Introduction – Le but de ce travail était de développer un modèle expérimental endoscopique de chirurgie bariatrique par technique NOTES, simple, reproductible et de le valider à la fois sur le plan clinique (faisabilité, tolérance) et sur le plan métabolique (physiopathologie et mode d’action). Matériels et méthodes - Les études furent menées au sein du CERC et de l’unité INSERM UMRS 1260. L’animal étudié fut le cochon domestique, âgé de 3 à 4 mois, sains et non obèse. Les endoscopies étaient réalisées à l’aide d’un gastroscope double canal opérateur et de matériel d’endoscopie couramment disponible. Plusieurs étapes de développement furent mises en place de la confection d’un modèle animal d’anastomose gastro-jéjunale par technique endoscopique NOTES exclusive à l’évaluation de l’impact métabolique d’un modèle de by-pass gastrique à visée bariatrique utilisant l’anastomose gastro-jéjunale par apposition prothétique luminale. Résultats – Le modèle d’anastomose gastro-jéjunale choisi pour sa faisabilité et son innocuité fut développé par apposition des lumières digestives gastriques et grêliques avec prothèse en technique NOTES trans digestive. L’évaluation métabolique expérimentale du by-pass gastrique utilisant ce mode opératoire permit de constater une amélioration significative de l’insulino-résistance non véhiculées par le GLP-1. Conclusion – Le concept d’anastomose digestive par NOTES exclusive et apposition luminale prothétique est établi et le modèle de by-pass endoscopique utilisant ce mode opératoire est faisable semblant présenter un impact métabolique significatif. / Introduction - The aim of this study was to develop an endoscopic experimental model of NOTES bariatric surgery using a simple, reproducible technique and to validate it both clinically (feasibility, tolerance) and metabolically (pathophysiology and action plan). Materials and Methods - The studies were conducted within the CERC and INSERM UMRS 1260 unit. The animal was the pig, aged 3 to 4 months, healthy and not obese. Endoscopies were performed using a dual channel gastroscope operator and the endoscopy equipment currently available. Several development stages were set up from the development of an animal model of gastrointestinal anastomosis using an exclusive endoscopic NOTES procedure to the evaluation of the metabolic impact of gastric bypass bariatric model described using the gastrointestinal anastomosis by luminal apposing stent technique. Results - The gastro-jejunal anastomosis model chosen for its feasibility and safety was developed by luminal apposing gastric and small bowel digestive lumens with a specific metallic covered stent and NOTES technique. The experimental evaluation of the metabolic gastric bypass using this procedure allowed to observe a significant improvement in insulin resistance none mediated by GLP-1 and incretin effect. Conclusion - The concept of anastomosis with luminal apposing stent and exclusive NOTES technique is established and endoscopic bypass model using this procedure is feasible pretend to present a significant metabolic impact.

Nous avons récemment démontré un bénéfice de l’implantation d’un drain biliaire interne (IBS-Internal Biliary Stent) afin de réduire les complications biliaires en transplantation hépatique. Le drain IBS en silicone est utilisé en pratique clinique, son utilisation nécessite une procédure d’ablation endoscopique, intervention qui n’est pas dénuée de complications. Afin d’éviter cela, et pour réduire les complications biliaires après transplantation hépatique, nous avons cherché à développer une prothèse biliaire interne résorbable (RIBS-Resorbable Internal Biliary Stent), fabriquée à partir d'un polymère dégradable radio-opaque. Pour être implantable, le RIBS doit répondre à un cahier des charges.Le premier objectif de ce travail était de synthétiser le matériau et le mettre en forme à partir d'un copolymère tribloc initialement sélectionné de PLA50-PEG-PLA50 avec un additif radio-opaque composé d’un copolymère de triiodobenzoate-poly(-caprolactone) (PCL-TIB). Le RIBS doit non seulement être toléré par l’organisme mais doit permettre de sécuriser l’anastomose biliaire et favoriser la régénération tissulaire biliaire pour ensuite être éliminée de l’organisme. Ce dispositif doit également répondre aux objectifs très strictes liés à l’implantation et au suivi en TH. Le second objectif était de caractériser le RIBS de PCL-TIB/PLA50-PEG-PLA50, en évaluant si les propriétés au cours de la dégradation in vitro et in vivo étaient conformes au cahier des charges. Une étude in vitro dans un environnement biliaire simulé et une étude in vivo chez le rat ont été réalisées. Nous avons observé les propriétés physico-chimiques, la visualisation radiologique, l'histologie et le comportement mécanique au cours de la dégradation. Enfin, le dernier objectif était d'évaluer l'implantabilité ex vivo dans les voies biliaires humaines, avec une étude du comportement mécanique des voies biliaires et des tests d'implantation sur des pièces anatomiques.Dans cette thèse, le comportement radiologique et mécanique du dispositif RIBS innovant a été évalué avec succès au cours la dégradation in vitro et in vivo, avec des propriétés qui répondaient aux exigences. Un prototype de RIBS a été implanté avec succès dans une pièce anatomique humaine. Ces travaux ont permis le développement d’un dispositif innovant, à savoir un IBS traçable et biodégradable utilisable pour réduire les complications biliaires en transplantation hépatique. / Benefit of implantation of an internal biliary stent (IBS) during liver transplantation to reduce biliary complications was recently demonstrated. Silicone IBS was used in practice, which require an endoscopic ablation procedure, a potentially morbid intervention for the patient. In order to avoid this, and to reduce biliary complications after liver transplantation we develop a resorbable internal biliary stent (RIBS), made from a degradable polymer visualizable by X-ray. To be usable and useful, RIBS must comply specifications, which are developed in this thesis.The first aim of the present work, was to synthetize a material based on a selected PLA50-PEG-PLA50 triblock copolymer with a triiodobenzoate-poly(-caprolactone) radiopaque copolymer (PCL-TIB) as additive and design a RIBS. It must be biocompatible, should secure the biliary anastomosis and enable biliary regeneration. This device will also have to meet the very strict objectives related to implementation and monitoring in liver transplantation. The second objective was to characterize the PCL-TIB/PLA50-PEG-PLA50 RIBS, by evaluating whether properties during in vitro and in vivo degradation complied the specifications. An in vitro study in a simulated biliary environment and an in vivo rats implantation study was realized. We observed physico-chemical properties, radiological visualization, histology, and mechanical behavior during degradation. The last aim was to evaluate ex vivo implantability in human bile ducts, with the study of the bile duct mechanical behavior, and implantation tests on anatomic specimens.In this thesis, radiological and mechanical behaviour of novel radiopaque and resorbable IBS was successfully evaluated during in vitro and in vivo degradation with properties that meet requirements. A RIBS prototype device was successfully implanted in human anatomic specimen. The results obtained will allow the development of a novel class of trackable and degradable IBS to reduce biliary complications after liver transplantation.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22037号 / 医博第4522号 / 新制||医||1038(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 髙橋 良輔, 教授 湊谷 謙司, 教授 井上 治久 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18878号 / 医博第3989号 / 新制||医||1008(附属図書館) / 31829 / 京都大学大学院医学研究科医学専攻 / (主査)教授 坂井 義治, 教授 坂田 隆造, 教授 平岡 眞寛 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

This masteral thesis describes phenomenon of electroporation and it’s use to deal with occluded self-expandable metalic stent. Thesis briefly summarizes theory of electroporation, currently used medical treatments of occluded stents. The next part of the thesis is dedicated to current state of mathematical simulations of electroporation. The core of the thesis are simulations of electroporation effects on tissue of occluded metal stents.

Die Hauptursache für menschliche Erkrankungen des Herz Kreislaufsystems in den westlichen Industrienationen ist die Atherosklerose. Die konventionelle minimalinvasive Therapie in der Humanmedizin ist die perkutane transluminale Angioplastie (PTA), bei der durch einen arteriellen Gefäßzugang die Stenose mittels Ballonkatheter aufgedehnt und optional eine Gefäßstütze (Stent) implantiert werden kann, um das atherosklerotische Gefäß offen zu halten. In 20 % der Fälle kommt es jedoch ein Jahr nach der Behandlung zum Gefäßwiederverschluss, der in-Stent Restenose (ISR). Einer der postulierten verantwortlichen molekularen Mechanismen ist die überschießende Monozyteninvasion, die durch die Freisetzung spezifischer Signalmoleküle, vor allem dem Monozyten-anlockenden Chemokin CCL2, ausgelöst wird. Die metabolische Stabilität von CCL2 wird durch das Enzym isoGlutaminylzyklase (isoQC) vermittelt. Diese enzymatische Modifikation ist relevant für die chemotaktische Potenz und schützt CCL2 vor einem N-terminalen Abbau durch Aminopeptidasen und der somit verbundenen Inaktivierung. Ziel dieser Arbeit war es, in einem geeigneten Tiermodell das Enzym isoQC nach Stentimplantation zu hemmen, dadurch die Konzentration von zyklisiertem CCL2 zu reduzieren und somit den potentiellen für die ISR mitverantwortlichen Wirkmechanismus der Monozyteninvasion in vivo zu darzustellen.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Endodontic treatment in teeth with pulp canal obliteration (PCO) is challenging. Guided Endodontic Access (GEA) combines information from a cone-beam computed tomography (CBCT) scan with an intra-oral scan to create a stent that can be used as a guide to treat teeth with PCO. GEA stents designed with traditional palatal accesses were shown to be successful in accurately negotiating these 3D printed teeth with simulated PCO, however, the difference in accuracy between the traditional palatal access compared to a conservative incisal access is not yet known. Objective: This in vitro study compares GEA stents designed with an incisal access approach to GEA stents designed with a traditional palatal access approach. The effect on the overall degree of deviation of the designed access path from the prepared path is evaluated by measuring the degree of angle of deviation and amount of deviation in millimeters. Materials and Methods: A 3-D printed maxillary model of an anonymous patient was used. PCO was simulated in a 3D printed natural #8 using the coDiagnostiX software tooth at two levels: coronal and mid-root. A GEA stent that extended from tooth #3 to tooth #14 with a guide sleeve over the simulated tooth #8 was accessed with a dedicated 1.0 mm diameter and 20 mm length drill that is designed to fit the access sleeve. 15 GEA stents had guides utilized for the incisal access approach, and 15 GEA stents had guides utilized for the traditional palatal access approach. Results: Angle, mesio-distal (base), and mesio-distal (tip) deviations were significantly lower for the incisal access compared to the traditional access. Inciso-apical (base) deviation was significantly more negative for incisal access compared to the traditional access. Bucco-lingual (base) deviation was significantly more negative for traditional access compared to the incisal access, while incisal and traditional accesses were not significantly different for bucco-lingual (tip) deviation. Coronal 1/3 calcification groups had significantly more mesio-distal (base) deviation than the middle 1/3 and no PCO groups. The no PCO group had significantly more negative inciso--apical (base) deviation than the coronal 1/3 calcification and middle 1/3 calcification groups, and the coronal 1/3 calcification group was significantly more negative than the middle 1/3 calcification group. The coronal 1/3 calcification group had significantly more mesio-distal (tip) deviation than the no PCO group. PCO level did not have a significant effect on angle, bucco-lingual (base), or bucco-lingual (tip) deviations. Conclusion: The utilization GEA via incisal access resulted in less degree and amount of drill deviation compared to the traditional access at all levels of calcification, however, the level of PCO did not influence the degree and amount of drill deviation between the incisal and traditional access approaches. It can be concluded that the use of a GEA stent that utilizes an incisal access approach in teeth with PCO will result in a more predictable outcome.

Background/Aims: Peripancreatic fluid collections (PFCs) result from acute or chronic pancreatic inflammation that suffers a rupture of its ducts. Currently, there exists three options for drainage or debridement of pancreatic pseudocysts and walled-off necrosis (WON). The traditional procedure is drainage by placing double pigtail plastic stents (DPPS); lumen-apposing metal stent (LAMS) has a biflanged design with a wide lumen that avoids occlusion with necrotic tissue, which is more common with DPPS and reduces the possibility of migration. We performed a systematic review and meta-analyses head-to-head, including only studies that compare the two main techniques to drainage of PFCs: LAMS vs DPPS. Methods: We conducted a systematic review in different databases, such as PubMed, OVID, Medline, and Cochrane Databases. This meta-analysis considers studies published from 2014 to 2020, including only studies that compare the two main techniques to drainage of PFCs: LAMS vs DPPS. Results: Thirteen studies were included in the meta-analyses. Only one of all studies was a randomized controlled trial. These studies comprise 1584 patients; 68.2% were male, and 31.8% were female. Six hundred sixty-three patients (41.9%) were treated with LAMS, and 921 (58.1%) were treated with DPPS. Six studies included only WON in their analysis, two included only pancreatic pseudocysts, and five studies included both pancreatic pseudocysts and WON. The technical success was similar in patients treated with LAMS and DPPS (97.6% vs 97.5%, respectively, P =.986, RR = 1.00 [95% CI 0.93-1.08]). The clinical success was similar in both groups (LAMS: 90.1% vs DPPS: 84.2%, P =.139, RR = 1.063 [95% CI 0.98-1.15]). Patients treated with LAMS had a lower complication rate than the DPPS groups, with a significant statistical difference (LAMS: 16.0% vs DPPS: 20.2%, P =.009, RR = 0.746 [95% CI 0.60-0.93]). Bleeding was the most common complication in the LAMS group (33 patients, [5.0%]), whereas infection was the most common complication in the DPPS group (56 patients, [6.1%]). The LAMS migration rate was lower than in the DPPS (0.9% vs 2.2%, respectively, P =.05). The mortality rate was similar in both groups, 0.6% in the LAMS group (four patients) and 0.4% in the DPPS group (four patients; P =.640). Conclusion: The PFCs drainage is an indication when persistent symptoms or PFCs-related complications exist. EUS guided drainage with LAMS has similar technical and clinical success to DPPS drainage for the management of PFCs. The technical and clinical success rates are high in both groups. However, LAMS drainage has a lower adverse events rate than DPPS drainage. More randomized controlled trials are needed to confirm the real advantage of LAMS drainage over DPPS drainage. / Revisión por pares

No description available.