Comparison of ultrasound features and lesion sites in dysfunctional arteriovenous fistula

This study aimed to investigate ultrasound features of arteriovenous fistula stenosis and their relationship with primary patency after percutaneous transluminal angioplasty (post-intervention primary patency) and compare this classification with that using lesion location. Hemodialysis patients who underwent ultrasound-guided percutaneous transluminal angioplasty for arteriovenous fistula stenosis from July 2020 to December 2021 were retrospectively evaluated. Lesions (excluding inflow arteries) were categorized into five groups based on ultrasound features, and the clinical characteristics and risk factors affecting the post-intervention primary patency of the arteriovenous fistula were analyzed. Among 185 patients, 100 (54.05%), 36 (19.46%), 22 (11.89%), 11 (5.95%), and 16 (8.65%) were classified into the intima-dominant, non-intima-dominant, valve obstruction, vascular calcification, and mixed groups, respectively. The dialysis duration and arteriovenous fistula use time were the highest in the vascular calcification group at 86 (interquartile range: 49-140) and 77 (interquartile range: 49-110) months, respectively. Diabetes mellitus was most common in the intima-dominant group (42.0%). In Kaplan-Meier and univariate Cox analysis, type III lesion location (stenosis in the venous confluence site) was associated with the lower post-intervention primary patency. In the multivariate Cox analysis, percutaneous transluminal angioplasty times (the number of times patients were treated with percutaneous transluminal angioplasty for arteriovenous fistula stenosis dysfunction), vascular calcification, calcification at the lesion site requiring percutaneous transluminal angioplasty, and serum parathyroid hormone levels were independent risk factors for post-intervention primary patency. Ultrasound features showed that calcification of the arteriovenous fistula was detrimental to the post-intervention primary patency of arteriovenous fistula.

Traumatic Iliac Arteriovenous Fistula Treated With the Amplatzer Vascular Plug II: A Case Report and Literature Review

Traumatic iliac arteriovenous fistula is a rare complication of vascular injury. Open surgical repair has an incidence of postoperative complications. In recent years, endovascular treatment has shown better efficacy. We report a 62-year-old female AVF patient with a stab injury history of more than 16 years. Computed tomography angiography (CTA) revealed a large arteriovenous fistula between the right internal iliac artery and the common iliac vein. After considering the patient's relevant conditions, an endovascular approach was satisfactorily performed with the implantation of an Amplatzer Vascular Plug II to interrupt the abnormal vascular communication and maintain arterial and venous patency. The final control images showed closure of the arteriovenous communication.

32-year-old Traumatic Arteriovenous Fistula Presenting With Leg Ulcer and High-output Heart Failure

Traumatic arteriovenous fistula (AVF) is not a common disorder, and dermatological signs and heart failure caused by AVF are rarely reported. We present the case of a 55-year-old woman who was referred for congestive heart failure symptoms. Echocardiography revealed preserved left ventricular ejection fraction. Due to edema of the right leg with a long-standing leg ulcer and palpable femoral thrill, duplex ultrasonography was performed. It showed an AVF between the right superficial femoral artery (SFA) and the right femoral vein (FV). The patient recalled a 32-year-old gunshot injury that was not medically treated. After the diagnosis of AVF she was referred to a surgeon for an AVF ligation, with subsequent resolution of her symptoms. The differential diagnosis of leg ulcer with leg edema should include the possibility of AVF as a cause.

Endovascular treatment of traumatic anterior communicating artery-cavernous sinus fistula

Traumatic anterior communicating artery (AcomA)-cavernous sinus (CS) fistula is rare. Flow diverter (FD) deployment associated with coiling may be an alternative but has never been reported. We reported such a case. A 61-year-old man who was involved in a traffic accident presented with progressive exophthalmos for 2 weeks. Digital subtraction angiography showed a fistula between the AcomA and CS. First, the fistula was coiled. Then, the FD was deployed to cover the rupture point of the AcomA. The fistula was obliterated. Postoperatively, the patient recovered well, and his eye symptoms disappeared. Follow-up angiography showed no recurrence of the fistula. Therefore, for traumatic AcomA-CS fistula, FD deployment associated with coiling may be a feasible alternative.

Spontaneous thrombosis of high flow pediatric arteriovenous fistulae: Case series of two patients and a comprehensive literature review

Pediatric pial arteriovenous shunts in the brain and spine are challenging to understand because of low incidence, variable presentation, and associations with genetic syndromes. What is known about their natural history comes from reviews of small series. To better understand the natural history and role for intervention, two cases are presented followed by a review of the literature. In the first case, an infant with a prior history of intracranial hemorrhage from a ruptured pial fistula returns for elective embolization for a second pial fistula which was found to be spontaneously thrombosed 2 weeks later. In the second case, a 5-year-old with a vertebro-vertebral fistula, identified on work up for a heart murmur and documented with diagnostic angiography, is brought for elective embolization 6 weeks later where spontaneous thrombosis is identified. In reviewing the literature on pediatric single-hole fistulae of the brain and spine, the authors offer some morphologic considerations for identifying which high-flow fistulae may undergo spontaneous thrombosis to decrease the potentially unnecessary risk associated with interventions in small children.

Comparison of pharmacological thrombolysis with mechanical thrombectomy in thrombosed arteriovenous fistulas and grafts: a systemic review and meta-analysis

AIM

To compare the effectiveness and safety of pharmacological thrombolysis and mechanical thrombectomy.

MATERIAL AND METHODS

This review was conducted in accordance with the PRISMA guidelines. Pooled proportions and subgroup analysis were calculated for primary and secondary patency rates, technical success, clinical success, major and minor complications rates.

RESULTS

This systematic review identified a total of 6,492 studies of which 17 studies were included for analysis. A total of 1,089 patients comprising 451 (41.4 %) and 638 (58.6 %) patients who underwent thrombolysis and mechanical thrombectomy procedures, respectively, were analysed. No significant differences were observed between thrombolysis and mechanical thrombectomy procedures in terms of technical success, clinical success, major and minor complications rates, primary and secondary patency rates; however, subgroup analysis of overall arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) demonstrated a significantly higher rate of major complications within the AVF group (p=0.0248).

CONCLUSION

The present meta-analysis suggests that pharmacological thrombolysis and mechanical thrombectomy procedures are similarly effective and safe; however, AVFs are subject to higher major complications compared to AVGs.

Successful Endovascular Salvage of Viabahn Stent Release Malfunction Using a Cutting Balloon: A Case Report

In the past two decades, the method of endovascular therapy, particularly utilizing covered stents, has been widely employed to treat arteriovenous fistulas (AVF) following traumatic injury. In this report, we present a case study of a patient with post-traumatic femoral arteriovenous fistula treated using a Viabahn endoprosthesis, during which a rare occurrence of stent deployment obstruction was overcome via successful endovascular intervention. Leveraging the unique release line-based deployment mechanism of the Viabahn stent, we were able to adroitly respond to this emergency situation by adopting a suitable approach via minimally invasive endovascular means, and ultimately resolving the impasse. This approach averted the significant trauma associated with open surgical procedures.

Prospective Study of Polytetrafluoroethylene-Covered Microplugs and Detachable Coils for Embolization of Pulmonary Arteriovenous Malformations: Technical Results, Procedure Times, and Costs

PURPOSE

To determine time to occlusion and procedure costs of embolization of pulmonary arteriovenous malformations (PAVMs) using a polytetrafluoroethylene-covered microplug compared with embolization using detachable coils.

MATERIALS AND METHODS

In this prospective study, 37 patients (mean age, 39.1 years [SD ± 17.6]) with 82 PAVMs underwent embolization with microplug or detachable coils between April 2019 and January 2023. Technical success, procedure time intervals, and costs were analyzed.

RESULTS

In 37 patients, 82 PAVMs and 101 feeding arteries were successfully treated (microplug, 64; microplug + another device, 5; detachable coils alone, 32). Time from embolic device inserted into the catheter to device deployed and time to occlusion differed significantly between microplug and detachable coil cohorts (P < .0001 for both). Embolization with ≥1 microplug had a significantly shorter occlusion time than embolization with detachable coils (median, 10.0 minutes saved per feeding artery) (P < .0001). Compared with detachable coil embolization, microplug embolization saved a median of 9.0 minutes per feeding artery (P < .0001) and reduced room cost by a median of $429 per feeding artery (P < .0001). Device costs per feeding artery did not differ significantly between microplug ($2,790) and detachable coil embolization ($3,147) (P = .87).

CONCLUSIONS

Compared with coils, microplugs had an equally high technical success rate but significant time to occlusion and room costs savings per feeding artery. Total room cost and device cost together did not differ significantly between microplugs and coils. Microplugs may be considered technically effective and at least cost-neutral for PAVM embolization where clinically appropriate.

Comparison of the transarterial, transvenous, and superior ophthalmic vein approaches in the treatment of indirect carotid-cavernous fistulas

OBJECTIVE

Indirect carotid-cavernous fistulas (CCFs) are abnormal arteriovenous shunting lesions with a highly variable clinical presentation that depends on the drainage pattern. Based on venous drainage, treatment can be either transarterial (TA) or transvenous (TV). The aim of this study was to compare the outcomes of indirect CCF embolization via the TA, TV, and direct superior ophthalmic vein (SOV) approaches.

METHODS

The authors conducted a retrospective analysis of 74 patients admitted to their institution from 2010 to 2023 with the diagnosis of 77 indirect CCFs as confirmed on digital subtraction angiography.

RESULTS

A total of 74 patients with 77 indirect CCFs were included in this study. Embolization was performed via the TA approach in 4 cases, the TV approach in 50 cases, and the SOV in 23 cases. At the end of the procedure, complete occlusion was achieved in 76 (98.7%) cases. The rate of complete occlusion at the end of the procedure and at last radiological follow-up was significantly higher in the SOV and TV cohorts than in the TA cohort. The rate of recurrence was highest in the TA cohort (25% for TA vs 5.3% for TV vs 0% for SOV, p = 0.68).

CONCLUSIONS

The rate of immediate complete occlusion was higher in the TV and SOV cohorts than in the TA cohort while the rate of complete occlusion at final follow-up was highest in the SOV cohort. The SOV approach was significantly associated with higher rates of postoperative complications. Indirect CCFs require careful examination of the fistulous point and the venous drainage to provide the most effective patient-tailored approach.

Transarterial Embolization of Simple Pulmonary Arteriovenous Malformations: Long-Term Outcomes of 0.018-Inch Coils versus Vascular Plugs

PURPOSE

To compare the safety, effectiveness, and persistence rates of 0.018-inch coils with those of Amplatzer vascular plugs (AVPs; Abbott Vascular, Abbott Park, Illinois) for the treatment of pulmonary arteriovenous malformations (PAVMs) in response to a growing concern that 0.018-inch coil embolization would increase the long-term persistence rate.

MATERIALS AND METHODS

This is a retrospective, single-center study of a database (2002-2020) of 633 PAVM embolizations. Complex PAVMs and those not embolized with 0.018-inch coils or plugs were excluded. PAVM embolization material was classified into 4 groups: (a) 0.018-inch nonfibered coils (NFCs), (b) 0.018-inch fibered coils (FCs), (c) NFCs and FCs, or (d) plugs. Persistence was defined as flow through the PAVM on digital subtraction angiography (DSA) or as <30% diameter reduction of the aneurysmal sac on unenhanced computed tomography (CT). Kaplan-Meier analysis and Cox regression were used to assess PAVM's persistence-free survival.

RESULTS

A total of 312 PAVM embolizations with NFCs (43 PAVMs), FCs (127 PAVMs), NFCs and FCs (12 PAVMs), or plugs (130 PAVMs) in 109 patients (28% men; mean age = 49 years) were included. All PAVM embolizations were technically successful without any major adverse events. PAVM persistence-free survival rates at 10 years' follow-up were 40.8% versus 44.7% in the NFC and FC groups (P = .22) and 47.3% versus 81.0% in the 0.018-inch coil (NFC or FC) and plug groups (P < .0001), respectively. There were 0.43 (79/182) and 0.08 (10/130) re-embolization procedures per PAVM in the 0.018-inch coil and plug groups, respectively (P < .001).

CONCLUSIONS

PAVM embolization with 0.018-inch coils was safe, but persistence rate with PAVM embolization was significantly higher than that with plugs, with no significant differences between FCs and NFCs.

Cortical malformation adjacent to a large pial arteriovenous fistula

The coexistence of an arteriovenous fistula (AVF) and neuronal migration abnormalities is a rare phenomenon. The underlying pathophysiology responsible for these anomalies remains elusive. Neuronal architectural irregularities arise from complex neuronal formation, migration and organisation dysfunctions. Isolated cases of these associations are rarely described in the literature. Here, we present an unusual case involving the coexistence of a pial AVF and a pachygyria-polymicrogyria complex in an early childhood boy. We have provided a detailed description of the neuroimaging characteristics and the therapeutic embolisation in this case, along with follow-up. Additionally, we conduct a comprehensive review of potential hypotheses about the association, referencing prior case reports. The presence of an aberrant blood supply or deviant venous drainage from the developing cortex may contribute to a variety of neuronal migration anomalies.

Closure of Post-thrombotic Iliac Arteriovenous Fistulas by Iliac Vein Recanalization

PURPOSE

The purpose of this study was to report the closure of iliac arteriovenous fistulas associated with a post-thrombotic iliac vein occlusion by iliac venous stent recanalization.

CASE REPORT

An 80-year-old woman presented with a worsening painful swelling of her left leg after an iliofemoral deep vein thrombosis 6 months ago. Duplex ultrasound and magnetic resonance venography revealed a post-thrombotic obstruction of her iliac veins as well as several arteriovenous fistulas between branches of her left external and internal iliac arteries and adjacent diseased venous segments. In a first attempt, coil embolization did not sustainably close these iliac arteriovenous fistulas. Direct stent recanalization of the chronically diseased iliofemoral venous segment, however, resulted in an immediate closure of arteriovenous shunt flow and subsequent improvement of clinical symptoms. Six months after iliac vein stent recanalization, still no fistulas could be detected any more, venous stents were fully patent, and the patient was free of symptoms.

CONCLUSION

Post-thrombotic iliofemoral obstructions might be associated with the development of arteriovenous fistulas. Direct stent recanalization of the chronically occluded veins results in closure of related arteriovenous fistulas.

CLINICAL IMPACT

This case suggests that the combined occurrence of post-thrombotic venous obstructions with arteriovenous fistulas, which are related to aforementioned venous lesions, should be evaluated for primary venous stent recanalization rather than fistula embolization.

Angiographic challenges of spinal dural and epidural arteriovenous fistulas: report on 45 cases

PURPOSE

The localization of the fistula level in spinal dural arteriovenous fistulas (dAVFs) and epidural arteriovenous fistulas (edAVFs) remains a diagnostic challenge.

METHODS

Consecutive patients with spinal dAVFs and edAVFs in the thoracic, lumbar, and sacral regions were included. The primary endpoint was to describe the characteristics of patients who required angiography with multiple catheterizations of segmental arteries (10 or more).

RESULTS

Forty-five patients (median age 69 years; male 89%; dAVFs, n = 31; edAVFs, n = 14) were included. Spinal dAVFs commonly developed in the thoracic region and edAVFs in the lumbosacral region. Fistulas were predicted at the correct level or plus/minus 2 level in less invasive examinations using multi-detector CT angiography (n = 28/36, 78%) and/or contrast-enhanced MR angiography (n = 9/14, 64%). We encountered diagnostic challenges in the localization of fistulas in 6 patients. They underwent angiography a median of 2 times. In each patient, spinal levels were examined at a median of 25 levels with a median radiation exposure of 3971 mGy and 257 ml of contrast. Fistulas were finally localized at the high thoracic region (T4-6) in 3 patients, the sacral region (S1-2) in 2, and the lumbar region (L3) in 1. Four patients were diagnosed with edAVFs and 2 with dAVFs. The correlation coefficient between the fistula level and the rostral end of the intramedullary T2 high-signal intensity on MRI was interpreted as none.

CONCLUSION

In patients in whom less invasive examinations failed for fistula localization, high thoracic or sacral AVFs need to be considered.

Efficacy of cutting balloon angioplasty versus high-pressure balloon angioplasty for the treatment of arteriovenous fistula stenoses in patients undergoing hemodialysis: Systematic review and meta-analysis

This systematic review and meta-analysis aimed to assess and compare the therapeutic outcomes of cutting balloon angioplasty and high-pressure balloon angioplasty for arteriovenous fistula stenosis in hemodialysis patients. All studies indexed in PubMed, Embase, and Cochrane Library Web of Science were retrieved. The retrieval deadline was July 15, 2023. Risk of bias 2.0 was used to evaluate the quality of the included studies. Revman 5.4 software was used for data analysis. This review included three studies and 180 patients, with 90 patients in the cutting balloon angioplasty group and 90 patients in the high-pressure balloon angioplasty group. The results of the meta-analysis suggested that compared with high-pressure balloon angioplasty, cutting balloon angioplasty can improve primary lesion patency rates of internal arteriovenous fistulas at 6 months (relative risk, 1.45; 95% confidence interval, 1.08-1.96; P = 0.01). However, there were no significant differences between the technical success rate (relative risk, 0.99; 95% confidence interval, 0.93-1.05; P = 0.72) and clinical success rate (relative risk, 1.01; 95% confidence interval, 0.95-1.07; P = 0.73). Therefore, cutting balloon angioplasty is likely to increase primary lesion patency rates at 6 months. However, more high-quality, large-sample, multicenter, randomized controlled trials are needed for further validation due to the limited number of included studies.

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.

Logistic regression analysis of risk factors for hematoma after autologous arteriovenous fistula in hemodialysis patients

To determine the risk factors and nursing countermeasures for post-operative hematoma in hemodialysis patients with autogenous arteriovenous fistula by logistic regression analysis. A retrospective analysis of 240 chronic hemodialysis patients admitted to our hospital from January 2019 to October 2022 was performed. Physical and vascular examinations of the patients were performed by surgeons. Continuous care measures were implemented for all patients. The patient serum creatinine (Scr) and blood urea nitrogen (BUN) were measured on the day of inclusion and after the implementation of care measures. Self-management scales were used to analyze patients' self-management. Fatigue symptoms were assessed using the Fatigue Scale 14. The WHO Quality of Life Scale (WHOQOL-BREF score) was used to assess patients' quality of life. Self-Rating Depression Scale and Self-Rating Anxiety Scale (SAS) were used to assess negative affect. Treatment compliance was assessed according to 3 levels: complete compliance, compliance, and noncompliance. In all, 240 patients underwent 240 initial and 48 repeat procedures; 18 of the 240 patients experienced fistula failure, with an overall success rate of 92.5% (222/240). There were no significant differences in renal function, self-management, General Self-Efficacy Scale, fatigue symptom scores, and WHOQOL-BREF scores between the postoperative hematoma group and no-hematoma group before the continuous care. After continuous care, renal function, self-management, General Self-Efficacy Scale, fatigue symptom scores, and WHOQOL-BREF scores were better in the postoperative no-hematoma group than in the hematoma group, and the difference was statistically significant (P < .05). Logistic regression analysis of risk factors for postoperative hematoma showed that elevated Scr and BUN levels, decreased self-management and SAS scores and poor treatment compliance were independent risk factors for postoperative hematoma in hemodialysis patients with autologous arteriovenous fistulas (P < .05). Elevated Scr levels, elevated BUN levels, decreased self-management scores, decreased SAS scores, and poor treatment compliance were independent risk factors for postoperative hematoma in hemodialysis patients with autogenous arteriovenous fistulas. By providing continuous care to hemodialysis patients based on timing theory, the negative emotions can be alleviated and the self-efficacy, quality of life, and treatment compliance of the patients can be improved.

Bilateral Dilated Superior Ophthalmic Veins in a Patient With an Arteriovenous Dialysis Fistula

A 64-year-old man presented with 4 months of diplopia. He had end-stage renal disease requiring a cephalic transposition brachiocephalic fistula that was no longer in use following successful renal transplantation. On presentation, he had bilateral proptosis, extraocular movement restriction, chemosis, tortuous episcleral vessels, and caruncular injection. Non-contrast CT of the orbits demonstrated dilation of both superior ophthalmic veins, and CT angiography showed asymmetric enlargement of both cavernous sinuses and superior ophthalmic veins. A carotid-cavernous fistula was suspected, but cerebral angiography revealed shunting from the old fistula with intracranial drainage and cerebral venous hypertension. Aberrant retrograde drainage resulted from anatomical compression of the left brachiocephalic vein. The fistula was ligated, and at 1-week follow-up, the patient had marked improvement in extraocular movements and orbital congestion with near complete resolution of diplopia. Postoperative CT angiography obtained 2 months later demonstrated decreased size of both superior ophthalmic veins, consistent with improvement of venous hypertension.

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.

Preliminary Experience with a Low-Profile High-Density Braid Occluder for Transcatheter Embolization of Pulmonary Arteriovenous Malformations

This brief report describes safety, technical feasibility, and early treatment effectiveness of the low-profile braided occluder (LOBO; Okami Medical, San Diego, Caliornia) for embolization of 9 pulmonary arteriovenous malformations (PAVMs) in 4 patients (3 female and 1 male; age range: 33 to 63 years; 3 patients showed positive results for hereditary hemorrhagic telangiectasia genes). A total of 10 occluders were deployed in 10 vessels (median treated vessel diameters, 3 and 4 mm for LOBO-3 and LOBO-5 groups, respectively). All devices were successfully deployed into the feeder pulmonary arteries, achieving complete cessation of flow. There were no severe adverse events or device migrations. Available short-term follow-up computed tomography (6 PAVMs: median, 7 months; range, 1.5-7 months) demonstrated complete occlusion without persistence or recanalization. The early experience of embolization of PAVMs using a low-profile braided occluder showed it to be safe and effective. Further studies with larger cohorts and longer follow-up periods are warranted.

Percutaneous transosseous embolization of a diploic vein arteriovenous fistula with intracranial and extracranial shunting

EDUCATIONAL MESSAGE

Transosseous embolization of diploic vein arteriovenous fistula is feasible when necessary in select cases.

Successful treatment of a brachial artery pseudoaneurysm in a brachiobasilic arteriovenous fistula using ultrasound-guided manual compression

Pseudoaneurysm is a well-recognized complication seen in arteriovenous fistula (AVF) which usually involves the venous segments. Ultrasound-guided manual compression (UGMC) is a non-invasive and effective treatment for the management of pseudoaneurysms involving the venous segment. Pseudoaneurysm of the arterial segment of AVF is rare complication which usually needs surgical intervention. We report the first successful treatment case of a brachial artery pseudoaneurysm in a brachiobasilic arteriovenous fistula using ultrasound-guided manual compression. The patient presented with a 30 × 30 mm pulsatile swelling below the cubital fossa after second session of hemodialysis using an AVF created 8 weeks earlier. Ultrasound doppler demonstrated a brachial artery pseudoaneurysm in the non-transposed brachiobasilic fistula. Complete occlusion of the cavity with thrombus formation was accomplished after 55 min of compression and the psuedoaneurysm did not recur. UGMC can be an alternative treatment option for select cases of arterial segment pseudoaneurysm in AVF.

Factors Associated with Dialysis Initiation in Patients with Predialysis Arteriovenous Fistula

INTRODUCTION

A large proportion of patients initiated hemodialysis with a central vein catheter rather than a permanent vascular access which was recommended by guidelines. One major barrier was the paucity of evidence regarding the optimal timing of vascular access creation in predialysis patients.

METHODS

Our study prospectively enrolled 300 patients undergoing predialysis arteriovenous fistula (AVF) creation in our center from 2015 to 2018. Cox proportional hazard regression was performed to identify which demographic and clinical factors were associated with the initiation of hemodialysis after AVF surgery. A receiver operating characteristic area under the curve (AUC) was used to assess the predictive power of preoperative factors for the likelihood of hemodialysis initiation.

RESULTS

Overall, 163 (54.3%), 214 (71.3%), and 275 (91.7%) patients initiated hemodialysis within 3 months, 6 months, and 1 year, respectively, after AVF creation. The median time between AVF creation and hemodialysis start was 71.5 days. Using multivariate Cox regression analysis, three factors were associated with hemodialysis initiation within 1 year: serum phosphorus (HR = 1.407, p = 0.021), diabetic kidney disease (DKD) (HR = 1.429, p = 0.039), and cystatin C (HR = 1.179, p = 0.009). Cystatin C alone had a moderate predictive value for dialysis initiation (AUC = 0.746; p < 0.001), whereas the full model had a higher predictive value (AUC = 0.800; p < 0.001).

CONCLUSION

DKD, serum cystatin C, and phosphorus at access surgery were associated with hemodialysis initiation within 1 year of the predialysis AVF creation. Our findings provide a basis for a more customized approach to planning AVF placement in patients with chronic kidney disease.

Endoscopic-assisted Orbitotomy for Obliteration of Orbital Arteriovenous Fistula Refractory to Endovascular Techniques

Orbital arteriovenous fistula is a rare acquired disorder. The coincidence of arteriovenous fistula with lymphaticovenous malformation is even rarer. The optimal treatment, thus, is controversial. Surgical approaches vary widely, with associated pros and cons. The purpose of this case report is to describe an orbital arteriovenous fistula in a 25-year-old man with congenital fronto-orbital lymphaticovenous malformation, refractory to endovascular techniques, which was later successfully ablated by a direct endoscopic-assisted orbital approach.

Renal artery stenosis stenting with unmasking and embolisation of a renal arteriovenous fistula

A man in his 70s was presented to the emergency department with uncontrollable hypertension and worsening renal function on a background of atherosclerosis-related bilateral renal artery stenosis. Following progressive deterioration in renal function and refractory hypertension, the patient was referred to interventional radiology for consideration of renal artery stenting. Following stenting of the right renal artery, a large renal arteriovenous fistula became apparent, which required emergent embolisation. Both procedures were successful, with excellent clinical and radiological responses.

Iatrogenic Vertebral Arteriovenous Fistula Involving Brachiocephalic Vein Due to Central Venous Catheterization: A Case Report

PURPOSE

To report a case of vertebral arteriovenous fistula (VAVF) caused by iatrogenic trauma of central venous catheterization (CVC) involving brachiocephalic vein (BCV).

CASE REPORT

A 79-year-old female was referred for assessment of a vertebral artery (VA) aneurysm at the V1 segment. The patient had no signs other than a vascular murmur on the right neck and was diagnosed 20 years after undergoing CVC. Right vertebral angiography revealed a high-flow shunt from the V1 segment of the right VA and draining into the right BCV. The fistula had a single communication between a pseudoaneurysm and large varix. We diagnosed the patient with CVCinduced VAVF (CIVAVF) involving BCV and obliterated the shunt by selective transarterial and transvenous embolization of the pseudoaneurysm under flow control using a balloon catheter with no complications.

CONCLUSION

This case highlights the point that CIVAVF involving BCV is rare but possible. In addition, there is a possibility that CIVAVF involving BCV does not demonstrate the findings of arterial steal or retrograde venous drainage and is undiagnosed for a long term due to lack of neurological manifestation and other subjective symptoms. We also showed that endovascular treatment can be feasible and useful for CIVAVF involving BCV.

Targeted embolisation for coexisting conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas with a varix on a shared drainer†

BACKGROUND

The coexistence of vascular malformations in the conus medullaris and cauda equina has been rarely reported, and the complex angioarchitecture in multiple arteriovenous lesions remains poorly understood.

CASE DESCRIPTION

A 17-year-old woman presented with a sudden-onset, stepwise worsening of weakness and pain in the bilateral legs. Angiography revealed conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas. One of the drainers was shared between the coexisting lesions and harboured a varix. Targeted embolisation of a fistulous point in the conus lesion was performed with precaution to prevent occluding the common drainage route, which led to symptom improvement with angiographical diminishment of the varix.

CONCLUSIONS

Recognising that communications between drainers can be observed in multiple spinal arteriovenous lesions is important in facilitating a safe embolisation. Cautious assessment of angiogram with fusion images of cone-beam computed tomography and volumetric T2 magnetic resonance imaging can help in establishing the diagnosis and treatment strategy.

Spinal Dorsal Intradural Arteriovenous Fistulas: Natural History, Imaging, and Management

In this review, we describe the pathophysiology, diagnosis, and treatment of spinal dorsal intradural arteriovenous fistulas (DI-AVFs), focusing on novel research areas. DI-AVFs compose the most common subgroup of spinal arteriovenous lesions and most commonly involve the thoracic spine, followed by lumbar and sacral segments. The pathogenesis underlying DI-AVFs is an area of emerging understanding, thought to be attributable to venous congestion and hypertension that precipitate ascending myelopathy. Patients with DI-AVFs typically present with motor, sensory, or urinary dysfunction, although a wide swath of other less common symptoms has been reported. DI-AVFs can be subdivided by spinal region, which in turn is associated with 4 distinct clinical phenotypes: craniocervical junction (CCJ), subaxial cervical, thoracic, and lumbosacral. Patients with CCJ and lumbosacral DI-AVFs have particularly interesting presentations and treatment considerations. High-value diagnostic findings on MRI include flow voids, missing-piece sign, and T2-weighted intramedullary hyperintensity. However, digital subtraction angiography is the gold standard for diagnosis and localization of DI-AVFs and for definitive treatment planning. Surgical disconnection of DI-AVFs is almost universally curative and frontline treatment, especially for CCJ and lumbosacral DI-AVFs. Endovascular techniques evolve in promising ways, such as improved visualization, distal access, and liquid embolic techniques. The pathophysiology of DI-AVFs is better understood using newly identified radiologic diagnostic markers. Despite new techniques and devices introduced in the endovascular field, surgery remains the gold-standard treatment for DI-AVFs.

The Role of Drug-Coated Balloon in Haemodialysis Arteriovenous Fistula Stenosis Management

Arteriovenous fistula (AVF) stenosis is a common problem leading to dialysis access dysfunction. The conventional balloon (CB) is the most commonly used device during angioplasty but suffers from poor durability of results due to neointimal hyperplasia-mediated recurrence. The drug-coated balloon (DCB) is an adjunct to balloon angioplasty that reduces neointimal hyperplasia, thereby improving post-angioplasty patency. Despite the heterogeneity of DCB clinical trials to date, the evidence suggests that DCBs of different brands are not necessarily equal, and that patient selection, adequate lesion preparation and proper DCB procedural technique are important to realize the benefit of DCB angioplasty.

Natural history, angiographic presentation and outcomes of anterior cranial fossa dural arteriovenous fistulas

BACKGROUND

Anterior cranial fossa dural arteriovenous fistulas (ACF-dAVFs) are aggressive vascular lesions. The pattern of venous drainage is the most important determinant of symptoms. Due to the absence of a venous sinus in the anterior cranial fossa, most ACF-dAVFs have some degree of drainage through small cortical veins. We describe the natural history, angiographic presentation and outcomes of the largest cohort of ACF-dAVFs.

METHODS

The CONDOR consortium includes data from 12 international centers. Patients included in the study were diagnosed with an arteriovenous fistula between 1990-2017. ACF-dAVFs were selected from a cohort of 1077 arteriovenous fistulas. The presentation, angioarchitecture and treatment outcomes of ACF-dAVF were extracted and analyzed.

RESULTS

60 ACF-dAVFs were included in the analysis. Most ACF-dAVFs were symptomatic (38/60, 63%). The most common symptomatic presentation was intracranial hemorrhage (22/38, 57%). Most ACF-dAVFs drained through cortical veins (85%, 51/60), which in most instances drained into the superior sagittal sinus (63%, 32/51). The presence of cortical venous drainage predicted symptomatic presentation (OR 9.4, CI 1.98 to 69.1, p=0.01). Microsurgery was the most effective modality of treatment. 56% (19/34) of symptomatic patients who were treated had complete resolution of symptoms. Improvement of symptoms was not observed in untreated symptomatic ACF-dAVFs.

CONCLUSION

Most ACF-dAVFs have a symptomatic presentation. Drainage through cortical veins is a key angiographic feature of ACF-dAVFs that accounts for their malignant course. Microsurgery is the most effective treatment. Due to the high risk of bleeding, closure of ACF-dAVFs is indicated regardless of presentation.

Endovascular treatment of traumatic penile arteriospongious fistula in a patient with erectile dysfunction: a case report and literature review

BACKGROUND

An arteriovenous fistula is an abnormal communication between an artery and a vein. Traumatic penile arteriospongious fistula is a rare complication and has been described as a cause of erectile dysfunction. Clinical evaluation of patients with erectile dysfunction after penile trauma includes a thorough history, physical examination, vascular assessment, and other complementary exams. Treatment consists of endovascular embolization, surgical ligation, or a combination of both techniques.

CASE PRESENTATION

A 40-year-old man presented with erectile dysfunction that had persisted since suffering blunt trauma a few months ago. He reported problems with short duration of erection and insufficient penile tumescence. Due to high suspicion of an arteriovenous fistula, he was referred to angiography, which confirmed the diagnosis of an abnormal connection between the pudendal vessels. The patient was treated with the coil embolization technique and the symptoms were successfully resolved after endovascular treatment.

CONCLUSIONS

The appearance of a post-traumatic arteriospongious fistula is a rare complication with almost non-existent literature reported. Rapid development in endovascular techniques, in which we use embolic agents to block anomalous blood flow, has allowed safe, effective and less invasive alternative to surgery. Our case demonstrates that endovascular approach is a successful treatment for post-traumatic arteriospongious fistula since the symptoms were resolved, and normal erectile function was regained after the intervention.

Angioarchitecture and prognosis of pediatric intracranial pial arteriovenous fistula

OBJECTIVE

Pial arteriovenous fistulas (PAVFs) are rare and mostly observed in children. However, the overall angioarchitecture, clinical features, treatments and long-term prognosis for pediatric patients remain unclear.

METHODS

Clinical data of consecutive 42 pediatric PAVFs were documented and analysed. According to the differences of age distribution and clinical features, they were split into a younger group (≤3 years old; 20 cases) and an older group (3-14 years old; 22 cases).

RESULTS

Their mean age was 4.9±3.9 years, and the mean preoperative modified Rankin Scale (mRS) score was 1.64±1.57. Fourteen patients (33.3%) were asymptomatic, followed by epilepsy (21.4%), intracranial haemorrhage (16.7%), hydrocephalus (9.5%), developmental delay (7.1%), intermittent headache (7.1%) and congestive heart failure (4.8%). Annual bleeding rate and rebleeding rate before treatment reached 3.86% and 3.17%. Poor venous drainage including sinus dynamic obstruction (21 cases, 50.0%) and sinus occlusion (17 cases, 40.48%) were found with high frequency among these patients. Finally, 33 cases were cured (78.57%), and 4 cases faced surgery-related complications (9.52%). During 24-140 months' follow-up, the mean mRS score reduced to 0.57±0.40. However, only 22 cases (52.38%) recovered to absolutely normal, and poor venous drainage was the risk factor for patients' incomplete recovery (p=0.028, Exp(B)=14.692, 95% CI 1.346 to 160.392). Compared with the older group, younger group showed more chronic symptoms, more secondary pathological changes, more times treatment and worse prognosis (p=0.013, 0.002, 0.000 and 0.032, respectively).

CONCLUSIONS

Pediatric PAVF has different angioarchitectures, clinical features and prognoses in different age groups. Poor venous drainage is an important factor leading to poor prognosis, and it accounts for incomplete recovery in nearly half of patients.

Clinical experience with the Bendit steerable microcatheter: a new paradigm for endovascular treatment

BACKGROUND

Vessel tortuosity poses a challenge during endovascular treatment of neurovascular lesions. Bendit Technologies (Petah Tikva, Israel) has developed flexible, steerable microcatheters designed with unique bending and torquing capabilities.

OBJECTIVE

To describe our first-in-human trial of Bendit21.

METHODS

Bendit21 was used in our exploratory, prospective, multicenter, open-label, single-arm clinical study, and in two compassionate use cases. Procedures were conducted at four centers in Austria, Germany, Israel, and the United States between May 2021 and March 2022, in patients with neurovascular conditions. The primary endpoints were device-related safety events, successful navigation through the neurovasculature, and, when intended, successful delivery of contrast or therapy.

RESULTS

Two patients with giant aneurysms were treated successfully under compassionate use approval. The clinical study included 25 patients (mean age: 63.4±11.8 years; 32.0% female). Fourteen patients (56.0%) had aneurysms, two had arteriovenous malformations/fistulas (8.0%), one had a stroke (4.0%), four (16.0%) had intracranial stenosis, and four (16.0%) had other conditions. Bendit21 was used without a guidewire in 12/25 (48.0%) procedures. Bendit21 was successfully navigated through the vasculature without delays or spasms in all cases (100%). Contrast was delivered as intended in 7/7 (100%) cases. Therapeutic devices were delivered successfully with Bendit as intended in 14/18 (77.8%) cases; four deficiencies occurred in three patients with aneurysms, in whom delivery of coils, an intrasaccular device, or a flow diverter was attempted. There were no device-related safety events or mortalities.

CONCLUSIONS

Our initial clinical experience with the Bendit21 microcatheter demonstrates its usefulness in achieving technical success in patients with challenging neurovascular conditions.

Comparison of drug-coated balloon angioplasty versus common balloon angioplasty for arteriovenous fistula stenosis: A systematic review and meta-analysis

Drug-coated balloons (DCBs) have been used in dialysis patients with arteriovenous fistula (AVF) stenosis, but whether DCBs have advantages over ordinary balloons is still controversial. A meta-analysis was designed to investigate the safety and efficacy of DCBs and common balloons (CBs) in the treatment of AVF stenosis. We searched the PubMed, EMBASE, and China National Knowledge Internet (CNKI) databases for randomized controlled trials that evaluated the comparison of DCB angioplasty versus CB angioplasty for AVF stenosis in dialysis patients and reported at least one outcome of interest. The results showed that the DCB group had a higher first-stage patency rate of the target lesion 6 months [odds ratio, OR = 2.31, 95% confidence interval, CI: (1.69, 3.15), p < .01] and 12 months [OR = 2.09, 95% CI: (1.50, 2.91), p < .01] after surgery. There was no statistically significant difference in all-cause mortality between the two groups at 6 months [OR = 0.85, 95% CI: (0.47, 1.52), p = .58] and 12 months [OR = 0.99, 95% CI: (0.60, 1.64), p = .97]. Compared with CB, DCBs as a new endovascular treatment for AVF stenosis have a higher primary patency rate of target lesions and can delay the occurrence of restenosis. There is no evidence that DCB can increase the mortality of patients.

Haemorrhage risk of brain arteriovenous malformation during pregnancy and puerperium

BACKGROUND

This study aimed to assess whether pregnancy and puerperium were associated with the risk of brain arteriovenous malformation (bAVM) haemorrhage.

METHODS

A retrospective review was conducted in Xiangya Hospital, Central South University from January 2012 to December 2021. A case-crossover design was adopted to calculate the incidence density of bAVM-related haemorrhage among female patients in risk (pregnancy and puerperium) and control (non-pregnancy and non-puerperium) periods, according to four scenarios observed in different populations (scenario I: patients with haemorrhagic bAVM of all ages; scenario II: patients with haemorrhagic bAVM of all ages, with at least one previous pregnancy; scenario III: patients with haemorrhagic bAVM who are of reproductive age (15-45 years); scenario IV: patients with haemorrhagic bAVM of reproductive age (15-45 years), with at least one previous pregnancy. Next, a comprehensive literature aggregation (up to April 2022) was performed for evidence synthesis.

RESULTS

Among the 311 female patients with haemorrhagic bAVM, a significant haemorrhage risk during pregnancy and puerperium was found in Scenarios I (relative risk [RR], 2.08; 95% CI, 1.28 to 3.39), II (RR, 3.21; 95% CI, 1.95 to 5.31) and IV (RR, 2.92; 95% CI, 1.73 to 4.93); however, a suggestive risk was found in scenario III (RR, 1.62; 95% CI, 0.99 to 2.67). Evidence synthesis revealed a consistent haemorrhage risk among patients of all ages (RR, 3.15; 95% CI, 1.93 to 5.15) and those of reproductive age (RR, 1.29; 95% CI, 0.89 to 1.86).

CONCLUSION

Compared with most previous studies, a higher but relatively moderate risk for bAVM-related haemorrhage was identified during pregnancy and puerperium. Individualised prevention and treatment strategies should be preferred when neurosurgeons make clinical decisions.

Embolic Stroke Associated With a Pulmonary Arteriovenous Fistula: An Unignorable Rare Causes of Stroke

INTRODUCTION

Here, we described a patient with ischemic stroke due to embolism, through an isolated pulmonary arteriovenous fistula (PAVF). Our case could be a paradigm of embolic stroke of undetermined source (ESUS) with an uncommon cause, providing an etiologic investigation process in addition to diagnostic pitfalls and pearls, eventually raising neurologists' ability to treat ESUS.

CASE REPORT

A 37-year-old right-handed woman presented to our emergency department with sudden onset left upper limb and lower limb weakness. She denied a past medical history of hypertension, diabetes, heart diseases, and other cerebrovascular disease risk factors, and she is without a family history of stroke, previous trauma, toxic exposure, or drug use. On admission, her physical and neurological examinations were negative, except for left-sided hemiparesis. Her routine evaluations, serum autoantibody testing, and digital subtraction angiography were negative. Subsequent diffusion-weighted brain magnetic resonance imaging demonstrated acute infarction in the right frontoparietal lobe. To find the etiology of this case, more detailed examinations were performed. Finally, she was diagnosed with ESUS, which was caused by the PAVF.

CONCLUSIONS

This case raises the awareness of a potential important emboligenic mechanism, the existence of an isolated PAVF as a right-to-left shunt in patients with a stroke of unknown origin should not be overlooked, even if a PAVF is not suggested by the initial physical findings or chest x-ray.

Large gastroduodenal artery pseudoaneurysm, arterioportal fistula and portal vein stenosis in chronic pancreatitis treated using combined transarterial embolization and transportal stenting: A case report

RATIONALE

Chronic pancreatitis is an ongoing fibroinflammatory disease of the pancreas characterized by irreversible damage to the pancreatic parenchyma and ductal system. Besides, chronic pancreatitis can present with a variety of life-threatening complications.

PATIENT CONCERNS

The patients visited our hospital due to abdominal pain and anemia, and had chronic pancreatitis as an underlying disease.

DIAGNOSES

Computed tomography showed a large gastroduodenal artery pseudoaneurysm, arterioportal vein fistula, and portal vein stenosis.

INTERVENTIONS

We would like to report the successful use of the coils, and N-butyl cyanoacrylate glue for the therapeutic embolization of the pseudoaneurysm and fistula between the gastroduodenal artery and the portal vein, and stenting for portal vein stenosis.

OUTCOMES

On the day following the endovascular management, the patient reported remission of abdominal pain, and hemoglobin level returned to normal after transfusion. It was confirmed that it was still well maintained in the follow-up examination after 1 month.

LESSONS

Although chronic pancreatitis causes many vascular complications, simultaneous occurrence of these lesions is extremely rare. Herein, we share our experience with a unique case of an extrahepatic arterioportal fistula induced by the rupture of gastroduodenal artery pseudoaneurysm with concomitant portal vein stenosis. In these complex cases, combined transarterial embolization and transportal stenting can be helpful.

Fatal hemorrhagic complication after coil embolization of a petrosal arteriovenous shunt

BACKGROUND

Cerebello-pontine AVMs (CPAVMs) and petrous apex dural arteriovenous fistulae (DAVFs) are rare and sometimes difficult to distinguish. We report a fatal hemorrhagic complication after coil embolization of the petrosal vein draining a trigeminal AVM misdiagnosed as a DAVF.

CASE PRESENTATION

A 73-year-old woman with a petrous apex arteriovenous shunt with dual dural and pial arterial supply presented with posterior fossa hemorrhage. The draining petrosal vein was catheterized and coiled via the superior petrosal sinus. Two episodes of contrast extravasation occurred during coiling, but the lesion was completely occluded at the end of the procedure. The patient developed a fatal posterior fossa hemorrhage in the recovery room. Microscopic pathology revealed numerous dilated vessels within the trigeminal nerve.

CONCLUSION

CPAVMs and DAVFs with pial drainage should be distinguished pre-operatively. Occlusion of a pial vein (as opposed to a sinus) in the treatment of an arteriovenous shunt carries hemorrhagic risk if a liquid embolic agent is not used to completely occlude all pathological vessels.

Recurrent pulmonary arteriovenous malformation in a patient with Sjögren syndrome: A case report

RATIONALE

Pulmonary manifestations of Sjögren syndrome (SS) are variable and may involve the airway or lung parenchyma and increase the risk of vascular and malignant disease. However, to date, only one case of pulmonary arteriovenous malformation (AVM) has been reported in a patient with SS. Here, we report a rare case of recurrent pulmonary AVMs with aggravating multiple cysts in a patient with SS during a period of 14 years.

PATIENT CONCERNS

A 45-year-old woman was diagnosed with SS and pulmonary AVM in the right lung. Her AVMs were embolized successfully and she was followed up annually for 14 years. Eleven years after the initial treatment, her chest computed tomography showed new pulmonary AVMs in the left lung with aggravating multiple cysts.

DIAGNOSIS

We diagnosed her with SS according to the American-European consensus group criteria of 2010. Chest computed tomography and angiographic findings confirmed the recurrence of pulmonary AVMs.

INTERVENTIONS

The patient's recurrent pulmonary AVMs were successfully treated by embolization.

OUTCOMES

Although her multiple cystic lung lesions had been aggravating during 14 years, she received embolization for the pulmonary AVMs twice and developed no complication related to these procedures. Currently, the patient is 56 years old and still alive with good performance state.

LESSONS

To date, only one case of pulmonary AVM has been reported in a patient with SS. The patient died 2.5 years after the diagnosis without recurrence of AVM. Here, we present a rare case of recurrent pulmonary AVMs associated with aggravating multiple cysts in both lungs, which were observed during long-term follow-up, in a patient with SS.

Combined transarterial and transvenous embolization of multi-hole pial arteriovenous fistula with large varix

BACKGROUND

Pial arteriovenous fistula (AVF) is a vascular fistulous disease in which the cerebral pial artery and vein are directly connected without the intervening nidus within a sub-pial space. Multi-hole pial AVFs, wherein multiple feeders flow into one drainer, are usually formed with complex angioarchitecture and are difficult to treat.

METHODS

A rare case of an adult patient with hereditary hemorrhagic telangiectasia and multi-hole pial AVF was described. A 23-year-old woman was referred to our hospital. She was previously diagnosed with left cerebellar pial AVF with multiple feeders (bilateral superior cerebellar artery and common trunk of the left anterior inferior cerebellar artery and posterior inferior cerebellar) and large varix that had been untreated for 9 years. The enlargement of the large varix with the new second varix formation was revealed by angiography. Although asymptomatic, considered to be a risk for future hemorrhage was the continuous high hemodynamic stress.

RESULTS

Endovascular embolization was performed by securing safe transarterial n-butyl-2-cyanoacrylate injection by transarterial and transvenous coil placement to the shunt points and feeders, resulting in total occlusion of the fistula without any complications. Extensive transvenous coil placement inside the varix allowed safe embolization of the entire fistula with multiple high-flow feeders. Moreover, bidirectional (transarterial and transvenous) retrograde coil embolization enabled firm obliteration of the shunt points.

CONCLUSIONS

Performing combined transarterial and transvenous embolization in a well-balanced manner was considered to treat multi-hole pial AVF to provide a safe and effective embolization.

Localized Perivascular Therapeutic Approaches to Inhibit Venous Neointimal Hyperplasia in Arteriovenous Fistula Access for Hemodialysis Use

An arteriovenous fistula (AVF) is the preferred vascular access for chronic hemodialysis, but high failure rates restrict its use. Optimizing patients' perioperative status and the surgical technique, among other methods for preventing primary AVF failure, continue to fall short in lowering failure rates in clinical practice. One of the predominant causes of AVF failure is neointimal hyperplasia (NIH), a process that results from the synergistic effects of inflammation, hypoxia, and hemodynamic shear stress on vascular tissue. Although several systemic therapies have aimed at suppressing NIH, none has shown a clear benefit towards this goal. Localized therapeutic approaches may improve rates of AVF maturation by providing direct structural and functional support to the maturating fistula, as well as by delivering higher doses of pharmacologic agents while avoiding the adverse effects associated with systemic administration of therapeutic agents. Novel materials-such as polymeric scaffolds and nanoparticles-have enabled the development of different perivascular therapies, such as supportive mechanical devices, targeted drug delivery, and cell-based therapeutics. In this review, we summarize various perivascular therapeutic approaches, available data on their effectiveness, and the outlook for localized therapies targeting NIH in the setting of AVF for hemodialysis use. Highlights: Most systemic therapies do not improve AVF patency outcomes; therefore, localized therapeutic approaches may be beneficial. Locally delivered drugs and medical devices may improve AVF patency outcomes by providing biological and mechanical support. Cell-based therapies have shown promise in suppressing NIH by delivering a more extensive array of bioactive substances in response to the biochemical changes in the AVF microenvironment.