Arteriovenous Fistula Outcomes Research Articles

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

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. This study was a single-centrerandomised 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. 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. 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 techniquemay providea better outcome for patients with small cephalic veins.

Heterogeneous gene expression during early arteriovenous fistula remodeling suggests that downregulation of metabolism predicts adaptive venous remodeling

Clinical outcomes of arteriovenous fistulae (AVF) for hemodialysis remain inadequate since biological mechanisms of AVF maturation and failure are still poorly understood. Aortocaval fistula creation (AVF group) or a sham operation (sham group) was performed in C57BL/6 mice. Venous limbs were collected on postoperative day 7 and total RNA was extracted for high throughput RNA sequencing and bioinformatic analysis. Genes in metabolic pathways were significantly downregulated in the AVF, whereas significant sex differences were not detected. Since gene expression patterns among the AVF group were heterogenous, the AVF group was divided into a ‘normal’ AVF (nAVF) group and an ‘outliers’ (OUT) group. The gene expression patterns of the nAVF and OUT groups were consistent with previously published data showing venous adaptive remodeling, whereas enrichment analyses showed significant upregulation of metabolism, inflammation and coagulation in the OUT group compared to the nAVF group, suggesting the heterogeneity during venous remodeling reflects early gene expression changes that may correlate with AVF maturation or failure. Early detection of these processes may be a translational strategy to predict fistula failure and reduce patient morbidity.

Multi-Center Two-Year Patency Outcomes of Endovascular Arteriovenous Fistulas (endoAVF) Created with a 4 French System.

To assess multicenter two-year patency outcomes of endovascular arteriovenous fistulas (endoAVF) created with the WavelinQ device. Patients who had fistulas created at three centers from January 2018 to December 2020 were included in this retrospective study. In total, 112 patients underwent endoAVF creation [40 females, 72 males; mean age 60years (range 18-88)]. Data collected included patient demographics, location of fistula creation, interventions performed, and brachial artery flows pre- and post-creation. Two-year cumulative patency, functional patency, and primary patency were assessed with Kaplan-Meier methodology. Factors affecting patency and maturation were examined using the Cox proportional hazards model. Technical success defined as angiographically successful endoAVF creation was 97.3% (109/112). In 11 patients the fistula did not mature for dialysis use. For 98 patients (87%) with endoAVF maturation, 12- and 24-month cumulative patency was 94.3% and 91.7%. Functional patency (two-needle cannulation) at 12 and 24months was 95.7% and 92.7%, respectively. Median maturation time is 95days (IQR 51-231days). Male gender and brachial vein coiling at the time of endoAVF creation were predictive of maturation. There were 34 censored events (four patients undergoing renal transplantation; 30 patients deceased). Number of reinterventions per patient year was 0.73 where 43 were maturation procedures and 101 were maintenance procedures. One Grade 3 complication occurred of arterial access puncture site pseudoaneurysm. A high two-year functional and cumulative patency following endoAVF creation with the WavelinQ device was observed in this multicenter real-world experience Level of Evidence: 3 Level of Evidence III.

Pathohistomorphometric and Immuno-Histologic Changes in Early Arteriovenous Fistula Failure in Patients with Chronic Kidney Disease.

Hemodialysis is a prevalent treatment for the end-stage chronic kidney disease (CKD) worldwide. The primary arteriovenous fistula (AVF), widely considered the optimal hemodialysis access method, fails to mature in up to two-thirds of the cases. The etiology of the early AVF failure, defined as thrombosis or inability to use within three months post-creation remains less understood, and is influenced by various factors including patient demographics, surgical techniques, and genetic predispositions. Neointimal hyperplasia is a primary histological finding in stenotic lesions leading to the AVF failure. However, there are insufficient data on the cellular phenotypes and the impact of the preexisting CKD-related factors. This study aims to investigate the histological, morphometric, and immunohistochemical alterations in the fistula vein, pre-, peri-, and post-early failure. Eighty-nine stage 4-5 CKD patients underwent standard preoperative assessment, including the Doppler ultrasound, before a typical radio-cephalic AVF creation. Post-failure, a new AVF was created proximally. The vein specimens were collected during the surgery, processed, and analyzed for morphometric analyses and various cellular markers, including Vimentin, TGF, and Ki 67. The study enrolled 89 CKD patients, analyzing various aspects of their condition and AVF failures. The histomorphometric analysis revealed substantial venous luminal stenosis and varied endothelial changes. The immunohistologic analysis showed differential marker expressions pre- and post-AVF creation. This study highlights the complexity of the early AVF failures in CKD patients. The medial hypertrophy emerged as a significant preexisting lesion, while the postoperative analyses indicated a shift towards neointimal hyperplasia. The research underscores the nuanced interplay of vascular remodeling, endothelial damage, and cellular proliferation in the AVF outcomes.

#1335 Distal radio-cephalic arteriovenous fistula survival: comorbid conditions and long-term surveillance in hemodialysis

Abstract Background and Aims With a low incidence of infection and distal ischemia, the distal radio-cephalic arteriovenous fistula (dRCF) is the reference access for hemodialysis (HD). Smaller venous diameter and obesity have been associated with poor distal arteriovenous fistula (AVF) outcomes in some studies. On the other hand, HD patients often suffer from multiple co-morbidities, resulting in an increased number of complications. The impact of all these factors on vascular access survival has not been entirely characterized. We evaluated long-term follow-up demographic and clinical data from a cohort of patients in relation to primary and secondary dRCF survival. Method The study included prevalent patients who had been receiving hemodialysis for at least 6 months at the same reference hospital. From 2008 to 2023, we retrospectively collected dRCF for HD performed by a single reference surgical team. All dRCF could be confirmed to be clinically useful for dialysis (i.e., functional patency). Socio-demographic data were collected. Our medical team (nephrologist and radiologist) periodically performs a physical examination and duplex ultrasound to identify physical signs of possible complications, understand the underlying cause and plan treatment in advance. The time to first repair is termed primary AVF survival, while secondary survival is the time after first repair. Primary and secondary survival analysis was performed using the Kaplan-Meier method. Results Of 253 prevalent patients receiving HD, 82.2% had an AVF. The mean HD vintage was 61 ± 50 months. HD was started on a planned basis in 61.4% of cases, with AVF being the initial access in 71.7% of cases. We included 145 dRCFs for HD. dRCF was the unique AVF that was placed in 74.5% of the patients. Mean age 69.5 ± 14.5 (years), women 31%, mean BMI 27.3 ± 6.08 kg/m2, non-smokers 46.9%, obesity 37.9%, diabetes mellitus 44.8%, ischemic cardiopathy 20%, peripheric vasculopathy 15.9%. Diabetic nephropathy was the most common cause of chronic kidney disease in our population, accounting for 44.8% of cases. dRCF primary failure was 11.11%, 40% of these patients were over 80 years of age. The dRCF was left-sided in 82.2%. dRCF median survival was 64.5 ± 50.4 months; survival rates at 12, 36 and 60 months were 92%, 67% and 41%, respectively. Primary and secondary dRCF median survival was 33 ± 39 months and 50 ± 45 months, respectively. Primary and secondary survival rates at 12, 36 and 60 months were 60%, 32% and 17% and 84%, 53% and 33%, respectively. With a median survival of 62 ± 44 months, 29.7% of the dRCF did not undergo repair either before or during dialysis. The dRCF requiring percutaneous intervention and/or surgical reanastomosis before dialysis was 16.7%. Factors identified as being associated with lower primary survival were obesity and peripheral vasculopathy (p=0.01 and p=0.001, respectively), as shown in Figs. 1 and 2. The percentage of salvage procedures (percutaneous, surgical or both) in obese was 78,2%; 76,7% involved surgical repair, most of which were lipectomies, superficializations with or without transposition. Although not statistically significant (p=0.056), dRCF secondary survival is decreased in diabetic patients (Fig. 3). No statistical impact was found between age, sex, smoking, or ischemic cardiopathy and either primary or secondary survival. Conclusion Our obese patients on HD are a special population with an increased need for surgical reintervention of dRCF, which impacts primary but not secondary survival. Primary dRCF survival is lower in patients with peripheral vascular disease compared to other comorbidities; however, this vasculopathy is not associated with worse secondary dRCF survival with active follow-up. It is likely that individualized and careful long-term active surveillance was a key aspect in improving the functional patency of dRCF in our patients with multiple comorbidities. Undoubtedly, these issues deserve further prospective investigation.

#281 AVF formation is a common complication of percutaneous ultrasound-guided renal biopsy: a single-center analysis of risk factors and clinical outcome

Abstract Background and Aims Percutaneous renal biopsy is a key procedure for the work-up of renal diseases. Among the possible complications of such procedure, prevalence, risk factors and clinical outcome of arterio-venous fistula (AVF) formation is unclear. We present here a single-center experience on renal biopsy-related complications with a focus on risk factors for AVFs formation and their management. Method We retrospectively analyzed all the kidney biopsies performed in our center between January 2012 and December 2022. All biopsies were conducted under real-time ultrasound (US) guidance by trained nephrologists. Kidney US and doppler mapping were performed routinely 6 and 24 hours post-procedure. In accordance with the description provided in the US report, AVFs were categorized into small, moderate, and high-flow rates. Patients’ comorbidities, histologic sample characteristics, blood tests results and the clinical course were recorded. Logistic regression was employed to investigate potential risk factors for complications. Results 1016 adult native renal biopsies were performed. The average age of patients was 55 ± 17 years, and 677/1016 (66.6%) were males. The histological sample was unsuitable in 29/1016 (2.9%) of the cases; moreover, prevalence of renal medulla and presence of large-caliber arteriole were observed in 88/1016 (8.7%) and 38/1016 (3.7%) of the samples, respectively. The most common complication was hematoma, detected by US in 175/1016 (17.2%), which was considered “complicated” in 21/1016 (2.1%) due to the association with macroscopic hematuria (n = 10), blood transfusion requirement (n = 8), or signs of active bleeding (n = 8), requiring embolization in 6/1016 patients (0.6%). AVFs were identified in 119/1016 (11.7%) biopsies; of these 20/119 (16.8%) required embolization after a median time of 16 days (IQR 5-65). Spontaneous resolution was documented in 65/119 (55%) of cases and occurred after a median of 27 days (IQR 15-49), with 50/55 (90.9%) of cases spontaneously resolving within the first month and the remaining cases no later than the fourth month (Fig. 1). High-flow AVFs more frequently necessitated angiographic intervention compared to moderate and small AVFs (75% vs 25% vs 7%), with a prolonged spontaneous resolution time (median 78 days; IQR 51-106) (Table 1). In the cases requiring embolization, the median creatinine level before and 6 months after procedure was respectively 1.7 mg/dL and 1.9 mg/dL (paired Wilcoxon signed-rank test: p = 0.908). In three cases post-embolization, a loss of renal vascularization at angiography higher than 30% was reported; however, even in these cases no differences in terms of renal function were observed at 6 months compared to the baseline. At multivariate logistic regression, hypertension (OR = 2,2; p = 0.003; 95% CI [1.3-3.7]), renal medulla prevalence (OR = 2,8; p = 0,001; 95% CI [1.6-4.8]), and large-caliber arteriole presence (OR = 2,9; p = 0,008; 95% CI [1.3-6.3]) were associated with a higher risk of AVFs, while obesity emerged as a protective factor (OR = 0,27; p = 0,013; 95% CI [0.1-0.8]). Conclusion AVF is a common complication following renal biopsy but therapeutic intervention is rarely required, as spontaneous resolution is typically observed within one month. In case of symptomatic or persistent AVFs, embolization may be required without an apparent impact on the renal function, at least in the short term. Hypertension and surrogate factors associated with a deeper penetration of the needle into the renal parenchyma are associated with an increased risk of AVF. Conversely, obesity was protective toward the risk of AVF development.

#2515 Optimizing brachial-basilic arteriovenous fistula outcomes: insights from a mapping and pre-transposition review

Abstract Background and Aims Brachial- Basilic arteriovenous fistulas (BBAVF) are an option for our patients when superficial vascular patrimony is lacking, but they pose technical and time challenges due to the necessity of a second-stage surgical transposition. The literature reports a 47% primary patency rate within the first year. BBAVFs are associated with higher incidences of steal syndrome and increased stenosis rates, commonly requiring interventions. This study aims to provide insights about optimizing BBAVF outcomes through a comprehensive mapping and pre-transposition evaluation. Method We developed a retrospective single-centre study from 2016 to 2022 that included 101 patients with BBAVFs mapped and constructed at Centro Hospitalar Universitário de Santo António. Mapping and pre-transposition evaluations data were collected from our digital records and the dialysis centre's provided insights about the BBAVFs outcomes through telephonic contact. A comparative analysis between patients achieving one-year primary patency (1Y-P) and those who did not (No 1Y-P) was performed, considering mapping variables (brachial artery and basilic vein diameters) and pre-transposition variables (brachial artery flow and basilic vein diameter). Results At 12 months our primary patency rate was 72.27%. The 1Y-P and No 1Y-P groups showed no significant differences concerning to baseline characteristics such as sex (p = 0.536), age (p = 0.489), and major comorbidities like diabetes (p = 0.929), ischemic heart disease (p = 0.741), peripheral arterial disease (p = 0.174), kidney transplantation (p = 0.384), and previous haemodialysis (p = 0.384). When the BBAVFs were constructed as the first access, they were significantly associated with less primary patency at 12 months (1Y-P n = 32 (43.84%) vs No 1Y-P n = 23 (82.14%); p < 0.001). In the vascular mapping the brachial artery (1Y-P 4.32 ± 0.86 mm vs No 1Y-P 4.11 ± 0.78 mm; p = 0.454) and basilic vein (1Y-P 3.90 ± 1.11 mm vs No 1Y-P 3.59 ± 0.88 mm; p = 0.249) diameters were larger in the 1Y-P group, although without statistically significance. It is important to emphasise that only 12 BBAVFs were constructed with less than 3 mm basilic veins and we only had 50% 12-month primary patency in those patients. Pre-transposition flow was significantly higher in patients with primary patency at 12 months (1Y-P 1069,77 ± 311,89 ml/min vs No 1Y-P 985,00 ± 500,83 ml/min; p = 0.018) and basilic vein diameter was higher in the same group, but without statistical significance (1Y-P 6.50 ± 1.19 mm vs No 1Y-P 6.14 ± 1.53 mm; p = 0.123). Conclusion Our primary patency rate was higher than the described in the literature, which could be a reflection of the organized mapping process in our centre that excludes limit size veins from the BBAVF construction. Patients with BBAVF as their initial access face worse outcomes with decreased primary patency time, probably due to lack of intrinsic vascular patrimony. Stringent construction criteria are warranted in those cases. Contrary to expectations, vessel diameters did not show significant relevance, prompting consideration of factors like distensibility or vessels calcifications as potentially influential. However, we have to underline that the average mapping basilic vein diameter was greater than 3 mm in both groups, which suggests a pre-selection is already carried out in our centre, and, even though there was not statistical significance, the 1Y-P group had bigger basilic veins in the vascular mapping. Our results were worst in the 12 BBAVFs constructed with less than 3 mm basilic veins. BBAVFs pre-transposition evaluation importance is emphasized by the association of higher pre-transposition brachial artery flow rates with improved outcomes. This research highlights the importance of mapping and pre transposition evaluation for optimal BBAVF outcomes, but further studies need to be done with longer follow up times and including more vascular access mapping criteria.

The role of glomerular filtration rate in AVF success: Should we intervene earlier?

End-stage kidney disease (ESKD) patients require life-sustaining kidney replacement therapies, with the natural arteriovenous fistula (AVF) being the preferred vascular access due to its low infection risk, high patency, and fewer complications. Factors like vessel diameter, gender, diabetes, age, and surgical technique influence AVF maturation. Our study focused on short-term AVF creation success, specifically examining estimated glomerular filtration rate (eGFR) levels using the CKD-EPI formula. Patients were categorized according to their eGFR levels to observe the effects of fistula timing and the severity of kidney disease. No significant demographic or outcome differences between eGFR groups have been observed except for gender. AVF maturation was notably associated with distal vein diameter (>2mm), while other factors did not significantly impact maturation rates. As a secondary outcome, it was concluded that the recording of patients' blood pressure values at preoperative and perioperative levels led to the conclusion that blood pressure levels may have an impact on fistula maturation. To ensure vascular access effectiveness, optimizing blood pressure, determining vein diameter, strategic AVF timing, and reducing catheter usage are crucial. Our study aimed to identify eGFR levels conducive to optimal AVF outcomes. Although significant results could not be obtained in this regard, it is considered worthwhile to re-examine the effect of blood pressure in secondary outcomes. Additionally, prospective studies may be appropriate for reevaluating the effect of GFR.

Relationship between effective blood flow rate and clinical outcomes in maintenance hemodialysis patients: a single-center study

The association between blood flow rate (BFR) and clinical outcomes in patients undergoing maintenance hemodialysis (MHD) is inconclusive. This retrospective study included 175 patients undergoing MHD treatment between July 2015 and March 2022, divided into two groups based on time-averaged effective blood flow rate (eBFR) median value. We investigated arteriovenous fistula (AVF) outcomes and the association of eBFR with all-cause mortality and new major adverse cardiovascular events (MACE). Mean ± SD and median time-averaged eBFR values were 276 ± 24 and 275 mL/min, respectively. After adjusting for relevant factors including age, sex, vintage, diabetes, CVD, receiving hemodiafiltration (HDF) treatment and spKt/V, Cox models indicated a low time-averaged eBFR (≤ 275 ml/min) was associated with increased risks of all-cause mortality (hazard ratio [HR] 14.18; 95% confidence interval [CI], 3.14–64.1) and new MACE (HR 3.76; 95% CI, 1.91–7.40) in MHD patients. Continuous Cox models demonstrated each 20 ml/min increase in eBFR linked to a 63% decrease in the risk of all-cause mortality (HR: 0.37, 95% CI: 0.23–0.59) and a 38% decrease in the occurrence of new MACE (HR: 0.62, 95% CI: 0.46–0.84). There was no significant difference in AVF outcomes between the two groups. Our study noted higher eBFR (>275 mL/min) is associated with lower risks of both all-cause mortality and new MACE compared with low eBFR (≤275 mL/min). Increased eBFR is not associated with a higher risk of AVF failure.

The negative impact of treatment delays on the long-term neurological outcomes of spinal dural arteriovenous fistulas: a longitudinal cohort study.

Dural arteriovenous fistulas are rare vascular malformations that affect the brain and spinal cord. Spinal dural arteriovenous fistulas (sdAVFs) are the most frequently encountered vascular malformation affecting the spinal cord. The object of this study was to evaluate the impact of treatment delays on the long-term neurological outcomes of either open surgical or interventional treatment of sdAVFs. In this retrospective, population-based cohort study, the authors examined consecutive patients with diagnosed sdAVFs at a tertiary care center between 2005 and 2020. Patients were assessed using the Aminoff-Logue disability scale (ALS) at various time points including symptom onset, primary care visit, first specialist outpatient visit, as well as both short and long-term follow-ups. The postoperative long-term ALS gait and bladder grades constituted the primary outcomes of the study. Among the 34 patients included in the study, the median age was 65 years, and there was a male predominance (71%). Most lesions were in the lumbar region (47%). Significant worsening in ALS gait and bladder grades was observed preoperatively, followed by postoperative improvements (p < 0.05). There was no difference in outcomes between surgical and endovascular treatments. Older age (OR 1.10, 95% CI 1.03-1.17, p = 0.007), worse preoperative ALS gait grades (OR 5.12, 95% CI 2.18-12.4, p < 0.001), and longer time from first specialist outpatient visit to first treatment (OR 1.00, 95% CI 1.00-1.01, p = 0.040) were independently associated with worse long-term gait outcomes. Only the preoperative ALS bladder score was a predictor of worse long-term bladder function (OR 92.7, 95% CI 28.0-306.7, p < 0.001). Both surgical and endovascular treatments for sdAVFs led to significant neurological improvements. However, treatment delays were associated with less favorable long-term outcomes. Prompt diagnosis and early intervention prior to symptom progression may enhance recovery and help to preserve neurological function.

Endovascular treatment strategy and clinical outcome of tentorial dural arteriovenous fistula.

To evaluate treatment strategies and clinical outcomes following endovascular embolization of tentorial dural arteriovenous fistulas. We retrospectively analyzed 19 patients with tentorial dural arteriovenous fistulas admitted to the Department of Neurosurgery at Jiangsu Provincial People's Hospital between October 2015 and May 2022, all treated with endovascular therapy. To collect and analyze patients' clinical presentation, imaging data, postoperative complications, and prognosis and to analyze the safety and clinical outcomes of endovascular treatment of tentorial dural arteriovenous fistulas. Imaging cure was achieved in 18 patients, with the arterial route chosen for embolization in 17 patients and the venous route in one patient; one patient received partial embolization. Staged embolization was performed in four patients. At postoperative follow-up of 9-83 months (37.8 ± 21.2), all 19 patients had recovered well (mRS score ≤ 2). Three patients experienced perioperative complications: intraoperative Onyx reflux into the middle cerebral artery in one patient; postoperative permanent limited left visual field loss and deafness in the left ear in one patient; and transient diplopia, vertigo, and decreased pain and temperature sensation of the left limb in one patient, with no abnormalities on post-procedure magnetic resonance examinations. A total of 17 patients completed a postoperative digital subtraction angiography review during follow-up, and one patient had a recurrence of an arteriovenous fistula. Endovascular treatment of tentorial dural arteriovenous fistulas is safe and effective. Reduction of the Borden or Cognard classification via eliminating cortical venous reflux through multi-staged embolization or combined open surgery is a reasonable goal of treatment where complete obliteration of the fistula is not achievable.

Early arteriovenous fistula failure associated with mortality and major adverse cardiovascular events in patients undergoing incident hemodialysis.

Arteriovenous fistula (AVF) patency is important for patients undergoing hemodialysis. The association between early AVF failure and the prognosis, including all-cause mortality and major adverse cardiovascular events (MACE), has not been fully investigated. The present study was performed to investigate the association between early AVF failure and 3-year mortality, cardiovascular disease (CVD) mortality, and MACE. We analyzed 358 patients who started hemodialysis in our institution from October 2008 to February 2020. We defined early AVF failure as cases requiring percutaneous transluminal angioplasty or reoperation within 1 year after AVF surgery. The patients were divided into two groups according to the presence or absence of early AVF failure, and the prognosis of each group was examined. The association between early AVF failure and outcomes (3-year all-cause mortality, CVD mortality, and MACE) was determined using Cox proportional hazards regression analysis. During the 3-year follow-up, 75 (20.9%) patients died (cardiovascular death: n = 39) and 145 patients developed MACE. According to the multivariable analysis, the early AVF failure group had a significantly higher risk of 3-year all-cause mortality (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.09-1.83; p = 0.009), CVD mortality (HR, 1.54; 95% CI, 1.29-2.08; p < 0.001), and MACE (HR, 1.68; 95% CI, 1.25-2.26; p < 0.001). When the patients were stratified by age, early AVF failure was associated with 3-year all-cause mortality in all groups except for the younger group (<65 years of age). Early AVF failure was associated with an increased risk of 3-year all-cause mortality, CVD mortality, and MACE.

Similar outcomes of arteriovenous fistulae created under general or regional anesthesia.

There is growing evidence that type of anesthesia can significantly change vascular access surgery outcomes. Still, there is limited evidence on the impact of regional anesthesia (RA) on patency and failure rates compared to general anesthesia (GA). The aim of this study was to compare the outcomes of RA and GA in patients who underwent vascular access creation at our center. Data collected in our prospectively maintained database of patients with chronic renal dysfunction requiring hemodialysis were analyzed, 464 patients were included. Outcome parameters such as maturation, primary failure, postoperative flow measurements, patency rates, and survival outcomes were compared between RA and GA groups. In this study 489 vascular access procedures were performed in 464 patients, 318 included in the RA group and 171 in the GA group. Median follow-up time was 29.9 (IQR 37.3) months in the RA group versus 33.0 (IQR 40.7) in the GA group (p = 0.252). Anesthesia type did not significantly affect patient survival (HR, 1.01; CI, 0.70-1.45; p = 0.976). No significant differences were found in vascular access flow volume, primary failure, or time to cannulation between the RA and GA groups for both radiocephalic arteriovenous fistulae and brachiocephalic arteriovenous fistulae. Anesthesia type did not significantly change patency outcomes. Based on our results, both RA and GA demonstrate similar results regarding patient survival, maturation, failure, or patency after vascular access creation. Still, patient-specific factors for each type of anesthesia as well as patient preference should be considered.

Clinical features, treatment, and outcomes of cavernous sinus dural arteriovenous fistulas: a cohort study of 141 patients.

The cavernous sinus (CS) region is a common region of dural arteriovenous fistula (DAVF). Over time, treatment strategies are gradually changing. In this study, we present our center's experience in managing CS-DAVF over the past 20years. Medical records of patients diagnosed with CS-DAVF between 2002 and 2021 were collected for analysis. Patients meeting the predefined inclusion and exclusion criteria were included. This study summarized and analyzed their clinical characteristics, CS-DAVF angioarchitecture, treatment strategies, and outcomes. A total of 141 patients (mean age 55years, 46 males) were included in this study. Ocular/orbital symptoms were the most frequently reported initial symptoms, with 84 (59.6%) patients experiencing these symptoms first. Presentation with ocular/orbital symptoms as the first symptom was associated with thrombosis of the inferior petrosal sinus (p = 0.032). Presentation with headache/dizziness and tinnitus/intracranial murmur as the first symptom was associated with sphenoparietal sinus/superficial middle cerebral vein drainage (p = 0.011). Among the patients, 131 (92.9%) patients received endovascular treatment, with 114 (87.0%) undergoing transvenous embolization. Onyx (92.4%) and coil (74.8%) were the most used embolic materials. 17 (13.0%) of the patients who received endovascular treatment suffered intraoperative or postoperative complications, and 11 (64.7%) patients fully recovered within 6months after discharge. Ocular/orbital symptoms were the most common first symptom of CS-DAVF. The mode of venous drainage played a significant role in determining the first symptoms. Transvenous embolization using Onyx or a combination of Onyx and coils was the primary treatment modality.

Standardization of Pre-operative Evaluation to Improve the Outcome of Arteriovenous Fistula for Vascular Access of Hemodialysis: A Review of 700 Cases.

Background With the advent of COVID-19, mortality rates of end-stage kidney disease (ESKD) rose by 37% which makes its treatment an important part of healthcare. Arteriovenous fistula (AVF) is linked to higher patient survival rates. Cimino-Brescia fistula is the most effective vascular access technique, but it has a high rate of primary failure (PF) and a several-week maturation period before it can be used. The current study aims to verify the preoperative evaluation in improving survival among AVF patients. Methodology The current study is a retrospective analysis of the hospital database from Jan 2022 to July 2023, with patients of a mean age of 60.2 years. The sample size was around 700, including the patients indicated for long-term hemodialysis (HD) with an estimated GFR of less than 20 mm/min/1.73m². Following AVF surgery, post-operative outcomes, PF, and maturation time were considered. Results Among the 757 AVF procedures, 588 (82%) were new cases, and 112 (16%) had prior AVF history on the same side. PF was observed in 126 (18%) AVFs, while 574 (84%) achieved maturation. Age at surgery did not correlate with PF. Male sex and brachiocephalic AVF (BCAVF) had lower PF rates, while female gender, non-BCAVF, and vascular chronic kidney disease (CKD) were independent predictors. Proximal fistulas had a higher failure risk (32%). During surgery, the PF occurred six times more frequently in patients with veins and arteries under 2 mm and without a bruit. Conclusion AVF maturation aims to achieve a functional AVF for easy dialysis, requiring meticulous vein selection, doppler vascular mapping, and a standardized process to reduce PF rates. Factors determining PF include thrill and bruit, flow rates, and comorbidities. These findings can help clinicians make informed decisions and improve outcomes for patients undergoing fistula surgery.

Obesity drives secondary procedures to achieve access maturation in end-stage renal disease

BackgroundEstablishing long-term arteriovenous access is an important component in the long-term care of a patient with end-stage renal disease. The increasing frequency of obesity is reported to impact the access management of end-stage renal disease patients. This study aims to evaluate the outcomes of arteriovenous fistulae (AVF) in obese and nonobese patients. MethodsA retrospective review of all patients over ten years with primary autogenous AVF (radiocephalic, brachiocephalic, and brachial-basilic) was undertaken at a single center. Patients were subcategorized by body mass index into nonobese, class I, II, and III obesity. Outcomes of maturation (successful progression to hemodialysis), reintervention, functional dialysis (continuous hemodialysis for 3 consecutive months), and patency were examined. ResultsFrom January 1999 to December 2019, 2311 patients (67% female; mean age, 61 ± 15 years) underwent primary AVF placement (12% radiocephalic, 53% brachiocephalic, and 35% brachial basilic). Forty-one percent were nonobese, 29% had class I obesity, 19% had class II obesity, and 11% had class III obesity. The majority of patients were diabetic and Hispanic. The 30-day major adverse cardiovascular event rate was elevated in class II (0.20%) and class III (0.50%) obesity compared with class I obesity (0.15%) and nonobese (0.05%). The 30-day morbidity rate was higher in all classes of obesity (0.5% vs0.3% vs 0.2% vs 0.05% for class III vs class II vs class I obesity and nonobese, respectively). Early thrombosis was significantly increased in class II (9%) and class III obesity (12%) compared with class I obesity (5%) and nonobese (3%). There was a two-fold increase in procedures to effect maturation in class II (51%) and class III (74%) obesity compared with class I obesity (22%) and nonobese (34%). Secondary patency at 3 years was significantly lower in class III (62 ± 4%) and class II (79 ± 3%) compared with class I obesity (87 ± 2%) and nonobese (93 ± 4%). All classes of obesity required significantly more secondary Interventions per year compared with nonobese (3.9 vs 3.1 vs 2.5 vs 1.4 secondary interventions per year for class III vs class II vs class I obesity and nonobese, respectively). ConclusionsAdvancing obesity class is associated with an increased number of procedures to achieve AVF maturation and is associated with poorer patency and functionality as the category of obesity advances.

The Role of Ultrasound Examination in the Assessment of Suitability of Calcified Arteries for Vascular Access Creation-Mini Review.

Arterial calcifications are present in 20-40% of patients with end-stage kidney disease and are more frequent among the elderly and diabetics. They reduce the possibility of arterio-venous fistula (AVF) formation and maturation and increase the likelihood of complications, especially distal ischemia. This review focuses on methods for detecting arterial calcifications and assessing the suitability of calcified arteries for providing inflow before the construction of an AVF. The importance of a clinical examination is stressed. A grading system is proposed for quantifying the severity of calcifications in the arteries of the arm with B-mode and Doppler ultrasound exams. Functional tests to assess the suitability of the artery to provide adequate inflow to the AVF are discussed, including Doppler indices (peak systolic velocity and resistive index during reactive hyperemia). Possible predictors of the development of distal ischemia are discussed (finger pressure, digital brachial index, acceleration and acceleration time), as well as the outcomes of AVFs placed on calcified arteries. It is concluded that a noninvasive ultrasound examination is probably the best tool for a morphologic and functional assessment of the arteries. An arterial assessment is of utmost importance if we are to create distal radiocephalic AVFs in our elderly patients whenever possible without burdening them with futile surgical attempts.

Long-term patency of arteriovenous fistulas for hemodialysis: A decade's experience in a transplant unit.

The heterogeneous quality of studies on arteriovenous fistulas outcome, with variable clinical settings and large variations in definitions of patency and failure rates, leads to frequent misinterpretations and overestimation of arteriovenous fistula patency. Hence, this study aimed to provide realistic and clinically relevant long-term arteriovenous fistula outcomes. We retrospectively analyzed all autologous arteriovenous fistulas at our center over a 10-year period (2012-2022). Primary and secondary patency analysis was conducted using the Kaplan-Meier method; multivariate analysis of variance was used to detect outcome predictors. Vascular access-specific endpoints were defined according to the European guidelines on vascular access formation. Of 312 arteriovenous fistulas, 57.5% (n = 181) were radio-cephalic (RC_AVF), 35.2% (n = 111) brachio-cephalic (BC_AVF), and 6.3% (n = 20) brachio-basilic (BB_AVF). 6, 12, and 24 months follow-up was available in 290 (92.1%), 282 (89.5%), and 259 (82.2%) patients, respectively. Primary patency rates at 6, 12, and 24 months were 39.5%, 34.8%, and 27.2% for RC_AVF, 58.3%, 44.4%, and 27.8% for BC_AVF, and 40.0%, 42.1%, and 22.2% for BB_AVF (p = 0.15). Secondary patency rates at 6, 12, and 24 months were 65.7%, 63.8%, and 59.0% for RC_AVF, 77.7%, 72.0%, and 59.6% for BC_AVF, and 65.0%, 68.4%, and 61.1% for BB_AVF (p = 0.29). Factors associated with lower primary and secondary patency were hemodialysis at time of arteriovenous fistula formation (p = 0.037 and p = 0.024, respectively) and higher Charlson Comorbidity Index (p = 0.036 and p < 0.001, respectively). Previous kidney transplant showed inferior primary patency (p = 0.005); higher age inferior secondary patency (p < 0.001). Vascular access care remains challenging and salvage interventions are often needed to achieve maturation or maintain patency. Strict adherence to standardized outcome reporting in vascular access surgery paints a more realistic picture of arteriovenous fistula patency and enables reliable intercenter comparison.

Outcomes of arteriovenous graft vs. fistula for haemodialysis access in the elderly: A systematic review and meta‑analysis.

The impact of the type of vascular access on the outcomes in the elderly haemodialysis patients is still unclear. The goal of the present study was to compare survival outcomes in elderly haemodialysis patients who received either arteriovenous graft (AVG) or arteriovenous fistula (AVF). A systematic literature search was performed in EMBASE, Cochrane, MEDLINE, ScienceDirect and Google Scholar databases for papers published from January 1954 until January 2022. Risk of bias in the selected publications was assessed by Newcastle Ottawa scale or Cochrane risk of bias tool depending on the study design. Meta-analysis was carried out using the random-effects model. Data were reported as pooled odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI). A total of 12 studies were included in the analysis. The majority of the studies had poor quality. Elderly patients receiving AVG had significantly worse survival rate compared with patients that received AVF for the haemodialysis access, with a pooled HR of 1.38 (95% CI, 1.24-1.53; I2=79.9%). Pooled HR for access survival was 1.60 (95% CI, 1.54-1.66; I2=0%). Pooled OR for primary patency rate, maturation failure and infections were 1.81 (95% CI, 0.73-4.49; I2=79.2%), 0.33 (95% CI, 0.12-0.91; I2=70.4%) and 9.74 (95% CI, 2.60-36.49; I2=52.4%), respectively. These results suggested that in elderly patients undergoing haemodialysis, AVG was associated with reduced overall survival and access survival, and higher infection rate, compared with AVF. Notably, AVG was also associated with a lower risk of maturation failure, presenting a potential advantage in specific patient populations (study registration: PROSPERO, no. CRD42022313199).

Comparison of wound complications between one-stage and two-stage brachiobasilic arteriovenous fistula: A meta-analysis.

Research assessing the outcome of brachiobasilic arteriovenous fistulas (BB-AVF) after a one- and two-stage technique was conducted. A strict review of the comprehensive literature up to May 2023 was carried out using four databases-PubMed，Embase, Cochrane Library and web of science. Inclusion and exclusion criteria developed for the study were then applied to assess the quality of the literature, it was decided to review 12 interrelated studies.95% confidence intervals (Cl) and odds ratios (OR) were calculated using fixed effects models. The data were meta-analysed using RevMan 5.3 software. The results showed that two-stage technique with BB-AVF reduced surgical site haematoma (SSH) formation, (OR, 2.28; 95% CI, 1.24-4.17, p = 0.008), and also reduced surgical site wound infection (SSWI) (OR, 1.86; 95% CI, 1.17-2.94, p = 0.008). There are, however, several small sample sizes in the selected studies for this meta-analysis, so caution should be used when processing their values. There are more high-quality studies with large sample sizes that should be considered for future meta-analyses.