Characteristics and outcomes of pediatric dural arteriovenous fistulas: a systematic review.

BACKGROUND: Dural arteriovenous fistulas (dAVF) are arteriovenous shunts in communication with the dural vasculature in the brain or spine. Apart from single-center series, risk factors and treatment outcomes for pediatric dAVFs are largely undescribed. METHODS: We performed a systematic literature review of pediatric (< 18 years at diagnosis) intracranial and spinal dAVF according to PRISMA guidelines. We queried PubMed, CINAHL, SCOPUS, and Embase databases without time/date restriction. Search strings included a variety of MeSH keywords relating to dural AV fistulas in combination with MeSH keywords related to pediatric cases (see Appendix). Manuscripts describing patients diagnosed with dural sinus malformations or pial AVF were excluded. RESULTS: We identified 61 studies describing 69 individual patients. Overall, dAVF were more common in males (55.1%) with a mean age of diagnosis (5.17 ± 4.42 years). Approximately 20.2% of patients presented with cardiovascular disease (CVD), and 31.9% were discovered incidentally on neuroimaging studies. Transverse-sigmoid junction was the most common location (17.3%). Ninety-three percent (64 patients) were treated, most commonly using endovascular embolization (68.1%) followed by surgery (8.7%) and radiosurgery (2.9%). Almost half (43.8%) of dAVFs were completely obliterated. Of the 64 procedures, there were 19 neurological complications (29.7%) of varying severity where 12.5% were considered transient (i.e., pseudomeningocele) and 17.2% permanent (i.e., mortality secondary to acute sinus thrombosis, etc.). CONCLUSION: There is a paucity of information on pediatric dAVFs. This systematic review summarizes the published cases of dAVFs in the pediatric population. While the rate of missing data is high, there is publication bias, and precise details regarding complications are difficult to ascertain, this review serves as a descriptive summary of pediatric dAVFs.

Pediatric non-galenic pial arteriovenous fistula's characteristics and outcomes: a systematic review.

INTRODUCTION: Pediatric non-galenic pial arteriovenous fistulas (pAVFs) are rare vascular malformations that are characterized by a pial arterial-venous connection without an intervening capillary bed. Outcomes and treatment strategies for pAVFs are highly individualized, owing to the rarity of the disease and lack of large-scale data guiding optimal treatment approaches. METHODS: We performed a systematic review of pediatric patients (< 18 years at diagnosis) diagnosed with a pAVF by digital subtraction angiogram (DSA). The demographics, treatment modalities, and outcomes were documented for each patient and clinical outcome data was collected. Descriptive information stratified by outcome scores were classified as follows: 1 = excellent (no deficit and full premorbid activity), 2 = good (mild deficit and full premorbid activity), 3 = fair (moderate deficit and impaired activity), 4 = poor (severe deficit and dependent on others), 5 = death. RESULTS: A total of 87 studies involving 231 patients were identified. Median age at diagnosis was 3 years (neonates to 18 years). There was slight male preponderance (55.4%), and 150 subjects (81.1%*) experienced excellent outcomes after treatment. Of the 189 patients treated using endovascular approaches, 80.3% experienced excellent outcomes and of the 15 patients surgically treated subjects 75% had an excellent outcome. The highest rate of excellent outcomes was achieved in patients treated with Onyx (95.2%) and other forms of EvOH (100%). High output heart failure and comorbid vascular lesions tended to result in worse outcomes, with only 54.2% and 68% of subjects experiencing an excellent outcome, respectively. *Outcomes were reported in only 185 patients. CONCLUSION: pAVFs are rare lesions, necessitating aggregation of patient data to inform natural history and optimal treatment strategies. This review summarizes the current literature on pAVF in children, where children presenting with heart failure as a result of high flow through the lesion were less likely to experience an excellent outcome. Prospective, large-scale studies would further characterize pediatric pAVFs and enable quantitative analysis of outcomes to inform best treatment practices.

Far infrared treatment on the arteriovenous fistula induces changes in sVCAM and sICAM in patients on hemodialysis.

INTRODUCTION: There is a substantial risk of developing stenosis and dysfunction in the arteriovenous fistula (AVF) in patients on hemodialysis (HD). Far infrared radiation (FIR) is a non-invasive local intervention with a potentially beneficial effect on AVF patency. The underlying mechanism is not clear. It was hypothesized that a single FIR treatment reduces factors of inflammation and promotes endothelial vasodilators in the AVF. METHODS: Forty HD patients with an AVF were included in an open-label intervention study. Patients were randomized to receive either FIR (FIR group) or no FIR (control group). Blood samples were drawn directly from the AVF and from a peripheral vein in the non-AVF arm before (T0) and 40 min after (T40) treatment during a HD session. The changes [median (interquartile range)] in circulating factors of inflammation, endothelial function and vasoreactivity during FIR were measured. RESULTS: In the AVF a single FIR treatment during dialysis resulted in a significantly diminished decrease in soluble vascular cell adhesion molecule, sVCAM [-31.6 (-54.3; 22.1) vs -89.9 (-121.6; -29.3), P = .005] and soluble intercellular adhesion molecule, sICAM [-24.2 (-43.5; 25.3) vs -49 (-79.9; -11.6), P = .02] compared with the control group. Other factors, such as interleukins, nitrite, nitrate and tumor necrosis factor 1, also declined during dialysis, but with no significant differences related to FIR in either the AVF or the non-AVF arm. CONCLUSION: A single FIR treatment attenuated the decrease in sVCAM and sICAM in the AVF compared with a control group during HD. Findings do not support the hypothesis of a vaso-protective effect of FIR. The long-term effects of FIR on the AVF are unknown.

Improving assessment and escalation of threatened haemodialysis access: results of a nursing-led program.

BACKGROUND: Optimal vascular access is critical to successful haemodialysis. Acute thrombosis of haemodialysis access often leads to unplanned hospital admissions and interventions to restore patency. Western Health is a large health service in Victoria, Australia. During the period February 2019 to January 2020, the rate of arteriovenous fistula (AVF) and arteriovenous graft (AVG) at Western Health satellite dialysis units was 0.33 episodes per 1000 patient-days, higher than the reported rate in the literature of 0.24 events per 1000 patient-days, and was associated with a cumulative total of 139 days of inpatient stay (2.2 per 1000 patient-days). METHODS: The above results prompted creation of an education and escalation pathway for threatened haemodialysis access, based upon clinical markers of vascular access stenosis or imminent thrombosis assessed by nursing staff in satellite haemodialysis centres. In the period February 2020 to January 2021, the education and escalation pathway was implemented. We assessed referrals via the pathway, rates of AVF/AVG thrombosis and associated hospital length of stay in the following 12-month period (February 2021 to January 2022). RESULTS: Following introduction of the pathway, rates of AVF/AVG thrombosis declined to 0.15 per 1000 patient-days (p = 0.02), associated with a decline in attributable cumulative inpatient stay to 55 days (0.69 per 1000 patient-days). CONCLUSIONS: Our program demonstrates that the majority of thrombosed vascular access can be predicted and potentially averted with vigilant and well-practiced routine clinical assessment by trained nursing staff. Our nursing-led education and escalation program successfully identified vascular access at risk of imminent thrombosis, reduced rates of acute thrombosis and associated healthcare costs. Despite these improvements, there are still disparities in outcomes for patients with thrombosed vascular access, with regards to length of stay and requirement for insertion of a temporary central venous catheter (CVC) for urgent dialysis whilst awaiting intervention, and these are areas for further investigation and improvement.

Optimal vascular access to hemodialysis, or what modern medicine offers us.

Hemodialysis is a life-saving method for patients with acute and chronic kidney failure. This treatment requires sufficiently large and safe vascular access. Ensuring optimal vascular access is therefore a prerequisite and an integral part of the care of these patients. In addition to commonly known vascular approaches such as non-tunnelized or tunneled hemodialysis catheters and AV fistulas, less well-known methods are also available, such as a translumbar or directly surgically inserted hemodialysis catheter into the right atrium. However, these alternative approaches are the only, life-saving alternative for some patients. The ambition of this review article is to offer a comprehensive view of the available options for vascular access, the algorithm for its selection and solutions to the most common complications in clinical practice.

Inadvertent aortocoronary arteriovenous fistula after CABG: Systematic review of case reports.

OBJECTIVE: To summarize published case reports of aortocoronary arteriovenous fistula (ACAVF) after coronary artery bypass grafting surgery (CABG). BACKGROUND: Inadvertent ACAVF is a rare complication following CABG. However, the incidence continues to rise, and its management details and clinical outcomes have not been well described. METHODS: To identify all published cases of ACAVF following CABG, PubMed, EMBASE, and Scopus were searched through November 2019. We defined ACAVF as inadvertent attachment of the grafting vessel onto a cardiac vein instead of targeted coronary artery. A systematic review was performed to identify the incidence, clinical features, and management outcomes. RESULTS: A total of 48 post-CABG ACAVF cases were gathered. Among these patients, the mean age was 61.9 years and 79.2% were men. Most common presenting symptoms were chest pain (60.4%) and dyspnea (27.1%). The average onset of symptoms was 3 years; however, 54.2% of patients developed symptoms within the first year. The majority of cases reported targeted native vessel LAD during CABG (62.5%). Of these cases, 9 (18.8%) were managed conservatively, 8 (16.7%) chose to undergo surgery including ligation of fistula and repeat CABG, and 27 (56.3%) underwent percutaneous closure. Among these patients 13 cases (27.1%) were managed with coil embolization, 5 (10.4%) with balloon embolization, 5 (10.4%) were treated with a covered stent, and 4 (8.3%) used a vascular plug. There were no reported complications following treatment in this group. CONCLUSIONS: Inadvertent ACAVF are rare following CABG. Percutaneous closure was feasible and safe in treating these patients.

Interventional closure of aortomitral perforation after TAVR: A case report.

Despite TAVR emerging as the gold standard for a broad spectrum of patients, it is associated with serious complications. In this report we present a case, where a TAVR procedure led to a perforation at the aortomitral continuity, discuss the risk factors for the occurrence of perforations and how we decided to treat the patient.

End-to-side versus side-to-side anastomosis with distal vein ligation for arteriovenous fistula creation.

INTRODUCTION: There is lack of compelling evidence about the best technique to carry out the anastomosis between the artery and the vein: end to side or side to side. This issue was addressed by very few randomized controlled studies. This topic has recently re-emerged with the advent of the endovascular fistula creation using the side-to-side technique.Objectives: To compare the results of both surgical techniques for the creation of arteriovenous anastomosis. METHODS: This is a randomized controlled prospective study. All renal failure patients, 18 years and older, referred to our institution requiring creation of a new arm arteriovenous fistulas, including distal radio-cephalic, ulno-basilic, proximal brachio-cephalic or brachio-basilic configurations were included. RESULTS: Between February 2018 and October 2018, 378 patients underwent creation of permanent haemodialysis access. A total of 100 patients were randomized equally into the end-to-side and side-to-side groups. Follow-up for the study purpose continued until May 2019 (mean = 9 months, range 1-12). Patients' age ranged from 19 to 68 years. Sevety-seven arteriovenous fistulas were created at the elbow (37 brachio-basilic and 40 brachio-cephalic). Radio-cephalic fistulae were 23, created at wrist and in the forearm. Primary technical success was 97%, and 35 (70%) and 17 (34%) cases achieved functionally maturation in the end-to-side and side-to-side groups, respectively (P = 0.0001). Primary and secondary patency rates at 12 months were 76% end to side versus 78% STS (P = 0.381) and 84% end to side versus 86% STS (P = 0.225), respectively. CONCLUSION: End-to-side technique should be used in all instances of arteriovenous fistulas creation.

Fetal valproate syndrome with coronary arteriovenous fistula: a case report.

Interestingly, our case presenting with coronary AV fistula firstly reported in the literature with fetal valproate syndrome. Although differential diagnosis is sometimes difficult, it can be diagnosed with detailed history, physical examination and appropriate laboratory tests. Fetal valproate syndrome can be prevented by discontinue of the valproic acid especially during first trimester of pregnancy.

A Case Report of Delayed Presentation of a Carotid-Jugular Fistula Caused by Blunt Injury from an Arrow.

BACKGROUND: Acquired arteriovenous fistulas (AVFs) are most commonly caused by direct arterial trauma, with 90% of traumatic AVFs due to penetrating trauma. Post-traumatic common carotid artery-internal jugular vein fistulae are rare, with an incidence of 4% to 7% of all traumatic AVFs. CASE REPORT: We present a case of delayed presentation of a patient with shortness of breath, neck pain, and worsening right upper extremity paresthesias 10 days after a blunt injury to the neck by an arrow. He was subsequently found to have a common carotid artery-internal jugular vein fistula and a common carotid pseudoaneurysm on computed tomography angiography. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Post-traumatic common carotid-jugular AVFs are uncommon, especially in patients with delayed presentations and a blunt injury mechanism. If left untreated, AVFs may progress to high-output cardiac failure, atrial fibrillation, and embolization. Clinicians must be aware of this finding, given the potential for significant morbidity.

Topical tranexamic acid (TXA) for the management of a bleeding arteriovenous fistula.

Tranexamic acid (TXA) is increasing in use in the Emergency Department (ED). While its topical uses have largely been observed in the management of epistaxis, other applications are utilized. We present a case of an 84 year old male with a bleeding arteriovenous fistula, responsive to topical application of tranexamic acid. This case report demonstrates another novel application of TXA in emergency care.

Vascular access type and mortality in haemodialysis: a retrospective cohort study.

BACKGROUND: Haemodialysis patients have a high mortality rate. Part of this can be attributed to vascular access complications. Large retrospective studies have shown a higher mortality in patients dialysed with a catheter, which is mostly ascribed to infectious complications. Since we observe very little infectious complications in our haemodialysis patients, the aim of our study was to assess if we could still detect a difference in survival according to vascular access type. METHODS: Patients that started chronic haemodialysis treatment between 1/1/2007 and 31/12/2016 at the 'Universitair Ziekenhuis Brussel' were retrospectively studied. The time to death was studied as a function of the two main vascular access types using survival analysis, considering the type of vascular access at the initiation of dialysis or as time varying, and accounting for the available baseline characteristics. RESULTS: Of 374 patients 309 (82.6%) initiated haemodialysis with a catheter, while 65 patients initiated with an arteriovenous access. Vascular access type during follow-up did not change in 74% of all patients. A Kaplan Meier plot did not suggest a survival dependent on the vascular access type at start. An extended cox proportional hazard analysis showed that vascular access type was not independently correlated with mortality. However, age, history of congestive heart failure and active cancer at initiation of dialysis were independently associated with mortality. CONCLUSIONS: In this retrospective cohort study, haemodialysis vascular access type was not independently correlated with patient survival, even after taking into account change of vascular access over time.

Innovations in vascular access for hemodialysis.

Worldwide, hemodialysis remains the prevalent dialysis modality for more than 2 million patients who require well-functioning vascular access for this procedure. Creation of an arteriovenous fistula for long-term hemodialysis was the first innovation since the Scribner shunt and was followed by the development of an arteriovenous graft and catheter. Bioengineered vessels were developed during the last century, but this field has been energized by recent technology relating to the creation of human vessels. Novel endovascular techniques for creating an arteriovenous fistula may resolve some of the logistical issues involved in obtaining a timely arteriovenous fistula. Treatment of access stenosis, infection, and thrombosis has remained suboptimal, and innovative technologies are evolving. Many new approaches are now targeting the biological and mechanical aspects of vascular access, such as creation and maturation of arterial and venous anastomoses, development of a biological conduit for outflow, and negotiating the problems of central vein stenosis. Importantly, processes of access care that have long focused on arteriovenous fistulas are now recognizing the new paradigm, providing a complementary niche to arteriovenous grafts and dialysis catheters in the algorithm for individualized access placement. Cumulatively, to the credit of the multidisciplinary team approach, the long overdue focus on the very existential issue of vascular access for hemodialysis is being approached with newfound evidence-based enthusiasm as the vexing challenges related to regulations and reimbursement in hemodialysis persist. Patient choice and experience, often missed and ignored in the challenging management of an end-stage organ failure, need to stay central as we focus on patient-centered care of vascular access.

Preeminent role of the cardiorenal axis in the antihypertensive response to an arteriovenous fistula: an in silico analysis.

Percutaneous creation of a small central arteriovenous (AV) fistula is currently being evaluated for the treatment of uncontrolled hypertension (HT). Although the mechanisms that contribute to the antihypertensive effects of the fistula are unclear, investigators have speculated that chronic blood pressure (BP) lowering may be due to 1) reduced total peripheral resistance (TPR), 2) increased secretion of atrial natriuretic peptide (ANP), and/or 3) suppression of renal sympathetic nerve activity (RSNA). We used an established integrative mathematical model of human physiology to investigate these possibilities from baseline conditions that mimic sympathetic overactivity and impaired renal function in patients with resistant HT. After a small fistula was stimulated, there were sustained increases in cardiac output, atrial pressures, and plasma ANP concentration (3-fold), without suppression of RSNA; at 8 wk, BP was reduced 14 mmHg along with a 32% fall in TPR. In contrast, when this simulation was repeated while clamping ANP at baseline BP decreased only 4 mmHg, despite a comparable fall in TPR. Furthermore, when chronic resetting of atrial mechanoreceptors was prevented during the fistula, RSNA decreased 7%, and along with the same threefold increase in ANP, BP fell 19 mmHg. This exaggerated fall in BP occurred with a similar decrease in TPR when compared with the above simulations. These findings suggest that ANP, but not TPR, is a key determinant of long-term BP lowering after the creation of an AV fistula and support a contribution of suppressed RSNA if resetting of the atrial-renal reflex is truly incomplete.NEW & NOTEWORTHY The mechanisms that contribute to the antihypertensive effects of a small arteriovenous (AV) fistula comparable to the size used by the ROX coupler currently in clinical trials are unclear and not readily testable in clinical or experimental studies. The integrative mathematical model of human physiology used in the current study provides a tool for understanding key causal relationships that account for blood pressure (BP) lowering and for testing competing hypotheses. The findings from the simulations suggest that after creation of a small AV fistula increased ANP secretion plays a critical role in mediating long-term reductions in BP. Measurement of natriuretic peptide levels in hypertensive patients implanted with the ROX coupler would provide one critical test of this hypothesis.

Trans-radial closure of coronary artery fistulae using Amplatzer vascular plug IV: A case series.

BACKGROUND: Trans-catheter closure of coronary artery fistulae (CAF) has become a successful alternative to cardiac surgery with excellent results and acceptable low rate of complications. Different techniques and devices are available to treat the extreme anatomical variability of CAF. AIM: We retrospectively describe our case series of five patients trans-radially treated using an Amplatzer vascular plug IV (AVP-IV) with telescoping catheter technique. RESULTS: Trans-radial closure of CAF using the "Child in Mother" technique with dedicated catheters to deliver the vascular plugs AVP-IV was successfully performed in all patients, in one case for a complex CAF, an hybrid step approach using coils and plugs was needed. CONCLUSIONS: Trans-radial closure of CAF using AVP-IV and a telescoping catheter appeared to be safe and feasible in our case series. A persistent closure of CAF was achieved in all patients at 2 year coronary angiography follow-up.

Staphylococcus aureus colonization in hemodialysis patients: a prospective 25 months observational study.

BACKGROUND: Dialysis patients are frequently exposed to Staphylococcus aureus due to stays in dialysis centers, hospitals or rest homes. The hemodialysis vascular access is a potential entry site for S. aureus, in particular when using a central venous catheter (CVC) which increases the risk of sepsis compared to arteriovenous (AV) fistula. We prospectively followed a cohort of 86 hemodialysis patients from an outpatient dialysis center over 25 months analyzing S. aureus carrier status, S. aureus infection rates and mortality. METHODS: Demographic data and patients´ medical histories were collected and followed from all hemodialysis patients. Blood samples, nasal swabs and swabs from the hemodialysis vascular access site were taken every six months for a period of 25 months and tested for S. aureus. Strains were cultured and further characterized by spa PCR and microarray-based genotyping. Resulting data were compared with those from the general population. RESULTS: In cross-sectional analyses, an average of 40% of hemodialysis patients were S. aureus carriers compared to 27% in the general population. Longitudinally, a total of 65% were S. aureus carriers: 16% were persistent carriers, 43% were intermittently colonized. The most common S. aureus lineage in the dialysis patient cohort was the clonal complex (CC) 8 and the spa type t008, while in the general population, the clonal complex CC30 dominates. During the study period, we observed six S. aureus-associated blood stream infections with one S. aureus attributable death. S. aureus carriers with an AV fistula were more densely colonized in the nasal mucosa compared to patients with a CVC. Overall mortality was lower for hemodialysis patients with a positive S. aureus carrier status compared to non-carriers (hazard ratio of 0.19). CONCLUSIONS: Compared to the general population, hemodialysis patients were more frequently colonized with S. aureus and displayed both different S. aureus colonization densities as well as lineages, possibly explained by more frequent exposure to health care environments. The lower overall mortality in carriers compared to non-carriers is intriguing and will be investigated in detail in the future. TRIAL REGISTRATION: ISRCTN 14385893 , 2. October 2018, retrospectively registered.

Embolization of a complex coronary to pulmonary artery fistula using balloon assisted liquid embolic injection: A novel technique.

Complex Coronary artery to Pulmonary artery fistulas (CPFs) can be difficult to manage with embolization or ligation. An 88-year-old woman with exertional angina was found to have a complex precordial CPF, severe Mitral regurgitation, and Pulmonary Hypertension. CPF treatment was recommended prior to minimally invasive mitral valve replacement (to avoid postoperative myocardial ischemia from worsened steal). The CPF was supplied by multiple branches from the LAD and RCA, and formed a complex common varicosity with multiple drainage channels to the pulmonary artery. The CPF was treated by injecting a liquid embolic agent, Ethylene Vinyl Alcohol Copolymer (Onyx, Medtronic, MN), into two of the feeding arteries arising from the RCA through a Scepter C Dual lumen balloon micro catheter (Microvention, Aliso Viejo, CA. This resulted in complete obliteration of the fistula, and the patient subsequently underwent successful mitral valve replacement surgery.

3D printed cardiac fistula: Guiding percutaneous structural intervention.

We present the case of a 21-year-old female with a complex right coronary sinus of valsalva to right atrial fistulae. 3D printing of the fistulae and surrounding anatomy was beneficial in assessment of the anatomy and perioperative planning. Successful percutaneous closure was achieved.

Percutaneous treatment of late complications of the Bentall procedure.

Aortic pseudo-aneurysm following the Bentall procedure is a rare but potentially severe complication. Surgical reintervention represents a high risk. We report on two cases with different pseudo-aneurysm types which were successfully treated using two different percutaneous techniques. © 2017 Wiley Periodicals, Inc.

Iatrogenic Arteriovenous Fistula of the breast following core-biopsy presenting in pregnancy.

Core-biopsy of the breast is the standard of care for assessment of breast lumps. It is rarely associated with a vascular injury resulting in the formation of an arteriovenous fistula. Though previously noted in the medical literature, it has never been reported in the context of pregnancy and lactation.