A case of pial arteriovenous fistula with giant venous aneurysm and multiple varices treated with coil embolization

A Systematic Review of Non-Galenic Pial Arteriovenous Fistulas

OBJECTIVE

Non-galenic pial arteriovenous fistulas (NGPAVFs) are rare cerebrovascular pathologies accounting for only 1.6%-4.8% of all brain vascular malformations. We performed a comprehensive review of NGPAVF cases reported in the literature to further characterize their clinical patterns of presentation, angiographic features, management, clinical outcomes, and complications.

METHODS

We searched PubMed, Google Scholar, and Embase from each database's earliest records to April 2022 for all relevant English language articles. A total of 3280 articles were screened to identify those that met prespecified inclusion criteria. Differences in clinical outcomes between children (≤18 years old) and adults (>18 years old) and those articles in which NGPAVFs were associated with the presence of a varix or a hemorrhage were statistically examined.

RESULTS

A total of 242 patients in 86 articles were included. The mean patient age was 18.51 ± 18.80 years. The male-to-female ratio was 1.44:1. Headache was the most common initial presentation (42.6%) in the study cohort. Hemorrhage occurred at a significantly higher frequency in adults (P = 0.004), whereas more children presented with congestive heart failure (P < 0.001). Surgical, endovascular, and combination therapy led to comparable rates of complete NGPAVF obliteration (86.8%, 85.2%, and 88.5%, respectively). Fifty-nine patients (24.4%) experienced a complication, ranging from minor neurological deficit to severe hemorrhage. The mortality rate for the overall cohort was 3.3%, and all deceased patients had a varix associated with their fistulas.

CONCLUSIONS

To our knowledge, we report the largest literature review describing the clinical course and characteristics of NGPAVFs. All treatment approaches resulted in favorable obliteration rates and overall patient outcomes.

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

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.

Pial-Dural Intracranial Arteriovenous Fistula with Flow-Associated Aneurysmal Rupture-Case Report with Review of Literature and Proposal on the Mechanism of Hemorrhage and Treatment Options

BACKGROUND

Vascular anomalies in the form of dural arteriovenous fistulas (DAVFs), arteriovenous malformations, and aneurysms are well described in the literature. Pial arteriovenous fistulas (PAVFs) are described to a lesser extent in the literature. When these anomalies are combined, diagnosis and treatment become complex.

CASE DESCRIPTION

A 55-year-old man presented with PAVF/DAVF with a ruptured flow-related aneurysm in the distal left posterior inferior cerebellar artery, which required surgical clipping and disconnection. We performed a PubMed search of all identifiable cases of PAVFs in adults. We then identified which cases had components of DAVFs and flow-related aneurysms. We identified 51 PAVF cases and identified which patients presented with hemorrhage and the treatment modalities of all cases. Of 51 cases identified, 4 were a DAVF/FRA, and 5 were a PAVF/DAVF. One case of PAVF/DAVF/FRA was identified.

CONCLUSIONS

The exact mechanism of PAVF/DAVF formation is unknown. Hemorrhage predilection of PAVF/DAVF is more difficult to predict than a sole fistula, likely secondary to the complex flow dynamics. To our knowledge, this literature review is the largest review to date regarding PAVFs in adult patients and can provide insight into decision making when evaluating treatment options.

Intracranial non-galenic pial arteriovenous fistula: A review of the literature

An intracranial non-galenic pial arteriovenous fistula (NGPAVF) is a direct connection between the intracranial artery and vein without a nidus. NGPAVFs are clinically rare, and the current understanding of NGPAVFs is limited. This study searched PubMed for the currently available literature, and a review of the relevant publications revealed that NGPAVFs require aggressive treatment, spontaneous occlusion is uncommon, and the prognosis following conservative treatment is poor. NGPAVFs can be divided into congenital and traumatic (including iatrogenic) types. Clinically, NGPAVFs are characterized by congestive heart failure, epilepsy, hemorrhage, mass effects, and nerve function deficits. For the imaging examination of NGPAVFs, digital subtraction angiography (DSA) is still the gold standard for diagnosis, although magnetic resonance DSA (MRDSA) and 4D computed tomography angiography (CTA) can also provide hemodynamic data in a non-invasive manner. Current treatments for NGPAVFs include surgical resection and endovascular embolization, both of which can yield clinical improvements. However, potential postoperative complications should be addressed, such as fatal bleeding due to rupture and deep vein thrombosis. Some studies recommend postoperative anticoagulation to reduce postoperative thrombotic complications.

A case of two pial arteriovenous fistulas with giant venous pouches treated by endovascular coil embolization: Therapy with and without anticoagulation

BACKGROUND

Endovascular coil embolization of pial arteriovenous fistulas (AVF) has been reported as an effective treatment. However, venous thrombosis and intracranial hemorrhage developing after endovascular occlusion of a pial AVF have not been adequately reported.

CASE DESCRIPTION

A 37-year-old man presented with left middle cerebral artery (MCA) AVF and right posterior cerebral artery (PCA) AVF with giant venous pouches. Staged endovascular coil embolization was performed. The MCA AVF was completely occluded by coils at the first stage. Intravenous heparin (3000 IU) was administered during the procedure, and then low molecular weight heparin (subcutaneous injection, 0.4 mL/12 hours) was administered for two days. The PCA AVF was near completely occluded by coils without anticoagulation therapy at the second stage. Rapid progressive venous thrombosis and intracranial hemorrhage were confirmed by computerized tomography brain scan postoperatively, and the patient was then transferred to the neurological intensive care unit for further treatment. Finally, the patient recovered well at the five-month follow-up.

CONCLUSIONS

Endovascular occlusion of a high-flow pial AVF with a giant venous pouch resulting in significant blood stasis could precipitate thrombosis in the venous system. Further studies are required to establish whether anticoagulation therapy is necessary.

Pial arteriovenous fistula with giant varices: report of two cases with good surgical outcome

Pial arteriovenous fistulas (pAVF) are rare vascular lesions consisting of one or more arterial connections to a single venous channel without any intervening nidus of vessels or capillaries. Case 1: A 65-year-old woman with a complaint of headache and left hand paresthesia was referred to us. Magnetic resonance imaging showed a large saccular lesion with signal void in the posterior part of the right sylvian fissure and catheter angiography showed a giant venous aneurysm fed by one branch of the middle cerebral artery (MCA) and draining into the vein of Trolard. Case 2: A 12-year-old boy was transferred to our hospital with a history of sudden loss of consciousness and hemiplegia. Brain computed tomography revealed a massive hemorrhagic mass in the right hemisphere and cerebral angiography showed a pAVF with a large aneurysmal varix, which was fed by multiple branches of the right MCA and draining into the superior sagittal sinus. Both patients underwent craniotomy and after ligation of vascular connections, aneurysmal varices were removed completely. Surgical resection can be a safe method for treatment of pAVFs, particularly in those with large varices.

Anchor coil technique for arteriovenous fistula embolization. A technical note

We describe a case of arteriovenous fistula (AVF) successfully treated by coil embolization with an anchor coil inserted in the varix to facilitate dense packing at the shunting site. AVF of the left anterior choroidal artery (AChoA) draining into the ipsilateral basal vein of Rosenthal was incidentally found in a newborn female. A single detachable coil was inserted as an anchor into the varix adjacent to the shunt, and the microcatheter was pulled back to the shunting point. Three more detachable coils were delivered at the shunting point without migration under the support of the anchor coil, and the AVF was successfully obliterated with preservation of AChoA blood flow. The anchor coil technique can reduce the risk of coil migration and the number of coils required.