Houston, TX, United States
Houston, TX, United States

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Van Eps J.,Houston Methodist Hospital | Van Eps J.,Houston Advanced Research Center | Fernandez-Moure J.,Houston Methodist Hospital | Fernandez-Moure J.,Houston Advanced Research Center | And 15 more authors.
Surgical Endoscopy and Other Interventional Techniques | Year: 2016

Background: Recurrence after ventral hernia repair (VHR) remains a multifactorial problem still plaguing surgeons today. Some of the many contributing factors include mechanical strain, poor tissue-mesh integration, and degradation of matrices. The high recurrence rate witnessed with the use of acellular dermal matrices (ADM) for definitive hernia repair has reduced their use largely to bridging repair and breast reconstruction. Modalities that improve classic cellular metrics of successful VHR could theoretically result in improved rates of hernia recurrence; autologous platelet-rich plasma (PRP) may represent one such tool, but has been underinvestigated for this purpose. Methods: Lewis rats (32) had chronic ventral hernias created surgically and then repaired with Strattice™ mesh alone (control) or mesh + autologous PRP. Samples were harvested at 3 and 6 months postoperatively and compared for gross, histologic, and molecular outcomes of: neovascularization, tissue incorporation, peritoneal adhesions, hernia recurrence, and residual mesh thickness. Results: Compared to control at 3 months postoperatively, PRP-treated rats displayed significantly more neovascularization of implanted mesh and considerable upregulation of both angiogenic genes (vEGF 2.73-fold, vWF 2.21-fold) and myofibroblastic genes (αSMA 9.68-fold, FSP-1 3.61-fold, Col1a1 3.32-fold, Col31a1 3.29-fold). Histologically, they also showed enhanced tissue deposition/ingrowth and diminished chronic immune cell infiltration. Peritoneal adhesions were less severe at both 3 (1.88 vs. 2.94) and 6 months (1.63 vs. 2.75) by Modified Hopkins Adhesion Scoring. PRP-treated rats experienced decreased hernia recurrence at 6 months (0/10 vs. 7/10) and had significantly improved ADM preservation as evidenced by quantification of residual mesh thickness. Conclusions: PRP is an autologous source of pro-regenerative growth factors and chemokines uniquely suited to soft tissue wound healing. When applied to a model of chronic VHR, it incites enhanced angiogenesis, myofibroblast recruitment and tissue ingrowth, ADM preservation, less severe peritoneal adhesions, and diminished hernia recurrence. We advocate further investigation regarding PRP augmentation of human VHR. © 2015, The Author(s).


Garbey M.,University of Houston | Garbey M.,Methodist Institute for Technology | Bass B.L.,Methodist Institute for Technology | Bass B.L.,Methodist Hospital | Berceli S.,University of Florida
Acta Mechanica Sinica/Lixue Xuebao | Year: 2012

This paper discusses some of the concept of modeling surgery outcome. It is also an attempt to offer a road map for progress. This paper may serve as a common ground of discussion for both communities i.e surgeons and computational scientist in its broadest sense. Predicting surgery outcome is a very difficult task. All patients are different, and multiple factors such as genetic, or environment conditions plays a role. The difficulty is to construct models that are complex enough to address some of these significant multiscale elements and simple enough to be used in clinical conditions and calibrated on patient data. We will provide a multilevel progressive approach inspired by two applications in surgery that we have been working on. One is about vein graft adaptation after a transplantation, the other is the recovery of cosmesis outcome after a breast lumpectomy. This work, that is still very much in progress, may teach us some lessons. We are convinced that the digital revolution that is transforming the working environment of the surgeon makes closer collaboration between surgeons and computational scientist unavoidable. We believe that "computational surgery" will allow the community to develop predictive model of the surgery outcome and greatprogresses in surgery procedures that goes far beyond the operating room procedural aspect. © The Chinese Society of Theoretical and Applied Mechanics and Springer-Verlag Berlin Heidelberg 2012.


Toti G.,University of Houston | Garbey M.,University of Houston | Garbey M.,Methodist Institute for Technology | Sherman V.,Houston Methodist Hospital | And 4 more authors.
Surgical Innovation | Year: 2015

Background. Operating rooms have become increasingly complex environments and more prone to errors because of loss of situation awareness. Adding computer intelligence to the operating room may help overcome these limitations particularly if the system can automatically track which step of an operation a surgeon is performing. To develop such a platform, it is necessary to track which laparoscopic instruments are being used and in which port they are inserted. This article describes the development and validation of a "Smart Trocar" that can automatically perform this function. Methods. A Smart Trocar system prototype was developed that uses a wireless camera attached to a standard laparoscopic port and custom software algorithms. The system recognizes color wheels attached to the handle of a laparoscopic instrument and compares the unique color pattern to an instrument library for proper tool identification. The system was tested for reliability in a box trainer environment using a variety of tool positions and levels of room light illumination. Results. Correct color classification was achieved in 96.7% of trials. There were no errors in detection of the color wheel in space. In addition, the distance of the color wheel from the camera did not influence results and correct classifications were evenly distributed among the 12 laparoscopic tool positions tested. Conclusion. This work describes a Smart Trocar system that identifies which laparoscopic tool is being used and in which port and proves its reliability. The system is an important element of a more comprehensive program being developed to automatically understand what step of an operation a surgeon is performing and use these data to improve situation awareness in the operating room. © The Author(s) 2014.


Desai R.J.,University of North Carolina at Chapel Hill | Ashton C.M.,Methodist Institute for Technology | Deswal A.,Michael bakey Va Medical Center | Deswal A.,Baylor College of Medicine | And 8 more authors.
Pharmacoepidemiology and Drug Safety | Year: 2012

Objective: There is little evidence on comparative effectiveness of individual angiotensin receptor blockers (ARBs) in patients with chronic heart failure (CHF). This study compared four ARBs in reducing risk of mortality in clinical practice. Methods: A retrospective analysis was conducted on a national sample of patients diagnosed with CHF from 1 October 1996 to 30 September 2002 identified from Veterans Affairs electronic medical records, with supplemental clinical data obtained from chart review. After excluding patients with exposure to ARBs within the previous 6months, four treatment groups were defined based on initial use of candesartan, valsartan, losartan, and irbesartan between the index date (1 October 2000) and the study end date (30 September 2002). Time to death was measured concurrently during that period. A marginal structural model controlled for sociodemographic factors, comorbidities, comedications, disease severity (left ventricular ejection fraction), and potential time-varying confounding affected by previous treatment (hospitalization). Propensity scores derived from a multinomial logistic regression were used as inverse probability of treatment weights in a generalized estimating equation to estimate causal effects. Results: Among the 1536 patients identified on ARB therapy, irbesartan was most frequently used (55.21%), followed by losartan (21.74%), candesartan (15.23%), and valsartan (7.81%). When compared with losartan, after adjusting for time-varying hospitalization in marginal structural model, candesartan (OR=0.79, 95%CI=0.42-1.50), irbesartan (OR=1.17, 95%CI=0.72-1.90), and valsartan (OR=0.98, 95%CI=0.45-2.14) were found to have similar effectiveness in reducing mortality in CHF patients. Conclusion: Effectiveness of ARBs in reducing mortality is similar in patients with CHF in everyday clinical practice. © 2011 John Wiley & Sons, Ltd.


Salmon R.,University of Houston | Garbey M.,University of Houston | Garbey M.,Methodist Institute for Technology | Moore L.W.,Houston Methodist | Bass B.L.,Methodist Institute for Technology
PLoS ONE | Year: 2015

Most women with early stage breast cancer do not require removal of the entire breast to treat their cancer; instead, up to 70% of women can be effectively and safely treated by breast conserving therapy (BCT) with surgical removal of the tumor only (lumpectomy) followed by radiation treatment of the remaining breast tissue. Unfortunately, the final contour and cosmesis of the treated breast is suboptimal in approximately 30% of patients. The ability to accurately predict breast contour after BCT for breast cancer could significantly improve patient decision-making regarding the choice of surgery for breast cancer. Our overall hypothesis is that the complex interplay among mechanical forces due to gravity, breast tissue constitutive law distribution, inflammation induced by radiotherapy and internal stress generated by the healing process play a dominant role in determining the success or failure of lumpectomy in preserving the breast contour and cosmesis. We have shown here from a first patient study that even in the idealistic situation of excellent cosmetic outcome this problem requires multiscale modeling. We propose a method to decide which component of the model works best for each phase of healing and what parameters should be considered dominant and patient specific. This patient study is part of a clinical trial registered on ClinicalTrial.gov, identifier NCT02310711. © 2015 Salmon et al.


PubMed | Houston Methodist, University of Houston and Methodist Institute for Technology
Type: Case Reports | Journal: PloS one | Year: 2015

Most women with early stage breast cancer do not require removal of the entire breast to treat their cancer; instead, up to 70% of women can be effectively and safely treated by breast conserving therapy (BCT) with surgical removal of the tumor only (lumpectomy) followed by radiation treatment of the remaining breast tissue. Unfortunately, the final contour and cosmesis of the treated breast is suboptimal in approximately 30% of patients. The ability to accurately predict breast contour after BCT for breast cancer could significantly improve patient decision-making regarding the choice of surgery for breast cancer. Our overall hypothesis is that the complex interplay among mechanical forces due to gravity, breast tissue constitutive law distribution, inflammation induced by radiotherapy and internal stress generated by the healing process play a dominant role in determining the success or failure of lumpectomy in preserving the breast contour and cosmesis. We have shown here from a first patient study that even in the idealistic situation of excellent cosmetic outcome this problem requires multiscale modeling. We propose a method to decide which component of the model works best for each phase of healing and what parameters should be considered dominant and patient specific. This patient study is part of a clinical trial registered on ClinicalTrial.gov, identifier NCT02310711.


Goh A.C.,Baylor College of Medicine | Goldfarb D.W.,Baylor College of Medicine | Sander J.C.,Baylor College of Medicine | Miles B.J.,Methodist Institute for Technology | Dunkin B.J.,Methodist Institute for Technology
Journal of Urology | Year: 2012

Purpose: We developed and validated a standardized assessment tool for robotic surgical skills, and report its usefulness, reliability and construct validity in a clinical setting. Materials and Methods: The Global Evaluative Assessment of Robotic Skills is a tool developed by deconstructing the fundamental elements of robotic surgical procedures in consultation with expert robotic surgeons. Surgical performance was assessed during robot-assisted laparoscopic prostatectomy on a 5-point anchored Likert scale across 6 domains. An overall performance score was derived by summing the ratings in each domain. Expert surgeons and postgraduate year 4 to 6 urology residents were evaluated to determine construct validity. Assessments were completed by the attending surgeon, a trained observer and the operator. Results: A total of 29 evaluations of 25 trainees and 4 attending surgeons were completed. Experts scored significantly higher on the assessment than novice operators (p = 0.004). Postgraduate year 4 and 5 residents scored significantly lower than the expert group (p <0.05) while no difference was observed between mean performance scores of postgraduate year 6 trainees and attending surgeons (p >0.05). The internal consistency of the assessment tool was excellent (Cronbach's α = 0.90 to 0.93). The overall assessment score ICC among raters was 0.80 (95% CI 0.650.90). Conclusions: The Global Evaluative Assessment of Robotic Skills is simple to administer and able to differentiate levels of robotic surgical expertise. This standardized assessment tool shows excellent consistency, reliability and validity. Further study is warranted to evaluate its usefulness for surgical education and the establishment of competency in robotic surgery. © 2012 American Urological Association Education and Research, Inc.

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