BACKGROUND: Growth and nutrition are key priorities in the management of pediatric inflammatory b... more BACKGROUND: Growth and nutrition are key priorities in the management of pediatric inflammatory bowel disease (IBD). Growth failure has been reported in up to 40% of children with Crohn's Disease (CD). The cause of growth failure in this population is multifactorial; malnutrition secondary to decreased intake, malabsorption, and GI losses, as well as psychosocial stressors are thought to be significant contributing factors. Ongoing inflammation and the release of cytokines such as TNFalpha, IL-6, and IL-1-beta may contribute to growth failure by suppressing growth factors. Infliximab, a chimeric murine-human monoclonal IgG1 antibody that targets TNF-alpha is used as a therapeutic agent for CD. As infliximab improves mucosal healing, it has been shown to potentially optimize growth. Data from the recent REACH study has shown improved linear growth in children with moderate to severe CD who were treated with infliximab. Due to the paucity of literature pertaining to pediatric IBD and how the current available treatments ultimately affect growth, a need for further research in this area has been noted. METHODS: A retrospective analysis reviewed medical records from 159 pediatric patients with CD, ages 2-18 years old, from a departmental IBD database who had completed at least 18 months of infliximab therapy from January 1998 to May 2009. Demographic data, height, weight, body mass index (BMI) and corresponding zscores at 2-month intervals during the 18 months prior to infliximab therapy through 18 months post-initiation of therapy were analyzed to determine whether significant changes in the patients' growth between these time periods could be observed. RESULTS: Regression analysis was performed for an 18-month period before and after infliximab therapy separately. No significant trend was detected in weight or BMI z-scores before and after therapy (p>0.05). Height z-score significantly increased at a rate of 0.0207þ0.0084 per month before therapy (p¼0.0145) but stayed unchanged after therapy (p¼0.5). After combining the monthly data into before-therapy and after therapy, we see significant increase in height (p¼0.0017) and weight z-scores (p¼0.0158) with no gender effect. CONCLUSIONS: Growth parameters of height and weight improved in this cohort after treatment with infliximab. Although height z-scores improved overall in the post-treatment group, regression modeling failed to detect a significant change in growth velocity after treatment with infliximab. This study is limited by its retrospective nature given the multi-dimensional nature of growth failure in this group. Further prospective analysis of TNF-alpha's effect on linear growth in children is recommended.
Objective: To describe long-term quality of life (QOL) outcomes after rectourethral fistula (RUF)... more Objective: To describe long-term quality of life (QOL) outcomes after rectourethral fistula (RUF) repair. RUF is a debilitating diagnosis and complex surgical dilemma with limited data regarding QOL after repair.
Minimally invasive surgery (MIS) involves a multi-dimensional series of tasks requiring a synthes... more Minimally invasive surgery (MIS) involves a multi-dimensional series of tasks requiring a synthesis between visual information and the kinematics and dynamics of the surgical tools. Analysis of these sources of information is a key step in mastering MIS but may also be used to define objective criteria for characterizing surgical performance. The BlueDRAGON is a new system for acquiring the kinematics and the dynamics of two endoscopic tools synchronized with the visual view of the surgical scene. It includes passive mechanisms equipped with position and force torque sensors for measuring the position and the orientation (P/O) of two endoscopic tools along with the force and torque (F/T) applied on them by the surgeon’s hands. The analogy between Minimally Invasive Surgery (MIS) and human language inspires the decomposition of a surgical task into its primary elements in which tool/tissue interactions are considered as “words” that have versions pronunciations defined by the F/T sig...
Minimally invasive surgery (MIS) is a technique introduced in the mid-1980s in which a few small ... more Minimally invasive surgery (MIS) is a technique introduced in the mid-1980s in which a few small incisions are made to allow for insertion of surgical tools and a camera through gasketed ports. Smaller incisions speed patient recovery times and lessen the chance of infection. They also introduce new interfaces as compared to more traditional open surgical techniques. These interfaces impose motion constraints and forces on the tool(s) and hand(s). These interfaces are not well characterized, yet surgical simulators and surgical robots are being developed without this vital information.
TPS3650 Background: Presence of cancer stem cells (CSC) appears to be the chief cause of drug res... more TPS3650 Background: Presence of cancer stem cells (CSC) appears to be the chief cause of drug resistance to cytotoxic or targeted chemotherapy. Experimental models suggest that these resistant canc...
classifi ed as drug reactions to CZP; and 1 (5.5%) patient was diagnosed with Hodgkins Lymphoma. ... more classifi ed as drug reactions to CZP; and 1 (5.5%) patient was diagnosed with Hodgkins Lymphoma. Th irty one patients (14 women, 17 men) were included in the split dosing analysis; 5 patients reported adverse events (16%) and the total number of distinct events was 6. 4 (67%) of the AEs reported were infectious; 1 (17%) was considered a complication secondary to CD; and 1 (3%) was an unrelated skin disorder. A majority of patients included in this analysis and reporting infectious adverse events were on concomitant immunosuppression (78% and 100% respectively) and 6 (67%) patients reporting infections in the standard dosing group had indwelling lines. Conclusion: At a single North American site, treatment with certolizumab pegol was found to be generally safe and well tolerated. In both the standard dosing group (400 mg once monthly) and the dose modifi cation group (200 mg ever 2 weeks) the most common adverse events reported were infections. Only 1 AE, an injection site reaction in the standard dosing group, was assessed by the treating gastroenterologist as probably related. Although the sample size in this analysis was limited, the number of adverse events reported at this single site is comparable to the frequency in previously published clinical trial data. Disclosure: Scott D. Lee, MD-Consultant: UCB Pharma; Speakers Bureau: UCB Pharma; Grant/Research Support: UCB Pharma Ghassan T. Wahbeh, MD-Consultant: UCB Pharma; Speakers Bureau: UCB Pharma.
The training of a surgeon includes the acquisition of a number of characteristics. These include ... more The training of a surgeon includes the acquisition of a number of characteristics. These include a cognitive knowledge base, problem formulation and decisionmaking abilities, appropriate psychosocial relationships, and other attributes that can be measured with objective testing, such as national board or specialty certifying examinations. Perhaps most critical to the surgeon, however, are the core technical skills of the profession. A battery of sophisticated devices is being created to teach and provide objective evaluations of the trainee’s technical abilities. These innovative state-of-the-art simulation devices, used to teach basic skills and surgical tasks through repetitive proctored challenges, will enable detection and analysis of surgical errors and near miss incidents without risk to patients. As with flight simulation, near miss detection capabilities anticipate potential errors before they occur and prevent resulting complications. In collaboration with a number of otol...
Studies in Health Technology and Informatics, 2005
Recent advances in technology have led to the fusion of MIS techniques and robot devices. However... more Recent advances in technology have led to the fusion of MIS techniques and robot devices. However, current systems are large and cumbersome. Optimizing the surgical robot mechanism will eventually lead to its integration into the operating room (OR) of the future becoming the extended presence of the surgeon and nurses in a room occupied by the patient alone. By optimizing a spherical mechanism using data collected in-vivo during MIS procedures, this study is focused on a bottom-up approach to developing a new class of surgical robotic arms while maximizing their performance and minimizing their size. The spherical mechanism is a rotational manipulator with all axes intersecting at the center of the sphere. Locating the rotation center of the mechanism at the MIS port makes this class of mechanism a suitable candidate for the first two links of a surgical robot for MIS. The required dexterous workspace (DWS) is defined as the region in which 95% of the tool motions are contained bas...
Studies in Health Technology and Informatics, 2007
With the development of new technologies in surgery, minimally invasive surgery (MIS) has drastic... more With the development of new technologies in surgery, minimally invasive surgery (MIS) has drastically improved the way conventional medical procedures are performed. However, a new learning curve has resulted requiring an expertise in integrating visual information with the kinematics and dynamics of the surgical tools. The Red DRAGON is a multi-modal simulator for teaching and training MIS procedures allowing one to use it with several modalities including: simulator (physical objects and virtual objects) and an animal model. The Red DRAGON system is based on a serial spherical mechanism in which all the rotation axes intersect at a single point (remote center) allowing the endoscopic tools to pivot around the MIS port. The system includes two mechanisms that incorporate two interchangeable MIS tools. Sensors are incorporated into the mechanism and the tools measure the positions and orientations of the surgical tools as well as forces and torques applied on the tools by the surgeo...
Abstract. We report a computerized endoscopic surgical grasper with computer control and a force ... more Abstract. We report a computerized endoscopic surgical grasper with computer control and a force feedback (haptic) user interface. The system uses standard unmodified grasper shafts and tips. The device can control grasping forces either by direct surgeon control, via teleoperation, or under software control. In this paper, we test an automated palpation function in which the grasper measures mechanical properties of the grasped tissue by applying a programmed series of squeezes. Experimental results show the ability to discriminate between the normal tissues of small bowel, lung, spleen, liver, colon, and stomach. We anticipate applications in tele-surgery, clinical endoscopic surgery, surgical training, and research. 1.
While there are many benefits to minimally invasive surgery, force feedback, or touch sensation, ... more While there are many benefits to minimally invasive surgery, force feedback, or touch sensation, is lacking in the currently available MIS tools, including surgical robots, creating the potential for excessive force application during surgery. The goal of this work was to develop a methodology with which to identify stress magnitudes and durations that can be safely applied with a grasper to different tissues, helping to improve MIS device design and reduce potential for clinically relevant consequences. Using the porcine model, stresses typically applied in MIS were applied to liver, ureter, and small bowel using a motorized endoscopic grasper. Acute indicators of tissue damage including cellular death, activation of the coagulation cascade, and infiltration of inflammatory cells were measured using histological and image analysis techniques. ANOVA and post-hoc analyses were used to detect stress magnitudes and durations that caused significantly increased tissue damage with the goal to ultimately identify safe stress 'thresholds' during grasping of the studied tissues. Preliminary data suggests a graded non-linear response between applied stress magnitude and apoptosis in liver and small bowel as well as granulocyte infiltration in small bowel.
Minimally Invasive Surgery (MIS) generates new user interfaces which create visual and haptic dis... more Minimally Invasive Surgery (MIS) generates new user interfaces which create visual and haptic distortion when compared to traditional surgery. In order to regain the tactile and kinesthetic information that is lost, a computerized Force Feedback Endoscopic surgical Grasper (FREG) was developed with computer control and a haptic user interface. The system uses standard unmodified grasper shafts and tips. The FREG can control grasping forces either by surgeon teleoperation control, or under software control. The FREG performance was evaluated using an automated palpation function (programmed series of compressions) in which the grasper measures mechanical properties of the grasped materials. The material parameters obtained from measurements showed the ability of the FREG to discriminate between different types of normal soft tissues (small bowel, lung, spleen, liver, colon and stomach) and different kinds of artificial soft tissue replication materials (latex/Silicone) for simulation...
BACKGROUND: Growth and nutrition are key priorities in the management of pediatric inflammatory b... more BACKGROUND: Growth and nutrition are key priorities in the management of pediatric inflammatory bowel disease (IBD). Growth failure has been reported in up to 40% of children with Crohn's Disease (CD). The cause of growth failure in this population is multifactorial; malnutrition secondary to decreased intake, malabsorption, and GI losses, as well as psychosocial stressors are thought to be significant contributing factors. Ongoing inflammation and the release of cytokines such as TNFalpha, IL-6, and IL-1-beta may contribute to growth failure by suppressing growth factors. Infliximab, a chimeric murine-human monoclonal IgG1 antibody that targets TNF-alpha is used as a therapeutic agent for CD. As infliximab improves mucosal healing, it has been shown to potentially optimize growth. Data from the recent REACH study has shown improved linear growth in children with moderate to severe CD who were treated with infliximab. Due to the paucity of literature pertaining to pediatric IBD and how the current available treatments ultimately affect growth, a need for further research in this area has been noted. METHODS: A retrospective analysis reviewed medical records from 159 pediatric patients with CD, ages 2-18 years old, from a departmental IBD database who had completed at least 18 months of infliximab therapy from January 1998 to May 2009. Demographic data, height, weight, body mass index (BMI) and corresponding zscores at 2-month intervals during the 18 months prior to infliximab therapy through 18 months post-initiation of therapy were analyzed to determine whether significant changes in the patients' growth between these time periods could be observed. RESULTS: Regression analysis was performed for an 18-month period before and after infliximab therapy separately. No significant trend was detected in weight or BMI z-scores before and after therapy (p>0.05). Height z-score significantly increased at a rate of 0.0207þ0.0084 per month before therapy (p¼0.0145) but stayed unchanged after therapy (p¼0.5). After combining the monthly data into before-therapy and after therapy, we see significant increase in height (p¼0.0017) and weight z-scores (p¼0.0158) with no gender effect. CONCLUSIONS: Growth parameters of height and weight improved in this cohort after treatment with infliximab. Although height z-scores improved overall in the post-treatment group, regression modeling failed to detect a significant change in growth velocity after treatment with infliximab. This study is limited by its retrospective nature given the multi-dimensional nature of growth failure in this group. Further prospective analysis of TNF-alpha's effect on linear growth in children is recommended.
Objective: To describe long-term quality of life (QOL) outcomes after rectourethral fistula (RUF)... more Objective: To describe long-term quality of life (QOL) outcomes after rectourethral fistula (RUF) repair. RUF is a debilitating diagnosis and complex surgical dilemma with limited data regarding QOL after repair.
Minimally invasive surgery (MIS) involves a multi-dimensional series of tasks requiring a synthes... more Minimally invasive surgery (MIS) involves a multi-dimensional series of tasks requiring a synthesis between visual information and the kinematics and dynamics of the surgical tools. Analysis of these sources of information is a key step in mastering MIS but may also be used to define objective criteria for characterizing surgical performance. The BlueDRAGON is a new system for acquiring the kinematics and the dynamics of two endoscopic tools synchronized with the visual view of the surgical scene. It includes passive mechanisms equipped with position and force torque sensors for measuring the position and the orientation (P/O) of two endoscopic tools along with the force and torque (F/T) applied on them by the surgeon’s hands. The analogy between Minimally Invasive Surgery (MIS) and human language inspires the decomposition of a surgical task into its primary elements in which tool/tissue interactions are considered as “words” that have versions pronunciations defined by the F/T sig...
Minimally invasive surgery (MIS) is a technique introduced in the mid-1980s in which a few small ... more Minimally invasive surgery (MIS) is a technique introduced in the mid-1980s in which a few small incisions are made to allow for insertion of surgical tools and a camera through gasketed ports. Smaller incisions speed patient recovery times and lessen the chance of infection. They also introduce new interfaces as compared to more traditional open surgical techniques. These interfaces impose motion constraints and forces on the tool(s) and hand(s). These interfaces are not well characterized, yet surgical simulators and surgical robots are being developed without this vital information.
TPS3650 Background: Presence of cancer stem cells (CSC) appears to be the chief cause of drug res... more TPS3650 Background: Presence of cancer stem cells (CSC) appears to be the chief cause of drug resistance to cytotoxic or targeted chemotherapy. Experimental models suggest that these resistant canc...
classifi ed as drug reactions to CZP; and 1 (5.5%) patient was diagnosed with Hodgkins Lymphoma. ... more classifi ed as drug reactions to CZP; and 1 (5.5%) patient was diagnosed with Hodgkins Lymphoma. Th irty one patients (14 women, 17 men) were included in the split dosing analysis; 5 patients reported adverse events (16%) and the total number of distinct events was 6. 4 (67%) of the AEs reported were infectious; 1 (17%) was considered a complication secondary to CD; and 1 (3%) was an unrelated skin disorder. A majority of patients included in this analysis and reporting infectious adverse events were on concomitant immunosuppression (78% and 100% respectively) and 6 (67%) patients reporting infections in the standard dosing group had indwelling lines. Conclusion: At a single North American site, treatment with certolizumab pegol was found to be generally safe and well tolerated. In both the standard dosing group (400 mg once monthly) and the dose modifi cation group (200 mg ever 2 weeks) the most common adverse events reported were infections. Only 1 AE, an injection site reaction in the standard dosing group, was assessed by the treating gastroenterologist as probably related. Although the sample size in this analysis was limited, the number of adverse events reported at this single site is comparable to the frequency in previously published clinical trial data. Disclosure: Scott D. Lee, MD-Consultant: UCB Pharma; Speakers Bureau: UCB Pharma; Grant/Research Support: UCB Pharma Ghassan T. Wahbeh, MD-Consultant: UCB Pharma; Speakers Bureau: UCB Pharma.
The training of a surgeon includes the acquisition of a number of characteristics. These include ... more The training of a surgeon includes the acquisition of a number of characteristics. These include a cognitive knowledge base, problem formulation and decisionmaking abilities, appropriate psychosocial relationships, and other attributes that can be measured with objective testing, such as national board or specialty certifying examinations. Perhaps most critical to the surgeon, however, are the core technical skills of the profession. A battery of sophisticated devices is being created to teach and provide objective evaluations of the trainee’s technical abilities. These innovative state-of-the-art simulation devices, used to teach basic skills and surgical tasks through repetitive proctored challenges, will enable detection and analysis of surgical errors and near miss incidents without risk to patients. As with flight simulation, near miss detection capabilities anticipate potential errors before they occur and prevent resulting complications. In collaboration with a number of otol...
Studies in Health Technology and Informatics, 2005
Recent advances in technology have led to the fusion of MIS techniques and robot devices. However... more Recent advances in technology have led to the fusion of MIS techniques and robot devices. However, current systems are large and cumbersome. Optimizing the surgical robot mechanism will eventually lead to its integration into the operating room (OR) of the future becoming the extended presence of the surgeon and nurses in a room occupied by the patient alone. By optimizing a spherical mechanism using data collected in-vivo during MIS procedures, this study is focused on a bottom-up approach to developing a new class of surgical robotic arms while maximizing their performance and minimizing their size. The spherical mechanism is a rotational manipulator with all axes intersecting at the center of the sphere. Locating the rotation center of the mechanism at the MIS port makes this class of mechanism a suitable candidate for the first two links of a surgical robot for MIS. The required dexterous workspace (DWS) is defined as the region in which 95% of the tool motions are contained bas...
Studies in Health Technology and Informatics, 2007
With the development of new technologies in surgery, minimally invasive surgery (MIS) has drastic... more With the development of new technologies in surgery, minimally invasive surgery (MIS) has drastically improved the way conventional medical procedures are performed. However, a new learning curve has resulted requiring an expertise in integrating visual information with the kinematics and dynamics of the surgical tools. The Red DRAGON is a multi-modal simulator for teaching and training MIS procedures allowing one to use it with several modalities including: simulator (physical objects and virtual objects) and an animal model. The Red DRAGON system is based on a serial spherical mechanism in which all the rotation axes intersect at a single point (remote center) allowing the endoscopic tools to pivot around the MIS port. The system includes two mechanisms that incorporate two interchangeable MIS tools. Sensors are incorporated into the mechanism and the tools measure the positions and orientations of the surgical tools as well as forces and torques applied on the tools by the surgeo...
Abstract. We report a computerized endoscopic surgical grasper with computer control and a force ... more Abstract. We report a computerized endoscopic surgical grasper with computer control and a force feedback (haptic) user interface. The system uses standard unmodified grasper shafts and tips. The device can control grasping forces either by direct surgeon control, via teleoperation, or under software control. In this paper, we test an automated palpation function in which the grasper measures mechanical properties of the grasped tissue by applying a programmed series of squeezes. Experimental results show the ability to discriminate between the normal tissues of small bowel, lung, spleen, liver, colon, and stomach. We anticipate applications in tele-surgery, clinical endoscopic surgery, surgical training, and research. 1.
While there are many benefits to minimally invasive surgery, force feedback, or touch sensation, ... more While there are many benefits to minimally invasive surgery, force feedback, or touch sensation, is lacking in the currently available MIS tools, including surgical robots, creating the potential for excessive force application during surgery. The goal of this work was to develop a methodology with which to identify stress magnitudes and durations that can be safely applied with a grasper to different tissues, helping to improve MIS device design and reduce potential for clinically relevant consequences. Using the porcine model, stresses typically applied in MIS were applied to liver, ureter, and small bowel using a motorized endoscopic grasper. Acute indicators of tissue damage including cellular death, activation of the coagulation cascade, and infiltration of inflammatory cells were measured using histological and image analysis techniques. ANOVA and post-hoc analyses were used to detect stress magnitudes and durations that caused significantly increased tissue damage with the goal to ultimately identify safe stress 'thresholds' during grasping of the studied tissues. Preliminary data suggests a graded non-linear response between applied stress magnitude and apoptosis in liver and small bowel as well as granulocyte infiltration in small bowel.
Minimally Invasive Surgery (MIS) generates new user interfaces which create visual and haptic dis... more Minimally Invasive Surgery (MIS) generates new user interfaces which create visual and haptic distortion when compared to traditional surgery. In order to regain the tactile and kinesthetic information that is lost, a computerized Force Feedback Endoscopic surgical Grasper (FREG) was developed with computer control and a haptic user interface. The system uses standard unmodified grasper shafts and tips. The FREG can control grasping forces either by surgeon teleoperation control, or under software control. The FREG performance was evaluated using an automated palpation function (programmed series of compressions) in which the grasper measures mechanical properties of the grasped materials. The material parameters obtained from measurements showed the ability of the FREG to discriminate between different types of normal soft tissues (small bowel, lung, spleen, liver, colon and stomach) and different kinds of artificial soft tissue replication materials (latex/Silicone) for simulation...
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Papers by Mika Sinanan