Proposed Criteria for Constipation in Palliative Care Patients. A Multicenter Cohort Study.

Although constipation is one of the most frequently reported symptoms in palliative care, there is no widely accepted definition of constipation and none suitable for patients unable to self-report or express symptoms. This study aimed to verify the objective and subjective symptoms of constipation to develop a diagnostic algorithm for constipation, which is also feasible in unconscious patients. In a pooled analysis of two observational studies, 369 out of 547 adult end-stage cancer patients met the inclusion criteria. The patient-reported difficulty of defecation correlated with observable measures, such as days since last bowel movement, and frequency of bowel movements. Difficulty became at least moderate when there were no bowel movements for ≥2 days, or the frequency of bowel movements was ≤3 per week. The diagnostic algorithm, comprising these three symptoms offers a simple, rapid, and comprehensive tool for palliative care, independent of the patient's state of consciousness. A clinical trial is necessary to confirm its validity and usefulness

Future of the nerve fibres imaging: tractography application and development directions

Tractography is a tool available in a growing number of centres, to enable planning of neurosurgical interventions. This method has some drawbacks and due to its increasing availability is causing a growing controversy over the possibility of an anatomical mapping of the nerve fibres. This article aims at summarising the application of the diffusion magnetic resonance in contemporary neurosurgery method, showing the usefulness and merits of its performance before surgical procedures, limitation of its application and recommendations for its improvement and more effective use for diagnostic purposes

The posterior communicating artery: morphometric study in 3D angio-computed tomography reconstruction. The proof of the mathematical definition of the hypoplasia

Background: The aim of this study was to investigate the morphometry of the posterior communicating artery (PCoA), on the basis of angio-computed tomography (CT), and to give proof of the mathematical definition of the term “hypopal sia of the PCoA“.Materials and methods: One hundred 3-dimensional (3D) angio-CT images, performed in adult patients with bilateral reconstruction of the PCoA (200 results) were used tocalculate the morphometry of the vessel.Results: The average length of the vessel on the right side was 14.48 ± 3.47 mm, andon the left side 14.98 ± 4.77 mm (in women 14.75 mm, in men 14.70 mm). The mean of the diameter at the “proximal” point (the junction with P1) on the right side was 1.49 ± 0.51 mm, and on the left 1.46 ± 0.47 mm (in women 1.44 mm and in men 1.51 mm). The mean of the diameter in the “distal” part (the connection with ICA) on the right side was 1.4 ± 0.49 mm, and on the left 1.37 ± 0.41 mm (in women 1.38 mm, and in men 1.39 mm). No statistical correlation between the length and the diameter of the PCoA in relation to the sex and side was shown. On the basis of our measurements, we defined the hypoplasia of the artery as the estimated value less than the average diameter minus the standard deviation. The percentage distribution was as follows: the left artery 15.5%, the right artery 24%, women 11.5%, and the men 9%. Similarly to the above parameters, we have not found any statistical differences. The presence of the foetal origin was noted in 25% of the radiological examinations. The infundibular widening was visualised in 11.5% of cases of 3D reconstructions. The agenesis of PCoA was found in 9% (never bilaterally), and in 1 case the unilateral duplication of the artery was observed. No statistical differences between those parameters in relation to sex and the examined side were revealed.Conclusions: Morphological calculation of the PCoA on the basis of angio-CT from adult patients did not show any statistical differences depending on sex or the investigated side. The presented method of the calculations proved to be useful for the mathematical definition of the term “hypoplasia of the PCoA”

Tractography-guided surgery of brain tumours: what is the best method to outline the corticospinal tract?

Background: Diffusion tensor imaging (DTI) is the imaging technique used in vivo to visualise white matter pathways. The cortico-spinal tract (CST) belongs to one of the most often delineated tracts preoperatively, although the optimal DTI method has not been established yet. Considering that various regions of interests (ROIs) could be selected, the reproducibility of CST tracking among different centres is low. We aimed to select the most reliable tractography method for outlining the CST for neurosurgeons. Materials and methods: Our prospective study consisted of 32 patients (11 males, 21 females) with a brain tumour of various locations. DTI and T1-weighed image series were acquired prior to the surgery. To draw the CST, the posterior limb of the internal capsule (PLIC) and the cerebral peduncle (CP) were defined as two main ROIs. Together with these main ROIs, another four cortical endpoints were selected: the frontal lobe (FL), the supplementary motor area (SMA), the precentral gyrus (PCG) and the postcentral gyrus (POCG). Based on these ROIs, we composed ten virtual CSTs in DSI Studio. The fractional anisotropy, the mean diffusivity, the tracts’ volume, the length and the number were compared between all the CSTs. The degree of the CST infiltration, tumour size, the patients’ sex and age were examined. Results: Significant differences in the number of tracts and their volume were observed when the PLIC or the CP stood as a single ROI comparing with the two- ROI method (all p < 0.05). The mean CST volume was 40054U (SD ± 12874) and the number of fibres was 259.3 (SD ± 87.3) when the PLIC was a single ROI. When the CP was a single ROI, almost a half of fibres (147.6; SD ± 64.0) and half of the CST volume (26664U; SD ± 10059U) was obtained (all p < 0.05). There were no differences between the various CSTs in terms of fractional anisotropy, mean diffusivity, the apparent diffusion coefficient, radial diffusivity and the tract length (p > 0.05). The CST was infiltrated by a growing tumour or oedema in 17 of 32 patients; in these cases, the mean and apparent diffusion of the infiltrated CST was significantly higher than in uncompromised CSTs (p = 0.04). CST infiltration did not alter the other analysed parameters (all p > 0.05). Conclusions: A universal method of DTI of the CST was not developed. However, we found that the CP or the PLIC (with or without FL as the second ROI) should be used to outline the CST

Frontal aslant tract projections to the inferior frontal gyrus

Background: Frontal aslant tract (FAT) is a white matter bundle connecting the pre-supplementary motor area (pre-SMA) and the supplementary motor area (SMA) with the inferior frontal gyrus (IFG). The purpose of the present study was to evaluate the anatomical variability of FAT. Materials and methods: Total number of fibres and the lateralisation index (LI) were calculated. We attempted to find factors contributing to the diversity of FAT regarding IFG terminations to the pars opercularis (IFG-Op) and to the pars triangularis (IFG-Tr). Magnetic resonance imaging of adult patients with diffusion tensor imaging (DTI) with total number of 98 hemispheres composed a cohort. V-shaped operculum was the most common (60.5%). Results: Total number of FAT fibres had widespread and unimodal distribution (6 to 1765; median: 160). Left lateralisation was noted in 64.3% of cases and was positively correlated with total number of FAT fibres and the bundle projecting to IFG-Op (p < 0.01). LI correlated with total number of FAT fibres (r = 0.43, p < 0.01). FAT projected predominantly to IFG-Op (88.9%; 88 of 99). Only in 3 (3.1%) cases more fibres terminated in IFG-Tr than in IFG-Op. Total number of FAT fibres and number of fibres terminating at IFG-Op did not correlate with the ratio of fibre numbers: FAT/IFG-Op, FAT/IFG-Tr and IFG-Op/IFG-Tr (p > 0.05). The greater total number of fibres to IFG-Tr was, the higher were the ratios of IFG-Tr/ /FAT (r = 0.57, p < 0.01) and IFG-Tr/IFG-Op (r = 0.32, p = 0.04). Conclusions: Among the IFG, the major termination of FAT is IFG-Op. Whereas the IFG-Tr projection seems to be related to the expansion of the entire FAT bundle regardless of side, domination and handedness. Nevertheless, FAT features a significant anatomical variability which cannot be explained in terms of DTI findings

Intracranial region of the vertebral artery: morphometric study in the context of clinical usefulness

Background: The aim of this study was to analyse the morphometry of the intracranial segment of the vertebral artery in the context of clinical usefulness. The results were compared with published data available in full-text archived medical journals. Materials and methods: More than 100 digital subtraction angiography (DSA) and 3-dimensional (3D) angio-computed tomography (CT) examinations were used to measure the following parameters: the whole and partial length of V4 in characteristic anatomical points, the diameter in three places (on the level of foramen magnum, in point of exit to the posterior inferior cerebellar artery, and in the vertebro-basilar junction), the angle of connection to the vertebral arteries, and all anatomical variations including fenestration, duplication, dolichoectasia or absent artery. Results: The left V4 section was predominant over the right artery, which is manifested by length, width, cases of ectasia and fewer cases of hypoplasia. The incidences of V4 ectasia were identified more often than those documented in the accessible literature, and they were found in the natural location of formation of saccular aneurysms. Conclusions: The presented knowledge of anatomical variation and abnormali­ties of vertebral circulation can improve the accuracy and “safety” of the surgical procedures in this region, help to determine the range of surgical approach and avoid associated complications. The radiological examinations using 3D CT, DSA reveal unlimited observation of anatomical structures in contrast to studies based on cadavers, and can complement the morphometry in anatomical preparations

Optymalizacja rozmieszczenia dwu materiałów w powłokach sprężystych

The two-phase layout problem within the plate theory was solved by Gibiansky and Cherkaev in 1984. The same problem in the plane stress formulation was solved by the same authors in eventually cleared up by Allaire and Kohn in 1993. In the thin shell theory both these formulations are coupled, which is clearly seen in the homogenization formulae found by Lewiński and Telega in 1988, Telega and Lewiński in 1998, and a general setting of the layout problem presented in the book by the same authors. The aim of the present paper is to set this problem within the Mushtari-Donnell-Vlasov approximation. The main result of the present examination is the lower bound of the complementary energy found by using the translation method. The translation matrix involves off-diagonal components, which leads to the effective complementary potential of a specific coupled form, expressible in terms of invariants of the stress and couple results.Zagadnienie optymalnego rozkładu dwóch materiałów izotropowych w sprężystych plytach cienkich rozwiązali Gibianskij i Czerkajew w roku 1984. Minimalizacji podlegała podatność płyty. Analogiczne zadanie dotyczące teorii tarcz rozwiązali ci sami autorzy w 1987r. Sformułowanie to uzupełnili i uściślili Allaire i Kohn w roku 1993. W zadaniu dotyczącym powłok cienkich oba te sformułowania są ze sobą sprzężone, co jasno jest widoczne w formułach homogenizacji znalezionych w pracach Lewińskiego i Telegi z roku 1988 oraz pracach Telegi i Lewińskiego z roku 1998; ogólne, niejawne sformułowanie tego zadania optymalizacji omówiono w książce tych samych autorów. Celem niniejszej pracy jest sformułowanie tego zadania w sposób jawny w zakresie technicznej teorii powłok Musztariego-Donnella-Własowa. W pracy wyprowadzamy w sposób jawny dolne oszacowanie energii komplementarnej z wykorzystaniem metody translacji. Macierz traslacji zawiera tutaj składniki pozadiagonalne. Ta postać macierzy translacji prowadzi do zastępczego potencjału o specyficznej postaci sprzężonej, wyrażalnej za pomocą niezmienników sił wewnętrznych w powłoce

Topology optimization in structural mechanics

Optimization of structural topology, called briefly: topology optimization, is a relatively new branch of structural optimization. Its aim is to create optimal structures, instead of correcting the dimensions or changing the shapes of initial designs. For being able to create the structure, one should have a possibility to handle the members of zero stiffness or admit the material of singular constitutive properties, i.e. void. In the present paper, four fundamental problems of topology optimization are discussed: Michell’s structures, two-material layout problem in light of the relaxation by homogenization theory, optimal shape design and the free material design. Their features are disclosed by presenting results for selected problems concerning the same feasible domain, boundary conditions and applied loading. This discussion provides a short introduction into current topics of topology optimization

Care of the adult cancer patient at the end of life: ESMO Clinical Practice Guidelines.

ESMO guideline on best clinical practice in the management of patients at end-of-lif