societies, Medical, Specialties, Surgical, Wounds, Gunshot epidemiology, Wounds, Gunshot prevention & control
- Published
- 2013
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19. Outcomes from a postgraduate biomedical technology innovation training program: the first 12 years of Stanford Biodesign.
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Brinton TJ, Kurihara CQ, Camarillo DB, Pietzsch JB, Gorodsky J, Zenios SA, Doshi R, Shen C, Kumar UN, Mairal A, Watkins J, Popp RL, Wang PJ, Makower J, Krummel TM, and Yock PG
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- History, 21st Century, Humans, Biomedical Engineering economics, Biomedical Engineering education, Biomedical Engineering history, Biomedical Engineering organization & administration, Biomedical Engineering trends, Education, Graduate economics, Education, Graduate history, Education, Graduate methods, Education, Graduate organization & administration, Education, Graduate trends
- 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.
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- 2013
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20. Symbiotic or parasitic? A review of the literature on the impact of fellowships on surgical residents.
- Author
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Plerhoples TA, Greco RS, Krummel TM, and Melcher ML
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- Fellowships and Scholarships, Internship and Residency, Specialties, Surgical education
- Abstract
Objective: 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., Background: As fellowship opportunities rise, resident training may be adversely impacted., Methods: 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., 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)., Conclusions: 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.
- Published
- 2012
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21. Applying a structured innovation process to interventional radiology: a single-center experience.
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Sista AK, Hwang GL, Hovsepian DM, Sze DY, Kuo WT, Kothary N, Louie JD, Yamada K, Hong R, Dhanani R, Brinton TJ, Krummel TM, Makower J, Yock PG, and Hofmann LV
- Subjects
- California, Needs Assessment organization & administration, Organizational Innovation, Radiology, Interventional methods, Radiology, Interventional trends
- Abstract
Purpose: To determine the feasibility and efficacy of applying an established innovation process to an active academic interventional radiology (IR) practice., Materials and Methods: 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., Results: 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., Conclusions: 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., (Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.)
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- 2012
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22. Halsted-Holman vascular trauma legacy.
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Rich NM, Krummel TM, and Burris DG
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- History, 19th Century, History, 20th Century, Humans, United States, Wounds and Injuries surgery, Blood Vessels injuries, Military Medicine history, Vascular Surgical Procedures history, Wounds and Injuries history
- Published
- 2010
- Full Text
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23. A patient-centered, ethical approach to medical device innovation.
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Chao KZ, Riskin DJ, and Krummel TM
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- 2010
- Full Text
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24. NOTES and other emerging trends in gastrointestinal endoscopy and surgery: the change that we need and the change that is real.
- Author
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Jay Pasricha P and Krummel TM
- Subjects
- Diffusion of Innovation, Gastrointestinal Diseases diagnosis, Humans, Endoscopy, Gastrointestinal trends, Gastroenterology trends, Gastrointestinal Diseases surgery
- 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.
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- 2009
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25. Inventing our future: training the next generation of surgeon innovators.
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Krummel TM
- Subjects
- Humans, Technology Assessment, Biomedical, Biomedical Technology, Diffusion of Innovation, General Surgery education, Pediatrics education
- Published
- 2009
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26. Inside the operating room--balancing the risks and benefits of new surgical procedures: a collection of perspectives and panel discussion.
- Author
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Cooper JD, Clayman RV, Krummel TM, Schauer PR, Thompson C, and Moreno JD
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- Bariatric Surgery, Child, Child, Preschool, Endoscopy methods, Evaluation Studies as Topic, Humans, Infant, Informed Consent, Laparoscopy, Nephrectomy, Randomized Controlled Trials as Topic, Robotics, Surgical Procedures, Operative
- Published
- 2008
- Full Text
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27. Simulation-based endovascular skills assessment: the future of credentialing?
- Author
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Tedesco MM, Pak JJ, Harris EJ Jr, Krummel TM, Dalman RL, and Lee JT
- Subjects
- Angioplasty instrumentation, Humans, Motor Skills, Radiography, Renal Artery Obstruction diagnostic imaging, Self-Assessment, Surveys and Questionnaires, Task Performance and Analysis, Treatment Outcome, Angioplasty education, Clinical Competence, Computer Simulation, Credentialing trends, Education, Medical, Continuing methods, Patient Simulation, Renal Artery Obstruction surgery, Stents
- Abstract
Objectives: 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., Methods: 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., Results: 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)., Conclusion: 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.
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- 2008
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28. Intellectual property and royalty streams in academic departments: myths and realities.
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Krummel TM, Shafi BM, Wall J, Chandra V, Mery C, and Gertner M
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- Academic Medical Centers economics, Creativity, Diffusion of Innovation, Humans, Leadership, Schools, Medical economics, United States, Universities, Academic Medical Centers organization & administration, Copyright economics, Copyright legislation & jurisprudence, Intellectual Property
- Published
- 2008
- Full Text
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29. Keratinocytes modulate fetal and postnatal fibroblast transforming growth factor-beta and Smad expression in co-culture.
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Colwell AS, Yun R, Krummel TM, Longaker MT, and Lorenz HP
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- Animals, Animals, Newborn, Cells, Cultured, Coculture Techniques, Fetus cytology, Mice, Mice, Inbred BALB C, Fibroblasts metabolism, Keratinocytes physiology, Smad Proteins biosynthesis, Transforming Growth Factor beta biosynthesis
- Abstract
Background: 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., Methods: 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., Results: 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)., Conclusions: 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.
- Published
- 2007
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30. Transforming growth factor-beta, Smad, and collagen expression patterns in fetal and adult keratinocytes.
- Author
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Colwell AS, Faudoa R, Krummel TM, Longaker MT, and Lorenz HP
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- Aging metabolism, Animals, Animals, Newborn metabolism, Cells, Cultured, Fetus metabolism, Gestational Age, Polymerase Chain Reaction, Rats, Rats, Sprague-Dawley, Smad4 Protein metabolism, Smad7 Protein metabolism, Collagen Type I metabolism, Keratinocytes metabolism, Smad Proteins metabolism, Transforming Growth Factor beta metabolism
- Abstract
Background: 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., Methods: 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., Results: 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)., Conclusions: 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.
- Published
- 2007
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31. IPEG panel on challenges of medical innovation: case one.
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Krummel TM, Azizkhan R, Holcomb GW, Winslade W, and Ziegler MM
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- Clinical Competence, Humans, Esophageal Atresia surgery, Informed Consent, Thoracoscopy
- Published
- 2007
- Full Text
- View/download PDF
32. IPEG panel on challenges of medical innovation: introduction.
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Krummel TM and Ziegler MM
- Subjects
- Child, Clinical Trials as Topic, Ethics Committees, Research, Humans, Physician's Role, Diffusion of Innovation, Endoscopy methods
- Published
- 2006
- Full Text
- View/download PDF
33. The ethics of innovation in pediatric surgery.
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Riskin DJ, Longaker MT, and Krummel TM
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- Child, Ethics Committees, Research ethics, Humans, Informed Consent ethics, United States, Diffusion of Innovation, Ethics, Medical, General Surgery education, Medical Laboratory Science ethics, Pediatrics ethics
- 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.
- Published
- 2006
- Full Text
- View/download PDF
34. What is surgery?
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Krummel TM
- Subjects
- Europe, Forecasting, General Surgery trends, History, 19th Century, History, 20th Century, Humans, Pediatrics trends, Surgical Equipment trends, Surgical Instruments trends, United States, Diffusion of Innovation, General Surgery history, Pediatrics history, Surgical Equipment history, Surgical Instruments history
- 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.
- Published
- 2006
- Full Text
- View/download PDF
35. Innovation in surgery: a historical perspective.
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Riskin DJ, Longaker MT, Gertner M, and Krummel TM
- Subjects
- History, 19th Century, History, 20th Century, History, 21st Century, Humans, General Surgery history, Surgical Procedures, Operative
- Abstract
Objective: To describe the field of surgical innovation from a historical perspective, applying new findings from research in technology innovation., Background: 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., Methods: 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., Results: 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., Conclusion: 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.
- Published
- 2006
- Full Text
- View/download PDF
36. Inventing our future: training the next generation of surgeon innovators.
- Author
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Krummel TM, Gertner M, Makower J, Milroy C, Gurtner G, Woo R, Riskin DJ, Binyamin G, Connor JA, Mery CM, Shafi BM, and Yock PG
- Subjects
- Child, Curriculum, Device Approval, Humans, Internship and Residency, United States, Diffusion of Innovation, Education, Medical, Graduate, Engineering education, General Surgery education, Medical Laboratory Science instrumentation, Surgical Equipment, Surgical Instruments, Training Support
- 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.
- Published
- 2006
- Full Text
- View/download PDF
37. Early-gestation fetal scarless wounds have less lysyl oxidase expression.
- Author
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Colwell AS, Krummel TM, Longaker MT, and Lorenz HP
- Subjects
- Animals, Cells, Cultured drug effects, Cells, Cultured enzymology, Cicatrix embryology, Cicatrix etiology, Collagen metabolism, Elasticity, Enzyme Induction drug effects, Fibroblasts drug effects, Gestational Age, Mice, Mice, Inbred BALB C, Protein-Lysine 6-Oxidase biosynthesis, Protein-Lysine 6-Oxidase physiology, Skin embryology, Skin enzymology, Skin growth & development, Transforming Growth Factor beta pharmacology, Transforming Growth Factor beta1, Wound Healing, Wounds and Injuries embryology, Wounds and Injuries enzymology, Cicatrix enzymology, Fetal Diseases enzymology, Fibroblasts enzymology, Protein-Lysine 6-Oxidase analysis, Skin injuries
- Abstract
Background: 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., Methods: 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., Results: 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)., Conclusions: 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.
- Published
- 2006
- Full Text
- View/download PDF
38. Wnt-4 expression is increased in fibroblasts after TGF-beta1 stimulation and during fetal and postnatal wound repair.
- Author
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Colwell AS, Krummel TM, Longaker MT, and Lorenz HP
- Subjects
- Animals, Cicatrix metabolism, Disease Models, Animal, Female, Fetus, Mice, Mice, Inbred BALB C, Pregnancy, Skin injuries, Skin metabolism, Transforming Growth Factor beta1, Wnt4 Protein, Wound Healing immunology, Wounds and Injuries metabolism, Fibroblasts metabolism, Immunologic Factors pharmacology, Proto-Oncogene Proteins biosynthesis, Transforming Growth Factor beta pharmacology, Wnt Proteins biosynthesis, Wound Healing drug effects
- Abstract
Background: Wnt-4 is a mitogen expressed during postnatal repair and scar formation; however, its expression profile during scarless repair is unknown. Transforming growth factor (TGF)-beta1 has high expression during healing with scar formation. Whether TGF-beta1 directly influences Wnt-4 expression in fetal or postnatal fibroblasts has not been examined., Methods: Primary fetal and postnatal mouse fibroblasts were stimulated with TGF-beta1 and Wnt-4 expression quantitated by real-time polymerase chain reaction. Fetal E17 and postnatal mouse excisional wounds were also analyzed for Wnt-4 expression by real-time polymerase chain reaction., Results: In E17 fibroblasts after TGF-beta1 stimulation, Wnt-4 expression increased 4-fold at 1 hour (p < 0.05) and peaked with an 11-fold increase at 2 hours (p < 0.05). By 24 hours, expression decreased to 2-fold baseline levels (p < 0.05). In postnatal fibroblasts, Wnt-4 expression also increased after TGF-beta stimulation, but peak expression was larger and relatively delayed, with a 17-fold increase at 12 hours (p < 0.005). Expression levels at 24 hours were still 4-fold greater than baseline (p < 0.05). In E17 fetal skin, Wnt-4 expression was 3.5-fold greater compared with 3-week-old mice (p < 0.005). Small increases in Wnt-4 expression (less than 2-fold) occurred during both fetal scarless and postnatal scarring mouse wound repair., Conclusion: The authors' data suggest that TGF-beta directly increases Wnt-4 expression in fetal and postnatal fibroblasts and that Wnt-4 is increased in both fetal and postnatal repair.
- Published
- 2006
- Full Text
- View/download PDF
39. Fetal and adult fibroblasts have similar TGF-beta-mediated, Smad-dependent signaling pathways.
- Author
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Colwell AS, Krummel TM, Longaker MT, and Lorenz HP
- Subjects
- Age Factors, Animals, Cell Culture Techniques, Cicatrix genetics, Collagen genetics, Collagen metabolism, Connective Tissue Growth Factor, Disease Models, Animal, Female, Fetus, Immediate-Early Proteins biosynthesis, Immediate-Early Proteins genetics, Intercellular Signaling Peptides and Proteins biosynthesis, Intercellular Signaling Peptides and Proteins genetics, Mice, Mice, Inbred BALB C, Pregnancy, Protein Isoforms, Signal Transduction, Smad Proteins genetics, Smad3 Protein biosynthesis, Smad3 Protein genetics, Smad7 Protein biosynthesis, Smad7 Protein genetics, Transforming Growth Factor beta1, Transforming Growth Factor beta3, Wound Healing genetics, Cicatrix metabolism, Fibroblasts metabolism, Smad Proteins biosynthesis, Transforming Growth Factor beta metabolism, Wound Healing physiology
- Abstract
Background: 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., Methods: 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., Results: 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., Conclusions: 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.
- Published
- 2006
- Full Text
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40. An in vivo mouse excisional wound model of scarless healing.
- Author
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Colwell AS, Krummel TM, Longaker MT, and Lorenz HP
- Subjects
- Animals, Cicatrix etiology, Cicatrix physiopathology, Female, Fetus, Gestational Age, Mice, Mice, Inbred BALB C, Models, Animal, Pregnancy, Skin pathology, Wounds and Injuries physiopathology, Cicatrix pathology, Skin injuries, Wound Healing physiology, Wounds and Injuries pathology
- Abstract
Background: The purpose of this study was to develop a reproducible murine model of fetal scarless wound healing., Methods: 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., Results: 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., Conclusions: 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.
- Published
- 2006
- Full Text
- View/download PDF
41. To simulate or not to simulate: what is the question?
- Author
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Dutta S, Gaba D, and Krummel TM
- Subjects
- Humans, Computer Simulation, Education, Medical methods, General Surgery education, Models, Educational, Surgical Procedures, Operative education, Surgical Procedures, Operative methods
- Published
- 2006
- Full Text
- View/download PDF
42. Laparoscopic resection of type 1 choledochal cysts in pediatric patients.
- Author
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Le DM, Woo RK, Sylvester K, Krummel TM, and Albanese CT
- Subjects
- Adolescent, Child, Child, Preschool, Female, Follow-Up Studies, Humans, Infant, Jejunostomy methods, Length of Stay, Male, Retrospective Studies, Time Factors, Treatment Outcome, Choledochal Cyst surgery, Laparoscopy adverse effects, Laparoscopy methods
- Abstract
Background: 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., Methods: 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., Results: 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., Conclusions: Laparoscopic resection of choledochal cysts can be performed safely in pediatric patients with minimal morbidity and good long-term results.
- Published
- 2006
- Full Text
- View/download PDF
43. Simulation: a new frontier in surgical education.
- Author
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Dutta S and Krummel TM
- Subjects
- Clinical Competence, Humans, Internship and Residency, Models, Educational, Research, User-Computer Interface, Computer Simulation, General Surgery education, Teaching methods
- 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.
- Published
- 2006
- Full Text
- View/download PDF
44. Portal vein thrombosis after laparoscopic splenectomy: an ongoing clinical challenge.
- Author
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Miniati DN, Padidar AM, Kee ST, Krummel TM, and Mallory B
- Subjects
- Adolescent, Anticoagulants therapeutic use, Female, Humans, Mesenteric Veins, Splenic Vein, Thrombosis therapy, Laparoscopy, Portal Vein, Splenectomy methods, Thrombosis etiology
- Abstract
Objectives: 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., Methods: 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., Results: 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., Discussion: 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.
- Published
- 2005
45. Stanford University School of Medicine.
- Author
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Mark JB and Krummel TM
- Subjects
- California, History, 20th Century, History, 21st Century, Schools, Medical history, Surgery Department, Hospital history
- Published
- 2004
- Full Text
- View/download PDF
46. Robot-assisted pediatric surgery.
- Author
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Woo R, Le D, Krummel TM, and Albanese C
- Subjects
- Adult, Animals, Cardiac Surgical Procedures, Child, Humans, Surgical Equipment, Surgical Instruments, Thoracic Surgical Procedures, Urologic Surgical Procedures, Robotics instrumentation, Surgery, Computer-Assisted instrumentation
- 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.
- Published
- 2004
- Full Text
- View/download PDF
47. Robotic technology in surgery: past, present, and future.
- Author
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Camarillo DB, Krummel TM, and Salisbury JK Jr
- Subjects
- Equipment Design, General Surgery classification, Humans, Robotics instrumentation, Surgical Equipment, Surgical Instruments, General Surgery trends, Robotics trends, Surgery, Computer-Assisted classification, Surgery, Computer-Assisted instrumentation, Surgery, Computer-Assisted trends
- 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.
- Published
- 2004
- Full Text
- View/download PDF
48. Trauma assessment training with a patient simulator: a prospective, randomized study.
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Lee SK, Pardo M, Gaba D, Sowb Y, Dicker R, Straus EM, Khaw L, Morabito D, Krummel TM, and Knudson MM
- Subjects
- Educational Measurement, Humans, Linear Models, Prospective Studies, Statistics, Nonparametric, Trauma Centers, Internship and Residency, Patient Simulation, Traumatology education
- Abstract
Background: Patient simulators are computer-controlled mannequins that may increase realism during trauma training by providing real-time changes in vital signs and physical findings during trauma scenarios. We hypothesized that trauma assessment training on a patient simulator would be as effective as training with a more traditional moulage patient/actor., Methods: This study was conducted during a surgery intern orientation at two academic trauma centers. Interns (n = 60) attended a basic trauma course, and were then randomized to trauma assessment practice sessions with either the patient simulator (n = 30) or a moulage patient (n = 30). After practice sessions, interns were randomized a second time to an individual trauma assessment test on either the simulator or the moulage patient. Two surgeon-judges rated each intern live and on video for completion of 50 predetermined assessment objectives (total score) divided into sections (primary and secondary survey, general performance, diagnostic studies/procedures, and plan) and the identification and management of an acute neurologic deterioration in the test patient (event score). Multiple linear regression with random student effects was used to estimate the independent effects of all study variables., Results: Within randomized groups, mean trauma assessment test scores for all simulator-trained interns were higher when compared with all moulage-trained interns (71 +/- 8 vs. 66 +/- 8, respectively; p = 0.02). Simulator training independently showed a small but statistically significant improvement in both the total score and the event score (+4.6 and +8.6, respectively; p < 0.05)., Conclusion: Use of a patient simulator to introduce trauma assessment training is feasible and compares favorably to training in a moulage setting. Continued research in this area of physician education is warranted.
- Published
- 2003
- Full Text
- View/download PDF
49. Virtual reality applied to procedural testing: the next era.
- Author
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Bloom MB, Rawn CL, Salzberg AD, and Krummel TM
- Subjects
- Computer Simulation, Digestive System, Humans, Models, Anatomic, Endoscopy, Gastrointestinal, Esophagoscopy, Gastroenterology education, General Surgery education, Internship and Residency, User-Computer Interface
- Abstract
Objective: To establish the construct validity of a virtual reality-based upper gastrointestinal endoscopy simulator as a tool for the skills training of residents., Summary Background Data: 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., Methods: 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., Results: 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., Conclusions: 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.
- Published
- 2003
- Full Text
- View/download PDF
50. Matrix metalloproteinases and the ontogeny of scarless repair: the other side of the wound healing balance.
- Author
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Peled ZM, Phelps ED, Updike DL, Chang J, Krummel TM, Howard EW, and Longaker MT
- Subjects
- Animals, Female, Fibroblasts, Gene Expression, Gestational Age, Phenotype, Pregnancy, Rats, Rats, Sprague-Dawley, Reverse Transcriptase Polymerase Chain Reaction, Skin embryology, Cicatrix prevention & control, Fetus physiology, Matrix Metalloproteinases physiology, Tissue Inhibitor of Metalloproteinases physiology, Wound Healing physiology
- 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.
- Published
- 2002
- Full Text
- View/download PDF
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