Proposal of a Classification System of Cavernous sinus dural arteriovenous fistulas and treatment strategies based on angioarchitecture: A Cohort Study of 116 Patients.

BACKGROUND: Cavernous sinus(CS) dural arteriovenous fistulas(DAVFs) are commonly treated by transvenous embolization, but the details of treatment need to be more clearly defined. We propose a classification of CS-DAVF that can contribute to formulating endovascular treatment process. METHODS: CS-DAVF was classified into seven categories based on the cumulative CS range and drainage patterns. CS-DAVF angioarchitecture, clinical characteristics, treatment strategies, and outcomes of CS-DAVF patients treated in our hospital from 2012 to 2021 were summarized and analyzed. RESULTS: Among the 116 patients with CS-DAVF: Type 1, 71(61.2%); Type 2, 9(7.8%); Type 3, 18(15.5%); Type 4, 2(1.7%); Type 5, 8(6.9%); Type 6, 3(2.6%); and Type 7, 5(4.3%). Intercavernous sinus or inferior petrosal sinus drainage was relatively rare in Types 1 and 6(p<0.001 and p<0.001); basilar venous plexus drainage was more prevalent in Types 2, 5, and 7(p=0.019). Inferior petrosal sinus occlusion was more commonly seen in Types 2, 3, and 5(p=0.005). The most frequent first symptoms and symptoms at admission in patients with CS-DAVF is ocular/orbital symptoms, occurring in 64 cases (55.2%) and 104 cases (89.7%), respectively. In this study, 108 patients (93.1%) underwent endovascular embolization. Among those who received endovascular embolization, 96(88.9%) CS-DAVFs were treated via transvenous embolization. In long-term follow-up, 98 cases (84.5%) achieved cure, and 17 cases (14.7%) showed symptomatic improvement. CONCLUSION: Our proposed classification system based on cumulative CS range and drainage patterns can assist in formulating treatment strategies for transvenous embolization.

Activation and disease control of patients on chronic hemodialysis: An observational study.

BACKGROUND AND OBJECTIVE: Patient activation is a concept that refers to the willingness to manage one's health and medical care. To assess it, a patient activation measure (PAM) has been developed and validated. Several studies report low activation in patients with chronic diseases. However, information on activation in hemodialysis patients is scarce. The aim of the present study is to describe the activation level of patients on chronic treatment in an HD unit and its relationship with disease control parameters. MATERIALS AND METHODS: Cross-sectional observational study in patients with advanced chronic kidney disease on chronic HD treatment. Ninety-six patients were included. Activation was measured with the PAM-13 questionnaire. Its relationship with descriptive variables (age, sex, comorbidity, studies, habitat) and disease control variables (vascular access, blood flow, potassaemia, phosphataemia, interdialytic gain) was studied. For this purpose, Spearman's correlation test, multiple linear regression model and logistic model were used as statistical methods. RESULTS: The mean (SD) PAM-13 score was 63.19 (15.21). Activation was significantly associated with vascular access (P = 0.003), blood flow (P = 0.024), and interdialytic gain of patients (P = 0.008). CONCLUSIONS: Activation in patients on chronic hemodialysis treatment is low. Higher activation is related having an arteriovenous fistula, higher blood flow and lower interdialytic gain. Future studies are needed to confirm and apply our results.

Arteriovenous Fistula: The Case of a Rare Complication after Minimal Percutaneous Nephrostomy and Brief Review.

Percutaneous renal surgery, although much less invasive than other procedures, is subject to several complications, which can occur at any time during the course of treatment, starting from the performance of the minimal nephrostomy procedure. We present an extremely rare vascular complication of percutaneous nephrostomy represented by arteriovenous fistula that occurred in a 24-year-old patient known to have right ureteropelvic junction obstruction operated with the absence of double-J catheter permeability and grade II-III hydronephrosis for which minimal percutaneous nephrostomy was urgently fitted. The arteriovenous fistula was resolved by supraselective artery embolization.

Out-Patient versus In-Patient Arteriovenous Fistula Creation for Dialysis: Assessing Cost-Effectiveness Alongside Clinical Implications.

(1) Background: The surgical procedure to create an arteriovenous fistula (AVF) can be performed in either an ambulatory or in-patient hospital setting, depending on the case's complexity, the anesthesia type used, and the patient's comorbidities. The main scope of this study is to assess the cost-effectiveness and clinical implications of surgically creating an AVF in both ambulatory and in-hospital settings. (2) Methods: We conducted a retrospective observational study, in which we initially enrolled all patients with end-stage kidney disease (ESKD) admitted to the Vascular Surgery Department, Emergency County Hospital of Targu Mures, Romania, to surgically create an AVF for dialysis, between January 2020 and December 2022. The primary endpoint of this study is to assess the cost-effectiveness of surgically creating an AVF in an ambulatory vs. in-hospital setting by comparing the costs required for the two types of admissions. Further, the 116 patients enrolled in this study were divided into two groups based on their preference for hospitalization: out-patients and in-patients. (3) Results: Regarding in-patient comorbidities, there was a higher prevalence of peripheral artery disease (PAD) (p = 0.006), malignancy (p = 0.020), and previous myocardial infarction (p = 0.012). In addition, active smoking (p = 0.006) and obesity (p = 0.018) were more frequent among these patients. Regarding the laboratory data, the in-patients had lower levels of white blood cells (WBC) (p = 0.004), neutrophils count (p = 0.025), lymphocytes (p = 0.034), and monocytes (p = 0.032), but there were no differences between the two groups regarding the systemic inflammatory biomarkers or the AVF type. Additionally, we did not register any difference regarding the outcomes: local complications (p = 0.588), maturation failure (p = 0.267), and primary patency (p = 0.834). In our subsequent analysis, we discovered no significant difference between the hospitalization type chosen by patients regarding AVF primary patency failure (p = 0.195). We found no significant association between the hospitalization type and the recorded outcomes (all ps > 0.05) in both multivariate linear regression and Cox proportional hazard analysis. (4) Conclusions: In conclusion, there are no significant differences in the clinical implications, short-term and long-term complications of AVF for out-patient and in-patient admissions. Additionally, we found no variation in the costs associated with laboratory tests and surgical supplies for an AVF creation. Therefore, it is safe to perform ambulatory AVFs, which can reduce the risk of hospital-acquired infections and provide greater comfort to the patient.

Nurse-assisted arterio-venous fistula cannulation during home hemodialysis: first results of the DIADIDEAL study / La ponction de fistule assistée par infirmier libéral en hémodialyse à domicile : premiers résultats de l'étude DIADIDEAL.

Introduction: We have launched a pilot study, called DIADIDEAL, to propose nurse-assistance at home for arterio-venous fistula (AVF) cannulation in home hemodialysis (HHD) patients. The aim of the present study was to describe enrollment of the patients and their nurses. Materials: All prevalent HD patients on 30th November 2018 with no medical contraindication to HDD treatment and all incident patients on dialysis from the 30th November 2018 to the 21st April 2023 were eligible. Results: Among 155 prevalent HD patients, 4 patients were included. Among the 276 incident patients on dialysis during the study period, 6 were included. We have phoned 23 nurse centers during the recruitment period. Eight of them agreed to learn in our unit how to cannulate AVF; 27 private nurses were enrolled. Discussion: The results of the DIADIDEAL study will be available in 2024; we hope it will lead to a reimbursement of nurse-AVF cannulation at home in HDD.

Introduction: L'étude DIADIDEAL est une étude pilote sur la ponction de fistule artério-veineuse (FAV) assistée par infirmier libéral en hémodialyse à domicile (HDD). L'objectif de l'étude actuelle est de rapporter le recrutement des patients et de leurs infirmiers diplômés d'État libéraux (IDEL). Matériels et méthodes: Tous les patients prévalents en HD au 30 novembre 2018 n'ayant pas de contre-indication médicale à un traitement par HDD ainsi que tous les patients incidents en dialyse du 30 novembre 2018 au 21 avril 2023 étaient éligibles. Résultats: Parmi les 155 patients prévalents en hémodialyse, 4 ont été inclus. Parmi les 276 patients incidents en dialyse sur la période, 6 ont été inclus dans l'étude. Parmi les 23 cabinets IDEL contactés pour l'étude, 8 ont accepté et 27 IDEL ont été formés à la ponction de FAV. Discussion: Les résultats de l'étude DIADIDEAL seront disponibles en 2024 et viseront à obtenir une nomenclature pour l'acte de ponction de FAV par les IDEL.

Radial Arteriovenous Fistula Formation After Transradial Cardiac Catheterization.

More than one million cardiac catheterization procedures are performed each year in the United States for both diagnostic and therapeutic purposes. Obtaining access through the radial artery has gained popularity in recent years due to its economic as well as its morbidity and mortality benefits over femoral artery access. However, with any invasive procedure there are associated risks, including arteriovenous fistula formation. This case illustrates the formation of an iatrogenic arteriovenous fistula as a complication of transradial coronary catheterization. Albeit rare, this case will discuss the presentation and clinical course of a patient who was diagnosed with a radial arteriovenous fistula seven weeks post-cardiac catheterization. Ultimately, she underwent direct surgical repair with ligation of the venous branches of the arteriovenous circulation.

Salvage Aneurysmorrhaphy as an Adaptable and Still Pertinent Technique in the Management of Challenging True Aneurysms of Arteriovenous Fistulas: A Case Series of Different Variations, With Illustrative Surgical Pictures.

Introduction: Aneurysmorrhaphy, described as reduction aneurysmoplasty, partial aneurysmectomy, or vessel wall recalibration, can be considered a suitable surgical plan for true aneurysms of arteriovenous fistulas (AVFs), allowing for a dynamic approach to reconstruction of aneurysmal AVFs of different severities, ensuring salvage of the native access. Report: Six challenging cases of AVF aneurysms are presented, some with extremely dilated and tortuous megafistulas, for which three surgical technique variations were performed. The patients had a mean age of 59.2 years, 50% were female, with brachiocephalic (n = 5, 83.3%) or brachiobasilic (n = 1, 16.7%) AVFs. The fistulas were created an average of 4.67 years previously, and the aneurysms had an average maximum diameter of 37.5 mm (range 25-60 mm). Surgical indications were rupture risk, thrombosis, or outflow stenosis compromising haemodialysis, infections, and concerns for quality of life (affected by post-puncture bleedings, disfiguring aesthetics, pain, and discomfort). The surgical techniques were simple aneurysmorrhaphy (n = 3, 50%), aneurysmorrhaphy with partial excision of aneurysmal segment with end to end anastomosis of venous ends (n = 2, 33.3%), and aneurysmorrhaphy with establishment of new venous outflow (n = 1, 16.7%). All AVFs were patent post-operatively and at follow up (mean 5.6 months, median one month). Haemodialysis was resumed through the AVFs at a mean of 2.17 weeks post-operatively, with placement of an alternative route for haemodialysis in the meantime. No patients experienced post-operative complications. Discussion: Experience with the more challenging cases shows that aneurysmorrhaphy can still be considered an acceptable, flexible, and pertinent method for salvage of megafistulas, giving the surgeon the much needed versatility to adapt to anatomical and pathological variations, with high patency rates and minimal complications, especially when other treatment options are not possible in complicated cases. AVF salvage through aneurysmorrhaphy allows for a dynamic approach to the reconstruction of severely tortuous, dilated veins, ensuring patency of the native AVF.

Evaluating the Effectiveness of Systemic Heparin During Arteriovenous Fistula Creation by Emulating a Target Trial.

Most of the 800,000 people living with end-stage kidney disease in the United States rely on a functioning vascular access to provide life-sustaining hemodialysis, yet one-third of arteriovenous fistulas experience early failures. Determining the safety and effectiveness of systemic heparin during fistula creation could improve the quality and quantity of life for these vulnerable patients. In this paper, a pragmatic randomized trial was emulated to assess the effect of systemic heparin administration (vs. none) during radiocephalic arteriovenous fistula creation on early bleeding and thrombosis using data from two international multicenter randomized trials performed between 2014 and 2019. Marginal risks were estimated using inverse probability weighted parametric survival analysis and confidence intervals were generated with bootstrapping. A total of 914 patients were enrolled and 61% received systemic heparin; median (IQR) age was 58 (49, 67) years and 45% were on hemodialysis at enrollment. No difference in the risk of bleeding events was observed, with a risk difference (95% CI) at 14 days of -0.1% (-1.6, 1.4). The risk of access thrombosis was lower in the heparin group, with a risk of 3.7% (2.6, 4.8) after heparin and 5.3% (3.4, 7.4) without heparin at 14 days (risk ratio 0.72, 95% CI 0.50, 0.98).

Effects to cerebral oxygenation by arteriovenous fistula creation in patients with chronic kidney disease.

BACKGROUND: Vascular access, including arteriovenous fistula (AVF), is essential in patients undergoing hemodialysis (HD). However, the presence of AVF is non-physiological in humans and could pose a burden to the systemic circulation or tissue microcirculation, potentially affecting tissue oxygenation, including in the brain. Recently, near-infrared spectroscopy has been used to measure regional oxygen saturation (rSO2) as a marker of cerebral oxygenation in various settings, including in patients undergoing HD. Thus far, no studies have reported changes in cerebral rSO2 before and after AVF creation. This study aimed to monitor the differences in cerebral oxygenation before and after AVF creation and to clarify the clinical factors affecting the changes in cerebral rSO2. METHODS: Forty-eight patients (34 men, 14 women) with chronic kidney disease (CKD) who were not undergoing dialysis and newly created AVF were recruited. Cerebral rSO2 values before and after AVF creation were evaluated using near-infrared spectroscopy (INVOS 5100c). RESULTS: Cerebral rSO2 values were significantly changed from 60.3% ± 7.5% to 58.4% ± 6.8% before and after AVF creation in all patients (p < 0.001). Cerebral rSO2 were also lower in patients with diabetes mellitus (DM) than in those without DM (57.5 ± 7.1 vs 63.7 ± 6.5, p = 0.003) before surgery; however, no differences of changes in cerebral rSO2 were observed between the two groups after AVF creation. Additionally, multivariate regression analysis identified changes in HR (standardized coefficient: 0.436) as independent factors associated with changes in cerebral rSO2. CONCLUSION: Surgically created AVF was associated with the deterioration of cerebral rSO2 in patients with CKD not undergoing dialysis. Notably, AVF could cause cerebral hypoxia, and thus further studies are needed to clarify the clinical factors influencing changes in cerebral oxygenation after AVF creation.

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

PURPOSE: To assess multicenter two-year patency outcomes of endovascular arteriovenous fistulas (endoAVF) created with the WavelinQ device. MATERIALS AND METHODS: 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 60 years (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. RESULTS: 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 24 months was 95.7% and 92.7%, respectively. Median maturation time is 95 days (IQR 51-231 days). 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. CONCLUSION: 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.

Pulsatile Tinnitus: Differential Diagnosis and Approach to Management.

PURPOSE OF REVIEW: The purpose of this review is to provide an updated approach to the evaluation and management of pulsatile tinnitus (PT), an uncommon but often treatable subtype of tinnitus. RECENT FINDINGS: Secondary PT can be due to either vascular or non-vascular etiologies, including, but not limited to: neoplasm, arteriovenous malformation or fistula, idiopathic intracranial hypertension, dural venous sinus stenosis, otoacoustic etiologies (e.g., otosclerosis, patulous eustachian tube) and bony defects (e.g., superior semicircular canal dehiscence). Computed tomography (CT) and magnetic resonance imaging (MRI) imaging have comparable diagnostic yield, though each may be more sensitive to specific etiologies. If initial vascular imaging is negative and a vascular etiology is strongly suspected, digital subtraction angiography (DSA) may further aid in the diagnosis. Many vascular etiologies of PT can be managed endovascularly, often leading to PT improvement or resolution. Notably, venous sinus stenting is an emerging therapy for PT secondary to idiopathic intracranial hypertension with venous sinus stenosis. Careful history and physical exam can help establish the differential diagnosis for PT and guide subsequent evaluation and management. Additional studies on the efficacy and long-term outcome of venous sinus stenting for venous stenosis are warranted.

Advancing arteriovenous fistula needling: The role of physical exam and doppler ultrasound.

BACKGROUND: The success of haemodialysis (HD) critically depends on the effective use of arteriovenous fistulas (AVFs). The precise needling technique is vital to minimise complications and ensure functional vascular access. OBJECTIVE: This study assesses the effectiveness of a nursing consultation protocol, which integrates physical examination (PE) with Doppler Ultrasound (DUS), in preparing patients for the first AVF needling. DESIGN/PARTICIPANTS: A cross-sectional analysis at a Portuguese National Health Service Hospital engaged thirty new HD patients, four HD needling experienced nurses and one HD vascular access nurse. This study examines the accuracy of PE in assessing the matured AVF by the four nurses compared to a trained vascular access nurse encompassing systematic PE and DUS. MEASUREMENTS: The primary data incorporated AVF characteristics derived from PE (inspection, palpation, and auscultation) and DUS findings (vein depth, diameter, and blood flow). A secondary focus was evaluating the change in nurses' perceived needling complexity following the nursing consultation. RESULTS: The nursing consultation significantly enhanced the identification of crucial AVF features, such as accessory veins (p = 0.002), and improved the accuracy of AVF morphology assessments. This led to identifying longer needling tracks (p = 0.031) and a higher number of safe needling points (p = 0.016). Nurses reported a notable reduction in perceived complexity and potential adverse events following this method (p = 0.027). CONCLUSIONS: Integrating structured PE with DUS in a nursing consultation framework significantly improves the preparation for AVF needling. This approach enhances the efficiency and safety of AVF needling and boosts nurse confidence and patient care in HD settings.

Atypical telencephalic reflux pattern in a cavernous sinus dural AV fistula related to an anatomical variation of the basal vein of Rosenthal.

Cavernous sinus dural arteriovenous fistula can cause cerebral edema and hemorrhage due to cortical venous reflux and congestion. Understanding complex venous reflux and drainage routes is crucial for treatment planning. Here, we present a case of a cavernous sinus dural arteriovenous fistula with cortical venous reflux via two separate terminations of the telencephalic veins caused by an aplastic basal vein of Rosenthal. The patient presented with diplopia and eye redness and was diagnosed with a Cognard type IIa + b cavernous sinus dural arteriovenous fistula. The shunt was supplied by the dural branches of the internal and external carotid arteries. Multiple shunt points involving the intercavernous sinus and the medial aspect of the left cavernous sinus were identified, with drainage into the supraorbital and intracranial veins, including two separate terminations of the telencephalic veins, one leading to the laterocavernous sinus via the superficial middle cerebral vein and the other to the cavernous sinus via the uncal vein, resulting in basal ganglia venous congestion in the absence of the basal vein of Rosenthal. During transvenous embolization, the intracranial veins, cavernous sinus, and intercavernous sinus were obliterated using a double-catheter technique with a combination of coils and liquid embolics. Telencephalic venous variations can lead to cavernous sinus drainage into the basal ganglia and orbitofrontal brain. This unique drainage pattern underscores the importance of recognizing anatomical variations when managing cavernous sinus dural arteriovenous fistula.

Right Coronary Artery-to-Coronary Sinus Fistula with Giant Tortuous Dilatation of the Right Coronary Artery.

Teaching points: A coronary artery fistula (CAF) is an uncommon anomaly characterized by a diverse clinical spectrum, ranging from asymptomatic cases to severe complications, including heart failure and myocardial infarction.

Determining the effect of arteriovenous fistula care training on the self-care behaviors of hemodialysis patients.

INTRODUCTION: The aim was to determine the effect of arteriovenous fistula (AVF) care training given to hemodialysis (HD) patients on the self-care behaviors of patients. METHODS: The randomized controlled experimental study was conducted in the HD unit. The study was carried out with a total of 66 patients. Patients in the intervention group were trained using the AVF Care Education Book for 4 weeks. The study data were collected using the scale for evaluating self-care behaviors related to AVF in HD patients (ASBHD-AVF). Shapiro-Wilk and Kolmogorov-Smirnov tests, independent t-tests, and ANOVA were used in the SPSS 25.0 package program. RESULTS: As a result of the research, it was determined that the average ASBHD-AVF score of the patients in the trained intervention group increased from 54.52 ± 7.41 to 73.77 ± 3.05 (p <0.05). The mean ASBHD-AVF score of the patients in the control group increased from 56.14 ± 4.51 to 58.14 ± 5.93 (p >0.05). When the difference between the two groups was examined, it was determined that the average ASBHD-AVF score of the patients in the intervention group was statistically significantly higher than the control group (p <0.05). CONCLUSION: AVF care education given to HD patients improves patients' self-care behaviors. Improved fistula self-care behaviors of patients will contribute to the healthy functioning of the AVF and the effective HD treatment of patients.

Challenges of Predicting Arteriovenous Access Survival Prior to Conversion from Catheter.

OBJECTIVE: The decision to convert from catheter to arteriovenous access is difficult yet very important. The ability to accurately predict fistula survival prior to surgery would significantly improve the decision making process. Many previously investigated demographic and clinical features have been associated with fistula failure. However, it is not conclusively understood how reliable predictions based on these parameters are on an individual level. The aim of this study was to investigate the probability of arteriovenous fistula maturation and survival after conversion using machine learning workflows. METHODS: A retrospective cohort study on multicentre data from a large North American dialysis organisation was conducted. The study population comprised 73 031 chronic in centre haemodialysis patients. The dataset included 49 variables including demographic and clinical features. Two distinct feature selection/prediction pipelines were used: LASSO regression and Boruta followed by a random forest classifier. Predictions were facilitated for re-conversion to catheter within one year. Additionally, all cause mortality predictions were conducted to serve as a comparator. RESULTS: In total, 38 151 (52.2%) had complete data and made up the main cohort. Sensitivity analyses were conducted in 67 421 patients (92.3%) after eliminating variables with a high proportion of missing data points. Selected features diverged between datasets and workflows. A previously failed arteriovenous access appears to be the most stable predictor for subsequent failure. Prediction of re-conversion based on the demographic and clinical information resulted in an area under the receiver operating characteristic curve (ROCAUC) between 0.541 and 0.571, whereas models predicting all cause mortality performed considerably better (ROCAUC 0.662 - 0.683). CONCLUSION: While group level depiction of major adverse outcomes after catheter to arteriovenous fistula/graft conversion is possible using the included variables, patient level predictions are associated with limited performance. Factors during and after fistula creation as well as biomolecular and genetic biomarkers might be more relevant predictors of fistula survival than baseline clinical conditions.

Application of modified no-touch technique in rabbit arteriovenous fistula model and its effect on venous neointimal hyperplasia.

BACKGROUND: To investigate the technical advantages of a modified no-touch technique (MNTT) in constructing arteriovenous fistulas (AVF) compared to the conventional technique (CT) and assess its potential to reduce neointimal hyperplasia in the outflow vein. METHODS: Forty-seven New Zealand rabbits were randomly divided into three groups: control, CT, and MNTT. Rabbits in control group were observed using ultrasound and then euthanized to obtain external jugular vein (EJV) for Hematoxylin-eosin (H-E). We established common carotid artery (CCA)-EJV AVF using MNTT in the MNTT group and the CT in the CT group. AVF patency and complications were compared between the CT and MNTT groups. Rabbits with patent AVF in both groups were observed using ultrasound 2 weeks after surgery to evaluate changes in the vessel diameter and blood flow spectrum of the AVFs. H-E staining measured the intima thickness of EJV adjacent to the anastomosis and histologic characteristics of the AVF at 2 and 4 weeks after surgery. RESULTS: Five rabbits died after surgery with common symptoms of sneezing, coughing, runny nose, anorexia, and diarrhea; two in the MNTT group and three in the CT group. There were significant differences in the diameter (p = 0.010) and peak systolic velocities (PSV) (p = 0.001) of EJV between the CT and MNTT groups 2 weeks after surgery. Spiral laminar flow (SLF) was observed in CCA and EJV adjacent to anastomosis in the MNTT group. Additionally, histological observations showed less venous neointimal hyperplasia in the MNTT group than in the CT group 4 weeks after surgery. CONCLUSION: The rabbit model of CCA-EJV AVF established using MNTT demonstrated fewer complications, larger vein diameters, and reduced venous neointimal hyperplasia, indicating that this maybe an ideal animal model to further investigate the application of MNTT in AVF surgery.

Incremental hemodialysis and vascular access complications: a 12-year experience in a hospital hemodialysis unit.

BACKGROUND: Incremental hemodialysis (HD) is considered a valid alternative for patients with residual kidney function. Evidence concerning its effect on vascular access is scarce. We present our 12-year experience of an incremental hemodialysis program with the aim of evaluating survival and complications of arteriovenous fistula in these patients compared to the thrice-weekly scheme. METHODS: From January 1st, 2006 to December 31st, 2017, 220 incident patients started hemodialysis, 132 (60%) of whom began hemodialysis with two sessions per week and 88 (40%) with three sessions per week. Demographic and clinical variables were assessed at the start of treatment. Data regarding arteriovenous fistula survival and complications were collected. RESULTS: Both groups had similar baseline sociodemographic and clinical characteristics. A total of 188 (85%) patients were dialyzed with an arteriovenous fistula during follow-up. Eighty-three patients had one or more fistula complications, with no differences between incremental and conventional groups (p = 0.55). Fistula survival rates showed no significant difference between the two groups, whether analyzed from the date of fistula creation (Log Rank p = 0.810) or from the date of initial fistula cannulation (Log Rank p = 0.695). CONCLUSIONS: We found no differences in arteriovenous fistula survival or complication rate between patients who started HD with an incremental versus a conventional treatment scheme. Randomized controlled clinical trials may be warranted to achieve a higher degree of evidence.

Case report: Atypical neurofibromatous neoplasm with uncertain biological potential of the sciatic nerve and a widespread arteriovenous fistula mimicking a malignant peripheral nerve tumor in a young patient with neurofibromatosis type 1.

We report an unusual constellation of diseases in a 32-year-old woman with neurofibromatosis type 1 (NF1) diagnosed with the recently described precursor entity of malignant peripheral nerve sheath tumor (MPNST), the so-called atypical neurofibromatous neoplasm with unknown biological potential (ANNUBP) and a large symptomatic cervical arteriovenous fistula. An [18F] 2-Fluoro-2-deoxy-D-glucose PET/CT (FDG-PET/CT) was performed to detect and stage a conspicuous symptomatic cervical tumor. The FDG-PET/CT showed high FDG uptake in one of the multiple known tumorous lesions associated with peripheral nerves. However, no relevant FDP uptake was observed in this affected cervical area. After digital subtraction angiography, the cervical mass turned out to be a widespread arteriovenous fistula of the vertebral artery. This was successfully treated using endovascular embolization. Subsequently, magnet resonance imaging (MRI) of the FDG-positive tumor revealed a well-enhanced homogeneous mass of the sciatic nerve measuring 5.2×2.4×2.8 cm. Microsurgical gross total tumor resection was performed using ultrasound. The final histopathological diagnosis was ANNUBP transformed from neurofibroma. The patient benefited excellently from the surgery; no recurrence or metastasis has been observed since resection. According to imaging, ANNUBP can be characterized as a well-enhanced homogeneous mass on MRI, displaying high uptake on FDG-PET/CT and hypoechogenic in ultrasound.

Evaluation of arteriovenous fistula maturation and early prediction of clinical eligibility, using ultrasound: The Fistula Maturation Evaluation (FAME) Study.

INTRODUCTION: The study of time-related alterations of ultrasound-determined parameters during maturation, and the assessment of time to hemodynamic maturation, enabling early prediction of clinical eligibility, of hemodialysis autologous arteriovenous fistulae (AVF). METHODS: This is an observational, prospective, study of only AVF-eligible patients referred for access creation, from 02/2019 to 02/2022 (ClinicalTrials.gov identifier: NCT0473687). Brachial artery diameter (dBA), access flow volume (FV), non-augmented efferent vein diameter (dEV), resistivity index (RI), and efferent vein total wall thickness (tEV), were assessed by ultrasound. Measurements were conducted daily in the first week and repeated on days 14, 21, 30, 60, and 90, postoperatively. The primary endpoint included the documentation of serial changes of flow and structural parameters related to AVF maturation in the first 90 days of the post-operative period and maturation early prediction. Secondary endpoints included the determination of factors affecting maturation. RESULTS: One hundred one participants (mean age, 67 ± 6 years; 76 males) were enrolled. Average dBA and FV reached maximum on day 60 (5.64 ± 0.85 mm) and 90 (1.172 ± 617 mL/min), respectively. Day 7 values of dBA (5.48 ± 0.73 mm) and FV (1.039 ± 531 mL/min) did not alter significantly during the follow-up period. Parameters indicative of clinical functionality, dEV (5.82 ± 0.90 mm) and tEV (0.493 ± 0.10 mm), reached approximately 90% of maximum (6.66 ± 1.42 mm and 0.526 ± 0.11 mm), by day 14. RI reached minimum on day 30 (0.46 ± 0.09), without significant changes after day 2 (0.48 ± 0.09, p = 0.284). A significant correlation was identified, between day 7 FV and day 60 dEV (r = 0.40, p = 0.0002). A FV cut-off value ⩾657.51 mL/min, on day 7, predicted successful fistula maturation with 85% sensitivity and 100% specificity. Multivariate analysis identified female gender, age >75, diabetes, and wrist access as independent predictors of decreased values of maturation parameters. CONCLUSION: Hemodynamic maturation is completed by the first postoperative week, while AVF is clinically functional, by the second. FV can be used for early prediction of maturation.