Fistulous Point Research Articles

Dual Volume Image Fusion Technique for Anatomical Evaluation of Cavernous Sinus Dural Arteriovenous Fistula: Usefulness for Transvenous Target Segment Embolization

In this preliminary study, we investigated the value of fusion techniques by flat detector computed tomography based dual volume rotational angiography (DVRA) for the evaluation of the anatomical relationship of cavernous sinus dural arteriovenous fistula (CSDAVF) and assessed the possibility of transvenous target segment embolization. Twenty-six patients with CSDAVF supplied by multiple feeders underwent DVRA for each feeding large vessel separately. We assessed the anatomical relationship of feeders, fistula points, and venous drainage with three dual volume image fusion techniques. Transvenous embolization was targeted to the segment of fistulous point for preserving those not involved and reducing coil mass effect. Dual vessel multi-planar reconstruction fusion technique could show which segment of the cavernous sinus supplied by feeding arteries. In the dual vessel volume rendering fusion technique, the association between feeding arteries, fistula points, and draining veins of 2 different vessels could be accurately identified in 3 dimensions. In addition, we could visualize the exact anatomical relationship between the components of CSDAVF and skull anatomy with the single vessel fusion technique. Based on various fusion images, target segment embolization was successfully performed in 8 patients. In this group, we achieved complete or near complete occlusion without complications, including cranial nerve palsy. Detailed anatomical information including accurate fistula point, specific feeding arteries, and draining veins could be obtained with various dual volume image fusion techniques. In addition, the target segment embolization of CSDAVF could be possible with understanding of the precise CSDAVF architectures.

ACCURACY OF SUSCEPTIBILITY WEIGHTED IMAGING AND 3D-TOF MRA IN DETECTION AND PRE-TREATMENT EVALUATION OF INTRACRANIAL DURAL ARTERIOVENOUS FISTULAS

Background: Dural arteriovenous fistulas (DAVFs) are abnormal connections between meningeal arteries and dural venous sinuses or cortical veins. A cerebral angiogram is the gold standard for diagnosing and treating DAVFs. Still, non-invasive techniques such as three-dimensional time-offlight magnetic resonance angiography (3D-TOF MRA) and susceptibility-weighted imaging (SWI) are also helpful in evaluating the location and severity of the fistulas, including cortical venous reflux (CVR) and cortical venous ectasia (CVE). This study aimed to compare the efficacy in detecting and pretreating DAVFs evaluating SWI and 3D-TOF MRA with cerebral angiography. Methods: The retrospective study included 35 patients with 41 DAVFs who underwent pre-treatment MR imaging and cerebral angiogram. The fistulous point at convexity and cavernous locations, arterial feeders, venous drainers, CVR, and CVE were evaluated. Results: SWI and 3D-TOF MRA showed high sensitivity and excellent specificity in detecting DAVFs Cognard II-IV at convexity location and high sensitivity in evaluating CVR. For DAVFs at cavernous sinus locations, arterial feeders and venous drainers were significantly identified in 3D-TOF MRA (p < 0.001). SWI exhibited superior sensitivity (87.5%) in detecting CVE at convexity locations (p < 0.001). Slow flow or low-grade fistulas in cavernous sinus locations (n = 2, 4.8%, Cognard I) were not identified using MR imaging. Conclusion: SWI and 3D-TOF MRA are helpful tools for evaluating high-flow DAVFs (Cognard II-IV). SWI is superior in detecting CVE in convexity locations but is limited in assessing the fistulous point in cavernous sinus locations. Thus, combining findings from both SWI and 3D-TOF MRA exhibited high accuracy in detecting and pretreating high-flow DAVFs.

Angioarchitecture of Dural Arteriovenous Fistulas: Definition of Fistulous Points

As histopathological aspects of dural arteriovenous fistulas (DAVFs) are often lacking, there can be controversies regarding their angioarchitecture. Depending on various statements or DAVF types, the shunts may be situated directly on the sinuses, at the confluence of sinuses and cortical veins, in adjacent vascular structures surrounding the sinus or even in the bone.1-5 Comprehensive knowledge of the intricate arteriovenous shunt anatomy is crucial for the secure and effective management of DAVFs.1 It has been confirmed that the dural arteries communicate with crack-like veins that connect one or more dural veins near the affected sinuses.3 In DAVFs, it is certain that one or more draining veins exist before draining into the venous sinus, as opposed to the commonly stated direct artery-to-sinus communication. Arteries branch and taper, while veins receive branches and thicken their lumens. We define fistulous points as the locations where the feeding arteries transition from thick to thin, and the draining veins transition from thin to thick. Here is an image description based based on superselective angiography.

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

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. 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. 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). 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.

Off-label use of large diameter Concerto fibered coils through a 0.017 inch microcatheter for transvenous embolization of indirect carotid-cavernous fistulas: two case reports

BackgroundA carotid-cavernous fistula is an abnormal communication between the arteries and veins within the cavernous sinus. While conservative management may be prudent in low risk cases, many patients require intervention and endovascular embolization has evolved as the preferred method of treatment. Embolization can be performed via either the transarterial or transvenous approach. One major challenge of the transvenous approach is the complex and variable compartmentation of the cavernous sinus, which often requires the use of low profile microcatheters to navigate and reach the fistulous point. Fibered coils are also preferred when performing transvenous embolization of carotid-cavernous fistula, as they are of higher thrombogenicity and allow for faster occlusion of the fistula. However, most low profile (0.017-inch) microcatheters are not able to deploy fibered coils based on the manufacturer’s instructions.Case presentationWe present two successful cases of off-label use of Medtronic Concerto fibered coils via a 0.017-inch microcatheter during transvenous embolization of carotid-cavernous fistula in a 60-year-old and an 80-year-old Chinese female, respectively.ConclusionOur case series highlight the possibility of deploying large diameter (up to 10 mm) Concerto fibered coils through a low profile (0.017-inch) microcatheter in an off-label manner for transvenous embolization of indirect carotid-cavernous fistula.

4D-DSA for Assessment of the Angioarchitecture and Grading of Cranial Dural AVF.

Time-resolved 3D rotational angiography (4D-DSA) has been used to demonstrate details of the angioarchitecture of AVM, whereas it has rarely been used to describe features of dural AVF. In this exploratory study, we analyzed dural AVFs with a novel 4D software prototype, developed and provided by Siemens, to determine whether identification of the location of the fistulous point, grading, and treatment planning were feasible. 4D-DSA volumes were calculated from existing 3D rotational angiography data sets of patients with dural AVFs. The 4D-DSA volumes were displayed in a virtual DSA mode and MPR or MIP in 3 orthogonal planes and compared with 2D-DSA by 2 experienced neuroradiologists. Fusions with unenhanced CT or MR images were used to improve visualization of adjacent anatomic structures. Comparison with 2D-DSA showed that evaluation of the fistulous point and grading according to the classification of Borden, Cognard, or Barrow was feasible in 26 of 27 cases. In 8 of 27 cases, 4D-DSA was considered advantageous for determining the fistulous point and the course of the draining vein in the dural AVF with cortical venous drainage, especially in the frontoethmoidal and frontoparietal regions. In 6 cases, the display of angioarchitecture was considered inferior to that of 2D-DSA due to motion artifacts, suboptimal selection of the injected vessel, and lack of temporal resolution. Detailed analysis of dural AVFs according to the standardized display of 4D-DSA volumes was feasible and helpful in understanding the angioarchitecture in selected cases. Further improvement and validation of the 4D software should solidify the complementary role of 4D-DSA to conventional 2D-DSA series.

Anatomical considerations regarding a high-flow arteriovenous fistula below the conus medullaris in a patient with hereditary hemorrhagic telangiectasia: Case report.

Cauda equina radicular arteriovenous fistulas are rare "low flow" shunting lesions characterized by direct communication between the radicular artery and vein of a cauda equina nerve root. None have been associated with hereditary hemorrhagic telangiectasia and a high-flow cauda equina radicular arteriovenous fistula has never been reported. We present a unique case of a high-flow cauda equina radicular arteriovenous fistula in a patient with hereditary hemorrhagic telangiectasia. Marked flow-induced vascular remodeling posed significant diagnostic and therapeutic challenges which will be highlighted in this report. A 39-year-old female with genetically confirmed hereditary hemorrhagic telangiectasia presented with progressive thoracic myelopathy secondary to a high-flow single-hole arteriovenous fistula below the conus. The feeding artery, arising from the anterior spinal artery, and draining vein had a paramedian course, favoring the diagnosis of a cauda equina radicular arteriovenous fistula (supplied by a proximal radicular artery) over a filum terminale arteriovenous fistula. Transarterial embolization was attempted but significant elongation and tortuosity of the anterior spinal artery precluded microcatheter access to the fistulous point. Surgical disconnection was successfully performed. The intraoperative findings supported the diagnosis of cauda equina radicular arteriovenous fistula. Delayed neurologic deterioration secondary to overshooting venous thrombosis was observed. She recovered after the initiation of therapeutic anticoagulation. To the best of our knowledge, we hereby report the first high-flow cauda equina radicular arteriovenous fistula. The accurate differentiation of cauda equina radicular arteriovenous fistula from filum terminale arteriovenous fistulas, while challenging, is important to avoid treatment-related complications. Careful preoperative planning, the use of specialized endovascular and surgical techniques, and meticulous postoperative care can ensure the safe and complete disconnection of high-flow cauda equina radicular arteriovenous fistulas.

Cavernous sinus dural arteriovenous fistula embolized through an occluded superior petrosal sinus: illustrative case.

Transvenous embolization for cavernous sinus (CS) dural arteriovenous fistulas (CS-DAVFs) with limitations of the major access routes to the CS is challenging. A 74-year-old woman presented with left-sided conjunctival injection and exophthalmos. Cerebral angiography showed a left CS-DAVF draining into the left uncal vein and superior ophthalmic vein, with the fistulous point located in the posterosuperior compartment of the left CS. The left inferior petrosal sinus and internal jugular vein were occluded, and no drainage route from the left superior ophthalmic vein was seen. The anterior segment of the left superior petrosal sinus (SPS) was occluded, but the posterior segment was not. Microangiography from the posterior segment of the left SPS showed a beak-like orifice in the anterior segment of the left SPS toward the left CS. A micro-guidewire was guided through the beak-like orifice, and the microcatheter was advanced into the left CS. The left CS was packed and the DAVF was occluded. Transvenous embolization through an occluded SPS may be an option in the endovascular treatment of CS-DAVFs. Penetration along the beak-like orifice of the occluded SPS visualized by venography at the blind end of the SPS may be useful in reaching the CS via the SPS.

Vein of Galen malformations in the newborn: case series.

Vein of Galen malformations (VoGMs) in newborns often represent life-threatening emergencies. Outcome is difficult to predict. The authors review 50 VoGM cases to correlate anatomical types with treatment and outcome. Four distinct types of VoGMs are identified: mural simple (type I), mural complex (type II), choroidal (type III), and choroidal with deep venous drainage (type IV). Seven patients presented with mural simple VoGMs with a "single hole" fistula supplied by only one large feeder. These patients were treated electively at >6 months; development was normal. Fifteen patients presented with complex mural VoGMs. Multiple large feeders joined a single fistulous point within the wall of the varix. Patients typically presented with congestive heart failure (CHF) and required emergent transarterial intervention. Mortality was 7.7% with less than two-thirds developing normally. Twenty-five patients presented with choroidal VoGMs. Multiple large arterial feeders joined at multiple fistulous sites. Severe CHF in most patients required emergent transarterial and sometimes transvenous intervention. Mortality was 9.5%; two-thirds of the patients had a normal development. Three babies presented with choroidal VoGMs with deep intraventricular venous drainage. This phenomenon caused fatal "melting brain syndrome" in all three patients. Recognition of the specific VoGM type determines treatment options and sets outcome expectations.

Image fusion technique using flat panel detector rotational angiography for transvenous embolization of intracranial dural arteriovenous fistula.

Precise evaluation of the feeders, fistulous points, and draining veins plays a key role for successful embolization of intracranial dural arteriovenous fistulas (DAVF). Digital subtraction angiography (DSA) is a gold standard diagnostic tool to assess the exact angioarchitecture of DAVFs. With the advent of new image postprocessing techniques, we lately have been able to apply image fusion techniques with two different image sets obtained with flat panel detector rotational angiography. This new technique can provide additional and better pretherapeutic information of DAVFs over the conventional 2D and 3D angiographies. In addition, it can be used during the endovascular treatment to help the accurate and precise navigation of the microcatheter and microguidwire inside the vessels and identify the proper location of microcatheter in the targeted shunting pouch. In this study, we briefly review the process of an image fusion technique and introduce our clinical application for treating DAVFs, especially focused on the transvenous embolization.

A Classification Proposal for Spinal Vascular Lesions.

A Classification Proposal for Spinal Vascular Lesions.

Left Distal Transradial Approach for the Treatment of a Sacral Extradural Arteriovenous Fistula: A Technical Note and Literature Review

Sacral extradural arteriovenous fistula (SEAVF) is relatively rare, and its etiology is unknown. They are mostly fed by the lateral sacral artery (LSA). For endovascular treatment, both the stability of the guiding catheter and accessibility of the microcatheter to the fistula, distal to the LSA are required for sufficient embolization of the fistulous point. Cannulation of these vessels requires either crossover at the aortic bifurcation or retrograde cannulation using the transfemoral approach. However, atherosclerotic femoral and tortuous aortoiliac vessels can make the procedure technically difficult. Although the right transradial approach (TRA) can reduce this difficulty by straightening the access route, a potential risk remains for cerebral embolism because it passes the aortic arch. Herein, we present a case of successful embolization of a SEAVF using a left distal TRA. We report a case of a 47-year-old man with SEAVF treated with embolization using a left distal TRA. Lumbar spinal angiography showed a SEAVF with an intradural vein through the epidural venous plexus fed by the left LSA. A 6-French guiding sheath was cannulated into the internal iliac artery via the descending aorta using the left distal TRA. A microcatheter could be advanced into the extradural venous plexus over the fistula point from the intermediate catheter placed at the LSA. Embolization with coils and n-butyl cyanoacrylate was successfully performed. The SEAVF completely disappeared on neuroimaging, and the patient gradually recovered. Left distal TRA could be a useful, safe, and less invasive option for the embolization of SEAVF, especially for patients with high-risk factors for aortogenic embolism or puncture site complications.

Abstract Number ‐ 79: Flow Diversion for Traumatic Vertebral Artery Arteriovenous Fistula: A Case Report

Introduction Arterial pseudoaneurysms and arteriovenous fistulas of intracranial and extracranial vessels are an uncommon occurrence following blunt and penetrating trauma and are commonly treated by vessel sacrifice,dependent on collateral flow1‐3. Others have treated these cases with covered stents4 and flow diversion5. Advances in flow diversion technology have led to their use in other pathologies, including carotid cavernous fistulas6 and vertebral artery pseudoaneurysms7. We present a case of a traumatic arteriovenous fistula of the dominant vertebral artery requiring vessel preservation and reconstruction. Methods A 42‐year‐old male presented with a gunshot wound to the face below the right eye. Trauma imaging identified fractures of the right maxillary sinus and orbital floor. CTA of the head/neck showed a dominant right vertebral artery dissection and pseudoaneurysm with a non‐dominant left vertebral artery (VA), effectively ending in PICA. Results Due to the inefficient supply to the posterior circulation via the left VA, the decision was made to preserve and reconstruct the right VA and the patient was brought to the angiography suite. Angiographically, the patient was noted to have retrograde filling of the posterior circulation, basilar and right VA through the anterior circulation in injection of both ICAs, suggesting decreased antegrade flow from the injured right VA. The right VA was catheterized which showed a high‐flow, high‐grade arteriovenous fistula from the V3 segment with venous drainage into multiple extraspinal cervical and epidural cervical veins. This also identified the fistulous point at the location of the pseudoaneurysm on CTA. The diagnostic catheter was exchanged for a guide catheter, and a Phenom 27 microcatheter (Medtronic; Minneapolis, MN) was navigated into the basilar artery. A Duo microcatheter (Microvention; Aliso Viejo, CA)/Synchro 2 (Stryker; Kalamazoo, MI) standard microwire complex was used to identify the fistulous point and positioned for jailing. A Pipeline Flex 4.75×20mm (Medtronic; Minneapolis, MN) was deployed from the proximal V4 segment across the pseudoaneurysm with persistence of the AVF. A second Pipeline Flex 5×20mm was placed in telescoping fashion with persistence of the AVF. A third Pipeline Flex 5×16mm was placed in telescoping fashion and flow diversion was observed. Using the jailed catheter, the pseudoaneurysm and fistulous point were coil embolized using a combination of helical and 3D HydroSoft coils (Microvention; Aliso Viejo, CA) of varying sizes. Final angiogram demonstrated resolution of the high‐flow AVF, improvement of antegrade flow through the right vertebral artery, and a slow‐flow low‐grade fistulous communication with the posterior extraspinal cervical veins. There were no thromboembolic complications and the patient recovered well from the procedure. Follow‐up angiography at 2 months post‐treatment showed obliteration of the AVF with a small remnant pseudoaneurysm of the right V3 segment. Conclusions Flow diversion is viable in the setting of a traumatic arteriovenous fistula requiring reconstruction of the parent vessel.

Abstract Number ‐ 80: Embolization of Carotid Cavernous Fistula Through Occluded Inferior Petrosal Sinus Access

Introduction Carotid cavernous fistula (CCF) is an abnormal communication between arteries and veins within the cavernous sinus. The most common presenting symptoms are proptosis, chemosis, orbital bruit and headache. Visual disturbances such as diplopia, ophthalmoplegia and cranial nerve deficits can also occur. Pulsatile tinnitus is an unusual finding which necessitates further workup in this population. Endovascular obliteration with transvenous embolization for indirect fistulas is the preferred approach for CCF closure. Navigation is achieved through the inferior petrosal sinus or facial and superior ophthalmic vein. Here, we describe a case of carotid cavernous fistula that was successfully treated through occluded right inferior petrosal sinus access using coil and Onyx embolic material. Methods A 56‐year‐old‐male with no past medical history presented with right eye proptosis and pulsatile tinnitus. His eye symptoms progressively worsened with decrease in visual acuity, gaze restriction and exophthalmos which correlated with the resolution of pulsatile tinnitus. MRI demonstrated significant inflammation involving the right orbit and atypical enhancement of basal frontal lobe adjacent to orbit. MRA suggested early opacification of the right superior ophthalmic vein and subtle flow voids in posterior lateral aspect of right cavernous sinus. Further evaluation with cerebral angiogram revealed a Barrow Type D right carotid cavernous fistula supplied by meningo‐hypophyseal branches of bilateral internal carotid arteries and right internal maxillary branch. It demonstrated high flow retrograde shunting in right superior ophthalmic vein and a basal frontal isolated cortical vein. There was near complete occlusion of the right sigmoid sinus and inferior petrosal sinus due to significant thrombus burden as well as stenosis of the right internal jugular vein. Results Patient underwent embolization of right carotid cavernous fistula with transvenous approach. A microcatheter was advanced to the origin of the intercavernous sinus but was not able to cross due to exceptionally small channels connecting both cavernous sinuses. The right internal jugular vein was subsequently identified and injection demonstrated occlusion of right sigmoid sinus due to near complete occlusive thrombus in addition to occlusion of the major channels of the inferior petrosal sinus. The microcatheter was blindly advanced into the inferior petrosal sinus maintaining the symmetry from contralateral inferior petrosal sinus trajectory. We were able to reach the fistulous point in the posterior medial aspect of the right cavernous sinus using an Echelon 1045 microcatheter. Coils were subsequently deployed and fistula was noted to be occluded. Onyx was injected through the microcatheter to avoid recanalization of fistula. A follow‐up left internal carotid artery and right common carotid artery injections confirmed angiographic cure of the fistula. Conclusions Carotid cavernous fistula is a rare but treatable cause of rapidly progressive vision loss with pulsatile tinnitus as an unusual finding. We present a case of challenging access and successful treatment with transvenous approach through near complete occlusion of the inferior petrosal sinus.

Four-dimensional digital subtraction angiography for the vascular anatomical diagnosis of dural arteriovenous malformation: Comparison with the conventional method.

Two-dimensional digital subtraction angiography (2D-DSA) and conventional three-dimensional digital subtraction angiography (3D-DSA) are used for the detailed analysis of dural arteriovenous fistula (DAVF). Recently, four-dimensional digital subtraction angiography (4D-DSA), a novel technology, has been attracting attention. The current study aimed to evaluate the capability of 4D-DSA in assessing anatomical angioarchitecture in DAVF. In total, 10 consecutive patients with DAVF who underwent 3D-DSA and 4D-DSA at a single institution were included in the analysis. Initially, one-slice multiplanar reconstruction (MPR) images obtained via 4D-DSA and 3D-DSA were compared to investigate the visibility of the feeding artery, fistulous point, and draining vein. Next, 4D-DSA images alone were compared and evaluated with and the MPR images of conventional 3D-DSA in terms of diagnosis of the angioarchitecture. In total, six men and four women (with a mean age of 65.6 ± 10.0 years) were included in the study. The MPR image obtained via 3D-DSA had a significantly better visibility of the feeding artery and fistulous point than that acquired via 4D-DSA (p < 0.05). As for the draining vein, the score was equivalent and not significant. The diagnosis of the vascular architecture of only 4D-DSA images was nearly equivalent to that of MPR images of 3D-DSA. There were no inter-rater differences. The MPR images obtained via 4D-DSA may be slightly inferior to those acquired via 3D-DSA in identifying fine angioarchitecture in DAVF. However, they were comparable in terms of diagnostic accuracy.

Recognition of the variant type of spinal dural arteriovenous fistula: a rare but important consideration.

Spinal dural arteriovenous fistulas (SDAVFs) typically represent abnormal shunts between a radiculomeningeal artery and radicular vein, with the point of fistulization classically directly underneath the pedicle of the vertebral body, at the dural sleeve of the nerve root. However, SDAVFs can also develop in atypical locations or have more than one arterial feeder, which is a variant of SDAVF. The aim of this study was to describe the incidence and multidisciplinary treatment of variant SDAVFs in a single-center case series. Following institutional review board approval, the authors retrospectively analyzed their prospectively maintained database of patients with SDAVFs who presented between 2008 and 2020. For all patients, spinal digital subtraction angiograms were reviewed and variant SDAVFs were identified. Variant types of SDAVFs were defined as cases in which the fistulous point was not located underneath the pedicle. Patient demographics, angiographic features, clinical outcomes, and treatment modalities were assessed. Of 59 patients with SDAVFs treated at the authors' institution, 4 patients (6.8%) were identified as having a variant location of the shunt zone, pinpointed on the dura mater at the intervertebral level, further posteriorly within the spinal canal. In 3 cases (75%), a so-called bimetameric arterial supply was demonstrated. Recognition of the variant type of SDAVF is crucial for management, as correct localization of the fistulous point and bimetameric supply are critical for successful surgical disconnection, preventing delay in achieving definitive treatment.

Endovascular Management of Intracranial Pial Arteriovenous Fistula with Giant Venous Varix: Case Report and Review of Literature.

Abstract: Background: Intracranial pial arteriovenous fistulas (AVFs) are rare intracranial vascular malformation and their treatment is challenging because of high-flow pial supply of the lesion. We report a case of intracranial pial AVF with associated giant venous varices managed successfully by embolization. Case Description: A 25-year-old male presented with sudden onset headache and altered sensorium. Computed tomographic scan was suggestive of frontal lobar hematoma that had dissected into the third ventricle with associated intraventricular hemorrhage. Magnetic resonance imaging revealed presence of large vascular channels with the presence of multiple flow voids in bilateral frontal location. Digital subtraction angiography revealed pial fistula with arterial supply from hypertrophied left anterior cerebral artery. Treatment was done using combined coil and onyx embolization after careful analysis of angioarchitecture of the lesion using three-dimensional rotational angiogram cross-sectional reconstructions. Postprocedure angiogram revealed closure of fistula and giant varices. Conclusion: Pial AVFs with giant venous varix in adults are rare vascular malformation and understanding the angioarchitecture with exact identification of fistulous point is important to plan for surgical/endovascular management strategies. Combined strategy of embolization using coils and onyx is a safe option in such cases with giant varices.

Rapid Ventricular Pacing Facilitates Transarterial Embolization in Vein of Galen Malformations.

Background: Mural type vein of Galen malformation (mVOGM) is a congenital high flow arteriovenous shunt between choroidal arteries and the prosencephalic vein of Markowski leading to heart failure and hydrovenous disorder in children. Embolizing fistulous connections can be challenging and typically requires adjunctive techniques such as induced hypotension, balloon-assisted flow control, and creation of a coil basket. These maneuvers add time, complexity, and unpredictability. Rapid ventricular pacing (RVP) has been proposed as an alternative strategy with fewer drawbacks, but has not been well studied. The approach involves catheterizing the right ventricle with a pacing catheter connected to a temporary external pacemaker. Prior to embolization, RVP is initiated to lower cardiac output. Following embolization, pacing is discontinued, and the heart returns to sinus rhythm. Methods: We performed RVP in five mVOGM patients from 4/2020 through 7/2021. Accounting for multiple procedures, RVP was utilized in ten cases and twenty-six pedicles. Results: Ventricular capture was achieved in all instances and was well tolerated, without arrhythmia. Casting the arterial pedicle with liquid embolic immediately adjacent to, or traversing, the fistulous point was achieved in 9/10 cases. There were no procedural complications. In 1 case, creation of a coil basket in the venous pouch was required to achieve a stable arterial cast Conclusions: This report describes the largest case series utilizing RVP in mVOGM. The technique appears safe and well tolerated.

Simultaneous transarterial and transvenous contrast injection to reveal the fistulous point in carotid cavernous fistula: illustrative case.

BACKGROUNDAccess of the cavernous sinus (CS) via venous route from the inferior petrosal sinus (IPS) can sometimes be challenging during the treatment of carotid cavernous fistulas (CCF), largely because of anatomical variations, tortuosity, and/or difficult visualization of IPS given high retrograde flow through the fistulous connection.OBSERVATIONSA 58-year-old male was transferred to our university hospital center after suspected diagnosis of CCF at another hospital by head computerized tomography-angiogram. His symptoms included three weeks of right eye pain that was later complicated by redness, diplopia, and blurry vision. In a diagnostic angiogram, separate contrast injections from the arterial side via internal carotid artery (ICA) and from the venous side via IPS did not reveal a connection point. Injecting contrast simultaneously from both arterial and venous ends resulted in visualization of a connection point allowing entry into the CS.LESSONSTechnique of simultaneous contrast injection from ICA and internal jugular vein is comparatively simple and saves an operator prolonged time and complexity of approach. In our case, it revealed fistulous point allowing navigation and completing the coiling.

Transvenous Approaches to Embolization of Dural Arteriovenous Fistulae of the Cavernous Sinus.

Dural arteriovenous fistulae of the cavernous sinus (CS) (previously often referred to indirect carotid cavernous fistulas) are rare vascular shunts involving meningeal branches and osseous branches of the external or internal carotid arteries and the CS. They typically present with ocular symptoms including pain, conjunctival injection, and proptosis. Left untreated there may be a risk of vision loss, and fistulas with cortical venous reflux through either the deep or superficial venous system may cause intracranial venous congestion or hemorrhage. Endovascular embolization is the standard treatment, and while transarterial routes may appear possible, transarterial embolization has considerable risks of ischemic complications. Conversely, transvenous routes achieve a high rate of fistula occlusion with a low risk of peri-procedural morbidity. Procedural success depends on identification of the venous outflows from the fistula and localization of the fistulous point, to select the best route of access to the CS, including the inferior petrosal sinus (IPS), intercavernous sinus, or superior ophthalmic vein, among others. Even if the IPS is not visualized, it may be possible to recanalize it to gain access to the CS. Embolization can be performed with a combination of coils, fibered coils, and liquid embolic agents, focusing on occlusion of the fistulous point or blocking high-risk venous outflow pathways. In this review we will highlight procedural pearls and potential pitfalls and our typical approach to these lesions based on illustrative examples.