Dural arteriovenous fistulae in a 6-year-old girl with trisomy 21 and congenital heart disease.

Dural arteriovenous fistula (DAVF) represents a pathological group of intracranial shunts arising from the dural artery to venous sinus and veins. Childhood-onset DAVF is generally considered to be poor in prognosis, whereas only limited information is available for the onset and long-term outcomes. We herein report a Japanese girl with trisomy 21, large ventricular septal defects, and pulmonary vein stenosis, for which a transcatheter stent had been placed after birth. At age 6 years, she developed bacterial meningitis due to S. pneumoniae, leading to the diagnosis of venous sinus thrombosis and multiple intracranial shunts. Cerebral angiography identified multiple shunts arising from the middle meningeal arteries to the superior sagittal sinus and a concurrent reflux to cortical vein. Endovascular embolization successfully occluded the shunts without neurovascular complications over 24 months. This report first demonstrates the favorable outcome of DAVF in a pediatric patient with trisomy 21 after the catheter intervention. For children at a risk for intracranial thrombosis, preemptive neurovascular evaluation and transcatheter intervention provide a chance of early diagnosis of DAVF to improve their survival and neurologic outcome.

Effect of no-touch versus conventional technique on arteriovenous fistula outcomes: a randomised controlled trial.

BACKGROUND: Autologous arteriovenous fistulae (AVFs) are the best type of vascular access in patients with kidney failure. However, the conventional technique has a high failure rate. We performed a randomised controlled trial to investigate whether the no-touch technique has a higher maturation and patency rate than that of the conventional technique for creating AVFs. METHODS: This study was a single-centre randomised controlled trial involving patients with kidney failure requiring an AVF for haemodialysis access. A total of 179 patients undergoing their first radial artery-cephalic fistula were randomized 1:1 to the no-touch technique (n = 90) or conventional technique (n = 89). The maturation and patency rate of the two techniques were compared and analysed. RESULTS: The preoperative baseline data showed no differences between groups. When comparing the no-touch technique to the conventional technique, the maturation rate was 93% vs. 89% and the 1-year primary function patency was 72% vs. 62%, respectively. Factors associated with AVF failure included age > 55 years (OR = 2.417, 95% CI 1.242-4.703), female sex (OR = 2.149, 95% CI 1.099-4.202), and vein diameter ≤ 1.8 mm (OR = 3.664, 95% CI 1.714-7.832). For patients with small veins the maturation rate was 92.98% vs. 80% and the 1-year primary function patency was 68.42% vs. 40% for the no-touch technique and conventional technique, respectively. CONCLUSIONS: The no-touch technique has a higher maturation and patency rate than the conventional technique for creating an autologous AVF, especially in patients with small veins. This technique may provide a better outcome for patients with small cephalic veins.

Disturbed flow in the juxta-anastomotic area of an arteriovenous fistula correlates with endothelial loss, acute thrombus formation, and neointimal hyperplasia.

Clinical failure of arteriovenous neointimal hyperplasia (NIH) fistulae (AVF) is frequently due to juxta-anastomotic NIH (JANIH). Although the mouse AVF model recapitulates human AVF maturation, previous studies focused on the outflow vein distal to the anastomosis. We hypothesized that the juxta-anastomotic area (JAA) has increased NIH compared with the outflow vein. AVF was created in C57BL/6 mice without or with chronic kidney disease (CKD). Temporal and spatial changes of the JAA were examined using histology and immunofluorescence. Computational techniques were used to model the AVF. RNA-seq and bioinformatic analyses were performed to compare the JAA with the outflow vein. The jugular vein to carotid artery AVF model was created in Wistar rats. The neointima in the JAA shows increased volume compared with the outflow vein. Computational modeling shows an increased volume of disturbed flow at the JAA compared with the outflow vein. Endothelial cells are immediately lost from the wall contralateral to the fistula exit, followed by thrombus formation and JANIH. Gene Ontology (GO) enrichment analysis of the 1,862 differentially expressed genes (DEG) between the JANIH and the outflow vein identified 525 overexpressed genes. The rat jugular vein to carotid artery AVF showed changes similar to the mouse AVF. Disturbed flow through the JAA correlates with rapid endothelial cell loss, thrombus formation, and JANIH; late endothelialization of the JAA channel correlates with late AVF patency. Early thrombus formation in the JAA may influence the later development of JANIH.NEW & NOTEWORTHY Disturbed flow and focal endothelial cell loss in the juxta-anastomotic area of the mouse AVF colocalizes with acute thrombus formation followed by late neointimal hyperplasia. Differential flow patterns between the juxta-anastomotic area and the outflow vein correlate with differential expression of genes regulating coagulation, proliferation, collagen metabolism, and the immune response. The rat jugular vein to carotid artery AVF model shows changes similar to the mouse AVF model.

Role of Doppler Evaluation in Assessing the Maturation of the Arteriovenous Fistula for Hemodialysis: An Observational Study.

Introduction Arteriovenous fistulas (AVFs) are the preferred type of vascular access for hemodialysis due to their lower risk of complications. This study aimed to determine the role of Doppler evaluation in assessing AVF. Materials and methods We conducted an 18-month prospective observational study of 33 hemodialysis patients who underwent a procedure for the creation of AVF at the Department of Radio-Diagnosis at Sri Devaraj Urs Academy of Higher Education and Research. Patients were evaluated using color Doppler ultrasound. Participants underwent a careful history and clinical examination to diagnose the disease. All relevant parameters were documented in a structured study proforma. AVF maturation was assessed postoperatively at four weeks using Doppler ultrasound color flow evaluation by looking for vascular components (flow volume, vein, and arterial diameter). Data were analyzed using CoGuide V 1.0.3 Statistical Software (CoGuide, Bangalore, India). Results A total of 33 patients, with a mean age of 54.6 ± 7.8 years, were evaluated. Of the 33 participants, 24 (72.7%) were male, and nine (27.3%) were female. The majority (47%, n=16) of participants had diabetes mellitus, eight (24%) had hypertension, and 10 (29%) had both diabetes mellitus and hypertension. A brachiocephalic fistula was created in 45.5% of participants, and 33.33% had radiocephalic anastomoses. Five participants were diagnosed with AVF complications: two had a pseudoaneurysm, and three had a cephalic vein thrombus. Clinical and demographic characteristics (age, vascular components, and complications) were not significantly related to AVF maturation. Conclusions Doppler ultrasound plays an important role in selecting vessels for AVF preoperatively and assessing AVF maturation postoperatively, thus reducing the primary fistula failure rate. The findings suggest that Doppler evaluation can be a reliable tool for assessing AVF maturation and predicting surgical success, which could help healthcare providers make informed decisions about the best course of treatment for their patients. Continued research is warranted in this area to further understand the role of Doppler ultrasound in evaluating AVF surgery.

Hormone Concentration Measurement in Intracranial Dural Arteriovenous Fistulae.

OBJECTIVE: Intracranial dural arteriovenous fistulae (DAVFs) represent a subset of cerebral vascular malformations associated with significant morbidity and mortality. In Japan, DAVF exhibits sex-based differences in anatomical distribution, with female predominance in the cavernous sinus (CS) and male predominance in the transverse sinus (TS). Nevertheless, the pathophysiology of DAVF is not fully understood, and hormonal influences are hypothesized to play a role in its development. This study aimed to investigate changes in the concentrations of sex steroid hormones between intracranial and peripheral sampling sites in patients with CS- and TS-DAVF. METHODS: We recruited 19 patients with CS-DAVF (n = 12) and TS-DAVF (n = 7) in this study. Blood hormone measurements were obtained from peripheral and jugular bulb samples during endovascular intervention. Hormone concentrations were analyzed using enzyme-linked immunosorbent assay kits, and statistical analyses were performed. RESULTS: Our study revealed a higher prevalence of CS-DAVF in females and TS-DAVF in males, which is consistent with previous studies. Estradiol concentration was significantly lower in the jugular bulb compared with in the periphery in both patients with CS- and TS-DAVF. This decrease in estradiol was observed irrespective of the patient's sex and independent of follicle-stimulating hormone levels. CONCLUSIONS: These findings indicate a local decrease in estradiol levels within the intracranial vasculature of patients with DAVF. This suggests a potential multifactorial role of estradiol in the pathomechanism of DAVFs, warranting further investigation to understand its influence on DAVF formation and potential targeted therapies, thereby enhancing patient outcomes.

New aneurysm formation after endovascular embolization of a vertebral epidural AV fistula: a rare sequelae of NF AV fistulae.

Background: Neurofibromatosis type 1 (NF-1) is a dominant genetic disorder often accompanied by lesions of the neurovascular system. Patients with NF-1 are predisposed to unique vertebral artery fistula (AVF). Case description: We report on a rare case of multiple neurovascular abnormalities in a 47-year-old man with neurofibromatosis. He was admitted due to a sudden headache and was found to have suffered a subarachnoid hemorrhage from a left vertebral arteriovenous fistula. He underwent two endovascular procedures complicated by a delayed extraspinal mass 7 days after treatment. Angiography revealed a new vascular abnormality, and although we performed another embolization, it failed to respond to further embolization. Conclusion: Vascular abnormalities in patients with NF-1 can be complex. Endovascular intervention remains feasible for NF-1 related AVF, however, partial occlusion of the fistula should be avoided to limit and iatrogenic damage to the blood vessels.

Association between vascular access type and depression in hemodialysis patients.

INTRODUCTION: Hemodialysis is the most common treatment used for end-stage kidney disease (ESKD) patients and an arteriovenous fistula (AV) fistula is the preferred vascular access. The goal of our study was to investigate potential associations between vascular access type and depression. METHODS: This was a cross-sectional survey of 180 patients receiving maintenance hemodialysis. The Beck Depression Inventory was used to assess degree of depression. Demographic factors, treatment details, and laboratory values were obtained from the hospital medical record. FINDINGS: Fifty-two percent (n = 93) of the patients were being dialyzed using an AV fistula and 48% (n = 87) via a tunneled cuffed catheter. No significant differences were found between access type use in terms of gender (p = 0.266), presence of diabetes, hypertension, or peripheral artery disease (p = 0.409, p = 0.323, p = 0.317; respectively). The prevalence of Beck Depression Inventory scores greater than 14 (marking presence of depression) was significantly higher in the patients being dialyzed with a tunneled cuffed catheters (61%) compared to patients dialyzed with an AV fistula (36%) (p = 0.001). DISCUSSION: We found statistically higher depression scores among patients receiving hemodialysis with a tunneled cuffed catheter.

Endovascular creation of hemodialysis arteriovenous fistulae: the current status and future perspective-a literature review.

Background and Objective: End-stage renal disease (ESRD) is increasingly prevalent among Americans. Traditionally, the gold standard of dialysis fistulae creation is surgical arteriovenous fistulae (AVF), which is preferred over central venous catheter (CVC) and arteriovenous graft (AVG). However, it is associated with many challenges, particularly its high primary failure rate, which is partially attributed to neointimal hyperplasia. Endovascular creation of arteriovenous fistulae (endoAVF) is a recently emerging method, and is thought to circumvent many of the surgical challenges. It is theorized to reduce the peri-operative trauma to the vessel, thus reducing the amount of neointimal hyperplasia. In this article, we aim to review the current status and future perspectives of endoAVF. Methods: An electronic search was performed on MEDLINE and Embase to identify relevant articles from 2015 to 2021. Key Content and Findings: The initial trial data has been promising, resulting in the increased adoption of endoAVF devices in clinical practice. Further, short- and mid-term data has shown that endoAVF has been associated with good maturation rate, re-intervention rate, primary and secondary patency rates. In comparison to historical surgical data, endoAVF has been shown to be comparable in certain aspects. Lastly, endoAVF has been used in an increasing range of clinical applications, including wrist AVF and two-stage transposition procedure. Conclusions: Although current data has been promising, endoAVF is associated with a host of unique challenges, and the current data has mostly been derived from selective patient population. Further studies are required to further assess its usefulness and its role in the dialysis care algorithm.

Thoracolumbar spinal dural arteriovenous fistulae present with longer arteriovenous transit compared to cranial and cervical dural fistulae.

BACKGROUND: Thoraco-lumbar spinal dural arteriovenous fistulae represent a rare subset of central nervous system vascular malformations. One of the unique features of spinal dural arteriovenous fistulae is their extremely low propensity to cause hemorrhage (either parenchymal or subarachnoid), with a distinct clinical presentation of myelopathy secondary to spinal venous congestion. The exact mechanism for this unique presentation is still unclear. METHODS: Following institutional review board approval, we retrospectively analyzed our prospectively maintained database of spinal dural arteriovenous fistulae and cranial (cr) DAVF cases presenting between 2008 and 2021. For all cases, angiograms were reviewed and arteriovenous transit times were calculated. Patient demographics, angiographic features, and clinical and radiological outcomes were assessed. RESULTS: In total, 66 patients presenting with confirmed thoracolumbar spinal dural arteriovenous fistulaes were identified and compared to patients presenting with cervical spinal dural arteriovenous fistulaes (n = 10), ruptured crDAVFs (n = 32) and unruptured crDAVFs (n = 20). Mean age in the target group was 66 ± 13 versus 57-62 in the other groups, p < 0.05 on one-way analysis of variance; with 80% males versus 50%-65% in other groups. Mean arteriovenous transit time in the thoracolumbar group measured 1.98 s ± 0.96 versus 0.25-0.5 s range in other groups (p < 0.0001 on one-way analysis of variance). CONCLUSION: Prolonged arteriovenous transit times may represent a distinct feature of thoracolumbar spinal dural arteriovenous fistulaes. This may, amongst other factors, play a role in the observed lesser likelihood of hemorrhagic complications compared to other dural arteriovenous shunts.

Paradoxical Worsening of Pulmonary Hypertension Following Closure of Arteriovenous Fistula: A Case Report and Literature Review.

This case report presents the atypical instance of a 59-year-old female patient with end-stage renal disease (ESRD) who was initially referred to the pulmonary clinic for evaluation due to a low diffusing capacity of the lung for carbon monoxide (DLCO). Pulmonary hypertension (PH) was suspected, and a subsequent right heart catheterization (RHC) confirmed PH attributed to group 5 PH, leading to the decision to close the unused arteriovenous fistula (AVF) to manage PH. Unexpectedly, a follow-up RHC showed a worsening of PH with elevated pulmonary capillary wedge pressure (PCWP), revealing an additional component of post-capillary group 2 PH. This case emphasizes the significance of recognizing a low DLCO as a potential trigger for PH assessment, especially in patients with comorbidities like ESRD. Furthermore, it highlights the unusual yet critical occurrence of PH exacerbation following AVF closure.

Novel classification of proximal forearm perforator vein in the planning and creation of percutaneous and surgical Gracz-type arteriovenous fistulae.

BACKGROUND: The perforator vein determines whether it is feasible to create a percutaneous (pAVF) or surgical "Gracz-type" arteriovenous fistula (sAVF). Creating a standard anatomic classification of the antecubital region is beneficial to both the selection of the appropriate device and/or procedure and technical outcomes. Accordingly, an analysis of a large cohort of patients undergoing pAVF/sAVF was performed, focusing on perforator vein anatomical suitability, and a novel anatomical classification of the antecubital region was developed and proposed. METHODS: Between August 2018 and July 2022, chronic or end-stage kidney disease patients as well as patients anticipated an initiation of apheresis, who were referred for vascular access planning, underwent a standardized evaluation of upper extremities. A vessel mapping summary detailing the vasculature and the access creation plan was completed, indicating the anatomical suitability for sAVF and pAVF (Ellipsys and WavelinQ) techniques. RESULTS: Of 524 patients, 36.5% were female (average age 65 years). 53.2% were on dialysis, 41.6% had diabetes, and 13.2% had a previously failed permanent dialysis access. The anatomy for successful pAVF creation was judged to be suitable in 54% of patients for an Ellipsys-pAVF, and 29.8% for WavelinQ-pAVF. Of the WavelinQ group, 54.4% had suitable anatomy for ulnar, 26.9% for radial, and 18.6% for both ulnar/radial anastomoses. Additionally, 60.7% had suitable anatomy for pAVF creation with at least one of the systems, while 22.5% were suited for both types of pAVF-systems. 80.3% were candidates for creation of a Gracz-AVF. CONCLUSION: Overall, we found that about 60% of patients are likely candidates for a pAVF, with 80% being candidates for creation of a Gracz-AVF. Male patients have significantly higher suitability for most types of AVF creation, and younger patients are more suitable for Ellipsys-pAVF and RCAVFs. Most importantly, a universal classification of perforator vein was developed, which is indispensable in modern vascular access planning.

Patient-specific computational haemodynamics associated with the surgical creation of an arteriovenous fistula.

Despite arteriovenous fistulae (AVF) being the preferred vascular access for haemodialysis, high primary failure rates (30-70%) and low one-year patency rates (40-70%) hamper their use. Furthermore, AVF creation has been associated with haemodynamic changes causing maladaptive cardiac remodelling leading to cardiovascular (CV) complications. In this study, we present a new workflow for characterising the haemodynamic profile prior to and following surgical creation of a successful left radiocephalic AVF in a 20-year-old end-stage kidney disease patient. The reconstructed vasculature was generated using multiple ferumoxytol-enhanced magnetic resonance angiography (FeMRA) datasets. Computational fluid dynamics (CFD) simulations utilising a scale-resolving turbulence model were completed to investigate the changes in the proximal haemodynamics following AVF creation, in addition to the post-AVF juxta-anastomosis flow patterns, which is impractical to obtain in-vivo. Following AVF creation, a significant 2-3-fold increase in blood flow rate was induced downstream of the left subclavian artery. This was validated through comparison with post-AVF patient-specific phase-contrast data. Proximal to the anastomosis, the increased flow rate yielded an increase in time-averaged wall shear stress (WSS), which is a key marker of adaptive vascular remodelling. In the juxta-anastomosis region, the success of the AVF was discussed with respect to the National Kidney Foundation's vascular access guidelines, where the patient-specific AVF met the flow rate and geometry criterion. The AVF venous diameter exceeded 6mm and the venous flow rate surpassed 600mL/min. This workflow may potentially be significant clinically when applied to multi-patient cohorts, with population-wide patient-specific conclusions being ascertained for the haemodynamic assessment of AVFs and improved surgical planning.

Pulmonary Arteriovenous Fistulae After Fontan Operation: Incidence, Clinical Characteristics, and Impact on All-Cause Mortality.

Background: The Fontan operation is a surgical procedure used in children with univentricular hearts. Pulmonary arteriovenous fistulae (PAVF) is a major complication after a Fontan operation. However, the incidence and related clinical pathophysiology of PAVF remain unclear. Purpose: This study aimed to clarify the incidence of PAVF, its clinical characteristics, and its influence on all-cause mortality. Methods and Results: We serially assessed the presence of PAVF using pulmonary artery angiography and/or contrast echocardiography during catheterization in 391 consecutive patients who underwent the Fontan procedure and compared the results with the Fontan pathophysiology and all-cause mortality. PAVF developed in 36 patients (9.2%), including 30 diffuse- and six discrete-PAVF types. The PAVF-free rates at 1, 5, 10, 15, 20, and ≥25 years after Fontan operation were 97, 96, 93, 88, 87, and 83%, respectively. The mean arterial blood oxygen saturation (SaO2) in patients with diffuse PAVF at each corresponding postoperative stage were 90, 91, 91, 91, 89, and 88%, respectively, indicating lower SaO2 levels than those in patients without PAVF (all p < 0.01). However, there was no difference in the SaO2 levels between patients with discrete PAVF and those without PAVF. During a median follow-up period of 2.9 years after the last catheterization, 31 patients, including 12 patients with PAVF, died. Patients with PAVF, especially those with diffuse PAVF, had a higher mortality rate (p = 0.01) than those without PAVF (hazard ratio: 3.6, 95% confidence interval: 1.6-7.8, p = 0.0026). Conclusion: Patients who underwent Fontan surgery had an increased incidence of PAVF as they aged. Discrete PAVF did not influence SaO2 or mortality, whereas the presence of diffuse PAVF caused hypoxia and was associated with all-cause mortality.

Bioinformatics identifies predictors of arteriovenous fistula maturation.

BACKGROUND: Arteriovenous fistulae (AVF) are the preferred access for hemodialysis but still have poor rates of maturation and patency limiting their clinical use. The underlying mechanisms of venous remodeling remain poorly understood, and only limited numbers of unbiased approaches have been reported. METHODS: Biological Gene Ontology (GO) term enrichment analysis and differentially expressed genes (DEG) analysis were performed for three AVF datasets. A microRNA enrichment analysis and L1000CDS2 query were performed to identify factors predicting AVF patency. RESULTS: The inflammatory and immune responses were activated during both early and late phases of AVF maturation, with upregulation of neutrophil and leukocyte regulation, cytokine production, and cytokine-mediated signaling. In men with failed AVF, negative regulation of myeloid-leukocyte differentiation and regulation of macrophage activation were significantly upregulated. Compared to non-diabetic patients, diabetic patients had significantly reduced immune response-related enrichment such as cell activation in immune response, regulation of immune-effector process, and positive regulation of defense response; in addition, diabetic patients showed no enrichment of the immune response-regulating signaling pathway. CONCLUSIONS: These data show coordinated, and differential regulation of genes associated with AVF maturation, and different patterns of several pathways are associated with sex differences in AVF failure. Inflammatory and immune responses are activated during AVF maturation and diabetes may impair AVF maturation by altering these responses. These findings suggest several novel molecular targets to improve sex specific AVF maturation.

Transarterial embolization for falx dural arteriovenous fistula through the artery of Davidoff and Schechter: A case report.

Endovascular transarterial embolization is the standard treatment for the nonsinus-type of dural arteriovenous fistulae. Here, we report a rare case of successful transarterial embolization from the artery of Davidoff and Schechter for falx dural arteriovenous fistulae. A 74-year-old-man was incidentally diagnosed with falx dural arteriovenous fistulae during head magnetic resonance imaging. Results revealed dilatation of the cortical veins in the right occipital lobe. Angiographically, falx dural arteriovenous fistula was observed to be fed by the right middle meningeal artery, right occipital artery, right posterior meningeal artery, and the artery of Davidoff and Schechter (Borden type III). However, due to the tortuosity, the first transarterial embolization surgery through the middle meningeal artery, occipital artery, and posterior meningeal artery was unsuccessful. Therefore, the second transarterial embolization was performed through the artery of Davidoff and Schechter. Arteriovenous fistulae disappeared after administering Onyx injections through the artery of Davidoff and Schechter. Based on our findings, the artery of Davidoff and Schechter can be an approach route to treat dural arteriovenous fistulae. Moreover, the most important point of transarterial embolization procedures through the artery of Davidoff and Schechter is to navigate the microcatheter along the falx.

The effect of percutaneous transluminal angioplasty in the treatment of autogenous arteriovenous fistula stenosis and influencing factors of restenosis/loss of function after PTA / 中国医师杂志

Objective:To analyze the effect of percutaneous transluminal angioplasty (PTA) in the treatment of autogenous arteriovenous fistula (AVF) stenosis and influcing factors of restenosis/loss of function after PTA.Methods:The medical records of 104 patients with AVF stenosis treated by PTA in People′s Hospital of Huadu District from March 2019 to July 2020 and the 1-year follow-up were retrospectively analyzed. Kaplan-meier curves were used to analyze the primary patency rates at 3 months, 6 months and 1 year. COX regression was used to analyze the influencing factors of restenosis/loss of function after PTA.Results:The primary patency rates of AVF at 3, 6 and 12 months after PTA were 86.2%, 83.2% and 64.7%, respectively. Guide wire entry into the distal end of radial artery, the use of two balloons in stepwise mode, postoperative dilatation diameter, and dialysis blood flow after PTA were independent risk factors for restenosis/loss of fuction after PTA for AVF stenosis (all P<0.05). Conclusions:The guide wire into the distal end of the artery and passive use of more than two balloons are important factors affecting AVF restenosis/loss of function after PTA .

Early Results Using N-Terminal pro-B-Type Natriuretic Peptide (pro-BNP) as a Biomarker for the Efficacy of Secondary Extension Technique (SET) in Improving Myocardial Function in Dialysis Patients With High Flow Fistulas.

BACKGROUND: The association of dialysis fistulas and heart failure is believed to be due to high cardiac output. N-terminal pro-B-Type Natriuretic Peptide (pro-BNP) which is secreted by the cardiac ventricles in response to excessive stretching of the myocytes has been used as a marker of heart failure with 90% sensitivity. We report our early experience using pro-BNP levels to test the efficacy of the novel 'secondary extension technique' (SET) in improving myocardial function by reducing fistula flow. METHODS: Eleven patients with high fistula flows (>3000 mL/m, all brachio-cephalic) and raised pro-BNP underwent SET between 2011 and 2015. SET involves extending the anastomosis from brachial to either proximal radial or ulnar arteries. We measured pro-BNP levels, fistula flow and clinical improvements both pre and post operatively. RESULTS: SET resulted in a median (IQR) flow rate decrease of 57.9 (11.9)% which correlated with a fall in pro-BNP of 69.6 (39)%. Seven of the 11 patients in the series pro-BNP level returned to a normal value at average follow-up of 3 months post SET. All patients had HOF-related symptom resolution post-procedure and remained asymptomatic at last follow-up CONCLUSIONS: Our pilot data suggests that SET is an effective way of reducing fistula flow. It also shows that BNP may be a reliable biomarker in assessing the impact of the technique on cardiac function. These results warrant further investigation in the form of a definitive, multicenter study.

Arteriovenous Fistula-induced Cardiac Remodeling Shows Cardioprotective Features in Mice.

OBJECTIVE---: Arteriovenous fistulae (AVF) placed for hemodialysis have high flow rates that can stimulate left ventricular (LV) hypertrophy. LV hypertrophy generally portends poor cardiac outcomes, yet clinical studies point to superior cardiac-specific outcomes for patients with AVF when compared to other dialysis modalities. We hypothesize that AVF induce physiologic cardiac hypertrophy with cardioprotective features. METHODS---: 9-11 week C57Bl/6 male and female mice were treated with sham laparotomy or an aortocaval fistula via a 25Ga needle. Cardiac chamber size and function were assessed with serial echocardiography, and cardiac CTA. Hearts were harvested at 5 weeks post-operatively, and collagen content assessed with Masson's trichrome. Bulk mRNA sequencing was performed from LV of sham and AVF mice at 10 days. Differentially expressed genes were analyzed using Ingenuity Pathway Analysis (Qiagen) to identify affected pathways and predict downstream biological effects. RESULTS---: Mice with AVF had similar body weight and wet lung mass, but increased cardiac mass compared to sham-operated mice. AVF increased cardiac output while preserving LV systolic and diastolic function, as well as indices of right heart function; all 4 cardiac chambers were enlarged, with slight decrement in relative LV wall thickness. Histology showed preserved collagen density within each of the 4 chambers without areas of fibrosis. RNA sequencing captured 19,384 genes, of which 857 were significantly differentially expressed, including transcripts from extracellular matrix-related genes, ion channels, metabolism, and cardiac fetal genes. Top upstream regulatory molecules predicted include activation of angiogenic (Vegf, Akt1), pro-cardiomyocyte survival (Hgf, Foxm1, Erbb2, Lin9, Areg), and inflammation-related (CSF2, Tgfb1, TNF, Ifng, Ccr2, IL6) genes, as well as the inactivation of cardiomyocyte antiproliferative factors (Cdkn1a, FoxO3, α-catenin). Predicted downstream effects include reduction to heart damage, and increased arrhythmia, angiogenesis, and cardiogenesis. There were no significant sex-dependent differences in the AVF-stimulated cardiac adaptation. CONCLUSIONS---: AVF stimulate adaptive cardiac hypertrophy in wild-type mice without heart failure or pathological fibrosis. Transcriptional correlates suggest AVF-induced cardiac remodeling has some cardioprotective, although also arrhythmogenic features.

Sex Differences in Inflammation During Venous Remodeling of Arteriovenous Fistulae.

Vascular disorders frequently have differing clinical presentations among women and men. Sex differences exist in vascular access for hemodialysis; women have reduced rates of arteriovenous fistula (AVF) maturation as well as fistula utilization compared with men. Inflammation is increasingly implicated in both clinical studies and animal models as a potent mechanism driving AVF maturation, especially in vessel dilation and wall thickening, that allows venous remodeling to the fistula environment to support hemodialysis. Sex differences have long been recognized in arterial remodeling and diseases, with men having increased cardiovascular events compared with pre-menopausal women. Many of these arterial diseases are driven by inflammation that is similar to the inflammation during AVF maturation. Improved understanding of sex differences in inflammation during vascular remodeling may suggest sex-specific vascular therapies to improve AVF success.