Poisson approximation for some point processes in reliability

The attached file may be somewhat different from the published versionInternational audienceIn this paper, we consider a failure point process related to the Markovian Arrival Process defined by Neuts. We show that it onverges in distribution to a homogeneous Poisson process. This convergence takes place in context of rare occurrences of failures. We also provide a convergence rate of the convergence in total variation of this point process using an approach developed by Kabanov, Liptser and Shiryaev for the doubly-stochastic Poisson process driven by a finite Markov process

Risque et acteurs au travail

Le Centre Hospitalier Privé (CHP) de Saint-Grégoire nous offre pendant trois ans la possibilité de suivre le déploiement d’un nouveau système d’information. C’est donc au cœur des questions de recompositions organisationnelles traversées par les TIC que nous situons cette proposition. La notion de risque et la place des TIC dans les processus de travail numérisés, peut selon nous être reliée à une question forte en communication organisationnelle, celle du lien entre risques et changement. Cette question du risque sera travaillée en lien avec les représentations issues de pratiques de travail, qui conduisent les acteurs à adopter des comportements, et qui contribuent à la production de nouvelles formes culturelles « groupales » (Martucelli) liées aux pratiques professionnelles et étant potentiellement source de « dislocation ». Dans le cadre de cette réflexion, nous envisagerons donc quel peut être l’apport d’une analyse communicationnelle à la compréhension des représentations et des comportements (Bouillon, Bourdin, Loneux, 2007). Au-delà des Risques Psycho Sociaux (RPS), des discours sécuritaires, etc., nous verrons une autre forme de risque, le risque de dérégulation de l’être professionnel au travail à travers les technologies du soi, idée que nous allons explorer dans cet article , le RO2i : risque organisationnel impactant l’individu.The Private Hospital Center of Saint-Grégoire has allowed us to follow, during three years, the implementation of a new information system. This paper gives an insight of organizational transformation issues caused by information and communication technologies. The notion of risk and the role of digital technologies in digitalized workflows, can, according to us, be connected to a key issue in the Communication of Organizations : that of the link between risk and change. This question of risk will be studied in relation with work representations, who engage players to adopt new behaviours and take part in the emergence of of new groupal and cultural entities that are linked to work habits and should be considered as a potential source of “dislocation”. In this perspective, we will study the contribution of a communicational analysis to the understanding of representations and behaviours. Beyond psychosocial disorder issues and speeches around safety, we will cover another kind of risk : that of work deregulation for human professional in the digital era, issue that will be studied in this article, the OR2i : Organizational Risk Impacting the Individual

Endovascular repair of bleeding aortoenteric fistulas: A 5-year experience

AbstractPurpose: Aortoenteric fistula (AEF) is an uncommon but catastrophic complication that can occur either primarily or after aortic reconstruction. Untreated, it is uniformly fatal. Conventional surgical management is associated with a perioperative mortality rate of 25% to 90% and frequent major complications. We reviewed our experience with the endovascular treatment of both primary and secondary AEFs in an effort to determine whether endovascular repair is a less morbid alternative to traditional surgical treatment in select patients. Methods: In a 5-year period, seven high-risk patients who had bleeding and an AEF documented by means of radiology or endoscopy (2 primary, 5 secondary) were treated with coil embolization (1) or placement of an endovascular aortic stent graft (3 aortouniiliac, 2 tube, 1 bifurcated). One patient underwent computed tomography (CT)-guided percutaneous catheter drainage of an infected perigraft collection. The average follow-up period was 27 months (range, 11-66 months), and follow-up consisted of physical examination, complete blood count, and contrast-enhanced helical CT scanning at 3, 6, and 12 months and yearly thereafter. All patients were treated with intravenous antibiotics perioperatively and were prescribed life-long oral antibiotics on discharge. Results: There was one perioperative death (14%) caused by fungal sepsis. Persistent sepsis after stent-graft placement necessitated laparotomy and bowel resection in one patient. One patient had three bouts of recurrent sepsis that were successfully treated with a change of antibiotic. There were three late deaths (43%) unrelated to the procedure or AEF. Three patients (43%) were alive and well an average of 36 months (range, 23-67 months) after the procedure, with no clinical or radiologic evidence of recurrent bleeding or infection. Conclusion: Endovascular management of AEFs is technically feasible and may be the preferred treatment in select patients with bleeding and no signs of sepsis. In the setting of gross infection, it may also be considered in high-risk patients as a bridge to more definitive treatment after hemodynamic stabilization and optimization. (J Vasc Surg 2001;34:1055-9.

Predicting iliac limb occlusions after bifurcated aortic stent grafting: Anatomic and device-related causes

AbstractObjective: Graft limb occlusion may complicate endovascular abdominal aortic aneurysm repair. The precise etiologic factors that contribute to the development of these graft limb thromboses have not been defined. We evaluated our experience with bifurcated aortic endografts to determine factors that may predict subsequent limb thrombosis. The management of the thrombosed limbs and the results after treatment were also investigated. Methods: During a 4-year period, 351 patients with aortic aneurysms underwent treatment with bifurcated endografts (702 graft limbs at risk). These 351 bifurcated devices included AneuRx (Medtronic, Minneapolis, Minn; n = 35), Ancure (Guidant, Menlo Park, Calif; n = 8), Gore (W.L. Gore & Associates, Sunnyvale, Calif; n = 25), Talent (World Medical, Sunrise, Fla; n = 255), Teramed (Teramed, Minneapolis, Minn; n = 10), and Vanguard (Boston Scientific Vascular, Natick, Mass; n = 18). Details regarding the type of device, mechanism of deployment, and aortoiliac artery anatomy were collected prospectively and analyzed. Graft limbs were analyzed for diameter, use of additional endograft iliac extensions, deployment in the external iliac artery, and endograft to vessel oversizing. Follow-up included physical examination, duplex ultrasonography, and spiral computed tomographic scans at 1 month, 6 months, and 12 months and annually thereafter. The follow-up period ranged from 2 to 54 months, with a mean follow-up period of 20 months. Results: Twenty-six of 702 limbs (3.7%) had an occlusion develop. The risk of limb thrombosis was associated with a smaller limb diameter. Mean graft limb diameter was 14 mm in the occluded population, and patent limbs had a mean diameter of 16 mm. Thrombosis occurred in 16 of 291 limbs (5.5%) that were 14 mm or less and in 10 of 411 limbs (2.4%) that were greater than 14 mm (P = .03). Extension of a graft to the external iliac artery was performed in 96 of the 702 limbs. Eight of these 96 limbs (8.3%) had thrombosis develop as compared with 18 of 606 (3.0%) that extended to the common iliac artery (P = .01). No significant association was present between limb thrombosis and the contralateral or ipsilateral side of a device, the configuration of the iliac graft limb end (closed web, open web, or bare spring), or the degree of iliac graft limb oversizing. AneuRx, Ancure, Vanguard, and Talent grafts each sustained limb occlusions, with no occlusions seen among the Gore and Teramed devices. No significant increased risk of graft limb thrombosis was observed in unsupported grafts (1/16; 6.3%) versus supported grafts (25/686; 3.6%; P = not significant). Thromboses occurred between 1 day and 23 months after surgery. Thirteen of the 26 thromboses (50%) occurred within 30 days of surgery. Presenting symptoms were mild to moderate claudication in eight patients (30.8%), severe claudication in 16 patient (61.5%), and paresthesia and rest pain in two patients (7.7%). Eighteen of 26 patients (69.2%) eventually needed intervention to reestablish flow to the occluded limb, including thrombolysis and stenting in two patients (7.7%), axillary femoral bypass in one patient (3.8%), femoral-femoral bypass in 13 patients (50.0%), and axillary-bifemoral bypass in two patients (7.7%). All patients with mild to moderate symptoms under observation had improvement in symptoms with no further interventions necessary. All revascularizations were successful in relieving symptoms. Conclusion: Graft limb occlusion is a recognized complication of endovascular treatment of abdominal aortic aneurysms that may be associated with smaller graft limb diameter and extension to the external iliac artery. Occlusions usually necessitate additional intervention for resolution of ischemic symptoms. The use of small diameter grafts should be avoided when possible to reduce the risk of graft limb occlusions. (J Vasc Surg 2002;36:679-84.

Upper Extremity Composite Tissue Allotransplantation Imaging

Objective: Upper extremity (UE) transplantation is the most commonly performed composite tissue allotransplantation worldwide. However, there is a lack of imaging standards for pre- and posttransplant evaluation. This study highlights the protocols and findings of UE allotransplantation toward standardization and implementation for clinical trials. Methods: Multimodality imaging protocols for a unilateral hand transplant candidate and a bilateral mid-forearm level UE transplant recipient include radiography, computed tomography (CT), magnetic resonance (MR) imaging, catheter angiography, and vascular ultrasonography. Pre- and posttransplant findings, including dynamic CT and MR performed for assessment of motor activity of transplanted hands, are assessed, and image quality of vessels and bones on CT and MR evaluated. Results: Preoperative imaging demonstrates extensive skeletal deformity and variation in vascular anatomy and vessel patency. Posttransplant images confirm bony union in anatomical alignment and patency of vascular anastomoses. Mild differences in rate of vascular enhancement and extent of vascular networks are noted between the 2 transplanted limbs. Dynamic CT and MR demonstrate a 15° to 30° range of motion at metacarpophalangeal joints and 90° to 110° at proximal interphalangeal joints of both transplanted hands at 8 months posttransplant. Image quality was slightly better for CT than for MR in the first subject, while MR was slightly better in the second subject. Conclusion: Advanced vascular and musculoskeletal imaging play an important role in surgical planning and can provide novel posttransplantation data to monitor the success of the procedure. Implementation of more standardized protocols should enable a more comprehensive assessment to evaluate the efficacy in clinical trials

A multicenter experience with the Talent endovascular graft for the treatment of abdominal aortic aneurysms

AbstractObjective: The Talent endovascular graft has been used in the treatment of abdominal aortic aneurysms (AAAs) in more than 13,000 patients worldwide. However, information regarding the results of its use has been limited. This report describes the experience with 368 patients with AAAs who underwent treatment at four medical centers as part of an investigator-sponsored investigational device exemption trial. Methods: Patients with AAAs were enrolled at four sites during a 32-month period from January 1999 to July 2001. All patients underwent treatment for infrarenal AAA with the Talent endovascular graft. Repair was performed with transrenal stent fixation under epidural (362/368 patients; 98.3%), local (4/368 patients; 1.1%), or general (2/368 patients; 0.5%) anesthesia. The average diameters were: maximum aortic aneurysm, 6.2 ± 1.2 cm; proximal aortic fixation site, 2.6 ± 0.4 cm; and distal iliac fixation site, 1.4 ± 0.6 cm. Bifurcated grafts were used in 276 of 366 patients (75%), aortouniiliac in 57 of 366 patients (16%), and tube aortoaortic in 33 of 366 patients (9%). Multiple comorbid medical conditions were present in all patients (average, 4.7 conditions/patient). The mean age was 75.8 years, and 85% of the patients were male. Follow-up period ranged from 2 to 33 months (mean, 7.3 months). Results: Endovascular graft deployment was accomplished in 366 of 368 patients. In the 263 patients followed for at least 6 months after endovascular repair, AAA diameter decreased by 5 mm or more in 83 patients (32%); diameter remained unchanged (change < 5 mm) in 157 patients (60%) and increased by 5 mm or more in 23 patients (8.7%). Major morbidity occurred in 46 of 368 patients (12.5%), and minor morbidity occurred in 31 of 368 (8.4%). The 30-day mortality rate was 1.9%. Secondary procedures were performed in 32 patients (8.7%). Late rupture occurred in two patients, and late deaths unrelated to AAA occurred in 32 patients (8.7%) during the follow-up period. The primary technical success rate for all patients was 93.4%. The 30-day primary procedural success rate was 73.3%. The 30-day secondary procedural success rate was significantly higher at 85.8%. Computed tomographic scan was performed within 1 month after surgery in 349 patients. An endoleak was present in 43 of 349 patients (12.3%). These endoleaks were comprised of 10 attachment site (type I; 2.9%), 31 retrograde side-branch (type II; 8.9%), and two transgraft (type III; 0.6%). Conclusion: These midterm findings show a high degree of technical and procedural success achieved in a patient population with extensive comorbid medical illnesses with low perioperative morbidity and mortality rates. Further follow-up study will be necessary to determine the effectiveness of the Talent endograft for the long-term treatment of AAA. (J Vasc Surg 2002;35:1123-8.

L’innovation, une (re)structuration de formes organisationnelles hospitalières ? Le cas de deux projets « innovants » au sein d’un groupe de santé privé

International audienceHospital organizations are today encouraged to implement so-called innovative digital projects, an approach that fits into a more global process of digitalisation of paths. Our contribution aims at questioning the semiology surrounding the theme of digital innovation in health and how, at a micro level, communication phenomena make it possible to identify changes in organizational forms. Based on data and field experiences, we seek to identify how these typologies of digital project management contribute to the emergence of actors' strategies, sometimes in tension, revealing the formation of a new [re] structured organizational design.Les organisations hospitalières sont aujourd’hui incitées à mettre en œuvre des projets numériques dits innovants, une démarche qui s’intègre dans un processus plus global de digitalisation des parcours. Notre contribution propose d’interroger la sémiologie qui enveloppe la thématique de l’innovation numérique en santé et comment, au niveau micro, les phénomènes communicationnels permettent d’identifier des changements de formes organisationnelles. En nous basant sur des données et expériences de terrain, nous cherchons à identifier comment ces typologies de conduite de projets numériques participent de l’émergence de stratégies d’acteurs, parfois en tension, révélatrices de la formation d’un nouveau design organisationnel [re] structuré

L’innovation, une (re)structuration de formes organisationnelles hospitalières ?

Les organisations hospitalières sont aujourd’hui incitées à mettre en œuvre des projets numériques dits innovants, une démarche qui s’intègre dans un processus plus global de digitalisation des parcours. Notre contribution propose d’interroger la sémiologie qui enveloppe la thématique de l’innovation numérique en santé et comment, au niveau micro, les phénomènes communicationnels permettent d’identifier des changements de formes organisationnelles. En nous basant sur des données et expériences de terrain, nous cherchons à identifier comment ces typologies de conduite de projets numériques participent de l’émergence de stratégies d’acteurs, parfois en tension, révélatrices de la formation d’un nouveau design organisationnel [re]structuré.Hospital organizations are today encouraged to implement so-called innovative digital projects, an approach that fits into a more global process of digitalisation of paths. Our contribution aims at questioning the semiology surrounding the theme of digital innovation in health and how, at a micro level, communication phenomena make it possible to identify changes in organizational forms. Based on data and field experiences, we seek to identify how these typologies of digital project management contribute to the emergence of actors’ strategies, sometimes in tension, revealing the formation of a new [re]structured organizational design

Reorganization of health organizations and appropriation of ICT : the case of Hospital Information Systems (HIS) and the Computerized Patient File (DPI)

Avec l’essor des technologies de l’information et de la communication, la société et les organisations se transforment, serecomposent tous secteurs confondus. On appelle communément disruption, le changement de paradigme économique etorganisationnel lié aux TIC, plus précisément, à la digitalisation des processus.Les modes d’échanges entre les hommes ont évolué. Notre mémoire de master 2 (Numérique, recomposition organisationnelles et appropriation des TIC, Gravereaux, 2013) nous aura permis de comprendre que les véritables changements qui opèrent en organisation se situent au-delà des usages des espaces numériques de travail et des outils TIC.Notre thèse s’inscrit dans la continuité de ce travail préliminaire qui nous avait offert de questionner, de manière introductive, quelle pouvait être la portée de la dimension politique dans l’appropriation des technologies numériques.Cette thèse de doctorat a pour but de saisir, d’identifier, d’analyser et de conceptualiser, tant sur le plan théorique que pratique, le processus de transition organisationnelle qui opère dans les établissements de santé traversés par l’informatisation du dossier de soin et par la maturation des Systèmes d’Information Hospitalier. Après avoir compris qu’il fallait dépasser les usages pour comprendre l’appropriation des TIC, nous orienterons nos réflexions et enquêtes de façon à confronter ce point de vue et à lui donner une portée opérationnelle.Les phénomènes communicationnels liés aux changements et aux transformations en organisations constituent un élément central de ces recompositions. Le chercheur doit enquêter pour questionner et saisir ces phénomènes à l’aune de la compréhension particulière d’un établissement de santé.Le regard communicationnel porté sur un espace, un vécu, en transition, tentera de mettre à jour les conditions qui participent de l’appropriation des nouveaux outils liés à la traçabilité des soins : la forme informatisée du dossier patient.Notre thèse de doctorat se propose d’apporter une contribution à des problématiques de recherches actuelles en questionnant l’individu au travail au regard des questions politico-organisationnelles liées à l’appropriation du dossier patient informatisé.Ces acteurs que nous sommes venus « étudié », soignants, médecins, personnels administratif, sont au coeur, vivent, en même temps que l’organisation, ce phénomène de disruption qui affecte l’intégralité du dispositif organisationnel.À partir d’une rupture disruptive, de nouvelles formes d’organisation du travail, liées aux changements de pratiques del’information médicale, apparaissent, émerge des dissonances. De la même façon, pour accompagner cette organisation émergente, les formes et normes de management en santé, sont amenées à se recomposer et donc à se spécialiser.Nous assistons à une recomposition globale de la Santé, dont les composantes du dispositif tendent à faire de la contribution, de la collaboration, de l’autonomie et de la traduction, les nouveaux fondamentaux du management en organisations de santé accompagnant la métamorphose digitale des routines des acteurs.With the growth of information and communication technologies, society and organizations are transforming, recomposing all sectors combined. The common paradigm shift is to change the economic and organizational paradigm linked to ICT, more precisely, to the digitalization of processes.The modes of exchange between men have evolved. Our Master 2 thesis (Digital, Organizational Reorganization andAppropriation of ICTs, Gravereaux, 2013) allowed us to understand that the real changes that operate in organization arebeyond the use of digital workspaces and ICT tools.Our thesis is part of the continuation of this preliminary work which offered us to question, in an introductory way, what could be the scope of the political dimension in the appropriation of digital technologies.This doctoral thesis aims at capturing, identifying, analyzing and conceptualizing, both theoretically and practically, the process of organizational transition that operates in the healthcare institutions through which the computerization of the care file And by the maturation of Hospital Information Systems. Having understood that we need to go beyond the uses to understand ICT appropriation, we will orient our reflections and investigations in order to confront this point of view and to give it an operational scope.The communicationa phenomena linked to changes and transformations in organizations are a central element of theserecompositions. The researcher must investigate and question these phenomena in terms of the particular understanding of a healthcare institution.The communicative look at a space, a experience, in transition, will try to update the conditions that participate in the appropriation of the new tools related to the traceability of care: the computerized form of the patient record.Our doctoral thesis proposes to make a contribution to current research questions by questioning the individual at work withregard to the politico-organizational issues related to the appropriation of the computerized patient record.These actors, who have come to be "studied", caregivers, doctors and administrative staff, are at the heart of this phenomenon of disruption, which affects the entire organizational system, at the same time as the organization.From a disruptive rupture, new forms of work organization, linked to changes in the practices of medical information, emerge, emerging from dissonances. In the same way, to support this emerging organization, the forms and standards of health management, are led to recompose and therefore to specialize.We are witnessing a global recomposition of health, whose components of the system tend to make contribution, collaboration, autonomy and translation, new fundamentals of management in health organizations accompanying the digital metamorphosis of routines actors