Arteriovenous fistulas thrombosis in hemodialysis patients with COVID-19.

BACKGROUND: The current Coronavirus disease 2019 (COVID-19) outbreak is associated with significant mortality, especially in patients suffering from end stage renal disease (ESRD) and hemodialysis patients. Several previous studies reported an over-risk of arterial and venous thrombosis, in particular pulmonary embolism and venous thrombosis of catheter in COVID19 patients in intensive care unit. However, arteriovenous fistula (AVF) thrombosis has rarely been reported yet in these patients. AVF thrombosis is a serious complication that impacts significantly patients outcome. Here, we aim to describe characteristics and prognosis of a cohort of COVID-19 hemodialysis (HD) patients presenting with AVF thrombosis. METHODS: In the Ile de France region (Paris area) during the March 11th-April 30th 2020 period, fistula thrombosis cases were collected among COVID-19 hemodialysis patients in seven dialysis units and in interventional vascular departments. These patients' characteristics were analyzed through a review of the patient's medical records. RESULTS: Seventeen patients were included in our study (median age 69 years). Ten patients (59%) were men. Ten patients (59%) were diabetic and 88% had a high blood pressure. The mortality rate in these patients was 47%. All thrombosis treated with a declotting procedures (64%) were successfully cleared, but with early relapse in 36%. CONCLUSION: Our study highlights AVF thrombosis as a severe complication in COVID-19 hemodialysis patients that contributed to the severity and accelerated death.

Impact of First Wave COVID-19 Crisis on Dialysis Parameters of COVID-Free Hemodialysis Patients: A NephoCare France Longitudinal Retrospective Cohort Study.

BACKGROUND: Chronic hemodialysis (HD) patients are at high risk of severe COVID-19 with a high risk of death. The organization of dialysis units to treat chronic HD patients with COVID-19 is demanding to prevent virus transmission both in COVID-free patients and the staff. These constraints may have an impact on the dialysis delivery to COVID-free HD patients. We report our experience in French NephroCare (NC) centers. METHODS: We report retrospectively dialysis and nutritional indicators among COVID-free prevalent chronic HD patients' cohort treated in French NC units from February 2020 to April 2020. The COVID-free HD patients were split into 2 subgroups for the analysis, Paris region and other regions because the incidence of COVID-19 was different according to the French regions. RESULTS: The Paris region was the most impacted by COVID-19 with 73% of all the contaminations that occurred in French NC units (n = 118). The dialysis frequency was not reduced all over the NC regions. 2,110 COVID-free HD patients were split into 2 subgroups including Paris region (748 patients) and other regions (1,362 patients). The weekly treatment time decreased significantly in Paris region from February to April (723-696 min [p < 0.00001]) but remained stable in the other regions. The processed blood volume, KT/V, and convective volume declined significantly in the Paris region subgroup but not in other regions. The 3-month weight loss significantly increased in the whole group of patients whatever the region from 0.0 to 0.2% between February 2020 and April 2020 (p < 0.00001). Ultrafiltration rate (UFR) and the normalized proteic catabolic rate remained stable all along the period. The stepwise regression analysis identified February serum albumin level and April UFR as negatively associated with 3-month weight loss. CONCLUSION: HD delivery to COVID-free HD patients was negatively impacted in the Paris region because of the strong constraints on units' organization related to the treatment of COVID-19+ HD patients and with a higher proportion of limited care/self-care units with less staff resources. The 3-month weight loss increase may be related to the suppression of intradialytic snack that impacted mostly the more malnourished patients or patients with lower interdialytic weight gain. These consequences of the COVID-19 crisis on COVID-free HD patients must be recognized and corrected to prevent further deleterious effects on patients' outcomes.

[COVID-19 crisis management during the first three waves in a large dialysis organisation: Feedback from NephroCare France]. / Gestion de la crise COVID-19 dans une organisation multicentrique de dialyse au cours des trois premières vagues : retour d'expérience de NephroCare France.

At the start of the COVID crisis, NephroCare operated 40 dialysis units in 7 regions, with 2,740 hemodialysis patients. The national COVID-19 crisis team implemented early the necessary measures to ensure the safety of dialysis patients and caregivers in the context of the pandemic. These measures were mostly traditional, but some were specific to our organization. They were modified during the 3 successive waves. The first wave mainly impacted NephroCare Ile-de-France which recorded 75% of the contaminations with an impact on the dialysis parameters of non-COVID patients which was not found during the second wave due to reduced stress (34% of contaminations) and a better management of COVID+ patients. The effectiveness of the measures put in place is suggested by the absence of PCR+ in asymptomatic patients and the perfect adequacy of the anti-SARS-CoV2 antibodies with the diagnosis of COVID in one severely impacted Ile-de-France unit, opposite to literature reporting significant rates of positive PCR or serology in asymptomatic patients. In addition, the contamination rate was calculated below the national rate reported by the Biomedicine Agency. The third wave was marked by the implementation of the anti-SARS-CoV2 vaccination with a proportion of vaccinated patients not different from national data and a decrease in COVID cases at the end of the third wave while the national incidence remained stable on the period. In conclusion, this experience of facing an unprecedented serious situation showed the responsiveness of the organization, significant innovations and the efficacy of the implemented measures.

COVID-19 in Patients on Maintenance Dialysis in the Paris Region.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) represents a serious threat to patients on maintenance dialysis. The clinical setting, mortality rate, and prognostic factors in these patients have not been well established. METHODS: We included all dialyzed patients with COVID-19 referred to our dialysis center between March 11 and April 11, 2020. Data were obtained through the review of the medical records and were censored at the time of data cutoff, on May 11, 2020. RESULTS: Forty-four patients on maintenance dialysis with COVID-19 were referred to our dialysis unit during the COVID-19 epidemic. Median age was 61 years (interquartile range [IQR]: 51.5-72.5); 65.9% were men. Comorbidities included hypertension (97.7%), diabetes mellitus (50%), and chronic cardiac (38.6%) and respiratory (27.3%) diseases. Initial symptoms were fever (79.5%), shortness of breath (29.5%), cough (43.2%), and diarrhea (13.6%). Three profiles of severity were distinguished based on the World Health Organization (WHO) progression scale. Forty-one (93.2%) were hospitalized and only 3 were maintained on outpatient hemodialysis. Thirty-three (75%) patients required oxygen therapy, including 15 (45.5%) who were referred to the intensive care unit. Overall, 27.3% of patients died, and 58.5% were discharged from hospital, including only 2 (13.3%) of those admitted to the intensive care unit. By multivariate analysis, cough, thrombopenia <120 g/l, lactate dehydrogenase (LDH) level greater than 2 times the upper limit of normal, and blood C-reactive protein (CRP) >175 mg/l were significantly associated with death. CONCLUSION: A major outbreak of COVID-19 occurred in the Paris region, and spread among dialyzed patients. Our study underscores the severity of COVID-19 in these patients and identified prognostic markers.

Midterm results of percutaneous arteriovenous fistula creation with the Ellipsys Vascular Access System, technical recommendations, and an algorithm for maintenance.

OBJECTIVE: The aim of this study was to report our midterm results of percutaneous arteriovenous fistula (pAVF) creation using the Ellipsys (Avenu Medical, San Juan Capistrano, Calif) device and to present technical recommendations and our algorithm of pAVF maintenance. METHODS: A single-center comprehensive database of all consecutive predialysis and end-stage renal disease patients who had a pAVF creation with the Ellipsys device was reviewed retrospectively. Study end points included technical success, maturation, functional patency, and required interventions. RESULTS: Between May 2017 and July 2019, there were 234 patients (mean age, 64 years; 148 male [63%]) who had a pAVF created. Technical success was achieved in 232 individuals (99%), and average duration of the procedure was 15 minutes (7-35 minutes). Average follow-up was 252 days (range, 83-696 days). The 1-year primary, primary assisted, and secondary patency rates were 54%, 85%, and 96%, respectively. Average pAVF flow was 923 mL/min (range, 425-1440 mL/min). There were no significant adverse events related to the procedure. Only three patients (1%) required a later conversion of the pAVF anastomosis to a surgical fistula. Twenty-four (10%) patients required superficialization of deep outflow veins because of difficult cannulation. Average maturation time was 4 weeks (range, 1-12 weeks). Fourteen patients (6%) had early (<2 weeks after creation) cannulation of the pAVF. CONCLUSIONS: The Ellipsys pAVF device allows the rapid and safe creation of a reliable autogenous access. Rates of technical success, patency, and maturation were excellent. For patients unsuited for a distal radiocephalic arteriovenous fistula, it should be considered the next preferred access option.

Feasibility for arteriovenous fistula creation with Ellipsys®.

OBJECTIVE: To investigate the feasibility of percutaneous arteriovenous fistula creation in consecutive patients screened for first access creation. METHODS: Prospective study of ultrasound mapping based on the following minimal anatomic requirements: a patent proximal radial artery and adjacent elbow perforating vein with straight trajectory, each greater than or equal to 2 mm in diameter and within 1.5 mm of each other. In addition, the same population was evaluated for feasibility of a distal radiocephalic fistula established. RESULTS: One hundred consecutive patients were examined between November 2018 and January 2019. Sixty-seven were male (67%) and mean age was 61 years. Sixty-three patients (63%) and a total of 100 limbs (50%) were found to be eligible for a percutaneous fistula creation with Ellipsys®. Thirty-seven percent of patients were ineligible because of the absence of both median cephalic and median cubital veins (15%), absence or inadequate elbow perforating vein and/or smaller than 2 mm proximal radial artery (14%), and/or distance greater than 1.5 mm (8%). We found suitable vessels for a surgical distal fistula creation in 91 extremities (45%), but this percentage dropped to 17% in patients over 70 years old. Among the 100 limbs eligible for percutaneous arteriovenous fistula, only 30 (30%) were eligible for radiocephalic arteriovenous fistula. CONCLUSION: More than 60% of patients were eligible for Ellipsys. The absence of veins at the elbow and a large distance between vessels were the most common limiting factors. Less than one half of the patients were candidates for surgical fistula and this percentage dropped significantly for older individuals.

Is high-volume post-dilution haemodiafiltration associated with risk of fluid volume imbalance? A national multicentre cross-sectional cohort study.

BACKGROUND: Fluid overload is frequent among hemodialysis (HD) patients. Dialysis therapy itself may favor sodium imbalance from sodium dialysate prescription. As on-line hemodiafiltration (OL-HDF) requires large amounts of dialysate infusion, this technique can expose to fluid accumulation in case of a positive sodium gradient between dialysate and plasma. To evaluate this risk, we have analyzed and compared the fluid status of patients treated with HD or OL-HDF in French NephroCare centers. METHOD: This is a cross-sectional and retrospective analysis of prevalent dialysis patients. Data were extracted from the EUCLID5 data base. Patients were split in 2 groups (HD and OL-HDF) and compared as whole group or matched patients for fluid status criteria including predialysis relative fluid overload (RelFO%) status from the BCM®. RESULTS: 2242 patients (age 71 years; female: 39%; vintage: 38 months; Charlson index: 6) were studied. 58% of the cohort were prescribed post-dilution OL-HDF. Comparing the HD and OL-HDF groups, there was no difference between HD and OL-HDF patients regarding the predialysis systolic BP, the interdialytic weight gain, the dialysate-plasma sodium gradient, and the predialysis RelFO%. The stepwise logistic regression did not find dialysis modality (HD or OL-HDF) associated with fluid overload or high predialysis systolic blood pressure. In OL-HDF patients, monthly average convective or weekly infusion volumes per session were not related with the presence of fluid overload. CONCLUSIONS: In this cross-sectional study we did not find association between the use of post-dilution OL-HDF and markers of fluid volume excess. Aligned dialysis fluid sodium concentrations to patient predialysis plasma sodium and regular monitoring of fluid volume status by bioimpedance spectroscopy may have been helpful to manage adequately the fluid status in both OL-HDF and HD patients.

Efficacy and Safety of Intra-gastric Balloon Placement in Dialyzed Patients Awaiting Kidney Transplantation.

BACKGROUND: The number of obese patients who are candidates for renal transplantation has considerably increased, but obesity can be a barrier to kidney transplantation. Weight loss is often difficult through diet alone. We studied the efficacy and tolerance of the intra-gastric balloon (IGB) procedure in obese patients who were undergoing dialysis and were candidates for a renal transplantation. PATIENTS AND METHODS: Obese patients (BMI > 30 kg/m2) who were candidates for renal transplantation were prospectively included in the study between 2010 and 2012. The balloon was inserted and removed during a gastric endoscopy under general anesthesia. The treatment lasted 6 months. The end point was a decrease in BMI after 6 months. Body impedance spectrometry (BIS) and nutritional statute were evaluated initially and then after IGB removal. RESULTS: Seventeen patients (nine females and eight males) with a mean age of 53.4 years [19.4-69.4] were included. The decrease in body mass index (BMI) during the 6-month placement was 3 kg/m2 (from 37.7 to 34.4 kg/m2). The mean weight loss was 7 kg. The mean percentage of excess weight loss after 6 months was 20.2 (± 11.4). The tolerance was good without any complications. Eleven patients underwent kidney transplantation. CONCLUSION: IGB in obese dialyzed patients who are candidates for renal transplantation is safe and effective. However, the amount of weight loss can vary.

Perioperative ultrasound: a critical element in diagnosis and salvage of complex vascular access dysfunction.

BACKGROUND: Perioperative ultrasound performed by the operative surgeon can improve outcomes of vascular access surgery. We present the case of a patient referred for dysfunctional vascular access with two separate and patent right arm arteriovenous fistulas (AVF). Pre-operative ultrasound vessel mapping defined the complex anatomy and intraoperative ultrasound allowed the optimal surgical approach for access salvage while avoiding the need for catheter placement. CASE REPORT: A 45-year-old male patient of African descent presented with a malfunctioning right forearm AVF and aneurysm formation in the arm. Clinical examination revealed a soft, low-flow forearm fistula merging into a high-flow and pulsatile AVF outflow aneurysm in the arm. Multiple well healed surgical incisions were present. Ultrasound examination revealed two separate AVFs. One was a low-flow radiocephalic AVF at the wrist that was used routinely for cannulation in the forearm, although with some difficulty due to low inflow pressure. The second AVF, a brachiocephalic anastomosis, was pulsatile, aneurysmal, and not in use. Blood flow in the proximal brachial artery was 3.0 L/min. Surgeon-performed ultrasound (SP-US) was used perioperatively to plan the surgical approach and incision, closing the existing brachial anastomosis and creating a veno-venous anastomosis between both outflow veins, establishing a mature and undisturbed cannulation conduit from the wrist through the arm. The revised AVF was immediately usable for hemodialysis with restored normal AVF flow in the forearm and appropriately reduced flow in the arm. Importantly, dialysis catheter placement was avoided.

Non-tolerability of double-filtration plasmapheresis in antibody-incompatible kidney transplant candidates.

Few studies have reported the use of double-filtration plasmapheresis (DFPP) in antibody-incompatible kidney transplantation. To assess the efficiency and tolerability of DFPP, we prospectively studied four chronic hemodialysis patients from two centers undergoing antibody-incompatible kidney transplantation. DFPP was used for ABO-incompatible transplantation (n = 1), for high human leukocyte antigen (HLA) immunization levels (n = 2) or for the presence of a donor-specific antibody (DSA) against a potential living donor (n = 1). In all the patients, the DFPP program was discontinued because of the adverse effects. Low blood pressure occurred during the first hour of the session in all the patients. A significant loss of plasma proteins, clotting factors and immunoglobulins also occurred during this treatment. In addition, fistula thrombosis was diagnosed in two patients. Three patients experienced gastrointestinal symptoms. The DFPP reduced the titers of the anti-B antibodies and reduced the levels of DSA in one patient, but had no effect on anti-HLA antibodies in the remaining two patients. Our study highlights the non-tolerability and poor efficacy of DFPP prior to antibody-incompatible kidney transplantation that limit its extensive use in the desensitization protocols.

Maturity onset diabetes of the young: clinical characteristics and outcome after kidney and pancreas transplantation in MODY3 and RCAD patients: a single center experience.

The diabetes and renal phenotype of patients with maturity-onset diabetes of the young (MODY) on a transplantation waiting list is not known; neither is their outcome after pancreas (PT) and/or kidney transplantation (KT). Between 2002 and 2009, we screened 50 of 150 patients referred for kidney and pancreas transplantation to the Kremlin-Bicêtre center for HNF1B and HNF1A mutations if one or more of the following criteria was present (i) an atypical history of diabetes (ii) diabetes with at least one affected parent or two affected relatives, (iii) an absence of auto-antibodies at diagnosis (iv) a persistent secretion of fasting C peptide (v) a personal or a family history of renal cysts or dysplasia. Their phenotype and their outcome were analyzed. Four HNF1A (MODY3) and eight HNF1B mutations [renal cysts and diabetes (RCAD)] were identified. All MODY3 patients had diabetic nephropathy, but only 50% of RCAD patients. Four patients underwent a kidney and pancreas transplantation and two a kidney transplant alone. After 4.1 ± 1.1 years of follow-up, 83% of patients still have a functioning kidney and 75% a functioning pancreas. PT can be proposed with good results for MODY3 and RCAD patients.

Efficacy and safety of the H1N1 monovalent vaccine in renal-transplant recipients and dialysis patients.

BACKGROUND: The (H1N)1v influenza virus infection emerged in 2009 as a serious disease in targeted populations. Herein, we report on the tolerability and efficacy of (anti-H1N1)v vaccination in dialysis and transplant patients. METHODS: 18 renal-transplant recipients (RTR) and 19 dialysis patients (DP) [12 patients treated with peritoneal dialysis (PDP), 7 patients treated with haemodialysis (HDP)] were enrolled. DPs received one monovalent H1N1 adjuvanted-vaccine injection, and RTRs received two unadjuvanted vaccine injections within a 21-day period. Serologic response was defined as a haemagglutination inhibition titre of > 40 (seroprotection) and/or at least a four-fold increase in antibody titre from baseline (seroconversion). RESULTS: Seroprotection rate after vaccination was greater in DPs than RTRs (p = 0.007), as was seroconversion (p = 0.001). Serologic response was similar in PDPs and HDPs. CONCLUSIONS: Serologic response was satisfactory in DPs, whichever dialysis mode (DPD or HDP). It was low in RTRs as compared to DPs.

Emerging strategies to preserve renal function.

Although there has been tremendous improvement in managing chronic kidney disease (CKD) with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) in the last 15 years, CKD still progresses. Therefore, new emerging strategies are needed. The gold standard still lies with optimum renin-angiotensin-aldosterone system blockade, although many questions remain about how this is best achieved, such as regarding the efficacy of combinations of ACE inhibitor and ARBs, supramaximal doses of ARBs alone and combinations of either ACE inhibitor or ARBs with direct renin inhibitors, antialdosterone agents. Other promising molecules currently being tested are endothelin receptor antagonists and glitazones. Also, the role of other current therapies being used during CKD, including statins, vitamin D and erythropoiesis-stimulating agents, will be discussed, as these may also exert nephroprotective effects.