Sylvian Vein Research Articles

NI-22 IMPROVED DELINEATION OF THE SUPERFICIAL CEREBRAL VENOUS SYSTEM IN BRAIN CT ANGIOGRAPHY BY ULTRAHIGH-RESOLUTION CT FOR ASSISTING BRAIN TUMOR SURGERY

BACKGROUNDIn brain CT angiography (CTA) for assisting brain tumor surgery, delineation of the superficial cerebral venous system is critical for selecting the optimal surgical approach. This delineation is, however, limited using conventional CT scanners, including an area-detector CT (ADCT) scanner, due to their insufficient spatial resolution. Since March 2017, a state-of-the-art ultrahigh-resolution CT (UHRCT) scanner has been clinically available to improve in- and through-plane spatial resolution compared with conventional CT scanners, mainly due to smaller slice thickness from 0.5 mm to 0.25 mm, larger channel number from 896 to 1792, and smaller x-ray focus from 0.9 x 0.8 mm to 0.4 x 0.5 mm.PurposeWe assessed usefulness of UHRCT to improve delineation of the superficial cerebral venous system in brain CTA for assisting brain tumor surgery compared with conventional ADCT.METHODSWe retrospectively enrolled patients with intra- and/or extra-axial brain tumors who underwent preoperative brain CTA for assisting brain tumor surgery by UHRCT or ADCT using our routine technique and generated the CTA to delineate the superficial cerebral venous system using the same technique. Two reviewers by consensus subjectively counted the number of the superficial sylvian veins and the cortical veins draining into these veins and the maximal bifurcation order of the cortical veins draining into the superior sagittal sinus. We compared these numbers and the maximal bifurcation order in the CTA between the UHRCT and ADCT groups using the intraoperative findings as the reference.RESULTSThe numbers and the maximal bifurcation order in the UHRCT group were significantly greater and more accurate than those in the ADCT group.CONCLUSIONSUse of UHRCT can be clinically useful for better delineating the superficial cerebral venous system in brain CTA and assisting brain tumor surgery.

Planning of Endocranial Supratentorial Basal Cistern and Skull Base Approaches Depending on Venous Patterns Using a Topogram

Because damage or sacrifice of venous drainage during supratentorial basal cistern and skull base approaches may have severe and harmful consequences, methods to identify preoperatively veins at risk are of paramount importance. Among methods, a codified assessment with a venous topogram is helpful, with practical implications. This technical note describes how to construct an easy-to-use topogram. Three regions of interest are defined as triangles. The anterior triangle corresponds to the anterior frontal veins draining to the superior sagittal sinus at risk during anterior cerebral fossa surgery, the middle triangle corresponds to the anterior sylvian veins draining to the cavernous sinus at risk during pterional approaches, and the inferior triangle corresponds to the inferior cerebral veins draining to the transverse sinus at risk in subtemporal approaches and temporal lobe surgery. Depending on predominance of the drainage, 4 situations were defined: an anterior, an inferior, and a middle predominance or equilibrium between the 3 triangles. These anatomic features have important practical implications in skull base and basal cistern approaches. This is, to our knowledge, the only topogram described in the scientific literature. Any well-defined approach should be adapted to the individual patient according not only to location and type of lesion but also to the venous drainage to be encountered along the way.

Awake Craniotomy for Resection of Left Temporal Cavernoma: 3-Dimensional Operative Video.

Cavernomas presenting with seizures refractory to medical treatment may require surgical excision for seizure control. If superficial, they can be surgically accessible but can pose additional risks when located in or near eloquent cortex. In this 3D operative video we illustrate the technique for the resection of a left temporal cavernoma located near eloquent cortex for speech with awake surgery and cortical mapping to avoid a speech deficit postoperatively. Informed consent was obtained for this procedure. Navigation is used to localize the cavernoma following which a large craniotomy is performed exposing the temporal lobe, frontal lobe, and sylvian vein. Bipolar stimulation is used to localize speech with the patient awake until speech arrest occurs. The cavernoma is situated immediately inferior to the sulcus over which speech arrest occurs. The sulcus immediately above the cavernoma is opened and adjacent arteries are carefully preserved. The glial plane around the cavernoma is used to dissect the cavernoma from the surrounding cortex. Care is taken to remove the haemosiderin as this can act as a precipitant for ongoing seizures. In this case the patient had no neurological deficits following surgery and was seizure free.

Transcranial approach for surgical-combined-endovascular treatment of a cavernous dural arteriovenous fistula: the superficial sylvian vein route.

Transcranial approach for surgical-combined-endovascular treatment of a cavernous dural arteriovenous fistula: the superficial sylvian vein route.

Transsylvian-Transinsular Approach for an Insular Cavernous Malformation Resection: 3-Dimensional Operative Video.

Surgical resection of insular lesions is challenging due to their proximity to critical neurovascular structures such as the middle cerebral arteries (MCA), Sylvian veins, thalamus, internal capsule (IC), and lenticulostriate arteries. A surgical series using the transsylvian-transinsular approach to treat cerebrovascular pathologies reported ∼5% permanent neurological morbidity.1,2 This case demonstrates the utility of this approach for resecting an insular cavernous malformation (CM).A 25-yr-old female presented with an acute-onset right homonymous hemianopsia. Neuroimaging revealed a large left insular CM, adjacent to the posterior limb of IC. After obtaining IRB approval and patient consent, a left pterional craniotomy with a wide distal Sylvian fissure split was completed. Using neuronavigation, an insular entry point was chosen for corticectomy. The CM was opened with subsequent hematoma evacuation and intracapsular resection technique. Inspection of the cavity revealed remnants anteromedially near the IC, which were removed meticulously, mobilizing the CM away from the IC. Postoperative MRI demonstrated gross total resection of the CM. The patient was discharged home on postoperative day 5 with persistent homonymous hemianopia.This case describes the use of a transsylvian-transinsular approach to access deep lesions with the shortest surgical distance and minimal cortical transgression. A wide Sylvian fissure split exposes the M2 MCA and accesses a safe insular zone, keeping the most eloquent structures deep to the lesion in the surgical corridor. This approach can safely expose vascular pathologies in the insular region without the risk of injury to overlying eloquent frontal and temporal lobes, even in the dominant hemisphere.

Retrosigmoid Intradural Suprameatal Approach for Petroclival Meningioma

Background Anterior transpetrosal approach and the combined transpetrosal approach are the major surgical approaches for petroclival meningiomas. However, anterior petrosectomy is not preferable in cases with postoperative venous drainage disorder of the sylvian vein due to anatomical variations. Here we present a case of the successful removal of petroclival meningioma by the retrosigmoid intradural suprameatal approach (RISA). Case Presentation The patient was a 59-year-old woman with incidentally detected right petroclival meningioma. Although she had no neurological deficit, the tumor manifested with gradual growth on annual magnetic resonance imaging (MRI) during an 8-year follow-up. Three-dimensional computed tomography venography (3D–CTV) revealed sphenobasal type of the sylvian vein throughout the lateral side of the foramen ovale. Because the suprameatal tubercle was an obstacle to observe the Meckel's cave, RISA was selected for complete tumor excision. RISA could provide an excellent operative field around the Meckel's cave to confirm the remnant tumor. Postoperative MRI showed no evidence of the tumor, and the patient was discharged without any neurological deficit. Conclusion RISA can provide a favorable operative field for petroclival meningioma, particularly for cases with high risk of postoperative complications related to the sylvian vein. The link to the video can be found at: https://youtu.be/cfci_zk0StU .

Anatomia Cirúrgica e Classificação das Veias Silvianas

Introdução: O entendimento da anatomia e variações das veias silvianas para o acesso transilviano dos aneurismas intracranianos se torna necessária para evitar complicações como trombose venosa ou contusão cerebral. Nesse sentido os autores realizam um estudo anatômicos das veias silvianas pelo acesso pterional clássico, com a abertura da aracnóide pelo lado frontal. Material e Métodos: De junho de 1994 a dezembro de 2008, 110 pacientes com aneurismas intracranianos foram abordados pela via pterional, dos quais foram analisados 45 hemisférios cerebrais. Resultados: Quinze casos apresentavam predomínio da veia ponte frontobasal e apenas um caso apresentou infarto venoso. Discussão: A abertura da aracnóide pelo lado frontal é mais seguro do que em comparação com a abertura pelo lado temporal. Conclusão: O entendimento anatômico das veias silvianas pode propiciar uma cirurgia mais segura para os aneurismas intracranianos.

Sylvian Arteriovenous Malformation Resection and Associated Middle Cerebral Artery Aneurysm Clipping: Technical Nuances of Concurrent Surgical Treatment.

Approximately 10-30% of brain arteriovenous malformations (AVM) have associated arterial aneurysms (AAA), and the management of these lesions can be challenging. In this video technical note, we demonstrate the microsurgical treatment of an unruptured, Spetzler-Martin grade I AVM in the distal Sylvian fissure with two AAAs arising proximally from the inferior M2 trunk immediately distal to the middle cerebral artery (MCA) bifurcation. First, we resected the superficially located AVM to normalize the blood flow through the Sylvian vein. Next, we performed a Sylvian fissure dissection to access and clip the two MCA AAAs. We also discuss the technical nuances of tandem surgical intervention for AVMs with AAAs as it pertains to this case, particularly with respect to the order of lesion treatment, Sylvian fissure dissection, nidal resection, and aneurysm clipping.

Stereoelectroencephalography Using Magnetic Resonance Angiography for Avascular Trajectory Planning: Technical Report.

Stereoelectroencephalography (SEEG) requires high-quality angiographic studies because avascular trajectory planning is a prerequisite for the safety of this procedure. Some epilepsy surgery groups have begun to use computed tomography angiography and magnetic resonance T1-weighted sequence with contrast enhancement for this purpose. To present the first series of patients with avascular trajectory planning of SEEG based on magnetic resonance angiography (MRA). Thirty-six SEEG explorations for drug-resistant focal epilepsy were performed from January 2013 to December 2015. A retrospective analysis of this consecutive surgical series was then performed. Magnetic resonance imaging included MRA with a modified contrast-enhanced magnetic resonance venography (MRV) protocol with a short acquisition delay, which allowed simultaneous arterial and venous visualization. Our criteria for satisfactory MRA were the visualization of at least first-order branches of the angular artery, paracentral and calcarine artery, and third-order tributaries of the superficial Sylvian vein, vein of Labbe, and vein of Trolard. Thirty-four patients underwent 36 SEEG explorations with 369 electrodes carrying 4321 contacts. Contrast-enhanced MRA using the MRV protocol was judged satisfactory for SEEG planning in all explorations. Postoperative complications were not observed in our series of 36 SEEG explorations, which included 50 transopercular insular trajectories. MRA using an MRV protocol may be applied for avascular trajectory planning during SEEG procedures. This technique provides a simultaneous visualization of cortical arteries and veins without the need for additional radiation exposure or intra-arterial catheter placement.

Applied anatomy of large unilateral frontotemporoparietal decompressive craniectomy

Objective To study the anatomy of unilateral frontotemporoparietal structures of the Chinese people and to provide the anatomical basis for approach design in large craniectomy. Methods Large unilateral frontotemporoparietal decompressive craniectomy were performed on 15 corpse skulls. Through dissection layer by layer, anatomical landmarks were identified and relevant data were documented. Results The vertical distance between the distal point of posterior edge of parietal eminence and the external auditory canal was 79.90±4.06 mm. The distance from the midpoint between nasal root and external occipital protuberance to the midpoint of zygomatic arch was 144.60±4.73 mm. The distance between the eyebrow arch and the parietal eminence was 163.50±4.75 mm. Within the bone window, the longest distance between arachnoid granulation in the superior sagittal and midline was 19.62±3.98 mm. The vertical distance between the superior margin of zygomatic arch and the point where the Sylvian vein drains into sphenoparietal sinus was 25.26±3.77 mm. Conclusions In order to achieve adequate decompression, the vertical distance from the farthest point of skin incision around parietal eminence to the external auditory canal should not be less than 8 cm, the bone window could be 2 cm from the midline, and the lower margin of the bone could be located at the upper margin of zygomatic arch. Key words: Craniology; Anatomy; Decompressive hemicraniectomy

Single fronto-temporal sylvian vein reconstruction when treating a large partially thrombosed aneurysm of the M1 middle cerebral artery

<p>The article describes a clinical case of clipping the neck of large partially thrombosed aneurysm by using a transsylvian approach. A feature of the case is an atypical structure of the Sylvian fissure, with just one vein draining both the frontal and the temporal lobes and hindering access to the Sylvian fissure. The problem was solved by cutting the vein, performing the aneurysm neck clipping and suturing the cut vein by means of end-to-end technique. </p><p>Received 19 April 2016. Accepted 7 September 2016.</p><p><strong>Funding:</strong> The study had no sponsorship.<br /><strong>Conflict of interest:</strong> The authors declare no conflict of interest.</p>

Correct Plane of the Sylvian Vein Dissection for Middle Cerebral Artery Aneurysm Using Indocyanine Green Videoangiography

Preservation of the superficial Sylvian veins (SSVs) is essential to prevent neurologic deficits during Sylvian dissection. We describe an appropriate surgical approach for unruptured middle cerebral artery (MCA) aneurysms to preserve these veins by using indocyanine green videoangiography (ICG-VA). Between August 2014 and August 2015, we performed microsurgical clipping for 37 unruptured MCA aneurysms in 36 patients. We classified all of the cases into 3 types according to the location between the Sylvian fissure and the SSV. We defined 3 surgical approaches (frontosylvian, intersylvian, and temporo-sylvian) based on the SSV and investigated the proper surgical approach according to the type of case. In our study, most SSVs were located above the Sylvian fissure (fissure type, 64.9%). The SSV was located on the temporal lobe in 10 cases (temporal type) and on the frontal lobe in 3 cases (frontal type). The frontosylvian approach (splitting between the SSV and frontal lobe) was performed in all of the patients with temporal type; the temporo-sylvian approach (splitting between the SSV and temporal lobe) was performed in all of the patients with frontal type and single SSV of fissure type. The intersylvian approach (splitting between the frontal and temporal SSV, or among multiple SSVs) was successfully performed in the patients with double or multiple SSVs of fissure type. No venous complications occurred that were related to the surgical approach. Correct dissection strategy using intraoperative ICG-VA is greatly useful to define the optimal surgical approach without vein injury.

Clinical and Anatomic Insights From a Series of Ethmoidal Dural Arteriovenous Fistulas at Barrow Neurological Institute

Ethmoidal dural arteriovenous fistulas (dAVFs) have a malignant natural history and an anatomy that make endovascular therapy challenging. Their uniqueness begs for stratified analyses, but this has largely been precluded by their rarity. We sought to summarize the anatomic, presentation, treatment approaches, and clinical outcomes of patients with these lesions. We reviewed our prospectively maintained institutional database to identify patients diagnosed with ethmoidal dAVFs from January 1, 2000, to December 31, 2015. We evaluated demographic, presentation, angiographic, treatment, and follow-up data. In total, 27 patients with ethmoidal dAVFs underwent endovascular and/or surgical treatment. Mean patient age was 62 years old and there was a male sex predilection (67% men; 2:1 male-female ratio). All dAVFs exhibited direct cortical venous drainage; venous ectasia was present in 59% of cases. Of the dAVFs, 30% drained posteriorly into the basal vein of Rosenthal or the sylvian veins. Embolization with casting of the draining vein was successful in 2 of 9 cases (22%), including 1 successful transvenous case. There were no clinical or permanent complications from embolization; specifically, no patients experienced visual loss after treatment. Surgical treatment with successful dAVF obliteration was carried out in 24 of 24 patients (100%). One patient declined surgical treatment after attempted endovascular embolization. There were no permanent complications after surgical treatment and no cases of wound infection or cerebrospinal fluid leakage. Surgical disconnection remains the gold standard in the treatment of ethmoidal dAVFs. Embolization is a consideration for well-selected cases with favorable arterial or venous access anatomy.

Abstract WP90: Intraoperative Premature Rupture of Middle Cerebral Artery Aneurysms: Risk Factors and Sphenoid Ridge Proximation Sign

Object: The investigation of surgical cases of a ruptured middle cerebral artery (MCA) aneurysm to identify the risk factors of an intraoperative premature rupture. Methods: Based on an 8-year period and among 927 patients with a ruptured intracranial aneurysm, the medical records of 182 consecutive patients with a ruptured MCA aneurysm were examined for cases of a premature rupture, and the risk factors were then investigated. The considered risk factors included: the patient age, gender, WFNS clinical grade, modified Fisher grade, presence of an ICH, frontal ICH, temporal ICH, volume of the ICH, maximum diameter of the ruptured MCA aneurysm, length of the pre-aneurysmal M1 segment between the carotid bifurcation and the MCA aneurysm, and the presence of a sphenoid ridge proximation sign. The use of axial source images and a three-dimensional reconstruction of the brain CTA revealed a sphenoid ridge proximation sign based on the spatial proximation between a potential rupture point of the MCA aneurysm and the cortical arachnoid of the sphenoidal sylvian fissure, adjacent superficial sylvian veins, and the sphenoid ridge. Results: A total of 11 patients (6.0%) suffered a premature rupture of the MCA aneurysm during surgery. The premature rupture occurrences were classified according to the stage of the surgery as follows: 1) craniotomy and dural opening (n = 1), 2) aspiration or removal of the ICH (n = 1), 3) retraction of the frontal lobe (n = 1), 4) dissection of the sphenoid segment of the sylvian fissure to access the proximal vessel (n = 4), and 5) peri-aneurysmal dissection (n = 4). Univariate and multivariate analyses revealed that the presence of a sphenoid ridge proximation sign, a frontal ICH associated with the ruptured MCA aneurysm, and the length of the pre-aneurysmal M1 segment were all statistically significant risk factors for a premature rupture of a MCA aneurysm. Conclusions: Patients exhibiting a sphenoid ridge proximation sign, the presence of a frontal ICH, and/or a short pre-aneurysmal M1 segment are high-risk patients for an intraoperative premature rupture of a MCA aneurysm. Such high-risk MCA aneurysms have a superficial location close to the arachnoid in the sphenoidal compartment of the sylvian fissure and have a rupture point directing anteriorly.

Safe and accurate sylvian dissection with the use of indocyanine green videoangiography.

Background:Sylvian dissection is an essential microneurosurgical skill for neurosurgeons. The safe and accurate opening of the sylvian fissure is desirable for a good prognosis.Methods:The aim of this report is to demonstrate the use of indocyanine green (ICG) videoangiography to recognize the superficial sylvian vein (SSV) and thus enable a wide opening of the sylvian fissure, especially in patients with subarachnoid hemorrhage (SAH).Results:The small tributary flowing into the SSV was distinguishable from a passing one, which deeply entered the insula. In addition, an entering point of a tributary to the SSV, which ran perpendicular to the insula, was occasionally determined. SSV, which was barely discernable in a reddish SAH involving the sylvian fissure, was clearly demarcated using ICG videoangiography. Two representative cases of sylvian dissection are herein presented.Conclusion:The performance of ICG videoangiography before sylvian dissection is a simple and useful method for identifying a vital approach route for safe and accurate sylvian dissection, and it reduces the risk of causing any accidental injury to the veins in the sylvian fissure.

Indocyanine Green (ICG) Videoangiography-Guided Dissection of the Sylvian Fissure on the Transsylvian Approach: Technical Note

The transsylvian approach is a standard method of approach for anterior circulation aneurysms or paraclinoid tumors. Care must be taken, however, to avoid inadvertent obliteration of sylvian veins to prevent postoperative brain swelling and venous infarction. Sometimes, the superficial sylvian veins have complex connections or are not visible because of the thickness of the arachnoid membrane, especially in the case of subarachnoid hemorrhage (SAH). The present report describes a simple method to dynamically visualize the sylvian vein via indocyanine green (ICG) angiography for the purposes of appropriately wide dissection of the sylvian fissure. Before dissection of the sylvian fissure and after opening the dura mater, a bolus of ICG is administered intravenously. ICG videoangiography is used for dynamic venography at 10 seconds after the depiction of branches of the middle cerebral artery. Clear documentation of the sylvian vein was obtained via ICG videoangiography, even in cases of SAH with ambiguous anatomical topography attributable to clot under the superficial arachnoid membrane. ICG was able to differentiate between the sylvian veins of the frontal and temporal lobes, which allowed wide dissection of the sylvian fissure while preserving the veins. ICG videoangiography is an easy and useful method for identifying the connections and tributaries of the superficial sylvian veins from a transsylvian approach. This method allows wide opening of the sylvian fissure while preserving the sylvian veins.

Venous-Preserving Sylvian Dissection

The Sylvian fissure has been dissected through the frontal side of the superficial Sylvian veins with sacrifice of the tributaries of the frontal superficial Sylvian vein, which may lead to venous infarction. In addition, disturbed venous drainage makes the brain susceptible to brain retraction. Therefore, preservation of the vein is essential in modern neurosurgery to decrease morbidity. We describe the technical nuances of Sylvian dissection with an emphasis on preserving the veins. The arachnoid between the frontal and temporal superficial Sylvian veins is divided as to enter the fissure. After the deep part in the Sylvian fissure is reached, the inside of the fissure is dissected along the "microvascular Sylvian fissure," the temporal side of the frontal vessels or the frontal side of the temporal vessels. The Sylvian fissure is dissected in a deep-to-superficial and posterior-to-anterior fashion ("paperknife technique") up to the skull base. The frontal superficial Sylvian vein usually tethers the brain to the dura, restricting the surgical corridor when approaching deep lesions. Peeling off the arachnoid that wraps this vein ("denude technique") allows the vein to stretch. Keeping the proper dissection plane ("microvascular Sylvian fissure") is crucial to preserve the veins. The "paperknife technique" makes the division of the frontal and temporal lobe easier. The "denude technique" provides a wider space between the frontal lobe and the skull base. These techniques make it possible to obtain a sufficiently wide surgical corridor to the basal cistern without sacrificing the veins and their tributaries.

Microsurgical anatomy of the central lobe.

The central lobe consists of the pre- and postcentral gyri on the lateral surface and the paracentral lobule on the medial surface and corresponds to the sensorimotor cortex. The objective of the present study was to define the neural features, craniometric relationships, arterial supply, and venous drainage of the central lobe. Cadaveric hemispheres dissected using microsurgical techniques provided the material for this study. The coronal suture is closer to the precentral gyrus and central sulcus at its lower rather than at its upper end, but they are closest at a point near where the superior temporal line crosses the coronal suture. The arterial supply of the lower two-thirds of the lateral surface of the central lobe was from the central, precentral, and anterior parietal branches that arose predominantly from the superior trunk of the middle cerebral artery. The medial surface and the superior third of the lateral surface were supplied by the posterior interior frontal, paracentral, and superior parietal branches of the pericallosal and callosomarginal arteries. The venous drainage of the superior two-thirds of the lateral surface and the central lobe on the medial surface was predominantly through the superior sagittal sinus, and the inferior third of the lateral surface was predominantly through the superficial sylvian veins to the sphenoparietal sinus or the vein of Labbé to the transverse sinus. The pre- and postcentral gyri and paracentral lobule have a morphological and functional anatomy that differentiates them from the remainder of their respective lobes and are considered by many as a single lobe. An understanding of the anatomical relationships of the central lobe can be useful in preoperative planning and in establishing reliable intraoperative landmarks.

Biocompatibility of Plastic Clip in Neurocranium - Experimental Study on Dogs.

A potential advantage of the use of the plastic clips in neurosurgery is their property of causing fewer artifacts than titanium clips as assessed by computed tomography and magnetic resonance scans. The biocompatibility of plastic clips was demonstrated in the peritoneal cavity, but their behavior in the neurocranium is not known. Twelve aggressive stray dogs designated for euthanasia were taken for this experimental study. The animals were divided into two groups. In all cases, after anesthesia, a craniotomy was performed, and after opening the dura, a proximal part titanium clip was placed on the isolated superficial Sylvian vein (a permanent Yasargil FT 746 T clip at a 90° angle, while a plastic Hem-o-lok clip ML was placed on another part of the vein). The first group of animals was sacrificed on the 7 < sup > th < /sup > postoperative day and the second group on the 60 < sup > th < /sup > postoperative day. Samples of tissue around the clips were taken for a histopathological evaluation. The plastic clip caused a more intensive tissue reaction than the titanium clip on the 7 < sup > th < /sup > postoperative day, but there was no statistical difference. Even on the 60 < sup > th < /sup > postoperative day there was no significant difference in tissue reaction between the titanium and plastic clips. These preliminary results confirm the possibility for the use of plastic clips in neurosurgery. Before their use in human neurosurgery, further studies are needed to investigate the long-term effects of the presence of plastic clips in the neurocranium, as well as studies of the aneurysmal model.

E-043 High-Grade Dural Arteriovenous Fistula Causing Subarachnoid Haemorrhage with Direct Visualization of the Rupture Site on CT Angiography

PurposeWe describe a case of subarachnoid haemorrhage caused by a high grade dural arteriovenous fistula (dAVF) with an identifiable venous rupture site on CT Angiography (CTA) in a patient with...