The effect of phosphate binder therapy with sucroferric oxyhydroxide on calcification propensity in chronic haemodialysis patients: a randomized, controlled, crossover trial.

BACKGROUND: Calcification propensity is associated with the risk for cardiovascular events and death in end-stage renal disease patients. Here we investigated the effect of lowering serum phosphate with oral phosphate binder therapy on calcification propensity. METHODS: We performed an open-label, randomized, controlled, crossover study in chronic haemodialysis patients with hyperphosphataemia. Patients (n = 39) were randomized in a 1:1 ratio to either low-dose (250 mg/day) sucroferric oxyhydroxide (SO) followed by high-dose (2000 mg/day) SO or vice versa, with washout phases before and after SO treatment. The primary endpoint was changed in calcification propensity as measured by calciprotein particle formation time (T50 test) between washout and high-dose SO treatment in patients with ≥85% adherence to the prescribed SO dose (per-protocol analysis). RESULTS: In the primary per-protocol analysis (n = 28), 2000 mg/day SO treatment resulted in a mean increase in T50 of 66 min (95% CI 49-84 min, P < 0.0001), from 243 ± 63 to 309 ± 74 min compared with phosphate binder washout. Serum phosphate decreased from 2.28 ± 0.5 to 1.63 ± 0.43 mmol/L (P < 0.0001). SO at 250 mg/day did not influence T50 (P = 0.4) or serum phosphate concentrations (P = 0.9) compared with phosphate binder washout. The secondary intention-to-treat analysis (n = 39) showed similar results: an increase in T50 of 52 min (95% CI 31-74 min, P < 0.0001) and a decrease in serum phosphate from 2.18 ± 0.5 to 1.64 ± 0.46 mmol/L. No major adverse cardiovascular event, case of calciphylaxis or death occurred during the study. CONCLUSION: Phosphate binder treatment with SO improves serum calcification propensity of haemodialysis patients and might lead to improved outcomes.

Iatrogenic or congenital arteriovenous fistula of left upper arm used for hemodialysis after venous superficialization.

The authors report a case of iatrogenic brachial arteriovenous fistula (AVF) on the left arm in a 20-year-old man with a history of autosomal dominant polycystic kidney and failing kidney transplant. An attempt to create vascular access for hemodialysis by utilization of an existing iatrogenic brachial AVF was undertaken. The patient underwent surgical superficialization of a concomitant enlarged and deeply located vein. Four weeks after the procedure, the AVF was successfully cannulated for hemodialysis. In this case, iatrogenic/congenital AVF was successfully converted to vascular access for hemodialysis.

Consider use of a collateral venous circuit before abandoning the arteriovenous fistula--the experience of a complex vascular access case.

We describe a 65-year-old woman with diabetes on hemodialysis maintenance, with a number of complications associated with high-flow arteriovenous fistula (AVF, anastomosis between brachial artery and medial vein of the forearm) requiring an extended diagnostic and individual approach. The patient was admitted to our hospital because of pain, edema of the limb, hand ischemia, and infection caused by steal syndrome. To reduce fistula flow, banding of the proximal cephalic vein was performed. Simultaneously because of necrosis, amputation of the fifth finger was necessary. Following this procedure, the cephalic vein on the arm thrombosed. The fistula was patent through the collateral circuit, which was diagnosed in detail during the late course. A long course of antibiotics and sessions in a hyperbaric chamber allowed limb rescue. Single-needle dialysis was carried out because of problems in finding an appropriate second place. After an episode of bleeding from the puncture site caused by ulceration, we were forced to search for an alternative needling point. On the basis of ultrasound scans, an anatomic schema of the blood circuit was created. The fistula demonstrated flow from the brachial artery resulting in retrograde flow in the section of the cephalic vein distal to the anastomosis in the upper forearm. This was then seen to drain in an antegrade direction via the median vein of the forearm after the 2 vessels connected in the mid forearm. Using the diagram, 2 alternative places for needling were found and it allowed the adequate hemodialysis to be continued. Complex and complicated cases associated with native AVF could be resolved using simple diagnostic tools to preserve the fistula use for hemodialysis. Both clinical examination and ultrasound scan with the Doppler option appear to be valuable methods for finding the optimal cannulation place.

Creation of arteriovenous fistulae for hemodialysis in octogenarians.

Elderly patients, defined as octogenarians and nonagenarians, are an increasing population entering renal replacement therapy. Advanced age appears as an exclusive factor negatively influencing dialysis practice. Elderly patients are referred late for the initiation of hemodialysis and more likely are offered catheters rather than arteriovenous fistulae (AVF), which increase mortality and negatively affect quality of life. We present our approach to the creation of vascular access for hemodialysis in this demanding population. In 2006-2012, 39 patients aged 85.9 ± 2.05 with end-stage renal disease, mainly resulting from ischemic nephropathy, were admitted to the Department of Nephrology to establish permanent vascular access for hemodialysis: preferably AVF. Temporary dialysis catheters were implanted in uremic emergency to bridge the time to fistula creation/maturation. AVF was attempted in 87.2% of the patients. Primary AVF function was achieved in 54% of the patients. Cumulative proportional survival of AVF at months 12 and 24 was 81.5%. Ninety-four percent of AVF were localized on the forearm: 74% in the distal and 20% in the proximal part. Mean duration of hemodialysis therapy was 20.80 ± 19.45 months. The mean time of AVF use was 15.9 ± 20.2 months. Until present, 38% have been dialyzed using AVF for 31.0 ± 18.8 months. Five patients died with functioning fistula. Eight patients initiated hemodialysis therapy with fistula. During further observation, the use of AVF increased to 62%. Elderly patients should not be denied creation of AVF as a rule. The outcome of AVF benefits more from acknowledging individual vascular conditions rather than age of the patient.

Superficialization of the radial artery--an alternative secondary vascular access.

PURPOSE: The standard approach in patients with a clotted arteriovenous fistula (AVF) on the forearm is the creation of another vascular access on the arm using the patient's own vessels or a prosthetic graft. Here we propose another option as secondary angioaccess for chronic hemodialysis (HD): superficialization of the radial artery. METHODS: Indications for the procedure were 1) long-standing forearm AVF that has irreversibly clotted and/or central vein stenosis resistant to angioplasty; 2) patients who have no other prospect for forearm or even brachial AVF. The procedure was undertaken in 7 chronic HD patients dialyzed by forearm AVF for 27±26 months. RESULTS: In one case the superficialization was abandoned intra-operatively due to small diameter of the artery (<4 mm). Five of 6 elevated arteries were patent and the follow-up period ranges from 11 to 15 (median 12) months. In 1 male patient with prothrombin G20210A mutation the artery clotted after 13 months of usage. CONCLUSIONS: Superficialized radial artery was successfully used for hemodialysis over one year. The only prerequisite for safe repeated puncture is a patent and enlarged radial artery. Due to avoidance of arteriovenous shunt this access type may be particularly suitable for patients with cardiac failure.

Balloon angioplasty for disruption of tunneled dialysis catheter fibrin sheath.

PURPOSE: Management of failing tunneled hemodialysis catheters, sometimes the only vascular access for hemodialysis, presents a difficult problem. In spite of various techniques having been developed, no consensus has been reached about the preferred technique, associated with the longest catheter patency. METHODS: We report disruption of the fibrin sheath covering dysfunctional tunneled hemodialysis catheter by means of angioplasty, followed by over guidewire catheter exchange. RESULTS: Following the procedure, the catheter placed in the recovered lumen of the vessel presented correct function. CONCLUSIONS: The described procedure allowed maintenance of vascular access in our patient. Additionally, dilatation of the concomitant central vein stenosis opens an option for another attempt for arteriovenous fistula creation.

Repair of damaged connectors of tunneled cuffed catheters with a two-piece adaptor for peritoneal dialysis.

PURPOSE: Although catheter use exposes the patient to several complications, tunneled cuffed catheters are widely applied for temporary or long-term vascular access. The aim of the study was to establish the rate of tunneled dialysis catheter damage and report our experience with breakage repair. METHODS: All 363 cuffed tunneled hemodialysis catheters inserted into 309 patients from May 2000 to December 2008 were followed up. When connector damage was encountered, repair with a two-piece adaptor for peritoneal dialysis was attempted. RESULTS: Mechanical breakage occurred in 33 (9.1%) of catheters with an incidence of 0.36/1000 catheter-days. The most frequent was connector damage, found in 25 cases (67.6%). Catheter repair using a peritoneal dialysis Luer adaptor was performed with good early and long-term outcome. CONCLUSIONS: Tunneled catheter breakage is a relatively rare complication. Catheter repair using the adaptor for peritoneal dialysis is easy to perform, safe, and cost-effective.

Endostatin and vascular endothelial growth factor: potential regulators of endothelial progenitor cell number in chronic kidney disease.

INTRODUCTION: Cardiovascular mortality is significantly increased in patients with chronic kidney disease (CKD). The number of circulating endothelial progenitor cells (EPCs) may affect vascular regenerative potential and thus influence cardiovascular mortality. OBJECTIVES: The aim of the study was to assess the number of circulating EPCs and the factors that potentially affect these cells, including vascular endothelial growth factor (VEGF) and endostatin, in patients with CKD. PATIENTS AND METHODS: The study involved 139 patients divided into groups depending on the severity of renal impairment: 67 predialysis patients with CKD, 46 patients on hemodialysis (HD), and 26 patients on peritoneal dialysis (PD). Plasma levels of VEGF and endostatin were measured by enzyme-linked immunosorbent assays. The number of circulating EPCs, defined as CD34+VEGFR2+, was assessed in the whole blood using flow cytometry. RESULTS: There was a positive correlation between VEGF and CD34+VEGFR2+ and the glomerular filtration rate. Endostatin levels increased with renal impairment. The highest endostatin levels were observed in HD and PD patients. The number of EPCs was significantly lower in predialysis patients with CKD and in HD patients, while in PD patients it was nonsignificantly lower compared with the control group. CONCLUSIONS: In patients with CKD, a decrease in circulating EPCs may impair vascular regenerative potential and thus contribute to a higher cardiovascular risk. The effect of significantly increased endostatin levels on the endothelial function and progenitors in patients with CKD requires further investigation.

Malignancy after renal transplantation in the new era of immunosuppression.

BACKGROUND: This retrospective single-center study was undertaken to assess the occurrence of de novo neoplasms in renal transplant recipients according to the immunosuppressive regimen and time after transplantation. MATERIAL/METHODS: Observation encompassed 1028 patients transplanted between the years 1983-2006 and followed for 0.5-23 years. Patients with skin cancer other than melanoma were excluded due to incomplete data collection. RESULTS: Malignancy appeared in 4.8% (49) of the patients after the period of 5.8 ± 4.7 years at the age of 54 ± 13 years. The most common malignancies were urinary tract tumors (22%) and non-Hodgkin lymphoma with post-transplant lymphoproliferative disease (PTLD) (16%). Malignancy occurred in 5.2% of patients on cyclosporine (CSA), azathioprine (AZA) and prednisone (P); in 3.4% of patients on mofetil mycophenolate (MMF) with CSA and P; in 3.3% of patients on MMF with tacrolimus (TAC) and P; and in 2 of 20 patients (10%) receiving AZA with P 15 years after transplantation. The regimen consisting of CSA, AZA with P could be distinguished by the higher risk of malignancy occurrence. The occurrence of malignancy was significantly earlier on MMF+TAC+P compared to other regimens (p<0.05). The highest incidence of malignancy on AZA with P could be attributed to the longer observation period. CONCLUSIONS: In the new era of immunosuppression, despite lower occurrence, malignancy tends to appear earlier after the transplantation.

Enhanced enzymatic activity of Candida species responsible for oral candidiasis in renal transplant recipients.

Renal transplant recipients (RTRs) are regarded to be predisposed to oral candidiasis. This study was undertaken to evaluate the activity of hydrolytic enzymes in strains causing oral candidiasis in RTR. A total of 123 Candida albicans and 10 Candida krusei strains were isolated from 200 RTRs (39 RTRs suffered from symptomatic candidiasis, the remaining patients had no clinical symptoms of infection). All fungi were identified based on routine mycological procedures. Because of a small number of non-albicans strains, only C. albicans isolates were compared for enzymatic activity. The activity of 19 hydrolytic enzymes was assessed by API ZYM(®) test. The usage of mycophenolate mofetil was connected with higher ratio of clinically apparent oral candidiasis compared to immunosuppressive regimens without this drug (74.4% vs. 46.8%, respectively, P < 0.01). Candida albicans from RTRs showed higher enzymatic activity compared with strains from immunocompetent patients. Only two enzymes were found to be more active in C. albicans causing symptomatic candidiasis in RTRs (cystine arylamidase: P = 0.001, and α-fucosidase: P = 0.01) compared with saprophytic strains. Atrophic candidiasis showed higher activity of esterase lipase (C8) and α-mannosidase compared with the pseudomembraneous type. We suggest that the enhanced enzymatic activity is responsible for higher invasiveness of Candida residing in the oral cavity of RTRs.

[Physical exercise in the rehabilitation of dialysis patients]. / Cwiczenia fizyczne w rehabilitacji chorych dializowanych.

A sedentary lifestyle is one of the main causes of low physical capacity and an independent risk factor for death in patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD). The physical capacity of ESRD patients is 60% of an age-matched population with normal kidney function. Although muscular dysfunction is of crucial significance in low physical capacity, its etiology is more complex. The influence of uremic toxins, vitamin D3 deficiency, hyperparathyroidism, anemia, insulin resistance, androgen deficiency, mitochondrial dysfunction, malnutrition, inflammation, and cachexia are all taken into consideration. Physical rehabilitation improves physical proficiency, the performance of daily activities, and quality of life. In this review possible methods of rehabilitation and their advantages, disadvantages, and possible complications are presented.

Native forearm fistulas utilizing the basilic vein: an underused type of vascular access.

BACKGROUND: Arteriovenous fistulas (AVFs) are the solution of choice among diverse types of vascular access. The forearm basilic vein is rarely used for creating autogenous vascular access. Its use presents a valuable option when autogenous wrist radial-cephalic direct access cannot be created due to the destruction of forearm veins. Results obtained with autogenous wrist ulnar-basilic direct access and autogenous wrist radial-basilic transposition are presented below. METHODS: In the decade 1993-2003, native fistulas utilizing the forearm basilic vein were performed in 27 patients (14 women, 13 men). The basilic vein was anastomosed to the ulnar artery or was transposed and anastomosed to the radial artery. RESULTS: AVF creation was successful in 22 patients (81.5%). The primary patency rate was 70.4% after 1 year, 61.6% after 2 years and 48.4% after 3 years. CONCLUSIONS: AVFs utilizing the forearm basilic vein can be considered for primary or secondary vascular access because of the acceptable survival rate and low incidence of hand ischemia. Transposition of the basilic vein is a valuable option in the reconstruction of a thrombosed or stenosed radial-cephalic fistula.

Anti-Fya antibodies as the cause of an unfortunate post-transplant course in renal transplant recipient.

BACKGROUND: Duffy glycoprotein, belonging to blood group alloantigens, is also recognized as chemokine-binding protein, therefore the role of Duffy antigen in chemokine distribution has been postulated. Duffy positive phenotype prevalent among Caucasians is associated with antigen expression on erythrocytes and endothelium of several organs including kidney. The role of anti-Duffy antibodies significant in transfusiology may be also important in kidney transplantation. CASE REPORT: The case of renal transplant recipient with Fy (a-b+) phenotype, possessing anti Fya antibodies, with unfortunate post-transplant course complicated with acute cellular and antibody-mediated graft rejections, with the presence of crescentic glomerular lesions, kidney graft insufficiency and recurrent urinary tract infections is presented. The role of anti-Duffy antibodies in acute antibody-mediated rejection is discussed. CONCLUSIONS: Fy(a )antibodies present in renal recipient with Fy(a-b+) phenotype may be the reason for unfavorable transplantation outcome resulting from reaction against Duffy antigen up-regulated on graft tissue during ischemia reperfusion injury and acute rejection episode. In renal transplant recipients with antibody-mediated rejection without antidonor specific antibodies, incompatibility in blood group antigens other than AB0 system could be considered.

Arteriovenous fistula reconstruction in patients with kidney allograft failure.

BACKGROUND: Kidney recipients with failing allograft function face the vascular access problem again before returning to hemodialysis. An autologous arteriovenous fistula (AVF), according to the recent Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines, is the optimal vascular access and the use of prosthetic grafts and catheters should be limited. The objective of this study was to assess the feasibility of AVF reconstruction in patients reentering hemodialysis after kidney allograft failure. MATERIALS AND METHODS: Two hundred and forty-one transplant recipients reentered hemodialysis between 1990 and 2005. Before kidney transplantation, 221 patients had a functioning AVF on the forearm. Fistula reconstruction was attempted in 112 (51%) patients because of AVF thrombosis. Three strategies were applied according to forearm vein patency: a new radial-cephalic fistula, a radial-perforating vein fistula, or a radial-basilic forearm transposition was created. RESULTS: Forearm AVFs were successfully reconstructed in 85 of the 112 patients (73%). The primary patency of the reconstructed AVFs was 57.6% and 44% at 12 and 24 months. Secondary patency was 64.9% and 54.9% at 12 and 24 months, respectively. CONCLUSIONS: The reconstruction of an old, thrombosed AVF is possible in kidney recipients returning to dialysis, even if the time from thrombosis to fistula repair is a few years.

Obesity is not an obstacle for successful autogenous arteriovenous fistula creation in haemodialysis.

BACKGROUND: Obesity, which is often associated with diabetes, is increasingly encountered in the haemodialysed population, and this may produce difficulty in autogenous arteriovenous fistula creation. Prosthetic angioaccess or catheters, when used in place of autogenous fistulas, increase thrombotic and infectious complications in these already challenged patients. METHODS: This prospective study was undertaken to assess the feasibility of autogenous arteriovenous fistula creation in 71 obese patients (BMI 34.6 +/- 7.8). We performed a two-stage procedure, in which radio-cephalic fistula formation was followed by subcutaneous transposition of the venous component for safe and easy puncture. RESULTS: Fistulas suitable for puncture, having blood flows of 799 +/- 285 ml/min, and sufficient to perform adequate haemodialysis (Kt/V 1.24) were achieved in 85% of the patients. Primary patency rates were 65% and 59% at 6 and 12 months, respectively, and secondary patency rates were 83% both at 6 and 12 months. CONCLUSIONS: Obesity does not prevent successful autogenous arteriovenous fistula formation, and may protect forearm venous vessels from the iatrogenic damage that occurs before the onset of haemodialysis therapy.

Radial artery-perforating vein fistula for hemodialysis.

BACKGROUND: The proximal forearm antecubital fistula described by Gracz is a valuable option for autogenous vascular access for hemodialysis in patients with destroyed forearm veins or advanced arteriosclerotic and calcified radial arteries. Results obtained with a variant of the Gracz fistula are presented. STUDY DESIGN: Patients with forearm vein destruction or failed distal radiocephalic fistulas were selected to have a variant of the Gracz fistula created and were followed up for 36 months. In each patient, the radial artery was anastomosed side to end or end to end to the perforating vein. Additionally, in some patients, the median cephalic or basilic vein was relocated subcutaneously to increase the accessibility of veins for puncture. SETTING & PARTICIPANTS: Native arteriovenous fistulas (AVFs) in the cubital region using a perforating vein were created in 77 patients (34 women, 43 men) referred to the Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Poland, from 1992 to 2006. OUTCOMES & MEASUREMENTS: Percentages of successful fistula creation and primary patency rates, defined from fistula placement to any maintaining intervention, and cumulative patency, defined from placement to fistula abandonment, were assessed. RESULTS: AVF creation was successful in 56 patients (73%). Primary patency rates during the follow-up period were 47% after 1 year, 43% after 2 years, and 39% after 3 years. Cumulative patency rates were 67% after 1 year, 56% after 2 years, and 53% after 3 years. LIMITATIONS: These results reflect performance of a single center and thus may not be generalizable to surgeons less experienced in this technique. CONCLUSIONS: Radial artery-perforating vein fistulas have an acceptable survival rate and do not produce circulatory complications. This method may be applicable for AVF creation in patients with forearm vein destruction/abnormalities and as a rescue procedure for an old clotted fistula after kidney transplant failure.