Anticoagulation helps shrink giant venous lakes and arteriovenous fistulas in dural sinus malformation.

BACKGROUND: Dural sinus malformations (DSMs) associated with high flow arteriovenous shunts are a challenging disease in babies that can lead to severe neurological damage or death. We report our treatment strategy in seven consecutive DSMs. METHODS: We performed a retrospective analysis of seven consecutive patients from four centres, treated with transarterial embolization and anticoagulants. RESULTS: Mean clinical and imaging follow-up was 2.8 years (IQR1-3 1.8-5.3). At baseline, the median size of the dilated venous pouch (giant lake) was 35 mm (IQR1-3 24-41) that decreased to a normal or near normal venous collector diameter of median size 11.5 mm (IQR1-3 8.5-13.8). This was achieved after a median of two embolization sessions targeted on dural feeders (IQR1-3 1.5-2.5), leaving associated pial feeders untreated. There were no cerebral hemorrhagic complications during the anticoagulation treatment. Median percentage of shunt remaining after embolization was 30% (IQR1-3 12-30), which spontaneously decreased with anticoagulation and even after discontinuation of anticoagulation, in parallel with the reduction in diameter of the dilated sinus, up to healing (or near healing). At the last clinical assessment, the modified Rankin Scale score was 0 in four patients, 1 in one patient, and 3 in two patients. CONCLUSIONS: Anticoagulants may help to potentiate transarterial embolization in DSMs in babies by decreasing venous dilatation and reducing the remaining arteriovenous shunt, particularly the pial feeders. We did not observe recurrence of arteriovenous shunts after treatment, especially during anticoagulation treatment. Further studies are needed to support our findings.

Efficacy and Safety of Clopidogrel in the Prevention of Primary Failure of Arteriovenous Fistula in Patients with End-Stage Renal Disease: A Systematic Review.

BACKGROUND: Arteriovenous fistula (FAV) is the most widely used vascular access for end-stage renal disease (ESRD) patients undergoing routine hemodialysis in Indonesia. However, FAV can become dysfunctional before it is used for the initiation of hemodialysis, a condition known as primary failure. Clopidogrel is an anti-platelet aggregation that has been reported to reduce the incidence of primary failure in FAV compared to other anti-platelet aggregation agents. Through this systematic review, we aimed to assess the role of clopidogrel to the incidence of primary FAV failure and the risk of bleeding in ESRD patients. METHODS: A literature search was carried out to obtain randomized Control Trial studies conducted since 1987 from Medline / Pubmed, EbscoHost, Embase, Proquest, Scopus, and Cochrane Central without language restrictions. Risk of bias assessment was performed with the Cochrane Risk of Bias 2 application. RESULTS: All of the three studies involved indicated the benefit of clopidogrel for the prevention of AVF primary failure. However, all of the studies have substantial differences. Abacilar's study included only participants with diabetes mellitus. This study also administered a combination of clopidogrel 75 mg and prostacyclin 200 mg/day, while Dember's study gave an initial dose of clopidogrel 300 mg followed by daily dose 75 mg and Ghorbani's study only gave clopidogrel 75 mg/day. Ghorbani and Abacilar started the intervention 7-10 days before AVF creation, while Dember started 1 day after VAF creation. Dember gave treatment for 6 weeks with an assessment of primary failure at the end of week 6, Ghorbani's treatment lasted for 6 weeks with an assessment at week 8, while Abacilar gave treatment for one year with an assessment at weeks 4 after AVF creation. In addition, the prevalence of bleeding did not differ between the treatment and control groups. CONCLUSION: Clopidogrel can reduce the incidence of primary FAV failure without significant increase of bleeding events.

Fístula arteriovenosa pulmonar tratada mediante lobectomía por VATS uniportal / Pulmonary Arteriovenous Fistula Treated by Uniportal VATS Lobectomy

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[Translated article] Pulmonary Arteriovenous Fistula Treated by Uniportal Vats Lobectomy / Fístula arteriovenosa pulmonar tratada mediante lobectomía por VATS uniportal

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Inhibition of Lysyl Oxidase with ß-aminopropionitrile Improves Venous Adaptation after Arteriovenous Fistula Creation.

BACKGROUND: The arteriovenous fistula (AVF) is the preferred hemodialysis access for end-stage renal disease (ESRD) patients. Yet, establishment of a functional AVF presents a challenge, even for the most experienced surgeons, since postoperative stenosis frequently occludes the AVF. Stenosis results from the loss of compliance in fibrotic areas of the fistula which turns intimal hyperplasia into an occlusive feature. Fibrotic remodeling depends on deposition and crosslinking of collagen by lysyl oxidase (LOX), an enzyme that catalyzes the deamination of lysine and hydroxylysine residues, facilitating intra/intermolecular covalent bonds. We postulate that pharmacological inhibition of lysyl oxidase (LOX) increases postoperative venous compliance and prevents stenosis in a rat AVF model. METHODS: LOX gene expression and vascular localization were assayed in rat AVFs and human pre-access veins, respectively. Collagen crosslinking was measured in humans AVFs that matured or failed, and in rat AVFs treated with ß-aminopropionitrile (BAPN), an irreversible LOX inhibitor. BAPN was either injected systemically or delivered locally around rat AVFs using nanofiber scaffolds. The major endpoints were AVF blood flow, wall fibrosis, collagen crosslinking, and vascular distensibility. RESULTS: Non-maturation of human AVFs was associated with higher LOX deposition in pre-access veins (N=20, P=0.029), and increased trivalent crosslinks (N=18, P=0.027) in human AVF tissues. Systemic and local inhibition of LOX increased AVF distensibility, while reducing wall fibrosis and collagen crosslinking in rat fistulas. CONCLUSIONS: Our results demonstrate that BAPN-mediated inhibition of LOX significantly improves vascular remodeling in experimental fistulas.

Medical treatment of uterine arteriovenous malformation: a systematic review and meta-analysis.

OBJECTIVE: To quantify the efficacy of medical management of uterine arteriovenous malformation (AVM) and compare efficacy between different classes of medication. In addition, we evaluated for factors associated with treatment success and pregnancy outcomes after medical management. DESIGN: Systematic review and meta-analysis. SETTING: Not applicable. PATIENT(S): Thirty-two studies representing 121 premenopausal women with medically-treated uterine AVM were identified via database searches of MEDLINE, Embase, Web of Science, and cited references. INTERVENTION(S): Medical treatment with progestins, gonadotropin-releasing hormone agonists (GnRH-a), methotrexate, combined hormonal contraception , uterotonics, danazol, or combination of the above. MAIN OUTCOME MEASURE(S): Primary outcome of treatment success was defined as AVM resolution without subsequent procedural interventions. Secondary outcome was treatment complication (readmission or transfusion). RESULT(S): The overall success rate of medical management was 88% (106/121). After adjusting for clustering effects, success rates for progestin (82.5%; 95% confidence interval [CI], 70.1%-90.4%), GnRH-a (89.3%; 99% CI, 71.4%-96.5%) and methotrexate (90.0%; 99% CI, 55.8%-98.8%) were significantly different from the null hypothesis of 50% success. The agents with the lowest adjusted proportion of complications were progestins (10.0%; 99% CI, 3.3%-26.8%) and GnRH-a (10.7%; 99% CI, 3.5%-28.4%). No clinical factors were found to predict treatment success. Twenty-six subsequent pregnancies are described, with no reported recurrences of AVM. CONCLUSION(S): Medical management for uterine AVM is a reasonable approach in a well selected patient. These data should be interpreted in the context of significant publication bias.

Medical management with interventional therapy versus medical management alone for unruptured brain arteriovenous malformations (ARUBA): final follow-up of a multicentre, non-blinded, randomised controlled trial.

BACKGROUND: In A Randomized trial of Unruptured Brain Arteriovenous malformations (ARUBA), randomisation was halted at a mean follow-up of 33·3 months after a prespecified interim analysis showed that medical management alone was superior to the combination of medical management and interventional therapy in preventing symptomatic stroke or death. We aimed to study whether these differences persisted through 5-years' follow-up. METHODS: ARUBA was a non-blinded, randomised trial done at 39 clinical centres in nine countries. Adults (age ≥18 years) diagnosed with an unruptured brain arteriovenous malformation, who had never undergone interventional therapy, and were considered by participating clinical centres to be suitable for intervention to eradicate the lesion, were eligible for inclusion. Patients were randomly assigned (1:1) by a web-based data collection system, stratified by clinical centre in a random permuted block design with block sizes of two, four, and six, to medical management alone or with interventional therapy (neurosurgery, embolisation, or stereotactic radiotherapy, alone or in any combination, sequence, or number). Although patients and investigators at a given centre were not masked to treatment assignment, investigators at other centres and those in the clinical coordinating centre were not informed of assignment or outcomes at any of the centres. The primary outcome was time to death or symptomatic stroke confirmed by imaging, assessed by a neurologist at each centre not involved in the management of participants' care, and monitored by an independent committee using an adaptive approach with interim analyses. Enrolment began on April 4, 2007, and was halted on April 15, 2013, after which follow-up continued until July 15, 2015. All analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, NCT00389181. FINDINGS: Of 1740 patients screened, 226 were randomly assigned to medical management alone (n=110) or medical management plus interventional therapy (n=116). During a mean follow-up of 50·4 months (SD 22·9), the incidence of death or symptomatic stroke was lower with medical management alone (15 of 110, 3·39 per 100 patient-years) than with medical management with interventional therapy (41 of 116, 12·32 per 100 patient-years; hazard ratio 0·31, 95% CI 0·17 to 0·56). Two patients in the medical management group and four in the interventional therapy group (two attributed to intervention) died during follow-up. Adverse events were observed less often in patients allocated to medical management compared with interventional therapy (283 vs 369; 58·97 vs 78·73 per 100 patient-years; risk difference -19·76, 95% CI -30·33 to -9·19). INTERPRETATION: After extended follow-up, ARUBA showed that medical management alone remained superior to interventional therapy for the prevention of death or symptomatic stroke in patients with an unruptured brain arteriovenous malformation. The data concerning the disparity in outcomes should affect standard specialist practice and the information presented to patients. The even longer-term risks and differences between the two therapeutic approaches remains uncertain. FUNDING: National Institute of Neurological Disorders and Stroke for the randomisation phase and Vital Projects Fund for the follow-up phase.

[An hereditary hemorrhagic telangiectasia of late revealed by a cerebral venous thrombosis: A case report]. / Une télangiectasie hémorragique héréditaire révélée tardivement par une thrombose veineuse cérébrale : à propos d'un cas.

INTRODUCTION: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterized by the triad of nose bleeding, telangiectasia and familial heredity. CASE REPORT: We report the case of a patient who had idiopathic venous cerebral thrombosis complicated by a cerebral infarction treated with warfarin. In the context of a psoas hematoma by warfarine overdose and immobilization, the patient had deep vein thrombosis of the left lower limb with pulmonary embolism revealing a pulmonary arteriovenous malformation. After a reexamination, the patient clinical phenotype of HHT was confirmed genetically. The patient was treated with rivaroxaban allowing clinical improvement and partial recanalization of all thrombosis after six months. Thrombotic overisk has already been studied in HHT patients but the use of anticoagulants is at higher risk in these patients. However this patient experienced no adverse event with rivaroxaban. CONCLUSION: This is the first case described of cerebral venous thrombosis treated with rivaroxaban revealing an HHT.

Role of aspirin and statin therapy in patients with cerebral cavernous malformations.

Stagnant blood flow and organizing thrombus are intralesional components of patients with cerebral cavernous malformations (CCM). Stasis and inflammation are mechanisms of growth, lesional instability and acute hemorrhages with or w/o symptoms. We evaluate the association of pre-diagnostic aspirin and/or statin use with acute hemorrhages at diagnosis. Patients with a CCM diagnosis were identified and categorized according to their medications on admission into four groups (no therapy, statin, aspirin, combined). The primary outcome was an acute hemorrhage (with or w/o symptoms) at diagnosis reported in a standardized manner from the T2 weighted magnetic resonance image. A multivariate generalized linear mixed models (GLMM) was utilized to conduct per-lesion analysis. We identified 446 patients with 635 lesions. An acute hemorrhage at diagnosis was observed in 31% of the patients. There were 328 patients without statin or aspirin therapy, 34% of whom presented with acute hemorrhage. Of patients on aspirin therapy at diagnosis, 25% presented with hemorrhage. Of patients on statin therapy, 26% had a hemorrhage at diagnosis. Combined therapy in 44 patients demonstrated a lower proportion of patients with acute hemorrhages (7 patients, 16% incidence). A GLMM showed that patients in the combined therapy group to have significantly lower odds of having an acute hemorrhage at diagnosis compared to the reference group of no therapy (OR 0.24; 95% CI 0.09-0.59; P = 0.002). Patients with a CCM receiving therapy with both aspirin and statins were less likely to present at diagnosis with acute hemorrhage.

Neurosyphilis complicated with pial arteriovenous fistula: A rare case report.

INTRODUCTION: Neurosyphilis is a chronic, infectious disease of the central nervous system. Pial arteriovenous fistulae (PAVF) are rare vascular malformations. Both can cause vascular damage, but it is quite rare for both to present at the same time. PATIENT CONCERNS: Here we present a 66-year-old man with affective disorder, hypomnesia, and recent convulsions. Magnetic resonance imaging revealed cerebral swelling, hyperintensity in the cortex/subcortex, and multiple lacunar cerebral infarctions. Computed tomography angiography revealed the presence of a pial arteriovenous fistula. DIAGNOSES: Based on laboratory tests and imaging, diagnoses of neurosyphilis and pial arteriovenous fistula were made. INTERVENTIONS: Antisyphilis therapy was provided. OUTCOMES: Symptoms improved and antisyphilis treatment continued as an outpatient. No intracranial hemorrhage was seen 6 months later. CONCLUSION: Treponema pallidum infection may be related to the formation of PAVF, and may also promote the progression of it; however, further work is required to confirm this.

Defective vascular signaling & prospective therapeutic targets in brain arteriovenous malformations.

The neurovascular unit is composed of endothelial cells, vascular smooth muscle cells, pericytes, astrocytes and neurons. Through tightly regulated multi-directional cell signaling, the neurovascular unit is responsible for the numerous functionalities of the cerebrovasculature - including the regulation of molecular and cellular transport across the blood-brain barrier, angiogenesis, blood flow responses to brain activation and neuroinflammation. Historically, the study of the brain vasculature focused on endothelial cells; however, recent work has demonstrated that pericytes and vascular smooth muscle cells - collectively known as mural cells - play critical roles in many of these functions. Given this emerging data, a more complete mechanistic understanding of the cellular basis of brain vascular malformations is needed. In this review, we examine the integrated functions and signaling within the neurovascular unit necessary for normal cerebrovascular structure and function. We then describe the role of aberrant cell signaling within the neurovascular unit in brain arteriovenous malformations and identify how these pathways may be targeted therapeutically to eradicate or stabilize these lesions.

Fish oil and aspirin effects on arteriovenous fistula function: Secondary outcomes of the randomised omega-3 fatty acids (Fish oils) and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED) trial.

BACKGROUND: Arteriovenous fistulas (AVF) for haemodialysis often experience early thrombosis and maturation failure requiring intervention and/or central venous catheter (CVC) placement. This secondary and exploratory analysis of the FAVOURED study determined whether omega-3 fatty acids (fish oils) or aspirin affected AVF usability, intervention rates and CVC requirements. METHODS: In 567 adult participants planned for AVF creation, all were randomised to fish oil (4g/d) or placebo, and 406 to aspirin (100mg/d) or placebo, starting one day pre-surgery and continued for three months. Outcomes evaluated within 12 months included AVF intervention rates, CVC exposure, late dialysis suitability failure, and times to primary patency loss, abandonment and successful cannulation. RESULTS: Final analyses included 536 participants randomised to fish oil or placebo (mean age 55 years, 64% male, 45% diabetic) and 388 randomised to aspirin or placebo. Compared with placebo, fish oil reduced intervention rates (0.82 vs 1.14/1000 patient-days, incidence rate ratio [IRR] 0.72, 95% confidence interval [CI] 0.54-0.97), particularly interventions for acute thrombosis (0.09 vs 0.17/1000 patient-days, IRR 0.53, 95% CI 0.34-0.84). Aspirin significantly reduced rescue intervention rates (IRR 0.45, 95% CI 0.27-0.78). Neither agent significantly affected CVC exposure, late dialysis suitability failure or time to primary patency loss, AVF abandonment or successful cannulation. CONCLUSION: Although fish oil and low-dose aspirin given for 3 months reduced intervention rates in newly created AVF, they had no significant effects on CVC exposure, AVF usability and time to primary patency loss or access abandonment. Reduction in access interventions benefits patients, reduces costs and warrants further study.

Three years' experience of dialysis event surveillance.

BACKGROUND: The main study aim was to track infections, evaluate performance, and identify opportunities for improved practice since infections, especially those associated with multidrug-resistant organisms, are the second most common cause of death among end-stage renal disease patients. METHODS: This study describes the establishment of baseline dialysis event surveillance at a large dialysis center. Every month, the dialysis center staff reported the total number of maintenance hemodialysis patients to the department of infection control and hospital epidemiology. The surveillance system for dialysis events included monthly monitoring of hemodialysis patients in outpatient settings for positive blood cultures, intravenous antimicrobial initiation, and local vascular access infections. RESULTS: We calculated the pooled mean rates of positive blood cultures, intravenous antimicrobial initiation, and local vascular access infections during the period from June 1, 2014 to September 30, 2017. Results indicated more dialysis events were attributed to the CVC than any other dialysis vascular access. Regardless of vascular access type, intravenous antimicrobial initiation was the most commonly reported dialysis-associated event. CONCLUSIONS: Dialysis events surveillance can be used to produce a decrease in both morbidity and mortality rates in hemodialysis patients.

Wyburn-Mason syndrome presenting with bilateral retinal racemose hemangioma with unilateral serous retinal detachment.

Wyburn-Mason syndrome is associated with unilateral retinal racemose hemangioma. Rarely, it presents with bilateral and symmetrical grade of malformation. We describe a 37-year old male, who presented with Wyburn-Mason syndrome presenting with bilateral but asymmetrical retinal hemangioma. The eye with advanced grade of hemangioma was complicated with exudation, intraretinal fluid, neurosensory detachment, and reduced vision. He was treated with one intravitreal injection of bevacizumab, after which both the intraretinal fluid and neurosensory detachment resolved. His vision improved and was maintained till 1 year of follow-up.

Antiplatelet agents maintain arteriovenous fistula and graft function in patients receiving hemodialysis: A nationwide case-control study.

BACKGROUND: In this study, we evaluated the effects of various medications on the patency of vascular access (VA) for hemodialysis. METHODS: We analyzed data from the Longitudinal Health Insurance Database of Taiwan. We adopted a case-control study design within a cohort of patients who had received regular hemodialysis between 2002 and 2012; 34,354 patients with first VA failure were identified, and the duration from VA creation date to the first VA failure date was calculated. We then classified these patients into two groups, namely arteriovenous fistula (AVF, n = 25,933) and arteriovenous graft (AVG, n = 8,421). Each group was further divided into two subgroups, namely short-term (<1 year) and long-term (≥1 year) patency. RESULTS: The risk factors for early VA failure were age ≥65 years, diabetes mellitus, hyperlipidemia, cerebral vascular disease, congestive heart failure, peripheral artery disease, and sepsis. Male sex, hypertension, cancer, and peptic ulcer were associated with early AVF failure. Antiplatelet therapy increased the AVF and AVG patency times with adjusted odds ratios of 0.748 (95% confidence interval [CI]: 0.703-0.796, p < 0.0001) and 0.810 (95% CI: 0.728-0.901, p = 0.0001), respectively. A significant decrease in the VA failure risk was observed with an increase in the cumulative defined daily dose of antiplatelet agents. CONCLUSION: This nationwide study demonstrated that some risk factors were associated with early VA failure and that the use of antiplatelet agents prevented the loss of VA patency in a dose-response manner. Thus, antiplatelet drugs should be routinely administered to high-risk patients receiving dialysis.

Ultrasound-guided thrombin injection for treatment of femoral artery pseudoaneurysm with concomitant AV-fistula - a retrospective single centre experience.

BACKGROUND: Increasing volume of complex percutaneous endovascular procedures in highly anticoagulated patients generate a not negligible percentage of femoral pseudoaneurysms (PSA) with concomitant arteriovenous fistulas (AVF). While ultrasound-guided thrombin injection (UGTI) is the therapy of choice for PSA, concomitant AVF is regarded as a contraindication for UGTI, as venous thromboembolism is feared. In this retrospective, register-based cohort study, we report on and evaluate the use of UGTI for the treatment of PSA with AFV. PATIENTS AND METHODS: All patients (n = 523), who underwent UGTI for femoral PSA at the German Heart Centre Munich from January 2011 until January 2018, were retrospectively reviewed for the presence of a concomitant AVF and outcomes were recorded. RESULTS: Forty femoral PSA/AVFs treated by UGTI were identified. The mean enddiastolic arterial-flow-velocity above the AVF, an estimate of the AVF size, was 14.61 ± 1.7 cm/sec. The Majority of patients exhibited flow-velocities < 25 cm/sec (n = 31; 77.5 %) and were on either uninterrupted oral anticoagulation (n = 32; 80 %) or dual antiplatelet therapy (n = 8). Twenty-eight (70 %) PSA/AVFs could be successfully closed by UGTI. In eight multicompartmental PSAs, partial obliteration necessitated combined treatment with manual compression, while one partial occlusion was treated by observation. There were three failures, of which two underwent covered-stent-graft-implantation and one surgical repair. One DVT (2.5 %) occurred two days after UGTI in the by far largest AVF (60 cm/sec) included in the study. Besides two late PSA recurrences treated by surgery, no other complications were observed. AVF persisted in 65 %, all of them asymptomatic. The mean follow-up was 6 ± 15.5 months. CONCLUSIONS: UGTI appears to be a treatment option in femoral PSA/AVF, at least under oral anticoagulation in small fistulas with enddiastolic arterial-flow-velocities ≤ 25 cm/sec. However, caution is necessary in larger AVFs, which should remain a contraindication for UGTI.

Valoración del flujo de la fístula arteriovenosa en pacientes en tratamiento con quelantes con calcio / Evaluation of arteriovenous fistula blood flow in patients with calcium chelation therapy

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