Arteriovenous Fistula Research Articles

Magnetic resonance imaging changes in spinal arteriovenous fistulae treated by endovascular means: are they reliable to predict complete cure of the fistula?

Regression or disappearance of MRI abnormalities is usually observed after treatment of spinal dural arteriovenous fistulae (sDAVF). To assess the correlation between spinal MRI (sMRI) changes with sDAVF exclusion and clinical outcome. Imaging data of patients treated with endovascular embolization for sDAVF between 2007 and 2023 were retrospectively analyzed. Spinal cord edema and perimedullary flow voids at baseline and 3-months' follow-up were compared between patients with and without sDAVF persistent occlusion and clinical improvement on the Aminoff and Logue Scale. Twenty-five patients were included in this study. At 3-months' follow-up, regression of spinal cord edema was significantly associated with sDAVF persistent occlusion (P=0.038). The combination of edema and flow voids regression was significantly associated with higher odds of a cured sDAVF (P<0.001) and clinical improvement (P<0.01). Improvement in the combination of the above-mentioned sMRI signs presented high sensitivity (100% (95% CI 78.20%-100%)) and negative predictive value (100% (95% CI 47.82%-100%)) for the detection of sDAVF cure compared with the criterion standard (digital subtraction angiography (DSA)). Patients with both spinal cord edema and flow voids regression at 3 months were more likely to present with a persistent occlusion of sDAVF and clinical improvement after endovascular embolization. Patients without sMRI improvement should be referred for DSA to seek recurrence of sDAVF.

Dural arteriovenous fistula associated with medullary ependymoma: an unusual association

Dural arteriovenous fistula associated with medullary ependymoma: an unusual association

Venous distensibility may be an indicator of early arteriovenous fistula failure, a retrospective single-centre cohort study

Background Arteriovenous-fistula (AVF) are crucial for hemodialysis access, yet they frequently experience early failure. While studies have identified potential patient and clinical risk factors, these findings remain inconsistent. This inconsistency might be attributed to the varying definitions of “early failure”. Our retrospective cohort study aimed to evaluate how common risk factors predict four frequently early-failure criteria: thrombosis/stenosis, <500 ml/min blood flow, <5 mm vein diameter, and ≥6 mm deep vein. We also assessed how well these risk factors predict early failure defined as meeting at least one of these criteria. Additionally, we examined the predictive ability of vein-distensibility, a previously overlooked factor in AVF failure. Methods Consecutive patients with first-time AVF employing standard minimum preoperative artery- and vein-diameters (1.8–2.0 mm) who underwent first Doppler-ultrasound (DUS) at ≤4 months in 2016–2022 were identified. Early AVF failure was defined as the presence of at least one of the following conditions on the first DUS: poor blood flow (Qa), poor vein diameter, poor vein depth, and thrombosis/stenosis. Factors associated with early AVF failure were explored with multivariate analyses. Results 105 patients were eligible and 63 (60%) had an early AVF failure. The only strong predictor of early failure was low vein-distensibility (Odds ratio = 0.57, 95% confidence intervals [CIs] = 0.38–0.83, p = 0.005). Female sex only predicted too-deep veins (Odds ratio = 14.29, 95% CIs = 2.00–100, p = 0.024). Conclusions venous distensibility may be a useful early-failure determinant when minimum preoperative vessel-diameter limits are met. Moreover, the female sex is associated with too-deep AVF veins.

Retrospective clinical study on the efficacy and complications of interventional embolization in the treatment of scalp arteriovenous fistula.

Scalp arteriovenous fistula (AVF) is a rare and intricate vascular anomaly characterized by a direct connection between an artery and a vein, without an intervening capillary system. This anomaly can induce significant local hemodynamic changes and is associated with various complications, such as pain, a pulsatile mass, increasing swelling, and venous hypertension skin ulcerations which may be non-healing. This study aimed to evaluate the efficacy and safety of interventional embolization treatments for scalp AVF at Shandong Provincial Hospital. This retrospective clinical analysis assessed 21 patients who underwent interventional embolization between 2018 and 2024. Patients included were those treated in the vascular surgery department at Shandong Provincial Hospital, who had comprehensive medical records and follow-up data. Treatment methods, outcomes, and complications were thoroughly analyzed through patient medical records. Among the patients studied, direct puncture was the most prevalent treatment method, employed in 42.86% (9/21) of cases, followed by various combinations of arterial, venous, and direct approaches. Ethanol, used in 85.71% (18/21) of the cases, demonstrated its broad efficacy and application in clinical settings. Immediate imaging post-treatment confirmed a cure rate of 85.71% (18/21). The main postoperative complications included swelling, with some patients also experiencing nodules, scabbing, or hair loss. Interventional embolization has proven to be a safe and effective method for managing scalp AVF, significantly minimizing complications. Future research should focus on further optimizing these treatment methods to enhance efficacy and improve patient quality of life.

White matter lesions as a prognostic marker of recurrence in cryptogenic stroke with high-risk patent foramen ovale

PurposeA high-risk patent foramen ovale (PFO) could be the cause of cryptogenic stroke, and an atrial septal aneurysm (ASA) increases the risk of stroke recurrence in cryptogenic stroke patients with a patent foramen ovale (PFO). Factors related to stroke recurrence according to PFO characteristics have not been fully evaluated. MethodsData from a multicenter, observational registry of ischemic stroke patients undergoing transesophageal echocardiography were used for this study. Patients were classified into three groups: high-risk PFO, PFO with large shunt (≥20 microbubbles) or ASA; right-to-left shunt (RLS), RLS including PFO with <20 microbubbles or without ASA, or pulmonary arteriovenous fistula; and negative RLS. Cox proportional hazards regression analysis was used to explore the factors related to stroke recurrence in these three groups. ResultsIn total, 586 patients (185 females; 65.5±13.2 years) were analyzed. In cryptogenic stroke (329 patients) with median follow-up of 4.2 (interquartile range, 1.0–6.1) years, 55 patients had stroke recurrence. The negative RLS, RLS, and high-risk PFO groups included 179, 90, and 60 patients, in which stroke recurrence occurred in 5.3%, 2.5%, and 4.6% per person-year, respectively. In patients with high-risk PFO, the National Institutes of Health stroke scale score (hazard ratio [HR] 1.257 [1.034-1.530]) and periventricular hyperintensity (HR 3.369 [1.103-10.294]) were predictors of stroke recurrence on multivariable Cox hazards analysis, but no factors were related to stroke recurrence in the RLS and negative RLS groups. ConclusionPeriventricular hyperintensity was shown to predict recurrent stroke in patients with a high-risk PFO.

High flow pial arteriovenous fistula with dural sinus malformation of the posterior circulation.

Posterior fossa congenital pial arteriovenous fistulas are rare vascular anomalies associated with high morbidity. These anomalies often present challenges to neurointerventionists due to their complex morphological features. We successfully treated two technically challenging, infratentorial large pial arteriovenous fistulas (AVFs) associated with complete flow steal in the basilar artery. The first case involved an 18-year-old male with a posterior fossa single-hole AVF characterized by dilated venous pouches and retrograde venous reflux. After an unsuccessful initial coiling attempt, this patient was treated using a double microcatheter coiling technique, supported by a large balloon for flow control. The second case involved a 9-month-old infant with a complex two-hole posterior fossa pial AVF and a large venous sac. This patient was treated with coil embolization of the fistula and with balloon protection of the vertebrobasilar junction. Both patients recovered without postoperative complications and showed significant improvement on follow-up. These cases provide valuable insights into the management and characteristics of pial arteriovenous fistulas.

Urine leak and vascular complications following robotic partial nephrectomy: a contemporary single-center experience.

Urine leak (UL) and vascular complications (VC), i.e., pseudoaneurysms and arteriovenous fistulas are well-described complications of robotic-assisted partial nephrectomy (RAPN). Historically, UL incidence ranges from 0.3 to 17% and VC from 0.8 to 5.6%. We report the contemporary experience of UL and VC from a single, high-volume center in cases of RAPN. 447 patients were identified from an IRB-approved Renal Tumor Database of 2174 cases who underwent RAPN from 1/2017 to 5/2023. VC occurred in 9 cases (4 pseudoaneurysms, 1 AV fistula, 4 concurrent AV fistula/pseudoaneurysm), UL occurred in 9 (2.0%), and there was one concurrent case of VC and UL. Collecting-system entry occurred in five VC cases and five UL cases. For VCs, the median nephrometry score and maximal tumor diameter was 8 (IQR 3.0) and 3.8 (0.9)cm, respectively, and 8 (3.0) and 3.7 (1.1)cm for UL cases, respectively. Most complications occurred with tumors ≤ 4mm from the collecting system (n = 7 VC, n = 6 UL). VCs presented after 18 (6.0)days, 6 with gross hematuria; 3 required clot irrigation, 1 required continuous bladder irrigation, and 8 required embolization. No patients required postoperative transfusion. Patients with UL presented after a median of 1 (12)day, with 5 cases detected by elevated creatinine in drain fluid and the remainder detected on routine ultrasound. The duration of UL was 13 (41)days with only 2 cases requiring stenting and one case requiring a drainage catheter. No patients required kidney re-operation or removal. Our rate of VC and UL following RAPN are low and consistent with other contemporary series. Complications occurred in patients with high nephrometry scores or tumors located close to the collecting system. Both complications generally present early and can be managed without kidney re-operation or removal.

Surgical reduction of a high-flow dialysis fistula has long-term positive effects of the heart

Abstract Introduction Part of chronic haemodialysis patients develop a high-flow arteriovenous fistula (AVF). The volume overload caused by the presence of a high-flow AVF leads to increased cardiac output, dilation of cardiac chambers, increased pulmonary artery pressure or even to the development of high-output heart failure. Our previous data showed a positive effect of AVF flow-reducing surgery in 6 weeks follow-up. Purpose The purpose of this study was to analyse the long-term effect of AVF blood flow (Qa) reduction on cardiac structure and function. Methods We included patients with high-flow AVFs (defined as Qa over 1500 mL/min) indicated for blood flow reduction surgery for heart failure symptoms or pre-defined echocardiographic changes (left ventricular hypertrophy, severe secondary valvular regurgitations, or pulmonary hypertension). Echocardiography was performed one day before the surgery, the 6 weeks, 6 months, and 12 months thereafter. Qa was measured by ultrasound during the same visits. Results 27 patients were included, 20 men and 7 women, aged 57 ± 13 years. The procedure led to an immediate decrease in Qa. However, we observed failure of the procedure within 1 year in 8 (= 30%) patients defined by increased Qa back to pre-surgery values. Detailed results are displayed in Table 1. Estimated pulmonary arterial systolic pressure and left atrial volume remained significantly lower after 1 year despite the Qa rise. Effective cardiac output (= difference of cardiac output and Qa) rose immediately and remained increased during the follow-up period despite the increase in AVF blood flow. Conclusions We observed a long-time positive effect of AVF blood flow reduction surgery on the heart despite a significant Qa rise. The effective cardiac output remained increased despite the gradual increase of Qa, probably due to the adaptation of systemic arterioles.

Safety and effectiveness of pulsed field ablation for pulmonary vein isolation in atrial fibrillation patients: a single centre experience

Abstract Introduction Atrial Fibrillation (AF) is the most frequent arrhythmia in the world with an exponentially increasing prevalence. Pulmonary veins (PV) are the primary triggering sites for AF and pulmonary veins isolation (PVI) is currently the standard therapy alongside pharmacological treatment and should be considered as first-line treatment. Pulsed-fieldablation (PFA) is a novel ablation modality that involves the application of electrical pulses causing cellular death, with preferential tissue specificity. Aim In this study, we evaluated the safety and efficacy of single-shot PFA in AF patients. Methods Single-center registry of consecutive patients undergoing PVI using the pentaspline PFA catheter (all with CARTO3D system v.7 and high-density mapping), between June 2022 and November 2023. Data on demographics, procedural characteristics, and electrocardiographic recurrence (assessed after a 3-month blanking period) were analyzed. Results 152 consecutive patients were included (63 ± 10 years, 57% male), with a mean CHA2DS2-VASc score of 2±1 points, median LVEF of 60% (IQR 59-65%), and a median CT-scan derived left atrial volume index of 56 mL/m2(IQR 44-69 mL/m2). A total of 40% had non-paroxysmal AF and a redo procedure was performed in 17% of patients. The median procedure time was 78 min (IQR 58-111 min) and fluoroscopy time was 11.6 min (IQR 8.2-15.6 min). Additionally, posterior wall isolation (PWI) was performed in 63 patients (41%). There were no esophageal complications, phrenic nerve injuries, cerebrovascular events, or procedure-related deaths. Two patients (1.3%) experienced acute cardiac tamponade, immediately treated with pericardiocentesis. Other complications were primarily vascular, in 5% of cases (4 femoral hematomas, 3 femoral pseudoaneurysms, 1 arteriovenous fistula). Over 293 (IQR 170 - 394) days of follow-up, considering electrocardiographic recurrence, 12% of patients had AF recurrence (5 with paroxysmal AF and 10 with persistent AF). These patients were older (69 ± 7y vs. 62 ± 11y, p=0.016), were more likely to undergo a redo procedure (33 vs. 8%, p=0.004), and had a higher percentage of posterior wall isolation (21 vs. 8%, p=0.038). Conclusions PFA for PVI wall ablation is safe and effective, with 100% intraprocedural technical success, a low rate of complications, and a high percentage of patients free from AF in the short-term.

Significant reduction of complications applying an optimized vascular access and post-interventional groin-site management during electrophysiology procedures

Abstract Background Catheter ablation of cardiac arrhythmias is an established treatment strategy. However, the optimal femoral vascular access strategy and post-interventional management in the electrophysiology (EP) setting is still under debate. Purpose To assess the impact of ultrasound-guided versus conventional femoral vascular puncture and of a modified post-interventional groin-site management strategy on complication rates. Method Patients undergoing EP procedures at the our university heart and vascular center are included in an institutional prospective registry. Conventional vascular access as well as post-interventional groin site pressure-bandage and bed rest of 6 hours (group I) was compared to a new strategy including ultrasound-guided vascular access, venous closure by a Z-suture and groin site pressure-bandage for only 2 hours plus additional 4 hours bed rest (group II). Incidences of minor and major groin site complications for both groups were compared. Hematoma, bleeding, arteriovenous fistula or pseudoaneurysm of the femoral artery without need for intervention (e.g. transfusion, thrombin injection, surgery) were classified as minor complications. Complications requiring intervention or retroperitoneal hematoma were defined as major complications. Results A total of 1535 procedures in 1381 patients (779 (51 %) procedures in 705 (51%) patients in group I and 756 (49%) procedures in 676 (49%) patients in group II) were analyzed. In group I and group II, respectively, 39%/44% procedures were index pulmonary vein isolations, 30%/29% repeat atrial fibrillation, 16 %/15% supraventricular tachycardia, 12%/11% PVC or VT ablations, and 4%/2% left atrial appendage occlusions. The total groin site complication rate was 9% (70/779 procedures) for group I, and 5% (38/756 procedures) for group II (OR 0.54 [95%-CI 0.35-0.82], p=0.003). Major groin site complications occurred in 2% (19/779 procedures) in group I and were reduced to 1% (10/756 procedures) in group II (OR 0.53 [95%-CI 0.22-1.22], p=0.156). Conclusion The overall groin site complication rate in EP-procedures was significantly reduced by implementing a novel institutional standard for vascular access management including ultrasound-guided puncture and a modified post-interventional groin site management.

Pulmonary hypertension in patients on chronic hemodialysis

Abstract Introduction Pulmonary hypertension (PH) is a common condition in patients with advanced chronic kidney disease and is associated with higher morbidity and mortality. High arteriovenous fistula (AVF) flow is one of known etiological factors, but the association of AVF flow within the acceptable range and PH has not been tested. Moreover, the prevalence of PH differed among various studies. Purpose The aims of this study were: 1. to describe the prevalence of PH in the Czech hemodialysis population; 2. to analyze the relation between dialysis fistula flow and PH; 3. to reveal other etiology of PH in a cross-sectional non-invasive trial. Methods We analyzed index visits of the cohort CZecking HF-CKD study (ISRCTN 18275480). Thus, this is a cross-sectional analysis based on detailed echocardiography with cardiac output (CO) calculation, evaluation of the central venous pressure (CVP) and AVF flow, bio-impedance and basic laboratory tests. All these measurements were done within an hour. The presence of PH was based on the peak systolic pulmonary arterial pressure (PASP) estimation above 35 mmHg. Results We analyzed data of 162 patients. They were 73,2 ± 12,6 years old, dialysis vintage 30 ± 69 months. Pulmonary hypertension was present in 35 % of analyzed patients. Among these patients, mild PH was present in 35 %, moderate in 53 % and severe in 12 %. There was no significant impact of AVF/AVG flow on the presence of PH or PASP value (Table 1.). However patients with PH had higher prevalence of heart failure (HF), which was present in 86 % of patients with PH and only in 46 % without PH (p&amp;lt;0.00001), see Figure 1. This and other differences presented in Table 1. document significant contribution of postcapillary PH. Patients with PH were also more overhydrated when considered by CVP, by overhydration measurement using bioelectrical impedance analysis and had higher N-terminal pro brain natriuretic peptide (NTproBNP) (Table 1.). There was a positive correlation between systemic vascular resistance (SVR) and PASP (R=0,333, p= .001). Conclusions PH is present in approximately one third of the dialysis patients. The presence of heart failure and changes of left heart chambers show for the postcapillary etiology of PH. Neither the prevalence nor the severity of PH were significantly related to arteriovenous access flow.

The effect of using a local skin cooling device on arteriovenous fistula cannulation pain and comfort level of patients on hemodialysis: A single-blind randomized controlled study.

The study aimed to investigate the impact of the using local skin cooling on arteriovenous fistula cannulation pain and the comfort levels of hemodialysis patients. The single-blind randomized controlled trial was formed with 50 patients between June 20, 2023, and July 31, 2023, in the hemodialysis units of two state hospitals in Turkey. Patients were randomly assigned to either the experimental group (n = 25) or the control group (n = 25) using the block randomization method. This data were collected through the use of the CoolSense device, the "Patient Information Form," the "Verbal Category Scale," and the "General Comfort Scale." Patients in the experimental group received the local skin cooling for five seconds during arteriovenous fistula cannulation, while the control group followed the standard hospital protocol. The study was registered on Clinical Trials (NCT06144801). The study revealed that the application of the local skin cooling during arteriovenous fistula cannulation significantly reduced pain and increased patients' comfort levels, demonstrating an anesthetic effect (p < 0.001). Furthermore, it was observed that as pain levels decreased, patient comfort levels increased (p < 0.001). It is concluded that the using lokal skin cooling is an effective tool for reducing pain and enhancing comfort during arteriovenous fistula cannulation in hemodialysis patients.

Comparative microanatomy and histology of spinal and cerebral veins: Implications for dural arteriovenous fistula clinical presentations

Cranial dural arteriovenous fistulas (DAVFs) that display cortical venous drainage are at risk of hemorrhage, unlike spinal DAVFs, which seldom bleed. The underlying mechanism for this difference is poorly understood. We hypothesized that cerebral veins are more fragile than spinal veins due to differences in histologic compositions. Thus, spinal and cerebral veins from five formalin-fixed human cadavers were examined through macroscopic and histological analysis, using hematoxylin, eosin and safran (HES), and orcein stains to compare them. Twenty-four cerebral veins and thirteen spinal veins were analyzed. The mean diameter of the cerebral veins was 1.02 ± 0.59 mm, while that of spinal veins was 0.52 ± 0.26 mm (p = 0.003). The mean thickness of cerebral veins was similar to their spinal counterparts (0.09 ± 0.07 mm vs 0.06 ± 0.02 mm; p = 0.12). The mean diameter-to-thickness ratio was 13.76 ± 6.05 mm for cerebral veins and 10.06 ± 7.23 mm for spinal veins (p = 0.023). In most of the analyzed vessels, the venous wall was composed of endothelial cells resting on layers of smooth muscle, separated by elastica lamina. Cerebral and spinal veins exhibit distinct calibers while maintaining comparable wall thicknesses, resulting in a greater diameter-to-thickness ratio for cerebral veins compared to spinal veins. This difference may after their resistance to pressure. Furthermore, variations in the transparietal pressure gradient between cranial and spinal subarachnoid space, along with differences in arterial blood flow through the fistulous veins, might contribute to the observed differences in clinical presentation.

Angiographically occult spinal dural arteriovenous fistula diagnosed by exploratory surgery with intraoperative ultrasound: illustrative case.

A 78-year-old male presented with progressive myelopathic symptoms. The clinical course and imaging findings raised a high suspicion for venous hypertensive myelopathy due to a spinal dural arteriovenous fistula (SDAVF). Magnetic resonance angiography and four complete spinal angiograms did not reveal the presence of an SDAVF. Despite multiple negative angiograms, intraoperative ultrasound revealed abnormal cord edema and arterialized pulsatile vessels, confirming the presence of an SDAVF. The fistula was found and cauterized, which resulted in a decrease in the caliber of the dilated veins and an observed reduction of spinal cord stiffness posttreatment. The patient exhibited gradual improvement in neurological function. Retrospective analysis of the multiple complete spinal angiograms failed to reveal an anomaly at the treated level or any other level. This case underscores the diagnostic utility of intraoperative Doppler ultrasound and the importance of maintaining a high index of suspicion for SDAVF in cases with consistent clinical characteristics and a lack of alternative diagnoses, even with negative spinal angiography. https://thejns.org/doi/10.3171/CASE24438.

Vascular complications in patients with peripheral veno-arterial extracorporeal membrane oxygenation: clinical-echocardiographic characteristics and predictors

Abstract Introduction Veno-arterial Extracorporeal membrane oxygenation (VA ECMO) is a salvage intervention in patients with cardiogenic shock (CS), and cardiac arrest (CA) refractory to standard therapies. Lower limb ischemia associated with peripheral VA ECMO is frequent, and is considered a serious complication with a significant impact on the morbidity and mortality. Purpose The aim of this study was to describe the clinical-echographic parameters and analyze predictors related to vascular complications in patients with peripheral VA ECMO. Methods The study was a single-center cohort analysis. It included all consecutive adult patients with peripheral femoro-femoral VA ECMO due to refractory cardiogenic shock (CS) or cardiac arrest (CA) between March 2014 and December 2022. Patients with central cannulation were excluded. The primary endpoint was evidence of vascular complications resulting in surgical intervention. A multivariate logistic regression model was used to adjust for variables of interest. Results The study included 83 patients (65± 12 years, 54% male). The main previous diagnosis was necrotic ischemic cardiomyopathy (33%), and the most frequent indication was postcardiotomy (40.9%), mainly in SCAI D (85.5%). Cardiopulmonary resuscitation was performed in 18.1%. Femoro-femoral cannulation was percutaneuos in 95.2%. Most patients had intra-aortic balloon pump (87.1%) and distal percutaneous cannula (88.8%). A total of 18 patients presented vascular complications (21.7%): 2 patients (11.1%) amputation, 5 patients (27.7%) compartment syndrome requiring fasciotomy, 9 patients (50.0%) thrombectomy, and 2 patients (11.1%) a surgical resolution post decannulation due to AV fistula. The median duration of VA ECMO was 5 days (IQR 2-8). Among the ultrasound variables, the systolic peak velocity (SPV) in the distal territory (tibioperoneal segment) had a median of 22 cm/sec (IQR 10-30). Pulsatile spectral Doppler flow in the cannulated limb was evidenced in 42 patients (50.6%) of total population, and only in 3 patients (16.6%) with vascular complications. The survival rate from VA ECMO was 57.8%, and the survival rate to discharge 42.1%. In-hospital mortality of patients with or without vascular complications did not show statistically significant differences (54.2 % vs 58.2 %, p= 0.26). After multivariate analysis, distal territory SPV less than 20 cm/sec (OR: 2.1, 95%CI: 1.3 – 12.1, p: 0.03), as well as history of previous vascular disease, were associated with a higher number of vascular complications (OR: 2.5, 95% CI: 1.5 – 10.1, P; 0.02). Conclusions Vascular complications in patients with femoro-femoral VA ECMO remain frequent and constitute an important cause of morbidity. Decreased peak systolic velocities in the cannulated tibio-peroneal territory, as well as a history of previous vascular disease were significantly associated with a higher rate of vascular complications.

Arterio-Venous Fistula Calcifications—Risk Factors and Clinical Relevance

(1) Background: Arterio-venous fistulas (AVFs) are considered the gold-standard vascular access (VA) in patients on maintenance hemodialysis (HD) therapy. AVF calcifications represent a less studied VA related complication, even though HD patients are at a higher risk for extraosseous calcifications. The aim of this study is to assess the prevalence and risk factors of AVF calcifications, as well as the 5-year impact on AVF functionality and on overall mortality. (2) Methods: We conducted a 5-year prospective study including 161 patients on maintenance HD therapy. At baseline, we collected data related to VA history, comorbidities, demographics, subjective global assessment scale (SGA), and biochemical parameters. All patients underwent a complete AVF ultrasound and we recorded AVF blood flow and the presence of AVF calcifications, stenoses, and aneurysms. (3) Results: In our study, we found an AVF calcification prevalence of 39%. In a univariate analysis, we found that patients with AVF calcifications were associated with other AVF complications as well (stenoses, aneurysms), had longer AVF and HD vintage, as well as higher serum calcium and PTH values. In a multivariate analysis, we found that patients with a longer HD vintage and higher calcium values were independently associated with AVF calcifications. AVF calcifications did not affect 5-year fistula patency, nor were they associated with a higher mortality risk in our group of patients. (4) Conclusions: AVF calcifications were a frequent finding in our analysis, but their presence does not seem to affect the 5-year AVF patency.

The relationship between post-anastomosis brachial artery flow rate and brachiocephalic arteriovenous fistula access maturity in end-stage kidney disease patients with diabetes mellitus

Background: From previous studies, evaluation of post-anastomosis draining-vein volume flow rate with Doppler ultrasound can be a predictor for arteriovenous fistula maturation. Due to the high variation in measurements by the effect of probe pressure in draining vein, measuring volume flow rate based on post-anastomosis feeding-artery may be an early alternative predictor of arteriovenous fistula maturation. This study aims to investigate the correlation of post-creation brachial artery volume flow rate on maturity of brachiocephalic arteriovenous fistula access in patients with end-stage kidney disease with diabetes mellitus. Methods: A retrospective cohort study was conducted on end-stage kidney disease patients with diabetes mellitus who underwent brachiocephalic arteriovenous fistula creation at three hospitals from July 2019 to March 2020. Doppler ultrasound examination of the brachial artery and draining vein volume flow rate was conducted at pre-operative, post-creation, 2 weeks, and 6 weeks post-creation. Maturity was evaluated at 6 weeks post-anastomosis. Results: A total of 71 subjects met the inclusion and exclusion criteria, with 44 (62%) achieving maturation within 6 weeks. There was a correlation between post-anastomosis brachial artery (p &lt; 0.001) and draining vein volume flow rate (p &lt; 0.001) with arteriovenous fistula maturity after 6 weeks post-operatively. Brachial artery volume flow rate of ⩾350 mL/min can predict AVF maturity with a sensitivity of 95.45% (95% confidence interval = 84.86–98.74) and a specificity of 85.19% (95% confidence interval = 67.52–94.08). Conclusion: Post-anastomosis brachial artery flow volume can be a valuable parameter to predict brachiocephalic arteriovenous fistula maturity. It is a potential alternative to draining vein volume flow, which is technically a difficult examination.

Evaluation of efficacy of open thrombectomy for recently thrombosed arteriovenous fistulae and synthetic grafts for hemodialysis

Evaluation of efficacy of open thrombectomy for recently thrombosed arteriovenous fistulae and synthetic grafts for hemodialysis

Bleeding and Thrombotic Events in Hemodialysis Patients with Atrial Fibrillation on Anticoagulation and Antiplatelet Therapy: A 24-Month Cohort Study

Background and Objectives: Patients undergoing chronic hemodialysis (HD) are predisposed to both thrombotic and bleeding complications due to the complex interplay of end-stage renal disease (ESRD), cardiovascular comorbidities, and the routine use of anticoagulant and antiplatelet therapies. This study aimed to investigate the incidence of bleeding and thrombotic events in chronic HD patients receiving anticoagulant and antiplatelet therapy, with a specific focus on those with atrial fibrillation (AF). Materials and Methods: A total of 224 patients, with 43 (19%) of them diagnosed with AF, were included in this single-center, observational cohort study conducted over 24 months. The cohort was divided into three groups: patients without anticoagulation, those on warfarin monotherapy, and those on combined warfarin and aspirin therapy. Bleeding events were classified as major, clinically relevant non-major bleeding (CRNMB), or minor bleeding, while thrombotic events included ischemic stroke, myocardial infarction, pulmonary embolism, and arteriovenous fistula thrombosis. Results: Overall, 35.7% of patients experienced a bleeding event, with major bleeding occurring in 9.4%. Patients with AF had significantly higher rates of major bleeding (18.6%) compared to those without AF (7.18%; p = 0.043), especially in the combined therapy group. Mortality due to bleeding was also higher in AF patients (14%). In contrast, thrombotic events occurred in 26.8% of patients, with AF patients experiencing significantly more events (48.8%) compared to non-AF patients (21.5%; p = 0.0006). The hazard ratio (HR) for major bleeding in patients on combined warfarin and aspirin therapy was 2.56 (p = 0.016), while the HR for thrombotic events was 2.34 (p = 0.0202). Conclusions: These findings highlight the increased risks of both bleeding and thrombosis in chronic HD patients with AF, particularly those on combined anticoagulation and antiplatelet therapy.

Blood osteoprotegerin is associated with arteriovenous access thrombosis in hemodialysis patients.

A functioning arteriovenous (AV) access is essential for hemodialysis efficiency and the quality of life in hemodialysis patients. Blood osteoprotegerin (OPG) and soluble receptor activator of nuclear factor kappa B ligand (RANKL) have been linked to cardiovascular diseases and vascular calcification. This study investigated the relationship between blood OPG, RANKL, and the occurrence of AV access thrombosis. This prospective cohort study was conducted from August 2016 to August 2021 and included patients undergoing prevalent hemodialysis in two hospital-based hemodialysis units. Cox proportional hazards models and Kaplan-Meier analysis were used to evaluate the association between blood OPG, RANKL, and AV access (AV fistula [AVF] and AV graft [AVG]) outcomes. A total of 333 hemodialysis patients were enrolled, with an AV access thrombosis rate of 22.2%. Cox regression identified several factors associated with AV access thrombosis: AV access type (AVF vs. AVG; hazard ratio [HR], 0.24; p < 0.001), C-reactive protein (HR, 1.07; p = 0.002), and log-transformed OPG (HR, 5.52; p = 0.005). Subgroup analysis revealed high log-transformed OPG and RANKL were associated with AVF thrombosis (HR, 10.77; p = 0.002 and HR, 3.26; p = 0.009, respectively), while high C-reactive protein increased the risk of AVG thrombosis (HR, 1.31; p < 0.001). Kaplan-Meier analysis showed that patients with AVF in the highest tertile of log OPG (>402 pg/mL) had the highest AVF thrombosis incidence (p = 0.03). High blood OPG was associated with AV access thrombosis, particularly in the AVF.