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In haemodialysis (HD), unwanted substances (uraemic retention solutes or ‘uraemic toxins’) that accumulate in uraemia are removed from blood by transport across the semipermeable membrane. Like all membrane separation processes, the transport requires driving forces to facilitate the transfer of molecules across the membrane. The magnitude of the transport is quantified by the phenomenon of ‘flux’, a finite parameter defined as the volume of fluid (or permeate) transferred per unit area of membrane surface per unit time. In HD, as transmembrane pressure is applied to facilitate fluid flow or flux across the membrane to enhance solute removal, flux is defined by the ultrafiltration coefficient (KUF; mL/h/mmHg) reflecting the hydraulic permeability of the membrane. However, in HD, the designation of flux has come to be used in a much broader sense and the term is commonly used interchangeably and erroneously with other measures of membrane separation processes, resulting in considerable confusion. Increased flux is perceived to reflect more ‘porous’ membranes having ‘larger’ pores, even though other membrane and therapy attributes determine the magnitude of flux achieved during HD. Adjectival designations of flux (low-, mid-, high-, super-, ultra-) have found indiscriminate usage in the scientific literature to qualify a parameter that influences clinical decision making and prescription of therapy modalities (low-flux or high-flux HD). Over the years the concept and definition of flux has undergone arbitrary and periodic adjustment and redefinition by authors in publications, regulatory bodies (US Food and Drug Administration) and professional association guidelines (European Renal Association, Kidney Disease Outcomes Quality Initiative), with little consensus. Industry has stretched the boundaries of flux to derive marketing advantages, justify increased reimbursement or contrive new classes of therapy modalities when in fact flux is just one of several specifications that determine membrane or dialyser performance. Membranes considered as high-flux previously are today at the lower end of the flux spectrum. Further, additional parameters unrelated to the rate of diffusive or convective transport (flux) are used in conjunction with or in place of KUF to allude to flux: clearance (mL/min, e.g. of β2-microglobulin) or sieving coefficients (dimensionless). Considering that clinical trials in nephrology, designed to make therapy recommendations and guide policy with economic repercussions, are based on the parameter flux they merit clarification—by regulatory authorities and scientists alike—to avoid further misappropriation.

Haemodialysis (HD) utilizes the bidirectional properties of semipermeable membranes to remove uraemic toxins from blood while simultaneously replenishing electrolytes and buffers to correct metabolic acidosis. However, the nonspecific size-dependent transport across membranes also means that certain useful plasma constituents may be removed from the patient (together with uraemic toxins), or toxic compounds, e.g. endotoxin fragments, may accompany electrolytes and buffers of the dialysis fluids into blood and elicit severe biological reactions. We describe the mechanisms and implications of these undesirable transport processes that are inherent to all HD therapies and propose approaches to mitigate the effects of such transport. We focus particularly on two undesirable events that are considered to adversely affect HD therapy and possibly impact patient outcomes. Firstly, we describe how loss of albumin (and other essential substances) can occur while striving to eliminate larger uraemic toxins during HD and why hypoalbuminemia is a clinical condition to contend with. Secondly, we describe the origins and mode of transport of biologically active substances (from dialysis fluids with bacterial contamination) into the blood compartment and biological reactions they elicit. Endotoxin fragments activate various proinflammatory pathways to increase the underlying inflammation associated with chronic kidney disease. Both phenomena involve the physical as well as chemical properties of membranes that must be selected judiciously to balance the benefits with potential risks patients may encounter, in both the short and long term.

BackgroundDue to a critical shortage of available kidney grafts, most patients with Stage 5 Chronic Kidney Disease (CKD5) require bridging dialysis support. It remains unclear whether treatment by different dialysis modalities changes the selection and/or preparation of a potential transplant candidate. Therefore, we assessed whether the likelihood of receiving kidney transplant (both living or deceased kidney donors) differs between haemodialysis (HD) and online haemodiafiltration (HDF) in patients with CKD5D.MethodsIndividual participant data from four randomised controlled trials comparing online HDF with HD were used. Information on kidney transplant was obtained during follow-up. The likelihood of receiving a kidney transplant was compared between HD and HDF, and evaluated across different subgroups: age, sex, diabetes, history of cardiovascular disease, albumin, dialysis vintage, fistula, and level of convection volume standardized to body surface area. Hazard ratios (HRs), with corresponding 95% confidence intervals (95% CI), comparing the effect of online HDF versus HD on the likelihood of receiving a kidney transplant, were estimated using Cox proportional hazards models with a random effect for study.ResultsAfter a median follow-up of 2.5years (Q1 to Q3: 1.9-3.0), 331 of the 1620 (20.4%) patients with CKD5D received a kidney transplant. This concerned 22% (n=179) of patients who were treated with online HDF compared with 19% (n=152) of patients who were treated with HD. No differences in the likelihood of undergoing a kidney transplant were found between the two dialysis modalities in both the crude analyse (HR: 1.07, 95% CI: 0.86-1.33) and adjusted analysis for age, sex, diabetes, cardiovascular history, albumin, and creatinine (HR: 1.15, 95%-CI: 0.92-1.44). There was no evidence for a differential effect across subgroups based on patient- and disease-characteristics nor in different categories of convection volumes.ConclusionsTreatment with HD and HDF does not affect the selection and/or preparation of CKD5D patients for kidney transplant given that the likelihood of receiving a kidney transplant does not differ between the dialysis modalities. These finding persisted across a variety of subgroups differing in patient and disease characteristics and is not affected by the level of convection volume delivered during HDF treatment sessions., CONVINCE study (European Union's Horizon 2020 research and innovation programme) [754803], Funding details are listed in Appendix 4. RWMV, PJB, and MLB are funded by the CONVINCE study (European Union's Horizon 2020 research and innovation programme under grant agreement No 754803).

Aim: To explore the anatomic features of the neural foramen in particularly at the T12-L1 level in order to assess reveal the safety and efficiency of the endoscopic transforaminal approach for paramedian and foraminal disc herniations at this level. Material and Methods: The study included 15 fresh human cadavers. The soft tissues were removed at the T12-L1 level and bony tissues, were exposed including the transverse processes. The bilateral facets and pars interarticulares at this level were resected revealing the foraminal anatomy and exiting roots. The anatomical structures constituting the triangular safe working zone (TSWZ) were explored. The nerve root length, nerve root width, nerve root angle, TSWZ height, and base of TSWZ base, nerve root width, nerve root angle and disc height were recorded. Results: The root length is the hypotenuse of the TSWZ between the axilla of the exiting root and the lateral margin of the pedicle, and the mean root length was 14.94 ± 2.45 mm. The dural height is the interval between the axilla of the exiting nerve root axilla and the superior end plate of the caudal vertebra, and the mean of the dural height was 10.95 ± 1.74 mm. The base of TSWZ is the distance between the lateral margin of the dural sac and the medial margin of the exiting root, and the mean measurement for the base measurement was 11.83 ± 2.26 mm. Conclusion: According to the results data from our cadaveric study, we believe that Kambin’s triangular working zone is a safe area to consider for the endoscopic transforaminal approach at the T12-L1 level, especially for paramedian and foraminal disc herniations.

Objectives Comparative economic assessments of renal replacement therapies (RRT) are common and often used to inform national policy in the management of end-stage renal disease (ESRD). This study aimed to assess existing cost-effectiveness analyses of dialysis modalities and consider whether the methods applied and results obtained reflect the complexities of the real-world treatment pathway experienced by ESRD patients. Methods A systematic literature review (SLR) was conducted to identify cost-effectiveness studies of dialysis modalities from 2005 onward by searching Embase, MEDLINE, EBM reviews, and EconLit. Economic evaluations were included if they compared distinct dialysis modalities (e.g. in-centre haemodialysis [ICHD], home haemodialysis [HHD] and peritoneal dialysis [PD]). Results In total, 19 cost-effectiveness studies were identified. There was considerable heterogeneity in perspectives, time horizon, discounting, utility values, sources of clinical and economic data, and extent of clinical and economic elements included. The vast majority of studies included an incident dialysis patient population. All studies concluded that home dialysis treatment options were cost-effective interventions. Conclusions Despite similar findings across studies, there are a number of uncertainties about which dialysis modalities represent the most cost-effective options for patients at different points in the care pathway. Most studies included an incident patient cohort; however, in clinical practice, patients may switch between different treatment modalities over time according to their clinical need and personal circumstances. Promoting health policies through financial incentives in renal care should reflect the cost-effectiveness of a comprehensive approach that considers different RRTs along the patient pathway; however, no such evidence is currently available.

INTRODUCTION Numerous studies showed that higher body mass index (BMI) is associated with better survival in hemodialysis (HD) patients. Most of them evaluated short-term mortality. It has been suggested that presence of inflammation may be a key modifier of relationship between BMI and mortality in incident HD patients. We examined whether presence of inflammation modifies the association between BMI and mortality in both short-term and long-term follow-up in a large group of prevalent HD patients. METHODS A total of 3.252 HD patients from 41 HD centers were enrolled; the patients were divided into quartiles based on time-averaged BMI (Q1

Objective:Spinopelvic parameters were identified and the association between sagittal spinopelvic alignment and lumbar disc diseases have been reported in several studies. The purpose of this study was to evaluate the spinopelvic parameters such as lumbar lordosis (LL) and sacral slope (SS) in normal healthy lumbar spine versus degenerative disc disease group.Methods:We retrospectively identified 140 patients suffered from back pain with/without radiculopathy between 2016-2017 in this study. Of these 70 patients had normal disc morphology and they constituted called control group, and the other 70 patients had lumbar degenerative disc disease and they constituted called disease patient group. All patients’ LL, and SS angles were measured on T2 weighted sagittal magnetic resonance imaging and degenerated disc levels were noted. We also recorded LL-SS ratio which was calculated by dividing of LL by SSLL divided by SS value as LL-SS ratio in both groups. We compared these parameters between two groups.Results:In disease patient group there was a positive correlation (r=0.947, p

Maxillomandibular harmony constitutes a major component of the ideal facial aesthetics. Improvement of facial aesthetics is one of the main reasons that patients request surgical correction of dentofacial deformities. Orthognathic surgery enables the correction of dentofacial skeletal or occlusal discrepancies. The need for this type of surgery has increased recently, as more adult patients are seeking orthodontic treatment (Nattrass & Sandy, 1995). Orthognathic surgery differs from other procedures of maxillofacial surgery procedures in a way that, the esthetic and psychosocial impact plays an important role in the patient perception of a successful treatment outcome. Therefore, a satisfying outcome of orthognathic surgery includes not only the decisive surgical technique and intermaxillary correction but also the accomplishment of the aesthetic goals that are successful to both patients and professionals (Sarver et al., 1988; Sarver & Johnston, 1990; Proffit & White, 1991). However, the concept of the ideal result is rather subjective and mainly determined by the consequency between the patient expectations and the actual result. Without a visual reference, it is hard for the patients to visualize the outcomes of the surgical procedures and to contribute to the treatment plan in the preoperative planning session (Turpin, 1995; Cunningham et al.1995). In this manner, visualized treatment objectives (VTO) are important predictive tools to interpret the patients’ perspectives of esthetics and to give an acceptable preview of the result. Furthermore, these VTOs facilitate the communication between the treatment team and the patient as well as provide guidance to the desired result. They also determine the need for bimaxillary versus single-jaw procedures and whether adjunctive treatments including rhinoplasty, genioplasty, liposuction or augmentation are necessary. Lateral cephalometric radiographs are commonly used to predict the surgical treatment outcomes. Visualized treatment prediction began with manual profile predictions. Tracing overlay approach or using templates are the two methods for profile prediction by pencil drawing. Tracing overlay approach involves manual repositoning of the overlaid tracings and is limited to simulate the effects of mandibular surgeries. In this method, cephalometric film is traced including all teeth with their occlusal surfaces on an acetate paper. Subsequently, the structures that will not be moved by mandibular surgery are traced over the original tracing with a new sheet of acetate paper. After sliding the overlay tracing so that the mandibular teeth can be seen in their desired postsurgical position, lower teeth and O pe n A cc es s D at ab as e w w w .ite ch on lin e. co m