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.

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 prospective cohort study of predictors of upper extremity arteriovenous fistula maturation.

BACKGROUND: A substantial proportion of arteriovenous fistulas fail to function adequately for hemodialysis. Existing studies on arteriovenous fistula failure prediction assess patency rather than the more clinically relevant outcome of arteriovenous fistula function. We hypothesized that preoperative demographic and ultrasound characteristics, and postoperative assessment by an experienced vascular access nurse would predict which arteriovenous fistulas will not function adequately for hemodialysis. METHODS: Prospective cohort study of chronic kidney disease patients at a tertiary care center in Vancouver, Canada, with arteriovenous fistula creation between 2009 and 2013. Pre and postoperative clinical assessment and ultrasound blood vessel mapping were performed by an experienced vascular access nurse. The primary outcome was failure to achieve a fistula used successfully for hemodialysis (FUSH). RESULTS: Outcomes were assessed in 200 patients; 123 (61.5%) arteriovenous fistulas were radiocephalic. Overall, 26.5% of arteriovenous fistulas had FUSH failure (34.1% of lower arm vs 14.3% of upper arm, p = 0.002). Univariate predictors of FUSH failure included older age (p = 0.03), female sex (p = 0.05), smaller arterial diameter (p ⩽ 0.001), lower artery volume flow (p = 0.04), and smaller vein diameter (p = 0.01). In multivariable analysis, artery diameter (odds ratio: 0.44, 95% confidence interval: 0.28-0.68) most significantly predicted FUSH failure. Vascular access nurse assessment 6 weeks postoperatively correctly predicted outcome in 83.8% of FUSH and 65.0% of FUSH failure. CONCLUSION: Smaller artery diameter most strongly predicted FUSH failure. Early postoperative nursing assessment was more useful to predict FUSH than FUSH failure, and as such was insufficient in determining which arteriovenous fistulas should be abandoned as many predicted to fail could be salvaged with further intervention.

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.

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.

Live kidney donation from a person with haemophilia.

There are many documented cases of a person with haemophilia successfully receiving a solid organ transplant, including liver and kidney. However, there is no literature reporting live organ donation by a person with haemophilia. Presumably, this is because the associated risks of excessive bleeding, inhibitor development after a period of intensive treatment with factor replacement and the possibility of variant Creutzfeldt-Jakob disease transmission in those previously treated with blood products, are considered excessive. This case describes a 24-year-old man who was diagnosed with mild haemophilia A during his pretransplant work up as a potential live kidney donor to his sister. He then went on to successfully donate his kidney, without complications. To the best of our knowledge, this is the first description of a person with haemophilia being a living organ donor.

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.

Nebulized pentamidine-induced acute renal allograft dysfunction.

Acute kidney injury (AKI) is a recognised complication of intravenous pentamidine therapy. A direct nephrotoxic effect leading to acute tubular necrosis has been postulated. We report a case of severe renal allograft dysfunction due to nebulised pentamidine. The patient presented with repeated episodes of AKI without obvious cause and acute tubular necrosis only on renal histology. Nebulised pentamidine was used monthly as prophylaxis for Pneumocystis jirovecii pneumonia, and administration preceded the creatinine rise on each occasion. Graft function stabilised following discontinuation of the drug. This is the first report of nebulized pentamidine-induced reversible nephrotoxicity in a kidney allograft. This diagnosis should be considered in a case of unexplained acute renal allograft dysfunction.

Acute stroke in a patient with advanced uraemia: should thrombolysis be given?

A 65-year-old gentleman with stage 5 chronic kidney disease developed an acute posterior circulation stroke, which was treated with intravenous thrombolytic therapy. This was complicated by a retroperitoneal haemorrhage. The patient made an excellent neurological recovery and was discharged to home, independently mobile, having been established on haemodialysis. This case highlights the challenges of managing acute ischaemic stroke in patients with advanced uraemia.

Improving recognition of inherited renal disease.

Polycystic kidney disease and Alport's syndrome are the most common causes of inherited renal disease in the UK. An average GP practice is likely to have at least six patients with autosomal dominant polycystic kidney disease (ADPKD). The disorder is characterised by the formation of fluid-filled cysts in the kidneys resulting in progressive renal impairment. Mutations in two genes have been identified. The PKD1 gene abnormality is responsible for 85% of cases of ADPKD, patients with PKD2 mutations typically present later and progress more slowly. Patients with ADPKD can present with a positive family history, hypertension, flank pain, haematuria, renal insufficiency or proteinuria. The diagnosis has traditionally been based on ultrasound imaging. Screening will reduce the incidence of a late diagnosis when renal disease is advanced but a normal ultrasound scan in those under 30 years old is not conclusive. It is not recommended that children are screened. The key to minimising the rate of progressive disease is tight BP control. ACE inhibitors are recommended as the initial antihypertensive agent unless contraindicated. Alport's syndrome is a disorder characterised by abnormal type IV collagen which is found in the kidney, eyes, skin and ears. Around one in ten practices are likely to have a patient with Alport's syndrome. Eighty per cent of patients have the X-linked form of the disease. All first-degree relatives of a patient with confirmed Alport's syndrome should be offered screening. The combination of reduced hearing and urinary abnormalities in a young boy should alert GPs to consider this as a possible diagnosis and initiate referral. Diagnosis can be confirmed by renal or skin biopsy.