Informatievoorziening in het financieel management van Nederlandse Ondernemingen

Informatievoorziening in het financieel mana­ gement van Nederlandse onderneminge

Anisotropic behaviour of human gallbladder walls

Inverse estimation of biomechanical parameters of soft tissues from non-invasive measurements has clinical significance in patient-specific modelling and disease diagnosis. In this paper, we propose a fully nonlinear approach to estimate the mechanical properties of the human gallbladder wall muscles from in vivo ultrasound images. The iteration method consists of a forward approach, in which the constitutive equation is based on a modified Hozapfel–Gasser–Ogden law initially developed for arteries. Five constitutive parameters describing the two orthogonal families of fibres and the matrix material are determined by comparing the computed displacements with medical images. The optimisation process is carried out using the MATLAB toolbox, a Python code, and the ABAQUS solver. The proposed method is validated with published artery data and subsequently applied to ten human gallbladder samples. Results show that the human gallbladder wall is anisotropic during the passive refilling phase, and that the peak stress is 1.6 times greater than that calculated using linear mechanics. This discrepancy arises because the wall thickness reduces by 1.6 times during the deformation, which is not predicted by conventional linear elasticity. If the change of wall thickness is accounted for, then the linear model can used to predict the gallbladder stress and its correlation with pain. This work provides further understanding of the nonlinear characteristics of human gallbladder

Is transanal total mesorectal excision a reproducible and oncologically adequate technique? A pilot study in a single center: Is transanal TME a safe procedure?

Purpose: An oncologically effective total mesorectal excision (TME) still represents a technical challenge, especially in the presence of a low rectal cancer and anatomical restraints such as obesity or narrow pelvis. Recently, few reports have shown that transanal TME was feasible and associated with good outcomes. Nevertheless, a widespread employment of the technique has yet to happen due to the doubts about the reproducibility of the results outside a tertiary specialized center. Methods: Between February 2014 and June 2015, patients with low rectal cancer underwent a transanal TME with laparoscopic assistance. The end points included the oncologic adequacy of the mesorectal excision and the perioperative outcomes. Results: Eleven patients (9 male, median age 70.5\ua0years) with proven low rectal cancer were enrolled in the study. The median distance of the tumor from the anal verge was 5\ua0cm (2\u20137). Four patients (36.4\ua0%) received preoperative chemoradiation. The median operative time was 360\ua0min (275\u2013445). Postoperative morbidity (36.4\ua0%) included one (9.1\ua0%) anastomotic leak requiring a reoperation. The median length of hospital stay was 8\ua0days (3\u201328). The median distance from the circumferential and distal resection margins were, respectively, 5 (1\u201320) and 10 (5\u201320) mm, and the mean number of harvested lymph nodes was 21.7 (11\u201350). All cases had a complete or nearly complete mesorectal plane of surgery. Conclusions: Although technically challenging, the initial results suggest that transanal TME could be a feasible, oncologically safe, and reproducible operation. However, more robust studies are required to assess the short- and long-term outcomes

Using a model of the performance measures in Soft Systems Methodology (SSM) to take action: a case study in health care

This paper uses a case study of a multidisciplinary colorectal cancer team in health care to explain how a model of performance measures can lead to debate and action in Soft System Methodology (SSM). This study gives a greater emphasis and role to the performance measures than currently given in typical SSM studies. Currently, the concept of performance measurement in SSM is in the form of a set of criteria used to judge the performance of the SSM model (the purposeful activity model). These performance criteria are definitions of efficacy, efficiency, effectiveness, ethicality and elegance. However, the use of performance measures within SSM is not clear and therefore criticized by some as nebulous. This paper uses a case study to explain how to involve the stakeholders in deriving a performance measurement model (PMM), which is a more detailed expansion of the performance criteria. The paper concludes with some reflections about how the PMM can fit in the SSM cycle, with two modes of practice put forward

Investigation of the functional three-dimensional anatomy of the human cystic duct: A single helix?

Clinical research into the formation of gallstones has indicated that the anatomy of the cystic duct is one of a number of factors contributing to the formation of gallstones. The cystic duct allows low-viscosity hepatic bile to enter the gallbladder under low pressure and the expulsion of a more viscous gallbladder bile, but little is known about this transport mechanism and the effect of anatomical variations in structure. This article describes the variation in geometry of the cystic duct, obtained from acrylic resin casts of the neck and first part of the cystic duct in gallbladders removed for gallstone disease and obtained from patients undergoing partial hepatectomy for metastatic disease. The data obtained allowed us to formulate a number of standard terms for describing cystic duct morphology and demonstrate that the term spiral valve is only partially correct when describing the duct anatomy. In over half of the casts, spiraling was not the dominant feature of the cystic duct. Additionally, the term valve implies active resistance to flow in one direction, whereas the internal baffles of the cystic duct would serve to regulate bile flow in both directions. These data are useful for realistic 3D modeling of fluid-structure interactions of the flow of bile in the human cystic duct. Clin. Anat. 19:528-534