Pial Arteriovenous Fistula Research Articles

Pial arteriovenous fistula with giant venous varix and dilation of vein of Galen, treated with surgical clipping

Pial arteriovenous fistula with giant venous varix and dilation of vein of Galen, treated with surgical clipping

Spinal Pial (Type IV) Arteriovenous Fistulae

Demographics, hemorrhage risk, and results of surgical and endovascular treatment of spinal pial (type IV) arteriovenous fistulae (AVFs) across a large patient group have not been previously reported. To report demographics, hemorrhage rates, and treatment results for these AVFs. We performed a pooled analysis via the PubMed and Embase databases through November 2012. Individualized patient data were extracted and analyzed using Cox proportional hazards regression to obtain hazard ratios for hemorrhage risk factors and pooled for baseline demographics and treatment results. We extracted information on 213 patients from 28 studies. Only 1% of lesions were incidental; 93% of patients presented with neurologic deficits and 36% with hemorrhage. Patients with type IVa lesions were significantly older (mean age, 46.9 years) and demonstrated a male sex predilection (68% male). Patients with type IVc lesions were significantly younger (mean age, 18.7 years), had no sex predilection, and had the highest prevalence of syndromic conditions (29% of cases). The annual hemorrhage rate was 2.5% (95% confidence interval [CI]: 1.4%-4.7%), increasing to 5.6% for hemorrhagic fistulae (95% CI: 3.0%-10.7%; hazard ratio: 6.31; 95% CI: 0.69-57.4; P = .10). Patient sex, fistula location, and fistula subclass were not significant risk factors for hemorrhage. The surgical obliteration rate was 88%; 68% of patients improved, 26% were the same, and 6% were worse. The endovascular obliteration rate was 74%; 75% of patients improved, 14% were the same, and 11% were worse. We demonstrate the utility of the Anson-Spetzler a-c subclassification and underscore the efficacy of surgical and endovascular spinal AVF treatment.

Surgical flow disconnection of cerebral pial dual-channel arteriovenous fistula with a large varix: the role of anti-platelet agent or anti-coagulation therapy

Intracranial pial arteriovenous fistula (AVF) is a rare cerebrovascular lesion, and the literature is sparse. Most authors insist that simple disconnection of arteriovenous shunting is enough to treat intracral single-channel pial AVF in most cases, either by microsurgery or endovascular embolization without resection of entire vascular malformation. We report an insidious onset of peri-lesional edema formation after abrupt disconnection of AVF shunting with surgical arterial ligation. Treatment entailed anti-platelet and anti-coagulation agent to slow down thrombus formation in intracranial dual-channel pial AVF. We suggest that slowing down thrombus formation in the large varix with anti-platelet and/or anti-coagulation agents seems to be necessary in case of abrupt disconnection of shunting in intracranial single- or dual-channel pial AVF to prevent postoperative cerebral edema or infarction.

Dynamic ICG Fluorescence Provides Better Intraoperative Understanding of Arteriovenous Fistulae

Sufficient perfusion is crucial during and after vascular neurosurgical procedures. Intraoperative indocyanine green (ICG) angiography has evolved into a useful tool in aneurysm and arteriovenous malformation surgery. Semiquantitative ICG fluorescence analysis Flow 800 may, in addition, lead to a better understanding of local perfusion. We report the applicability and utility of semiquantitative ICG fluorescence in the surgical treatment of 5 patients with pial or dural arteriovenous fistulae. Five patients with pial or dural arteriovenous fistulae were operated on using intraoperative semiquantitative ICG fluorescence Flow 800 (5 mg ICG bolus via central venous line). Before and after occlusion of fistulae, rise time of parenchyma and transit time from artery to parenchyma were measured. The analysis of flow parameters allowed detection of small fistulae and revealed a significant change in flow dynamics in the draining vein after surgical occlusion. ICG "flow" analysis showed rise time and transit time to be significantly shorter comparing pre-occlusion with post-occlusion (P = .025 and P = .039, respectively), leading to a significantly enhanced perfusion of neighboring brain parenchyma. In all 5 patients, dynamic analysis of fluorescence revealed a better understanding of intravascular rheology intraoperatively, allowing confident identification and treatment of pathology. Dynamic ICG fluorescence measurements provide additional perfusion information about flow characteristics in the draining vein and tissue perfusion, which facilitates surgical treatment of arteriovenous fistulae.

Intracerebral pial arteriovenous fistula with large venous varix: A rare case report

Background:Intracerebral pial arteriovenous fistulas (AVFs) are rare vascular lesions of the brain. These lesions are composed of one or more direct arterial connection to a single venous channel without true intervening nidus and usually have associated venous varix or giant venous aneurysms. Intracerebral varices are occasionally associated with high-flow AVF, and usually treated by interrupting the feeding arteries leaving the varices intact.Case Description:We report a rare case of a 24-year-old male with a single-channel pial AVF of the left cerebral hemisphere, which was fed by the left anterior cerebral artery (ACA) and was associated with large venous varix and continuous varicose venous dilatation. This superficially located varix was over 6 cm in diameter posing significant mass effect and had calcified walls. Direct surgical flow disconnection followed by removal of large varix resulted in complete disappearance of pial AVF without complication.Conclusion:Though endovascular occlusion of feeding arteries offers a simple and safe option, direct surgical removal should be considered in rare cases of intracerebral superficially located large AVF with calcified wall and mass effect.

Congenital Pial Arteriovenous Fistula in the Temporal Region Draining into Cavernous Sinus: A Case Report

This report concerns a 4-month-old infant with progressive prominent and redness of his left eye since birth. This report concerns a 4-month-old infant with progressive prominent redness of his left eye since birth. Angiography revealed a congenital pial arteriovenous fistula between the temporal branch of the left posterior cerebral artery and left cavernous sinus through the sphenoparietal sinus, a condition not reported in the literature. The fistula was successfully occluded with two micro-coils by vertebrobasilar approach.

手術治療を行った成人頭蓋内pial AVFの1例

要旨：症例は63歳女性．1週間前から頭痛と言語障害があり当科を受診した．初診時言語表出が低下しており，錯語が著明であった．頭部CTで左側頭頭頂葉皮質下出血を認め同日入院となった．頭部MRIでは出血の原因となる病変は確認できなかった．脳血管撮影で左後側頭動脈の末梢枝からnidusを介すことなく脳表の静脈への動静脈短絡を認めた．Pial arteriovenous fistula(pial AVF)を原因とする皮質下出血と診断した．開頭術を行いすべての動静脈シャントを離断し，血腫を除去した．術後新たな神経症状の出現はなく，言語障害は改善した．Pial AVFは出血発症例に対して保存的治療を行った場合予後が悪いとされているが，適切な治療を行えば再発を予防しうる疾患である．皮質下出血の患者においてはpial AVFも鑑別診断にいれ出血原因の検索を行うべきであると考えられた．

Pial Arteriovenous Fistula as a Cause of Bilateral Thalamic Hyperintensities—an Unusual Case Report and Review of the Literature

Isolated bilateral thalamic congestion due to an arteriovenous malformation (AVM) is a rare entity. Few case reports of dural arteriovenous fistula associated with it have been reported in the literature. The association of pial arteriovenous fistula (pial AVF) with thalamic hyperintensities has never been described before. The pial AVF is a recently recognized lesion in which the multiple pial arterial feeders drain into a single venous channel without a nidus like in conventional AVM. In spite of being congenital in origin, these lesions may have expression in adulthood due to abrupt change in the venous drainage system. Successful management of pial AVF associated with bilateral thalamic hyperintensities is described here with review of the literature. A 60-year-old man presented with rapidly progressive gait disturbance and cognitive decline. Magnetic resonance imaging (MRI) showed hyperintensities in the thalami on T2-weighted and fluid attenuated inversion recovery image. Digital subtraction angiography revealed a pial AVF near the splenium of corpus callosum. It had feeders from posterior choroidal arteries and drained into the vein of Galen through an abnormal mesencephalic vein. The stagnation and increase of pressure in the deep venous system led to congestion in the thalami. He was treated by partial transarterial embolization of the feeders followed by gamma knife therapy (GKT). The clinical symptoms and MRI improved rapidly after embolization and further reduction in shunt flow was observed after GKT. Strong suspicion of vascular malformation as a cause of bilateral thalamic hyperintensities helps in early detection. Such lesions like pial AVF presented here require active intervention by surgery or endovascular therapy. GKT is an important adjuvant in lesions refractory to either of them.

Tratamiento endovascular de las fístulas arteriovenosas piales no galénicas

Pial arteriovenous fistulas are infrequent vascular malformations. They are generally congenital and their natural history is ominous. The objective of this work is to describe our experience in their endovascular management and to review the existing literature. This is a retrospective and descriptive study of patients treated by endovascular approach during 3 years at 3 Latin-American hospitals. The study included 6 patients with a mean age of 22 years. One case was caused by cranial trauma. In total, 50% suffered intracranial haemorrhage and 66% developed symptoms attributable to volume effect or retrograde blood flow. Intracranial varices were identified by CT and MRI scans in 83% of cases. Digital subtraction angiography showed arteriovenous fistulas from anterior circulation in 67% of cases and deep venous drainage in 50%. One endovascular procedure was performed in 5 cases (83%), while 2 procedures were required in one case. A single embolic agent was used to occlude fistulas in 67% of cases; whilst 33% required a combination. Coils were used in 4 cases (67%) and onyx was injected in another 4 (67%). One case required stent and balloon deployment. The fistulas were uneventfully occluded in all cases. The follow-up period was one year in 5 cases and 6 months in one case. All patients remained symptom-free. Endovascular management can be considered as the treatment of choice. It consists in the embolisation of arterial pedicles with one or more embolic agents and should be performed as close as possible to the drainage vein, avoiding migration of the embolic agent towards the venous side.

De novo development of dural arteriovenous fistula after endovascular embolization of pial arteriovenous fistula

BackgroundThe development of de novo dural arteriovenous fistula(s) following endovascular embolization of a prior high-flow pial arteriovenous fistula (PAVF) has not previously been reported and the natural history is unknown....

Pial arteriovenous fistulae in pediatric patients: associated syndromes and treatment outcome

ObjectivePediatric pial arteriovenous fistulae (pAVF) are rare vascular lesions of the CNS, reported to have up to a 25% association with hereditary hemorrhagic telangiectasia. The presentation, treatment and syndromes associated...

Giant Calcified Thrombosed Varices Secondary to a Pial Arteriovenous Fistula Associated With Hereditary Hemorrhagic Telangiectasia

A 28-year-old woman presented with an unusual case of giant thrombosed varix with calcified walls that had mass effects secondary to a pial single-channel arteriovenous fistula (AVF) associated with hereditary hemorrhagic telangiectasia (HHT). She consulted our hospital for chronic headache. She had been diagnosed with HHT based on genetic testing when her 3-year-old son presented with subarachnoid hemorrhage due to spinal AVF. Imaging studies revealed pial single-channel AVF with multiple varices. The varices in the right frontal lobe were over 6 cm in diameter and had laminar thromboses and calcified walls. Because of the mass effect, direct surgical flow disconnection was performed followed by removal of the varices using an internal decompression technique. Postoperatively, the patient was discharged with no neurological symptoms and no longer suffered chronic headache. Intracerebral varices are occasionally associated with high-flow AVF, and usually treated by interrupting the feeding arteries leaving the varices intact. This extremely rare case of intracerebral giant thrombosed varices with calcified wall and mass effect indicates that surgical removal of varices should be considered.

Intracranial Pial Arteriovenous Fistula Presenting with Hemorrhage: A Case Report

Intracranial pial arteriovenous fistula (AVF) is a rare cerebrovascular malformation, which has a single or multiple arterial connections to a single venous channel without intervening nidus, and is different from arteriovenous malformation (AVM). We report on a case of a surgically treated pial AVF. A 15-year-old girl with an altered mental state was brought to our hospital. Computed tomography (CT) showed a subcortical hematoma of approximately 24 ml in her right temporal lobe. Cerebral angiography showed an AVF supplied by the right middle cerebral artery with early drainage into the Sylvian vein and the vein of Labbe. She underwent surgical treatment with feeding artery obliteration using a clip and hematoma removal. The patient was discharged without neurologic deficits. Despite the rarity of pial AVF, for correct diagnosis and treatment, neurosurgeons should recognize this condition. Pial AVF can be managed simply by disconnection of the shunt by surgery or endovascular treatment, and a good result can be achieved.

Open surgical disconnection for congenital, multi-hole, pial arteriovenous fistulae in non-eloquent cortex

Intracranial pial arteriovenous fistulae (pAVFs), a direct shunt between a feeding artery and a venous channel with the absence of a true nidus characteristic of other types of arteriovenous malformations, are rare. We report a seven-year-old girl with an incidental intracranial pAVF. Following partial embolization with a combination of platinum coils and liquid embolic material, this lesion was surgically disconnected and a definitive cure was achieved. Based on the particular characteristics of this lesion-multiple, small arterial feeders, superficial location, and proximity to the non-eloquent cortex-we feel this vascular lesion represents a subset of pAVFs that may be most reasonably and safely treated by open surgery. While staged embolization has recently gained popularity as a treatment option, the additive risk of multiple embolizations as well as repeated exposure to ionizing radiation should not be understated, especially in the pediatric population. Furthermore, given the paucity of data on the long-term effectiveness of embolization, surgery remains an elegant and durable treatment option for pAVFs in carefully selected patients.

High-flow Neonatal Macrocerebral Arteriovenous Fistulas in Hereditary Hemorrhagic Telangiectasia

Although some cases of vein of Galen aneurysmal malformation (VGAM) present initial clinical symptoms such as cardiopulmonary disturbance in the neonatal period, pial arteriovenous fistula is very seldom present as a clinical symptom immediately after birth. A neonatal patient, the first-born to his family, presented with tachypnea postpartum. This baby had a family history of hereditary hemorrhagic telangiectasia. A cerebral MR image revealed multiple macrocerebral arteriovenous fistulas (MCAVFs), resulting in a large partially thrombosed venous pouch within the cerebral cortex. Trans-arterial embolizations of the main two fistulas were performed using N-butyl cyanoacrylate (NBCA) with tantalum powder six months after birth. Post-embolization angiography confirmed the obliteration of the fistulas and magnetic resonance imaging (MRI) revealed thrombosis and reduction in size of the venous component. His tachypnea disappeared completely. There were no neurological complications due to the treatment. The prognosis of multiple MCAVFs mainly depends on the presence of medullar signs and symptoms and a delay before treatment. Pure glue endovascular intervention, as used in our case, is considered to be the first therapeutic choice to decrease the risk of neurological consequences.

Giant Intracranial Pial Arteriovenous Fistula Treated by Endovascular Intervention

Arteriovenous fistulas (AVF) are rare vascular lesions of the brain that differ from arteriovenous malformations as they present a direct connection between artery and vein, without interposition of the nidus. They are fed by one or more arterial branches, with a single draining vein. Clinically they can be revealed through cerebral hemorrhage, convulsive crisis, neurological deficit, heart failure in neonates and infants, headache, bruit, or intracranial hypertension symptoms. A 30-year-old patient was found unconscious on a public street, presenting a generalized tonic-clonic convulsive crisis. At admission, she presented with ocular proptosis, conjunctival hyperemia and bilateral jugular turgescence. The cranial computed tomography showed diffuse subarachnoid hemorrhage, and the cerebral angiography evidenced a giant intracranial pial AVF with high flow supplied by 2 branches of the left anterior cerebral artery.The patient underwent endovascular treatment in 2 sessions, using a mixture of histoacryl and lipiodol for complete occlusion of the lesion. She was discharged after a month, alert, devoid of motor deficit, and the ocular proptosis and the conjunctival hyperemia had decreased. AVFs are rare vascular lesions that require prompt treatment. The endovascular treatment must be considered, especially when the lesions are deep and the risks of neurological deficit associated with the surgery are high. Endoscopic intervention represents an effective and safe option for the treatment of this type of lesion.

Pial arteriovenous fistula in the posterior fossa

Intracranial pial arteriovenous fistulas (AVFs) are rare congenital abnormality that can cause severe morbidity and mortality, particularly in neonates1. AVFs are rare cerebrovascular lesions of the brain that were considered to be distinct from other arteriovenous malformations (AVMs) by Lasjaunias, in 19862. Intracranial pial AVFs have a single or multiple arterial connections to a single venous channel. They differ from brain AVMs in that they lack a true nidus […] Pial arteriovenous fistula in the posterior fossa

Balloon-assisted Onyx embolization of cerebral single-channel pial arteriovenous fistulas

Pial arteriovenous fistulas (AVFs) of the brain are rare vascular malformations associated with significant risks of hemorrhage and neurological deficit. Depending on their location and high-flow dynamics, these lesions can present treatment challenges for both endovascular and open cerebrovascular surgeons. The authors describe a novel endovascular treatment strategy that was used successfully to treat 2 pediatric patients with a pial AVF, and they discuss the technical nuances specific to their treatment strategy. A single-channel high-flow pial AVF was diagnosed in 2 male patients (6 and 17 years of age). Both patients were treated with endovascular flow arrest using a highly conformable balloon followed by Onyx infusion for definitive closure of the fistula. Neither patient suffered a complication as a result of the procedure. At the 6-month follow-up in both cases, the simple discontinuation of blood flow had resulted in durable obliteration of the fistula and stable or improved neurological function. Onyx can be delivered successfully into high-flow lesions after flow arrest to allow a minimally invasive and durable treatment for pial AVFs.

Endovascular Treatment of a Pial Arteriovenous Fistula With Occipital Remodeling Secondary to Giant Torcular Dilation

Intracranial arteriovenous fistulas are vascular malformations in which clinical suspicion and prompt diagnosis, with a subsequent appropriate therapeutic approach, are crucial to avoid the development of irreversible neurological damage or even patient death because these lesions can be associated with heavy bleeding and high mortality rates. The authors present the case of a direct pial arteriovenous fistula in an infant and its unusual presentation as a large occipital protuberance with hard consistency and an audible murmur that produced bone remodeling. The patient was successfully treated by endovascular therapy, with complete regression of the occipital protuberance during follow-up.

Pial arteriovenous fistula: a review of literature

Pial arteriovenous fistula (AVF) is a rare vascular lesion, with less than 120 reported cases in the English literatures (Hoh et al., Neurosurgery 2001;49(6):1351). The angio-architecture, clinical course and therapeutic options are all different from arteriovenous malformation (AVM), dural AVM or other intracranial vascular lesions. A review of literatures to analyse the clinical course of pial AVF was carried out. The presence of varix dictates the clinical course and presentation. Paediatric type had high percentage of varix, and mass effect as clinical presentation while the adult type usually manifest by haemorrhage. Disconnection of direct shunting, either by endovascular or surgically, is sufficient to achieve successful treatment; therefore, total resection of the lesion is unnecessary.