Preoperative radial artery volume flow is predictive of arteriovenous fistula outcomes.

OBJECTIVE: Guidelines recommend the creation of a wrist radiocephalic arteriovenous fistula (RAVF) as initial hemodialysis vascular access. This study explored the potential of preoperative ultrasound vessel measurements to predict AVF failure to mature (FTM) in a cohort of patients with end-stage renal disease in Northern Ireland. METHODS: A retrospective analysis was performed of all patients who had preoperative ultrasound mapping of upper limb blood vessels carried out from August 2011 to December 2014 and whose AVF reached a functional outcome by March 2015. RESULTS: There were 152 patients (97% white) who had ultrasound mapping and an AVF functional outcome recorded; 80 (54%) had an upper arm AVF created, and 69 (46%) had a RAVF formed. Logistic regression revealed that female gender (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.12-5.55; P = .025), minimum venous diameter (OR, 0.6; 95% CI, 0.39-0.95; P = .029), and RAVF (OR, 0.4; 95% CI, 0.18-0.89; P = .026) were associated with FTM. On subgroup analysis of the RAVF group, RAVFs with an arterial volume flow <50 mL/min were seven times as likely to fail as RAVFs with higher volume flows (OR, 7.0; 95% CI, 2.35-20.87; P < .001). CONCLUSIONS: In this cohort, a radial artery flow rate <50 mL/min was associated with a sevenfold increased risk of FTM in RAVF, which to our knowledge has not been previously reported in the literature. Preoperative ultrasound mapping adds objective assessment in the clinical prediction of AVF FTM.

A decade of arteriovenous fistula creations in the ⩾75 years population: Equal opportunity or sub-optimal use of resources.

BACKGROUND: The optimal vascular access in the elderly remains contentious in the context of increasingly limited resources and anticipated survival on hemodialysis. Research focus has shifted to include the impact of vascular access on quality of life. This study explored clinical outcomes in individuals aged ⩾75 years who had an arteriovenous fistula (AVF) created in a single center over a 10-year period. MATERIALS AND METHODS: Demographic and clinical data concerning AVFs created January 2009-December 2019 were identified from a prospective database for retrospective analysis. Outcome measures were AVF patency and failure to mature rates plus overall patient and vascular access survival. The Vascular Access Specific Quality of life measure (VASQoL) was completed in a contemporary cohort aged ⩾75 years established on HD in October 2021. RESULTS: AVF outcomes were available for 272 patients (93%). The failure to mature (FTM) rate was 36% with the significant predictors of AVF FTM being the creation of a radiocephalic AVF (OR 8.13, 95% CI 8.02-8.52, p < 0.01), female gender (OR 4.84, 95% CI 4.70-5.41, p < 0.01), and a history of peripheral vascular disease (OR 5.25, 95% CI 5.22-6.00, p value = 0.02). Functional patency was associated with a median 12-month survival benefit compared to those whose fistula FTM (p < 0.01). The median patency duration for a functionally patent AVF was 3 years. Elderly patients with a fistula reported a lower quality of life in VASQoL scoring than those with central venous catheters. CONCLUSIONS: In this cohort, AVF creation in individuals aged ⩾75 years AVFs was associated with comparable AVF patency rates to younger patients. AVF functional patency was associated with superior patient survival compared to those with AVF FTM. A multi-disciplinary surveillance program may help reduce AVF loss. Further work on how vascular access choice impacts quality of life in elderly patients is required.

Optimizing AVF creation prior to dialysis start: the role of predialysis renal replacement therapy choices.

BACKGROUND: In British Columbia, multidisciplinary predialysis clinics encourage patients to consider independent modalities of renal replacement therapy (RRT) such as peritoneal dialysis (PD) 'first'. Despite up to 50% of patients choosing PD, PD incidence rates are ~30%. We explored the relationship between predialysis RRT choice and arteriovenous fistula (AVF) creation prior to hemodialysis (HD) start with particular focus on the group of patients who despite PD choice actually commence HD, and thus may contribute to 'suboptimal' HD starts without AVF creation. METHODS: We conducted a retrospective cohort study of all patients starting dialysis between 31 December, 2006 and 31 December 2008 in the province of British Columbia. Inclusion criteria were >3 months predialysis nephrology follow-up, at least one predialysis RRT education session and maintenance on dialysis for a minimum of 3 months (to ensure chronic dialysis). Patients with any prior history of RRT were excluded. RESULTS: There were 508 patients included in the study: 127 (25%) patients chose HD, 114 (22%) PD, 13 (3%) pre-emptive transplant, 5 (1%) conservative management and 249 (49%) had no documented modality decision. Of those who chose HD, 94% commenced HD. For those who chose PD, 64% commenced PD and 36% HD. In the undecided group, 68% started HD and 32% PD. For those patients who chose PD predialysis, the presence of cardiovascular disease [odds ratio (OR) 2.36, 95% confidence interval (CI) 1.02-5.43] and lower serum albumin levels (OR 0.92, 95% CI 0.86-0.98) were associated with failure to commence PD. Predialysis AVF creation rates were 79% of those who chose and started HD, 39% of those who chose PD but started HD and 50% of those in the undecided group who commenced HD. CONCLUSIONS: AVF creation rates prior to HD start were lower in those patients with no documented dialysis modality choice and in those who failed to commence PD. Cardiovascular disease and lower serum albumin levels were associated with failure to start PD. Further work to ensure the efficacy of RRT modality choice pathway and to better predict those patients who will fail to commence PD is necessary, so that dialysis start can be 'optimized' with AVF creation in high-risk groups.

Dedication of a nurse to educating suboptimal haemodialysis starts improved transition to independent modalities of renal replacement therapy.

BACKGROUND: Haemodialysis (HD) initiation is unplanned in up to 50% of patients, mainly due to late diagnosis and/or late nephrology referral. In these patients, time does not permit the multidisciplinary predialysis care that is associated with increased independent renal replacement therapy (RRT) modality choice and better access to kidney transplantation. We established a Renal Triage Nurse (RTN) position to educate suboptimal HD starts and to facilitate transition to independent modalities of RRT. METHODS: Adult patients starting HD from 1 January 2005 to 31 December 2008 with < 180 days nephrology follow-up and surviving at least 180 days were included (suboptimal HD starts). The RTN educated suboptimal HD starts beginning in December 2006. Patients initiating RRT via the multidisciplinary predialysis clinic (MPC) were included for comparison. Multivariable logistic regression was used to determine the association between being seen by the RTN and achieving independent modalities of RRT. RESULTS: There were 176 patients: 78 suboptimal HD starts (38 of these were educated by the RTN) and 98 patients initiated RRT after a minimum 180-day follow-up at the MPC. Of the RTN patients, 27.8% switched to independent RRT modalities (peritoneal dialysis n = 7, home haemodialysis n = 1, transplant n = 2). RTN patients were more likely to live alone (33.3% versus 10.8%, P = 0.02) and to have cerebrovascular disease (25.0% versus 7.1%, P = 0.03); however, adjusting for these variables, suboptimal HD starts seen by the RTN were more likely to transition to independent RRT (OR 3.75, 95% CI 1.08-13.05) than those not seen. The proportion starting on an independent modality via the MPC was 39.8%. The RTN achieved a rate of independent RRT not statistically different to that observed in patients starting RRT via the MPC (OR 0.74, 95% CI 0.19-2.94 in multivariable analysis). CONCLUSIONS: Addition of the RTN to the HD care team facilitated transition to independent modalities of RRT in suboptimal HD starts. This standardized approach to the care of such patients should be considered in HD units where suboptimal HD starts are common.

The arteriovenous access stage (AVAS) classification.

BACKGROUND: Key anatomical factors mean that individuals needing arteriovenous access are unique and have different possibilities for fistula creation. The aim of this article is to describe a new classification system for all patients needing haemodialysis vascular access in the upper extremity with the purpose to simplify sharing the information about suitability for surgical access creation depending on vascular anatomy. METHODS: According to the patient's vascular anatomy in right and left superior extremities, patients were separated into three arteriovenous access stages (AVAS). The AVAS was validated by three blinded observers using a sample of 70 upper limb arteriovenous maps that were performed using ultrasound on patients referred for vascular access assessment. A sample size calculation was performed and calculated that for three observers, a minimum of 67 maps were required to confirm significant agreement at a Kappa value of 0.9 (95% confidence interval 0.75-0.99). RESULTS: The Kappa value for inter-rater reliability using Fleiss' Kappa coefficient was 0.94 and all patients fitted into the AVAS classification system. CONCLUSION: The AVAS classification system is a simplified way to share information about vascular access options based on a patient's vascular anatomy with high inter-rater reliability.

A UK Expert Consensus Approach for Managing Symptomatic Arteriovenous Fistula (AVF) Stenosis in Haemodialysis Patients.

PURPOSE: Stenoses in mature arteriovenous fistulas (AVFs) are common and can negatively impact on the quality of haemodialysis, the longevity of the AVF and lead to debilitating symptoms. Multiple treatment options exist; however, management can vary between different centres. We aimed to establish multidisciplinary consensus on the optimal stepwise application of interventions based on evidence and consensus. METHODS: A modified Delphi process was conducted with 13 participants from hospitals across the UK, all of whom have high-volume dialysis access practice. RESULTS: The usual intervention to rectify de novo stenoses of mature AVFs is fistuloplasty, although surgery for inflow segment stenoses is also clinically acceptable. Appropriate first-line interventions include plain old balloon angioplasty or high-pressure balloon angioplasty; if these fail during the fistuloplasty, consider upsizing the balloon, prolonged balloon inflation or using alternative interventions, such as cutting or scoring balloons and ultra-high-pressure balloons. Alternative or subsequent interventions vary by anatomical site and may require additional multidisciplinary team input. For a stenoses recurring between 3 and 12 months, it is appropriate to consider interventions used de novo, but with a lower threshold for using drug-coated balloons (DCBs) in all regions and for using stent grafts in all regions but inflow segment. Recurrence after 12 months should be treated as a de novo lesion, with DCBs considered if they have been used successfully during previous interventions. CONCLUSIONS: These recommendations aim to provide a practical guide to multidisciplinary teams in order to optimise the use of multiple interventions for rectifying AVF stenoses and provide unified evidence-based practice guidelines.

Five-Year Graft Survival and Clinical Outcomes of 500 Consecutive Cases After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To report the 5-year graft survival and clinical outcomes after Descemet membrane endothelial keratoplasty (DMEK). METHODS: A retrospective, interventional case series was performed at a tertiary referral center. Five hundred eyes of 393 patients that underwent DMEK for Fuchs endothelial corneal dystrophy, bullous keratopathy, failed previous corneal transplants other than DMEK, or other indications were evaluated for graft survival, best-corrected visual acuity (BCVA), endothelial cell density, postoperative complications, and retransplantation rate. RESULTS: Kaplan-Meier analysis demonstrated an estimated survival probability of 0.90 [95% confidence interval, 0.87-0.94] for the entire cohort at 5 years after DMEK. At this time point, 82% of the eyes achieved a BCVA of ≥20/25 (0.8), 54% achieved ≥20/20 (1.0), and 16% achieved ≥20/17 (1.2). BCVA continued to improve from 6 to 36 months after DMEK surgery (P ≤ 0.005) and then remained stable up to 60 months postoperatively (P > 0.08). Preoperative donor endothelial cell density averaged 2530 (±210) cells/mm and decreased by 37% at 6 months, 40% at 1 year, and 55% at 5 years after DMEK surgery (P < 0.001 between all follow-up time points). During the study period, allograft rejection episodes developed in 2.8% of the eyes, primary graft failure occurred in 0.2%, and secondary graft failure in 2.8% of the eyes. Re-keratoplasty was required in 8.8% of the eyes. CONCLUSIONS: Five-year graft survival after DMEK is high, and visual acuity outcomes remain excellent and are accompanied by a low longer-term complication rate.

The changing pattern of adult primary glomerular disease.

BACKGROUND: Published biopsy series have shown geographical and temporal variations in the patterns of primary glomerulonephritis (GN). IgA nephropathy is the most common type of GN in most European studies, but there is evidence suggesting that focal segmental glomerulosclerosis (FSGS) is increasingly common in the USA in all ethnic groups. We report the analysis of 30 years of native renal biopsies and the temporal pattern of primary glomerular disease in a single United Kingdom (UK) region. METHODS: All 1844 adult native kidney biopsies for 30 years (1976-2005 inclusive) were analysed. The data were divided into three 10-year time frames, and trends in the biopsy rate and diagnosis of primary glomerular disease were considered. RESULTS: Biopsy rates increased significantly from 2.02 to 7.08 per hundred thousand population per year (php/year) (chi(2) = 55.9, P < 0.001), and the mean patient age at biopsy rose from 33 to 49 years over the study period (F = 58, P < 0.001). Primary GN was documented in 49% of biopsies; the most common diagnoses within this group were IgA nephropathy (38.8%), membranous nephropathy (29.4%), minimal change disease (9.8%), membranoproliferative GN type 1 (9.6%) and FSGS (5.7%). There was a significant increase in the proportion of IgA nephropathy (chi(2) = 9.6, P = 0.008) and a decrease in membranous nephropathy (chi(2) = 7.2, P = 0.03) over time. The population incidence of FSGS was low and unchanged at 0.18 php/ year from 1986 to 2005. CONCLUSIONS: Consistent with several other European studies, IgA nephropathy was the most common primary glomerular disease in this UK region. The diagnosis of FSGS was uncommon with no evidence of a rise in incidence.

Patient factors and haemodialysis arteriovenous fistula outcomes.

Arteriovenous fistulas (AVF) improve survival and morbidity for most haemodialysis (HD) patients. Are they better for all patients? In the enthusiastic pursuit of AVFs for all, concerns have been raised regarding high primary AVF failure rates, continued high incident central venous catheter (CVC) use in some countries, and the limited life expectancy of some HD patients. "Fistula first" is changing to "catheter last". The focus must be on decreasing AVF failure to mature and decreasing incident CVC use. An optimal outcome should be sought for each individual patient, and multiple failed attempts at AVF creation avoided.

Arterial stiffness and arteriovenous fistula failure of maturation.

PURPOSE: Increased arterial stiffness is a common finding in patients with end-stage renal disease. Following creation of an arteriovenous fistula (AVF), appropriate dilation of the feeding artery must occur to facilitate AVF maturation. Arterial stiffness may impair the arterial dilation required to facilitate AVF development and contribute to subsequent failure to mature (FTM). The aim of this pilot study was to investigate the association between measurements of central and peripheral arterial stiffness, and AVF FTM. METHODS: Patients undergoing AVF creation in a single centre (Belfast City Hospital, UK) between January and December 2015 were invited to have their carotid-femoral pulse wave velocity (PWV), brachial-radial PWV and augmentation index (AI) measured prior to AVF creation. Subsequent AVF outcomes were identified. RESULTS: Fifty-nine patients who had an AVF procedure were included in the final analysis (mean age 62 years); 50.8% had diabetes mellitus. The mean pre-operative arterial diameter for all AVFs was 3.9 mm. Average values for carotid-femoral PWV were 9.5 m/s, brachial-radial PWV 7.7 m/s and AI 25.6%. Using logistic regression, these arterial stiffness parameters did not predict AVF FTM: carotid-femoral PWV (P = 0.20), brachial-radial PWV (P = 0.13), AI (P = 0.50). CONCLUSIONS: This is the largest study to date exploring the association between arterial stiffness and AVF FTM. The measured central and peripheral arterial stiffness parameters were not associated with AVF FTM. Further research is needed to define if non-invasive arterial physiological measurements would be clinically useful in the prediction of AVF FTM.

Investigating clinical predictors of arteriovenous fistula functional patency in a European cohort.

BACKGROUND: Arteriovenous fistula (AVF) failure to mature (FTM) rates contribute to excessive dependence on central venous catheters for haemodialysis. Choosing the most appropriate vascular access site for an individual patient is guided largely by their age, co-morbidities and clinical examination. We investigated the clinical predictors of AVF FTM in a European cohort of patients and applied an existing clinical risk prediction model for AVF FTM to this population. METHODS: A prospective cohort study was designed that included all patients undergoing AVF creation between January 2009 and December 2014 in a single centre (Belfast City Hospital) who had a functional AVF outcome observed by March 2015. RESULTS: A total of 525 patients had a functional AVF outcome recorded and were included in the FTM analysis. In this cohort, 309 (59%) patients achieved functional AVF patency and 216 (41%) patients had FTM. Female gender [P < 0.001, odds ratio (OR) 2.03 (CI 1.37-3.02)] and lower-arm AVF [P < 0.001, OR 4.07 (CI 2.77-5.92)] were associated with AVF FTM. The Lok model did not predict FTM outcomes based on the associated risk stratification in our population. CONCLUSIONS: In this European study, female gender was associated with twice the risk of AVF FTM and a lower-arm AVF with four times the risk of FTM. The FTM risk prediction model was not found to be discriminative in this population. Clinical risk factors for AVF FTM vary between populations; we would recommend that units investigate their own clinical predictors of FTM to maximize AVF functional patency and ultimately survival in dialysis patients. Clinical predictors of AVF FTM may not be sufficient on their own to improve vascular access functional patency rates.

Optimizing outcomes in the elderly with end-stage renal disease--live long and prosper.

BACKGROUND: The elderly form an expanding proportion of patients with chronic kidney disease and end-stage renal disease worldwide. The increased physiological frailty and functional morbidity associated with the aging process pose unique challenges when planning optimal management of an older patient needing renal replacement therapy (RRT). AIMS: This position paper discusses current evidence regarding the optimal management of end-stage renal disease in the elderly with an emphasis on hemodialysis since it is the most common modality used in older patients. Further research is needed to define relevant patient-reported outcome measures for end-stage renal disease including functional assessments and psychological impacts of various forms of RRT. For those older patients who have opted for dialysis treatment, it is important to study the strategies that encourage greater uptake of home-based dialysis therapies and optimal vascular access. CONCLUSIONS: The management of advanced chronic kidney disease in the elderly can be challenging but also extremely rewarding. The key issue is adopting a patient-focused and individualized approach that seeks to achieve the best outcomes based on a comprehensive holistic assessment of what is important to the patient.

The challenges of antiphospholipid syndrome: experience from diagnosis to self-care.

A young woman presented to our unit with pancreatitis and acute kidney injury (AKI) 4 weeks after initiation of an oral contraceptive. She subsequently developed seizures due to posterior reversible encephalopathy syndrome and required ongoing haemodialysis for oliguric AKI. Routine antiphospholipid antibody screen was normal, but arterial and venous thromboses were identified on renal biopsy. Further coagulation studies identified an antiphospholipid-dependent inhibitor confirming the suspected diagnosis of antiphospholipid syndrome. She remained seizure free with control of hypertension and was established on anticoagulation. She remained haemodialysis dependent performing this independently at a new self-care unit. She provides us with valuable insights into her experience encouraging us to reconsider our current methods of education and communication in our younger population of patients living with chronic disease.