Dural arteriovenous fistulas in the falx cerebri: case series and literature review

Dural arteriovenous fistulas (DAVFs) within the falx cerebri are infrequently documented and may be linked with the falcine sinus/venous plexus. The falcine sinus/venous plexus, often regarded as a normal venous structure, can exhibit pathological characteristics, differing from the persistent fetal falcine sinus. A retrospective analysis was conducted at a single center to identify all cases of DAVFs within the falx cerebri spanning from 2002 to 2022. Demographic data, fistula features, treatment modalities, clinical outcomes, and fistula closure were collected and analyzed. Additionally, relevant literature on DAVFs in this location was reviewed. Ten cases were identified at our center, supplemented by 13 cases reported in the literature. In our cohort, patients had an average age of 49.4 ± 8.1 years, with a male predominance of 90%. Trans-arterial embolization (TAE) alone achieved immediate complete occlusion in eight cases, while conservative treatment was pursued in two cases. No treatment-related complications or fistula recurrences were observed. In the literature, seven patients underwent direct surgery, three underwent TAE, and one underwent both direct surgery and radiosurgery for complete fistula closure. No instances of fistula recurrence or treatment complications were reported. Dural arteriovenous fistulas within the falx cerebri are rare, with limited literature available. They typically present as aggressive lesions. Treatment options include direct surgery or TAE. However, due to a lack of long-term DSA follow-up, the cure and recurrence rates are unknown for endovasdcular therapy. Further investigation is warranted to elucidate the involvement of the falcine sinus/venous plexus in falx cerebri DAVFs.

Worldwide Research Trends on Transvenous Embolization of Brain Arteriovenous Malformations: A Bibliometric and Visualized Study

BACKGROUND

Transvenous embolization (TVE) of brain arteriovenous malformations (bAVMs) is an emerging endovascular technique that has shown high cure rates in selected cases. The rationale of our study was to determine authorship and worldwide institutional trends and contributions to the knowledge in this topic.

METHODS

Web of Science database was used. A total of 63 articles were included based on predefined inclusion criteria, which were manually reviewed. The bibliometric analysis involved the use of quantitative bibliometric indicators and network analysis with co-authorship and co-occurrence of terms, which were performed using the bibliometrix package in R and VOSviewer, respectively.

RESULTS

The first article was published in 2010, with the largest number of articles published in 2022 (10 articles). The average number of citations per document was 11.38, and the annual growth rate was 14.35%. The top 10 authors with the most scientific production on TVE of bAVMs were from France, and the most cited study was published by Iosif C in 2015, followed by Consoli A in 2013, and Chen CJ in 2018. Journal of Neurointerventional Surgery was the journal with the most articles published. The most commonly used keywords were dural arteriovenous fistula, Onyx, vascular disorders, and neurological surgery around 2016, and intervention around 2021.

CONCLUSIONS

TVE of bAVMs is an emerging technique. Our search identified some scientific articles, without randomized clinical trials, but many case series from single institutions. French and German institutions are the pioneers in the field, and further research is required in specialized endovascular centers.

Case report: A combination of nitroglycerin and adenosine proves effective in repairing a cerebral arteriovenous malformation

Hemorrhage secondary to rupture of a brain arteriovenous malformations (AVM) is one of the initial manifestations, and the main cause of, morbidity and mortality in patients with this condition. Current treatment strategies include endovascular embolization with the goal of AVM obliteration and neurological preservation. In the transvenous endovascular embolization procedure, adenosine is the preferred agent to induce temporary hypotension and allow adequate AVM embolization. We describe the intraoperative management of an adenosine-resistant 38 year-old male who underwent a successful intracranial AVM embolization after concomitant administration of gradually increasing doses of nitroglycerin. This report suggests that nitroglycerin infusion can be combined with adenosine boluses to create a pronounced and dose-dependent hypotension in patients partially unresponsive to adenosine alone.

Endovascular treatment of spinal AVM: report of two cases with transvenous approach in combination with retrograde pressure cooker technique

PURPOSE

Endovascular treatment of spinal AVMs is limited by low complete cure rates. Transarterial extensive treatment with liquid embolics carries the risk of clinically relevant ischemic complications. We report two cases of symptomatic spinal AVMs treated by a transvenous approach with retrograde pressure cooker technique.

METHODS

In two selected cases, transvenous navigation aimed at retrograde pressure cooker embolization.

RESULTS

Retrograde venous navigation was possible with two parallel microcatheters, and the pressure cooker technique with ethylenvinylalcohol-polymer was applicable in both cases. One AVM was occluded completely, and one subtotally due to a second draining vein. No clinical complications occurred.

CONCLUSION

A transvenous approach for embolization with liquid embolics may offer advantages in treating certain spinal AVMs.

Perioperative Complications of Transvenous Embolization of Ruptured Intracranial Arteriovenous Malformations

Purpose

To investigate the perioperative complications of transvenous embolization of ruptured intracranial arteriovenous malformations.

Materials and Methods

A total of 27 patients with ruptured intracranial arteriovenous malformations underwent transvenous embolization were enrolled from November 2016 to May 2020 in our prospective database. Perioperative complications and angiographic characteristics were analyzed retrospectively.

Results

Complete disappearance of the nidus occured in 22 (88%) of 25 patients with technically feasible AVMs immediately after embolization. Two cases were partially treated by transarterial embolization due to the failure of microcatheter placement into the draining vein. Seven (25.9%, 7/27) patients had perioperative complications, including three cases of intraoperative hemorrhage, three cases of postoperative hemorrhage and one case of ischemic infarction. No significant differences in complication rates between patients with nidus ≥3 cm and <3 cm (P = 0.659), eloquent area and non-eloquent (P = 0.137), deep location and superficial (P = 0.637), deep venous drainage and cortical vein (P = 1.0), the number of venous drainage (P = 0.49), the angle of draining vein entering venous sinus <90° and ≥90° (P = 1.0), aneurysms (P = 0.058) and the time between hemorrhage and TVE (P = 1.0) were found. Three of these patients received ventriculostomy, two of which received lumbar drainage treatments at the same time, and four patients just received conservative management. Good outcomes (mRS ≤ 2) at the 1-month evaluation were achieved in 5 of the patients who had complications, but poor outcome (mRS = 5) at the 1-month evaluation was in 1 patient, and 1 lethal complication occurred.

Conclusion

The most common complication of AVMs with transvenous endovascular embolization is cerebral hemorrhage. The prevention of complications may improve the efficacy of AVM embolization, but the current quality of evidence is low and limited in guiding policy development and improving the TVE for AVMs. It is, therefore, necessary to develop clinical research programs in this field.

Anomalous location of intracranial vessels in adults

Anomalous intracranial vessels are not uncommon, and this finding is not always associated with arteriovenous malformations. Other conditions such as anomalous connections between arteries or phlebitc patterns can also present as vessels with abnormal intracranial locations. Noninvasive diagnosis is important to determine whether to do more invasive tests such as cerebral digital subtraction angiography or to estimate the risk of bleeding in arteriovenous malformations and therefore to evaluate the need for endovascular/surgical treatment. In this paper, we present an algorithm for the differential diagnosis of anomalous intracranial vessels according to their location (intra/extra-axial) and function (whether the vessels are arterialized). Moreover, we analyze the important points of the angioarchitecture of the principal arteriovenous malformations with risk of intracranial bleeding, such as pial arteriovenous malformations and dural fistulas.

Endovascular Management of Hemorrhagic Stroke

Significant advances in endovascular neurosurgery tools, devices, and techniques are changing the approach to the management of acute hemorrhagic stroke. The endovascular treatment of intracranial aneurysms emerged in the early 1990s with Guglielmi detachable coils, and since then, it gained rapid popularity that surpassed open surgery. Stent-assisted coiling and balloon remodeling techniques have made the treatment of wide-necked aneurysms more durable. With the introduction of flow diverters and flow disrupters, many aneurysms with complex geometrics can now be reliably managed. Arteriovenous malformations and fistulae can also benefit from endovascular therapy by embolization using n-butyl cyanoacrylate (NBCA), Onyx, polyvinyl alcohol (PVA), and coils. In this article, we describe the role of endovascular treatment for the most common causes of intracerebral and subarachnoid hemorrhages, particularly ruptured aneurysms and vascular malformations.

4D Flat Panel Conebeam CTA for Analysis of the Angioarchitecture of Cerebral AVMs with a Novel Software Prototype

BACKGROUND AND PURPOSE

Time-resolved 3DRA (4D-DSA) and flat panel conebeam CTA are new methods for visualizing the microangioarchitecture of cerebral AVMs. We applied a 4D software prototype to a series of cases of AVMs to assess the utility of this method in relation to treatment planning.

MATERIALS AND METHODS

In 33 patients with AVMs, 4D volumes and flat panel conebeam CTA images were recalculated from existing 3D rotational angiography data. The multiplanar reconstructions were used to determine intranidal arteriovenous branching patterns, categorize them according to common classifications of AVM angioarchitecture, and compare the results with those from 2D-DSA.

RESULTS

4D flat panel conebeam CTA showed angioarchitectural features equal to or better than those of 2D-DSA in 30 of 33 cases. In particular, the reconstructions helped in understanding the intranidal microvasculature. Fistulous direct arteriovenous connections with a low degree of arterial branching (n = 22) could be distinguished from plexiform arterial networks before the transition to draining veins (n = 11). We identified AVMs with a single draining vein (n = 20) or multiple draining veins (n = 10). Arteriovenous shunts in the lateral wall of the draining veins (n = 22) could be distinguished from cases with increased venous branching and shunts between corresponding intranidal arteries and veins (n = 11). Limitations were the time-consuming postprocessing and the difficulties in correctly tracing intranidal vessels in larger and complex AVMs.

CONCLUSIONS

4D flat panel conebeam CTA reconstructions allow detailed analysis of the nidal angioarchitecture of AVMs. However, further improvements in temporal resolution and automated reconstruction techniques are needed to use the method generally in clinical practice.

Adenosine-induced transient circulatory arrest in transvenous embolization of cerebral arteriovenous malformations

Due to advances in interventional techniques, the transvenous approach may present an effective treatment option for embolization of brain arteriovenous malformations (AVMs). Contrary to the transarterial method, the transvenous approach can only be utilized in a specific subset of patients and is not suitable as a standard procedure for all AVM lesions. While this technique can be helpful in certain patients, careful patient selection to ensure patient safety and favorable clinical outcomes is important. However, especially in high-flow AVMs, targeted deposition of embolic materials through a transvenous access can be challenging. Therefore, a temporary flow arrest may prove helpful. Transient cardiac arrest by use of adenosine has been applied in cerebrovascular surgery but is not common for endovascular embolization. Adenosine-induced arrest and systemic hypotension may be a feasible, safe method to reduce flow and help endovascular transvenous embolization of certain AVMs. Our study evaluated the efficiency and safety of adenosine-induced circulatory arrest for transvenous embolization of cerebral AVMs.

Combined Use of Color Doppler Ultrasound and Contrast-Enhanced Ultrasound in the Intraoperative Armamentarium for Arteriovenous Malformation Surgery

BACKGROUND

Safety and efficacy in surgical treatment of cerebral arteriovenous malformations (AVMs) are dictated by thorough understanding of angioarchitectural features, intraoperative identification of feeding vessels, and appreciation of surrounding eloquent areas. Our aim was to describe the preliminary results of combined application of color Doppler ultrasound (CDUS) and contrast-enhanced ultrasound (CEUS) in a consecutive surgical series of AVM. We pointed out the tool's efficacy in distinguishing feeding from bystander vessels and in identifying pattern of venous drainage. We examined its role as an adjunct for semiquantitative evaluation of the nidus inflow.

METHODS

We used combined CDUS and CEUS in patients surgically treated for cerebral AVMs. We adopted these techniques following a designed protocol to guide safer AVM resection as an adjunct to indocyanine green videoangiography. Intraoperative assessment by ultrasound was performed before, during, and following nidus resection.

RESULTS

Four surgically treated cerebral AVMs availed of the ultrasound protocol. Postoperative conventional angiography showed complete resection of the AVMs. CDUS and CEUS proved to be valuable adjunctive tools to indocyanine green videoangiography and micro-Doppler in properly navigating and discerning vascular structures, especially vessel feeders from bystanders. The protocol allows us to identify flow direction, estimate blood velocity within the nidus, and appreciate flow modifications following temporary clipping. Ultimately, it allows us to evaluate the degree of nidus deafferentation, residual flow, restoration of venous drainage and absence of arteriovenous shunts.

CONCLUSIONS

The CDUS and CEUS protocol is safe and repeatable and works as real-time imaging, further supporting complete surgical resection of AVMs.

Selection of Patients for Treatment of Brain Arteriovenous Malformations by the Transvenous Approach: Relationship with Venous Anatomy and Risk of Hemorrhagic Complications

BACKGROUND AND PURPOSE

Intracranial hemorrhage represents a severe complication of brain arteriovenous malformation treatment. The aim of this cohort was to report the rate of hemorrhagic complications after transvenous endovascular embolization and analyze the potential angioarchitectural risk factors as well as clinical outcomes.

MATERIALS AND METHODS

During an 11-year period, 57 patients underwent transvenous endovascular embolization. All cases of hemorrhagic complications were identified. We analyzed the following variables: sex, age, hemorrhagic presentation, Spetzler-Martin grade, size of the AVM before the transvenous treatment, number of venous collectors, pattern of drainage, presence of dilated veins, and technical aspects. Univariate and multivariate multiple regression analyses were performed to evaluate the potential risk factors for procedure-related hemorrhagic complications.

RESULTS

Hemorrhagic complications (either intraprocedural or periprocedural) unrelated to a perforation due to micronavigation occurred in 8 (14.0%) procedures. Significant (mRS > 2) and persistent neurologic deficits were present in 2 (3.5%) patients at 6-month control. Larger nidi, especially >3 cm (P = .03), and a larger number of venous collectors have shown a statistically significant correlation with hemorrhagic complications. Only the number of venous collectors was identified as an independent predictor of hemorrhagic complications in the multivariate analysis (OR, 8.7; 95% confidence interval, 2.2-58.2) (P = .006).

CONCLUSIONS

Larger nidus sizes and an increased number of venous collectors may increase the risk of hemorrhagic complications when implementing transvenous endovascular treatment of AVMs. The technique is effective and promising, especially with small nidi and single venous collectors.

N-Butyl Cyanoacrylate Transvenous Arteriovenous Malformation Embolization with Arterial Balloon Assistance: Defining Parameters for a Transvenous Approach as a Potential Upfront Treatment Option in Managing Cerebral Arteriovenous Malformations

Complete obliteration of arteriovenous malformations (AVMs) using a transvenous approach as the primary and stand-alone treatment modality has been increasingly considered as a useful endovascular approach in the treatment of AVMs. AVMs are typically treated with microsurgery, stereotactic radiosurgery, endovascular embolization, or some combination of the three methods. Preservation of the draining vein is a key requisite common to all treatment modalities. Transvenous embolization (TVE) is conventionally not recommended as a stand-alone treatment for the vast majority of AVMs and has been thought to be best indicated when traditional approaches are considered less safe and when specific evaluation criteria are met. We report a case of a 35-year-old asymptomatic male diagnosed with a small intracranial AVM adjacent to the right motor strip which was managed utilizing this approach. We employed endovascular embolization via a transvenous approach with arterial balloon assistance due to the small size of the nidus, eloquent location, en passage arterial supply proximal to the venous varix, and a single draining vein from the fistula. This case illustrates the selective indications and technical nuances of TVE approach in managing AVMs as a potential upfront treatment option. When patients harbor AVMs with specific angio-architectural findings as outlined, TVE utilizing Onyx or N-butyl cyanoacrylate can be safely performed as a primary treatment modality.

Visual Field Defect Before and After Endovascular Treatment of Occipital Arteriovenous Malformations

BACKGROUND

Occipital arteriovenous malformations (AVMs) carry a high risk of postoperative morbidity because of their anatomic relation to the visual cortex and optic radiations. Data regarding endovascular management of these lesions are scant.

OBJECTIVE

To report our single-center experience with occipital AVMs, most of which were treated endovascularly, with a special interest for postoperative visual impairment.

METHODS

From a prospective database, we assessed the clinical and radiological data of all patients with an occipital AVM managed between 1997 and 2018. The extension of the nidus to the primary visual cortex was assessed and correlated to the pre- and postintervention visual symptomatology. Modified Rankin Scale and visual fields (VFs) were assessed pre- and post-treatment and at the last follow-up.

RESULTS

A total of 83 patients (47 males [56.6%]) with an occipital AVM were included in the study. Mean age at presentation was 33.5 ± 15.0 yr (min-max = 7-76). A total of 34 patients (41%) presented with hemorrhage related to the AVM. A total of 57 patients (68.7%) underwent endovascular treatment (EVT) alone, 20 (24.1%) underwent embolization and surgery, 3 (3.6%) underwent embolization and radiosurgery, and 3 (3.6%) were conservatively managed. A complete obliteration of the AVM was achieved in 53 patients (66.3%). A post-treatment worsening of the VF was found in 24 of the treated patients (30%), 3 patients (9%) for ruptured AVMs, and in 21 patients (46%) for unruptured AVMs. Morbidity rate was 3.7% and mortality rate was 2.5%.

CONCLUSION

EVT of occipital AVM carries a non-negligible rate of complications, especially regarding visual functions.

Safety and Efficacy of Transvenous Embolization of Ruptured Brain Arteriovenous Malformations as a Last Resort: A Prospective Single-Arm Study

BACKGROUND AND PURPOSE

The efficacy and safety of transvenous embolization for brain arteriovenous malformations remains unclear, given the very limited number of cases reported. This prospective study was performed to assess this technique in ruptured AVMs.

MATERIALS AND METHODS

Twenty-one consecutive patients with ruptured brain AVMs who underwent transvenous embolization were prospectively followed between November 2016 and November 2018. The Spetzler-Martin grade was I in 3 AVMs (14.3%), II in four (19.0%), III in eleven (52.4%), and IV in three (14.3%). The complete AVM occlusion rate was calculated from 6-month follow-up DSA images. Occurrence of hemorrhage and infarction after embolization was evaluated using CT and MR imaging within 1 month after the operation. The mRS was used to assess the functional outcomes.

RESULTS

Complete AVM nidus obliteration was shown in 16 (84%) of 19 patients with technically feasible AVMs immediately after embolization. One (5%) patient with a small residual nidus after treatment showed complete obliteration at 13-month follow-up. There were 5 hemorrhages and 1 infarction; 4 patients' symptoms improved gradually. The percentage of cases with mRS ≤ 2 rose from 57.1% (12/21) before embolization to 66.7% (14/21) at 1-month follow-up. Both the morbidity and mortality rates were 4.8% (1/21).

CONCLUSIONS

Transvenous embolization can be performed only in highly selected hemorrhagic brain AVMs with high complete obliteration rates, improved functional outcomes, and acceptable morbidity and mortality rates, but it should not be considered as a first-line treatment.

Transvenous embolization of arteriovenous malformations

Embolization of arteriovenous malformations is characteristically used as part of a multimodal treatment approach, pre-operatively to facilitate microsurgical resection or as a preradiosurgical adjunct. The concept of AVM cure via embolization alone has gained popularity in recent years. Embolization of AVMs has been most commonly performed transarterially, with the transvenous route traditionally eschewed given concern over precipitating premature venous occlusion and consequent hemorrhage. However, the transvenous approach in treating AVMs offers several distinct advantages compared to the transarterial route and can be used in instances when the latter is not feasible, with several series having proven its efficacy and safety. Conceptually, AVM embolization performed via the transvenous route achieves complete obliteration by directly and facilely targeting the nidus. Nidal embolisate penetration is facilitated by control of arterial inflow via systemic or local hypotension. Innovation in endovascular strategies has led to significantly improved obliteration rates. The experience with transvenous AVM embolization is reviewed and discussed.

Transvenous embolization of brain arteriovenous malformations: a review of techniques, indications, and outcomes

Endovascular embolization of brain arteriovenous malformations (AVMs) is conventionally performed from a transarterial approach. Transarterial AVM embolization can be a standalone treatment or, more commonly, used as a neoadjuvant therapy prior to microsurgery or stereotactic radiosurgery. In contrast to the transarterial approach, curative embolization of AVMs may be more readily achieved from a transvenous approach. Transvenous embolization is considered a salvage therapy in contemporary AVM management. Proposed indications for this approach include a small (diameter < 3 cm) and compact AVM nidus, deep AVM location, hemorrhagic presentation, single draining vein, lack of an accessible arterial pedicle, exclusive arterial supply by perforators, and en passage feeding arteries. Available studies of transvenous AVM embolization in the literature have reported high complete obliteration rates, with reasonably low complication rates. However, evaluating the efficacy and safety of this approach is challenging due to the limited number of published cases. In this review the authors describe the technical considerations, indications, and outcomes of transvenous AVM embolization.

Curative Transvenous Embolization for Ruptured Brain Arteriovenous Malformations: A Single-Center Experience from China

OBJECTIVE

To evaluate feasibility and safety of transvenous embolization for brain arteriovenous malformations (AVMs).

METHODS

Between November 2016 and August 2017, a transvenous endovascular embolization protocol was implemented at the Henan Provincial People's Hospital for consecutive patients with ruptured brain AVMs. Therapeutic decision making was based on Spetzler-Martin grade, brain AVM location, pattern of venous drainage, and angioarchitecture. Transvenous embolization was combined with transarterial support. Complete angiographic obliteration of the nidus was the objective of treatment.

RESULTS

Among 10 patients with ruptured brain AVMs, 8 were male. Spetzler-Martin grades before transvenous embolization were IV in 3 patients, III in 5 patients, II in 1 patient, and I in 1 patient. Modified Rankin Scale score before the procedure was 0-2 for 6 of 10 patients. Five patients also had deep venous drainage. Arterial blood pressure control and venous pressure cooker technique were used in all 10 patients; 9 patients had immediate angiographic occlusion. Two patients had a ventricular hemorrhage, which did not cause any disability after medical treatment. Seven patients underwent angiography 3-5 months after the procedure, and complete obliteration of the nidus was confirmed. Median clinical follow-up for all 10 patients was 8 months (range, 3-12 months). Epilepsy occurred in 1 patient 3 months after the procedure, and modified Rankin Scale scores for all patients were ≤1.

CONCLUSIONS

Transvenous embolization of brain AVMs is feasible and may improve cure rates. The safety and long-term effects need further validation.

Indications for the Performance of Intracranial Endovascular Neurointerventional Procedures: A Scientific Statement From the American Heart Association

Intracranial endovascular interventions provide effective and minimally invasive treatment of a broad spectrum of diseases. This area of expertise has continued to gain both wider application and greater depth as new and better techniques are developed and as landmark clinical studies are performed to guide their use. Some of the greatest advances since the last American Heart Association scientific statement on this topic have been made in the treatment of ischemic stroke from large intracranial vessel occlusion, with more effective devices and large randomized clinical trials showing striking therapeutic benefit. The treatment of cerebral aneurysms has also seen substantial evolution, increasing the number of aneurysms that can be treated successfully with minimally invasive therapy. Endovascular therapies for such other diseases as arteriovenous malformations, dural arteriovenous fistulas, idiopathic intracranial hypertension, venous thrombosis, and neoplasms continue to improve. The purpose of the present document is to review current information on the efficacy and safety of procedures used for intracranial endovascular interventional treatment of cerebrovascular diseases and to summarize key aspects of best practice.

Trans-venous embolization of a basal ganglia ruptured arteriovenous malformation with open surgical arterial control: A hybrid technique

Treatment of ruptured deep-seated arteriovenous malformations is challenging and associated with elevated risks. This is due to the proximity or involvement of critical brain structures and the specifically fine and delicate angioarchitecture of these lesions, making both endovascular and surgical access technically complicated. We present the advantages of a true combined, open surgical and endovascular transvenous approach in a hybrid operating room. The technique may overcome in part the difficulties and may improve safety and risk related concerns.

Eyelid arteriovenous malformation treated with pre-surgical embolization: A case report

Background Arteriovenous malformations are potentially serious vascular anomalies that are rarely encountered in the eyelid and require a multidisciplinary approach. Objectives We would like to describe the technical and clinical aspects related to the treatment of palpebral arteriovenous malformation with selective embolization, followed by surgical resection. Methods A 40-year-old patient presented with an isolated high-flow palpebral arteriovenous malformation. Transarterial embolization, using a liquid embolic agent (PHIL™), was performed in this patient. Results Angiographic and clinical follow-up revealed good results with clinical regression of the mass. Conclusion Although endovascular treatment of palpebral arteriovenous malformations is technically challenging, good functional and cosmetic result was achieved. Arteriovenous malformation embolization using PHIL™ seems to be very effective and makes subsequent surgical procedure safe and feasible. Level IV Evidence obtained from multiple time series with or without the intervention, such as case studies. Dramatic results in uncontrolled trials might also be regarded as this type of evidence.

In-room assessment of intravascular velocity from time-resolved rotational angiography in patients with arteriovenous malformation: a pilot study

Background

Time-resolved rotational angiography (t-RA) enables interventionists to better comprehend complex arteriovenous malformations (AVMs), thereby facilitating endovascular treatment. However, its use in evaluating hemodynamic changes has rarely been explored.

Objective

This study uses t-RA to estimate intravascular flow in patients with AVM to compare this with flow in the normal population.

Methods

Patients with available t-RA scans were prospectively categorized into one of three groups: hemorrhagic AVM, non-hemorrhagic AVM and control. Pulsatile time–density curves (TDCs) for C1, C6 and VOIMCA were used for amplitude and velocity estimation. C1 was at the cervical internal carotid artery (ICA), 2–3 cm below the carotid canal, C6 was at the paraclinoid segment of the ICA, and VOIMCA was at the junction of the first and second segment of the middle cerebral artery (MCA). A waveform amplitude ratio was defined as (peak − trough)/trough contrast intensity. VICA was defined as the distance between C6 and C1 divided by the time required for the wave to pass, and correspondingly, the average velocity of MCA (VMCA) was defined as the distance between C6 and VOIMCA divided by the duration for the same peak to travel from C6 and VOIMCA, AVM volume was estimated by MR angiography.

Results

Amplitude ratios AC1 and AC6, and average flow velocities VICA and VMCA were significantly larger in the non-hemorrhagic group than in the control group, while the hemorrhagic AVM group was not significantly different from the controls. VICA and VMCA showed moderate to good correlations with AVM volume (r=0.51 and 0.73, respectively). VMCA (33.0±9.1) was significantly lower than VICA (41.3±13.2) in the control group, but not in the two AVM groups.

Conclusion

TDC waveform propagation derived from t-RA can quantify hemodynamic differences between AVM and the control group. t-RA provides both real-time anatomic and hemodynamic evaluation, and can thus potentially improve the interventional workflow.

Transvenous retrograde AVM embolization: Indications, techniques, complications and outcomes

Objective Transvenous retrograde arteriovenous malformation (AVM) embolization (TRAE) has been proposed. The present study was to review the techniques, their conjunctions and effectiveness. Methods Eligible related articles were identified by searching the PubMed and Web of Science databases using "transvenous" and "arteriovenous malformation." Results A total of 16 eligible studies, with 60 cases of AVM treated with TRAE, were analyzed. Prior to TRAE procedure, transarterial Onyx 18 was performed in 23 (38.3%), cyanoacrylate in three (5%) and coiling in two (3.3%), neurosurgery in one (1.7%) and radiosurgery in three (5%). These prior treatments were used to reduce the size of the nidus to <3 cm and TRAE was performed. One anterior choroidal artery aneurysm was coiled before TRAE. Systemic hypotension (blood pressure<100 mmHg) occurred in six (10%) patients and local hypotension (proximal arterial temporary balloon protection) in five (8.3%) patients. Complete obliteration was achieved in 56 (93.3%) AVMs, four (6.7%) with residual, of which one was supplemented with radiosurgery. During mean one-year follow-up (1 month to 3.2 years), there were five cases (8.3%) of permanent disability and one (1.7%) mortality resulting from initial hemorrhage. Fifty-four (90%) patients were independent (mRS ≤ 2) at follow-up. Ruptured AVMs and Spetzler-Martin I-III were associated with a high cure rate. Conclusion According to previous reports, selected AVMs could undergo TRAE. TRAE is safe and curative with Onyx after the nidus size is reduced sufficiently by transarterial embolization, neurosurgery or radiosurgery, with or without the aid of proximal arterial temporary balloon protection.

Curative and adjunctive AVM Onyx embolization of AVMs through the choroidal arteries

Objective The anterior or posterior choroidal artery is often recruited to supply deep location arteriovenous malformations (AVMs). This study is to report curative and adjunctive AVM Onyx embolization through these arteries. Methods This study retrospectively reviewed six patients with cerebral AVMs who underwent endovascular embolization through the choroidal arteries between October 2015 and October 2016. Embolization was performed as a curative procedure in five patients and adjunctive procedure in one patient. Results Four patients underwent embolization through the anterior choroidal artery (AchA), and two patients underwent embolization through the lateral posterior choroidal artery (LPchA). One of the four patients in whom embolization was from the AchA (distal to the plexal point) developed transient hemiparesis. Complete obliteration was confirmed by angiography at the last follow-up in five patients. Conclusions Onyx embolization of cerebral AVMs through the choroidal arteries is possible as a curative or adjunctive procedure.

Extending the indications for transvenous approach embolization for superficial brain arteriovenous malformations

INTRODUCTION

Transarterial embolization is the standard endovascular treatment strategy for intracranial arteriovenous malformations (AVMs). The transvenous approach has been indicated for the embolization of deep AVMs meeting a set of strict eligibility criteria. The present study aims to assess the safety and efficacy of the transvenous approach for superficial AVMs.

METHODS

A retrospective series of 12 patients presenting with cortical AVMs were treated by endovascular embolization using a transvenous approach with a curative intent.

RESULTS

Nine patients (75%) had ruptured AVMs at admission. The mean nidus size was 1.9 cm, six patients (50%) had a nidus in eloquent areas and the median Spetzler-Martin grade was 2. The rate of immediate angiographic occlusion of the AVMs was 91.6% (11/12). One patient in whom immediate angiographic occlusion was not achieved showed spontaneous occlusion at the 6-month follow-up. No procedural or clinical complications were observed. The mean and median modified Rankin scale (mRS) scores at discharge were 1.7 and 2 (range 0-3, SD=0.96), and the mean and median mRS scores at 6 months were 1.6 and 2 (0-3, 1.16). Nine patients (75%) were independent (mRS ≤2) at discharge and 11 patients (91.6%) were independent (mRS ≤2) at the 6-month follow-up.

CONCLUSIONS

The curative transvenous embolization of superficial intracranial AVMs is feasible and appears safe and effective when strict anatomical selection is respected. This technique extends the current indications for transvenous embolization of intracranial AVMs and may improve cure rates while reducing embolization-related complications.

The transvenous pressure cooker technique: A treatment for brain arteriovenous malformations

The treatment of brain arteriovenous malformations (AVMs) remains a significant challenge, especially hemorrhagic AVMs which are unsuitable for microsurgery or radiosurgery. We demonstrate an AVM located in the left basal ganglia area, supplied by slender arteries, and treated by the transvenous pressure cooker technique. Herein, we describe the procedure and outline the crucial points and indications for this technique.

Onyx Embolization for Tentorial Dural Arteriovenous Fistula with Pial Arterial Supply: Case Series and Analysis of Complications

OBJECTIVE

We describe treatment with Onyx embolization in a series of cases of tentorial dural arteriovenous fistula (DAVF) with pial arterial supply. The aim of this study was to analyze the cause of intraoperative hemorrhage and to explore therapeutic strategies.

METHODS

Retrospective review was performed of 53 consecutive patients with DAVF treated by Onyx embolization between February 2009 and December 2014. Tentorial DAVF with pial arterial supply was diagnosed in 6 patients (2 women and 4 men; mean age, 47.3 years ± 10.2), and transarterial Onyx embolization was performed in these patients. Fisher exact test was used to analyze differences of incidence of procedure-related complications.

RESULTS

Intraoperative hemorrhage occurred in 2 of 6 patients with pial arterial supply. One patient died as a result of hemorrhage, and the other patient survived after craniotomy. The incidence of complications for these 6 patients (2 of 6; 33.3%) was significantly higher (P = 0.0309) compared with patients with DAVF without pial arterial supply (1 of 47; 2.1%).

CONCLUSIONS

Pial arterial supply may be a risk factor for intraoperative hemorrhage during transarterial embolization of DAVF through dural feeders. Identification of pial feeders and early superselective occlusion of such feeders are important for safe management.

Endovascular treatment of arteriovenous malformations

Cerebral arteriovenous malformations (AVM) are tangles of blood vessels that permit shunting of blood from the arterial to venous phase without intervening capillaries. The malformation's arterialization of a low-pressure system creates a risk of rupture that is substantially higher when associated with an aneurysm. The annual hemorrhage rate is 2.2% per year as reported in the randomized trial of unruptured brain AVMs (ARUBA; rupture risk is increased after the first event. Ruptured AVMs have a 10% mortality rate and 20%-30% morbidity rate. The treatment of choice for AVMs is microvascular resection with or without preoperative embolization. Surgical risk can be stratified based on the Spetzler-Martin grading system. Liquid embolic material and coils may be used for the treatment of AVM associated aneurysms, especially in the setting of acute rupture as a bridge to delayed surgical resection. There is some limited reported success in total endovascular treatment of AVMs, but this is not considered standard therapy at this time. Stereotactic radiosurgery (SRS) has been recently described but mainly limited to AMVs deemed too risky to approach in an open fashion and limited to 2.5cm-3cm in size. The delayed protection from hemorrhage (approximately 2-3 years) and high marginal failure/recurrence rate are the greatest concerns.