A physically based trunk soft tissue modeling for scoliosis surgery planning systems

One of the major concerns of scoliotic patients undergoing spinal correction surgery is the trunk's external appearance after the surgery. This paper presents a novel incremental approach for simulating postoperative trunk shape in scoliosis surgery. Preoperative and postoperative trunk shapes data were obtained using three-dimensional medical imaging techniques for seven patients with adolescent idiopathic scoliosis. Results of qualitative and quantitative evaluations, based on the comparison of the simulated and actual postoperative trunk surfaces, showed an adequate accuracy of the method. Our approach provides a candidate simulation tool to be used in a clinical environment for the surgery planning process.

Simulation of the postoperative trunk appearance in scoliosis surgery

Persistence of external trunk asymmetry after scoliosis surgical treatment is frequent and difficult to predict by clinicians. This is a significant problem considering that correction of the apparent deformity is a major factor of satisfaction for the patients. A simulation of the correction on the external appearance would allow the clinician to illustrate to the patient the potential result of the surgery and would help in deciding on a surgical strategy that could most improve his/her appearance. We describe a method to predict the scoliotic trunk shape after a spine surgical intervention. The capability of our method was evaluated using real data of scoliotic patients. Results of the qualitative evaluation were very promising and a quantitative evaluation based on the comparison of the simulated and the actual postoperative trunk surface showed an adequate accuracy for clinical assessment. The required short simulation time also makes our approach an eligible candidate for a clinical environment demanding interactive simulations.

Changes in Trunk Appearance After Scoliosis Spinal Surgery and Their Relation to Changes in Spinal Measurements

Study Design Retrospective study of surgical outcome. Objectives To evaluate quantitatively the changes in trunk surface deformities after scoliosis spinal surgery in Lenke 1A adolescent idiopathic scoliosis (AIS) patients and to compare it with changes in spinal measurements. Summary of Background Data Most studies documenting scoliosis surgical outcome used either radiographs to evaluate changes in the spinal curve or questionnaires to assess patients health-related quality of life. Because improving trunk appearance is a major reason for patients and their parents to seek treatment, this study focuses on postoperative changes in trunk surface deformities. Recently, a novel approach to quantify trunk deformities in a reliable, automatic, and noninvasive way has been proposed. Methods Forty-nine adolescents with Lenke 1A idiopathic scoliosis treated surgically were included. The back surface rotation and trunk lateral shift were computed on trunk surface acquisitions before and at least 6 months after surgery. We analyzed the effect of age, height, weight, curve severity, and flexibility before surgery, length of follow-up, and the surgical technique. For 25 patients with available three-dimensional (3D) spinal reconstructions, we compared changes in trunk deformities with changes in two-dimensional (2D) and 3D spinal measurements. Results The mean correction rates for the back surface rotation and the trunk lateral shift are 18% and 50%, respectively. Only the surgical technique had a significant effect on the correction rate of the back surface rotation. Direct vertebral derotation and reduction by spine translation provide a better correction of the rib hump (22% and 31% respectively) than the classic rod rotation technique (8%). The reductions of the lumbar Cobb angle and the apical vertebrae transverse rotation explain, respectively, up to 17% and 16% the reduction of the back surface rotation. Conclusions Current surgical techniques perform well in realigning the trunk; however, the correction of the deformity in the transverse plane proves to be more challenging. More analysis on the positive effect of vertebral derotation on the rib hump correction is needed. Level of evidence III.

Non-invasive quantitative assessment of scoliosis spinal surgery outcome

Improving the appearance of the trunk is an important goal of scoliosis surgical treatment, mainly in patients' eyes. Unfortunately, existing methods for assessing postoperative trunk appearance are rather subjective as they rely on a qualitative evaluation of the trunk shape. In this paper, an objective method is proposed to quantify the changes in trunk shape after surgery. Using a non-invasive optical system, the whole trunk surface is acquired and reconstructed in 3D. Trunk shape is described by two functional measurements spanning the trunk length: the lateral deviation and the axial rotation. To measure the pre and postoperative differences, a correction rate is computed for both measurements. On a cohort of 36 scoliosis patients with the same spinal curve type who underwent the same surgical approach, surgery achieved a very good correction of the lateral trunk deviation (median correction of 76%) and a poor to moderate correction of the back axial rotation (median correction of 19%). These results demonstrate that after surgery, patients are still confronted with residual trunk deformity, mainly a persisting hump on the back. That can be explained by the fact that current scoliosis assessment and treatment planning are based solely on radiographic measures of the spinal deformity and do not take trunk deformity into consideration. It is believed that with our novel quantitative trunk shape descriptor, clinicians and surgeons can now objectively assess trunk deformity and postoperative shape and propose new treatment strategies that could better address patients' concern about their appearance. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Modulation allostérique du récepteur FP dans le cancer colorectal

Les prostaglandines modulent d’importants rôles physiologiques. Elles sont aussi impliquées dans le développement d’une variété de conditions pathologiques telles l’inflammation, la douleur et le cancer. La prostaglandine PGF2α et son récepteur (récepteur FP) se trouvent impliqué dans la modulation de nombreuses pathologies tels lors de l’accouchement préterme et le cancer colorectal. Récemment, nous avons fait partie d’un groupe de recherche ayant développé des modulateurs allostériques du récepteur FP. Dans une première étude, l’action du PGF2α sur le déclenchement des contractions myométriales a été évaluée, car peu d’information est connue sur la signalisation de cette prostaglandine lors de l’accouchement. Ainsi, nous avons utilisé un peptidomimétique de la deuxième boucle extracellulaire, dénommée PDC113.824. Nos résultats ont démontré que le PDC113.824 permettait de retarder la mise bas chez des souris gestantes, mais agissait de manière différente sur les multiples voies de signalisation de la PGF2α. Ainsi, le PDC113.824 inhibait la voie RhoA-ROCK, dépendante de l’activation de la protéine Gα12 par le. Les protéines RhoA-ROCK sont des acteurs clés dans le remodelage du cytosquelette d’actine et des contractions myométriales lors de l’accouchement. De plus, le PDC113.824 en présence de PGF2α agit comme un modulateur positif sur la voie dépendante de l’activation de la protéine Gαq. Le PDC113.824 serait donc un modulateur allostérique non compétitif possédant des actions à la fois de modulateurs positifs et négatifs sur la signalisation du récepteur FP Dans une seconde étude, des analogues du PDC113.824 ont été conçus et analysés dans un second modèle pathologique, le cancer colorectal. Ce cancer possède de hauts niveaux de récepteur FP. Nous avons donc étudié le rôle du récepteur FP dans le développement et la progression du cancer colorectal et l’effet de modulateurs allostériques. Il est généralement accepté que dans le cancer colorectal, la prostaglandine PGE2 permet la croissance et l’invasion tumorale, ainsi que l’angiogenèse. Toutefois, peu d’informations sont connues sur le rôle du PGF2α dans le cancer colorectal. C’est dans ce contexte que nous avons décidé d’examiner la contribution de ce récepteur dans la progression du cancer colorectal et cherché à déterminer si la modulation des fonctions du récepteur FP a un impact sur la croissance de tumeurs colorectales. Nos recherches ont révélé que l’activation du récepteur FP permet la migration et la prolifération de plusieurs lignées cellulaires humaines et murines d’adénocarcinomes colorectaux. Dans ce contexte, nos expériences ont démontré que la migration des cellules cancéreuses était dépendante de l’activation de la voie Rho. Nos résultats démontrent qu’en effet, l’activation de RhoA, une petite GTPase clé de la voie Gα12, est inhibée de façon sélective par nos composés. De plus, nos molécules allostériques sont également efficaces pour inhiber la voie de signalisation de la ß-caténine, une protéine impliquée dans la genèse du cancer colorectal. In vivo, le traitement de souris avec un des ces modulateurs a permis une inhibition effective de la croissance tumorale. Dans l’ensemble, nos résultats suggèrent donc que les modulateurs allostériques des récepteurs FP pourraient constituer une nouvelle classe de médicaments utilisés pour le traitement du cancer colorectal.

Association entre les affections buccodentaires et le cancer colorectal : une revue et synthèse de la littérature

Position du problème: La parodontite chronique et l’édentement sont des affections buccodentaires chroniques qui, depuis quelques décennies, sont incriminées dans la survenue de différents types de cancers. Cette revue de littérature avait pour but d’examiner l’association entre le cancer colorectal et ces affections buccodentaires. Résultats: Les études épidémiologiques évaluant une association potentielle entre la parodontite, l’édentement et le cancer colorectal sont peu nombreuses. Cependant, plusieurs mécanismes plaident en faveur de cette association, notamment l’inflammation, la nutrition et possiblement l’infection par certains pathogènes, comme le suggère cette revue de la littérature.

“Reconstruction of Gene Regulatory Network from Expression Profile of Plasma RNA Data of Colorectal Cancer Patients using Soft Computing Techniques”

Microarray data analysis is one of data mining tool which is used to extract meaningful information hidden in biological data. One of the major focuses on microarray data analysis is the reconstruction of gene regulatory network that may be used to provide a broader understanding on the functioning of complex cellular systems. Since cancer is a genetic disease arising from the abnormal gene function, the identification of cancerous genes and the regulatory pathways they control will provide a better platform for understanding the tumor formation and development. The major focus of this thesis is to understand the regulation of genes responsible for the development of cancer, particularly colorectal cancer by analyzing the microarray expression data. In this thesis, four computational algorithms namely fuzzy logic algorithm, modified genetic algorithm, dynamic neural fuzzy network and Takagi Sugeno Kang-type recurrent neural fuzzy network are used to extract cancer specific gene regulatory network from plasma RNA dataset of colorectal cancer patients. Plasma RNA is highly attractive for cancer analysis since it requires a collection of small amount of blood and it can be obtained at any time in repetitive fashion allowing the analysis of disease progression and treatment response.

Video Object Tracking And Analysis For Computer Assisted Surgery

Pedicle screw insertion technique has made revolution in the surgical treatment of spinal fractures and spinal disorders. Although X- ray fluoroscopy based navigation is popular, there is risk of prolonged exposure to X- ray radiation. Systems that have lower radiation risk are generally quite expensive. The position and orientation of the drill is clinically very important in pedicle screw fixation. In this paper, the position and orientation of the marker on the drill is determined using pattern recognition based methods, using geometric features, obtained from the input video sequence taken from CCD camera. A search is then performed on the video frames after preprocessing, to obtain the exact position and orientation of the drill. An animated graphics, showing the instantaneous position and orientation of the drill is then overlaid on the processed video for real time drill control and navigation

Evaluation Of A Novel Method Of Real Time Computer Assisted Spine Surgery

In this paper the effectiveness of a novel method of computer assisted pedicle screw insertion was studied using testing of hypothesis procedure with a sample size of 48. Pattern recognition based on geometric features of markers on the drill has been performed on real time optical video obtained from orthogonally placed CCD cameras. The study reveals the exactness of the calculated position of the drill using navigation based on CT image of the vertebra and real time optical video of the drill. The significance value is 0.424 at 95% confidence level which indicates good precision with a standard mean error of only 0.00724. The virtual vision method is less hazardous to both patient and the surgeon

Infecciones en pacientes tratados con citorreducción peritoneal mas quimioterapia hipertérmica intraperitoneal

Introducción:Los individuos en quienes se realiza el sugarbaker tienen diagnósticos tumorales bien caracterizados. Actualmente no se dispone en la literatura médica universal de comparadores previos que permitan estimar la morbilidad relacionada específicamente con procesos infecciosos en pacientes sometidos al procedimiento, por tanto se presenta la caracterización de procesos febriles e infecciosos en el postoperatorio de la cohorte de pacientes intervenidos en la FSFB y de los factores de riesgo asociados a su manifestación. Métodos:Estudio descriptivo con componente analítico de una cohorte ambidireccional compuesta por pacientes intervenidos en la FSFB mediante el procedimiento de Sugarbaker. Resultados:En total se incluyeron en el estudio 53 pacientes consecutivos (37mujeres y 16hombres), quienes fueron llevados al procedimiento de peritonectomía radical más quimioterapia hipertérmica intraperitoneal entre el mes de nov/2007 y jun/2012 en el Hospital-Universitario Fundación Santa Fe de Bogotá. Los desenlaces de morbilidad asociada al procedimiento fueron caracterizados, indicando que las principales causas de morbilidad son los eventos tromboticos y las infecciones. Se caracterizaron como estadísticamente significativos para estancia hospitalaria el requerimiento transfusional (r=0,451, p=0,001), colecistectomía (p=0,016), el riesgo anestésico ASA≥3 (p=0,03), entre otros. El perfil de infección mostró relación estadísticamente significativa con resecciones de órganos específicas (p<0,05 para colectomía derecha [OR=5,3], colecistectomía [OR=21,8] y esplenectomía [OR=4,2]), el riesgo anestésico ASA≥3 (OR=1,2, p=0,036), anemia (OR=7,1, p=0,004), fístula (OR=5,2, p=0,036), entre otros. Conclusiones: El procedimiento de Sugarbaker es eficaz y seguro en nuestra institución. Se requiere de más estudios en poblaciones diversas que permitan comprender el comportamiento de las infecciones en la población sometida al procedimiento.

Predictors of Attitudes toward Cosmetic Surgery among U.S. and Colombian College Women: The Roles of Eating Behaviors and Demographic Variables

Cross-cultural studies on eating behaviors and related constructs can identify cultural and social factors that contribute to eating disorder symptomatology. Eating disorders (EDs) are a major cause for concern in the U.S., and recent studies in Colombia have shown growing rates among their female population. In addition, cosmetic surgery procedures have been increasing rapidly in both the U.S. and Colombia, and preliminary research suggests a positive relation between disordered eating and endorsement of plastic surgery. In samples of college women from Colombia and the U.S., we investigated patterns of association between disordered eating variables and cosmetic surgery acceptance. Our approach utilized separate analyses for various subcomponents of disordered eating (to determine their unique associations with cosmetic surgery acceptance) while adjusting for potentially relevant covariates and examining cross-cultural patterns. Participants were students at an urban, public college in the U.S. (n=163) and an urban, private college in Colombia (n=179). Overall, our findings suggested that participants from Colombia with greater disordered eating were more likely to endorse cosmetic surgery for social reasons, while those from the U.S. were more likely to consider undergoing cosmetic surgery for personal reasons. Differing findings between the two samples may be due to cultural and social factors, which we delineate. These findings also have potential implications for presurgical counseling of cosmetic surgery candidates.

Primary Prevention and Screening Strategies for Colorectal Cancer: Which Strategy Should Take?

Objective: To explore and define the utility of different strategies for primary prevention (ASA, diet, physical activity) and strategies of screening test (FOBT, sigmoidoscopy, colonoscopy, etc.) for colorectal cancer. Data source: Databases consulted were MEDLINE (1966 to 2006), DARE (1980 to 2006), Cochrane Central Register of Controlled Trials, Cochrane Collaboration’s Registry of Clinical Trials, Cochrane Database of Systematic Reviews and LILACS. Study selection: Studies such clinical trial, cohort and case-control studies of the effectiveness of tests for screening and primary prevention adenoma and colorectal cancer were identified by two reviewers. Data Extraction: The extraction of data and its evaluation is done in most of the process so paired. Limitations: Not strictly complies with the methodology of a systematic review and therefore reproducibility is questionable, the conclusions of this study should be extrapolated with caution. Conclusions: The major strategy of screening on the effectiveness of early detection of premalignant lesions or cancer is colonoscopy every 5 years, however it is necessary to evaluate this measure cost-effectiveness studies. For primary prevention, aspirin and cyclooxygenase-2 inhibitors reduce the incidence of colorectal adenomas. Aspirin can reduce colorectal cancer incidence. However, these medications may be associated with a significant risk of cardiovascular events and gastrointestinal bleeding. The balance between risks and benefits must be evaluated in future studies.

Factores asociados a tratamiento quirúrgico en pacientes con obstrucción intestinal por adherencias

El manejo de la obstrucción intestinal por adherencias es un reto para cualquier especialista en Cirugía debido a que existe controversia sobre el alcance del manejo médico y el momento adecuado para llevar el paciente a cirugía para la resolución del cuadro clínico. En el presente trabajo se pretende, identificar los factores asociados a tratamiento quirúrgico en pacientes con obstrucción intestinal por adherencias. Metodología: Se realizó un estudio de casos y controles en una relación de 1:1, con una recolección de muestra estadística de 48 pacientes en cada grupo, entre mayo 2012 y mayo 2014 en el Hospital Universitario Mayor Mederi y en Barrios Unidos. Se consideraron casos los pacientes intervenidos quirúrgicamente por obstrucción intestinal por bridas y controles los pacientes manejados con tratamiento médico. Se evaluaron factores como edad, antecedentes personales patológicos y quirúrgicos, tiempo de evolución del cuadro clínico, hallazgos en imágenes y laboratorio entre otros. Resultados: Se recolectaron un total de 158 pacientes, (78 casos, 80 controles). Ambas poblaciones fueron comparables (p=0.13). Los factores asociados a tratamiento quirúrgico estadísticamente significativos fueron género masculino, presencia de fiebre al ingreso, el hallazgo de engrosamiento de la pared intestinal y de obstrucción de asa cerrada en imágenes diagnósticas (p<0,05). Discusión: Los principales factores asociados para que un paciente con obstrucción intestinal por bridas requiera de manejo quirúrgico son consistentes con literatura. Se requiere la socialización de los resultados para disminuir la morbimortalidad de nuestros pacientes.

Experiencia en el manejo de cancer colorrectal en el hospital universitario mayor - Mederi

Introducción: El cáncer colorrectal es el tercer cáncer más diagnosticado en los hombres y el segundo en las mujeres a nivel mundial. Hasta 1.000 casos nuevos se diagnostican en Colombia cada año, por lo que es importante conocer la experiencia con esta patología en un centro de experiencia recientemente creado en el “Méderi, Hospital Universitario Mayor”. Materiales y métodos: Se realizó un estudio de corte transversal de la población con diagnóstico de cáncer colorrectal atendida entre agosto 2012 y diciembre 2014 que corresponde al tiempo de funcionamiento del servicio de Coloproctología. Resultados: Se atendieron un total de 152 pacientes con cáncer colorrectal en la institución. Se operó el 91% de los pacientes. El estadío más frecuente fue el IV. Solo el 4.9% presentó dehiscencia de anastomosis, datos concordantes con la literatura cuando el manejo es a cargo de expertos. El subtipo histológico más frecuente fue adenocarcinoma moderadamente diferenciado y la mortalidad perioperatoria de 2.63%. Discusión: El cáncer colorrectal es una entidad con alta morbimortalidad lo cual puede cambiar si se realizan pruebas de tamizaje, para realizar un manejo temprano y oportuno. Además juega un papel importante la experiencia del cirujano y la discusión de los pacientes en juntas multidisciplinarias. Palabras clave: cáncer de colon, cáncer de recto, epidemiología, estadificación