Konstantia Kantartzi

Can dialysis modality influence quality of life in chronic hemodialysis patients? Low-flux hemodialysis versus high-flux hemodiafiltration: a cross-over study.

Background: Hemodiafiltration with online preparation of the substitution [online high-flux hemodiafiltration (OHDF)] and hemodiafiltration with prepared bags of substitution (HDF) are important, recently widely used renal replacement therapies in patients with end-stage renal disease. However, there is little information on the comparative impacts of these modalities versus conventional low-flux hemodialysis (HD) on the quality of life (QoL) of HD patients. This study investigates the effect of dialysis modality on QoL in chronic HD patients. Methods: In this prospective, randomized, cross-over, open label study, 24 patients were enrolled. Their age were 62 ± 13.34 years (mean ± SD), with the duration of dialysis of 31 ± 23.28 months (mean ± SD). Five of the patients were women. QoL was measured by the Short-Form Health Survey with 36 questions (SF-36) and subscale scores were calculated. Each patient received HD, OHDF, and HDF for 3 months, with the dialysis modality subsequently being altered. They completed the questionnaire of QoL at the end of each period. Results: There were statistical significant differences in QoL for the total SF-36 [36.1 (26.7–45.7) and 40.7 (30.2–62.8)], for classic low-flux HD and high-flux hemodiafiltration, for bodily pain [45 (26.9–66.9) and 55 (35.6–87.5)], and for role limitations due to emotional functioning [0 (0–33.3) and 33.3 (0–100)], respectively. The scores did not differ significantly between the two types of hemodiafiltration. Conclusions: Our study indicates that QoL differs significantly among patients receiving low-flux HD and high-flux hemodiafiltration, on total SF-36, bodily pain, and role limitations due to emotional functioning. Convective modalities may offer better QoL than diffusive HD.

Comparative in vitro Study of Different Peritoneal Dialysis Solutions on Cytokine Production by Peripheral Blood Mononuclear Cells

Background/Aims: Peritoneal dialysis solutions (PDS), new and conventional, do not yet have a clinical biocompatibility profile. We aimed at a comparative laboratory profile based on the effect of PDS on peripheral blood mononuclear cell (PBMC) cytokine release. Method: PBMCs from 19 healthy volunteers were incubated at a concentration of 106/ml in fresh PDS and control medium (RPMI 1640), and stimulated or not with 10μg/ml Escherichia coli lipopolysaccharide. The tested PDS were glucose/lactate 1.5 and 4.25%, glucose/pyruvate 1.0 and 4.0%, icodextrin and amino acid solutions. The initial incubation in culture flasks for 15 min was followed by 1:1 dilution with RPMI and by additional incubation for 22 h as a ‘recovery period’. At the end, the supernatants were tested for cytokines IL-6 and TNFα by ELISA. Results: The hypertonic glucose solutions, irrespective of the buffer, had the most adverse effect on PBMC cytokine release. The icodextrin and amino acid solutions seemed close to the isotonic glucose PDS. The substitution of pyruvate for lactate buffer seemed to offer an advantage only for the hypertonic glucose-based solutions. Conclusions: Icodextrin and amino acid solutions seem to offer an advantage only compared to hypertonic glucose PDS.

The effect of bicarbonate peritoneal dialysis solutions on cardiac structural and functional alterations

BACKGROUND The systemic effects of absorbed glucose degradation products (GDPs) contained within the conventional peritoneal dialysis solutions (cPDS) are largely unknown, while they appear to affect also cardiovascular function. The aim of the present study was to evaluate if the new bicarbonate-based less bioincompatible new peritoneal dialysis solutions ameliorate cardiac structural and functional status as well as the peritoneal net ultrafiltration (UF) and residual renal function. Patients and methods. This is a single centre, prospective cohort study of 12 stable continues ambulatory peritoneal dialysis patients (four women, eight men) mean aged 71.3 ± of 6.01 years and mean peritoneal dialysis (PD) duration 31.9 ± 21.33 months, treated with the usual cPDS (Medital Bieffe®, with increased GDPs, low pH and lactate as a buffer system). The patients changed for a 6-month period to the newer biocompatible PD solutions (BicaVera, Fresenius® low GDPs, normal pH, bicarbonate as a buffer) and at the end of this time, they returned to their previous schema of conventional solutions, for another 6 months. During the study period, the left ventricle ejection fraction (EF), left ventricle end systolic and diastolic diameter (LVESD, LVEDD), left ventricle mass index (LVMI), glyoxal serum and peritoneal concentrations, net UF and 24 h urine volume were repeatedly estimated: at the beginning of the study (T0), after 6 months with the biocompatible solutions (T6) and at the end of study (T12), after the 6-month period using again the cPDS. The UF volume and glyoxal concentrations were estimated at end of a 4 h dwell of an exchange with a PD solution of 2.27 % glucose. RESULTS There was a statistically significant difference between the mean levels of EF, LVESD, LVEDD, LVMI, UF and glyoxal serum and peritoneal concentrations at the beginning (T0) and in the middle of the study (T6) (for serum glyoxal P = 0.005, for peritoneal glyoxal P = 0.0004, for EF P = 0.0004, for LVESD P = 0.023, for LVEDD P = 0.002, for LVMI P = 0.0005 and for UF P = 0.005) as well as between the mean values in the middle (T6) and at the end of the evaluation period (T12) (for serum glyoxal P = 0.043, for peritoneal glyoxal P = 0.006, for EF P = 0.00009, for LVESD P = 0.012, for LVEDD P = 0.00014, for LVMI P = 0.00013 and for UF P = 0.048). On the other hand, no statistically significant difference was revealed between the T0 and T12 mean values of glyoxal (serum and peritoneal), EF, LVESD, LVEDD, LVMI and UF. During the study period, there was no statistically significant difference in daily urine volume and glomerular filtration rate. CONCLUSIONS The use of bicarbonate-based PDS induced a statistically significant improvement of left ventricle structure (LVESD, LVEDD and LVMI) and functional (EF) indicators. These beneficial effects on left ventricle in combination with the improvement of net UF may designate a protective role of the newer bicarbonate peritoneal solutions on cardiovascular function morbidity and mortality risk of PD patients.

Endovascular Repair of an Inadvertent Right Vertebral Artery Rupture during Dialysis Catheter Insertion

Central venous (CV) catheterization is not only an invaluable diagnostic modality but also an essential therapeutic tool for the treating physician, enabling rapid and reliable intravenous administration of drugs and fluids, providing venous access to patients undergoing long-term continuous or repeated intravenous treatment such as chemotherapy, or it can be used for hemodialysis in patients suffering from acute or chronic renal disease. On the other hand, CV catheterization can lead to a wide range of life-threatening complications for the patient especially if left untreated or become late-diagnosed. In particular, arterial injuries are among the most feared complications that require early clinical suspicion for prompt diagnosis and management. We report the case of a 79-year-old female dialysis patient who suffered from a vertebral artery (VA) injury complicated by a herald bleeding on the third postintervention day after an internal jugular vein dialysis catheter replacement. The patient initially presented neurological signs of a stroke and urgently treated endovascularly after immediate diagnosis of VA rupture was made. Imaging techniques are evidence-based tools that help minimize these mechanical complications, including inadvertent arterial puncture and therefore should be practiced and taught in training programs to avoid the potentially devastating consequences of CV catheterization.

Comparison of standard forearm prosthetic loop grafts to composite semiloop forearm grafts ("semi-grafts") in hemodialysis patients: A prospective study.

Introduction: To prospectively assess the performance of composite semiloop antebrachial grafts (“semi‐grafts,” SGs) in hemodialysis patients.

Plain pelvic/aorta radiographs as a simple guideline to predict vascular macro-calcifications; one step earlier or a late sign to best weight the enemy of coronary calcification and mortality?

Dear Editor, We praise Hong et al. for their excellent study demonstrating that both lateral abdominal and pelvic plain radiographs in hemodialysis patients are acceptable alternatives to computed tomography (CT) to efficiently evaluate vascular macro-calcification (Vmac) meaning that the presence of Vmac detected in series of simple X-rays has similar prognostic and therapeutic implications as modern expensive technologies. However, their earlier study found that coexistence of pelvic and hand artery macrocalcification rather than abdominal aorta calcification itself was associated with mortality in hemodialysis patients. Complicated risk factors, including local hemodynamic response to fistula construction promoting radial artery calcification, was the explanation for this discrepancy. Although the grading of the disease, absent or present is valid in both articles, semiquantitative evaluation of the pelvic arteries/aorta calcifications performing simple soft tissue X-ray techniques are likely to underestimate the true calcium load. For example, discrete arterial wall microcalcifications in all territories, not evident in simple X-rays have zero score like the scenario of no calcifications. Similarly, small scattered or spot calcifications in all four anterior/posterior parts of aorta or extensive concentric calcifications in only one anterior part would give unexpected high and low scores, respectively (24-scored system 5 8 and 3, respectively). Furthermore, the primary exposure of interest, whether intima or medial type of calcification could not be differentiated as correctly pointed out by the authors. Could these facts explain the different outcomes described in both important studies published by the authors? Furthermore, could different types of vascular calcification (Vc) correlate with significantly different coronary artery calcification (CAc) scores and possibly mortality? Given these findings, should the authors perform preoperative assessment of arterial micro-calcification by ultrasound in every case, before simple X-rays? Sonographic pre-existing arterial micro-calcification in radial-cephalic fistulas was associated with histologic calcification in a recent study. Furthermore, although ultrasonography techniques are less useful at quantitating Vc, implying that the quantity of calcium per gram of tissue cannot be determined, intimal and medial types of arteriosclerosis are easily distinguished. Thus, this ultrasound structural information if performed, would increase the likelihood of detecting micro-calcifications and also differentiating the calcifications and plaques observed, either to medial, atherosclerotic, or to the very common mixed in nature. This standard way, i.e., rating ultrasonographically the vessels prior to X-rays, leads to good reproducibility between the examiners and lower probability of biased results and also eliminates errors due to subjective judgment. We also have shown recently that the existence of high degree of upper extremity medial arterial calcification instead of no calcification, prior to radial-cephalic fistula creation (Figure 1) in diabetic patients, confers a survival Correspondence to: G. S. Georgiadis, MD, Alexandrou Papanastasiou 7 str., Alexandroupolis, 68131, Greece. E-mail: ggeorgia@med.duth.gr or georgiadis_gs@hol.gr