Endovascular treatment of medullary bridging vein-draining dural arteriovenous fistulas: foramen magnum vs. craniocervical junction lesions

Comparative outcomes of endovascular vs. surgical treatment in craniocervical junction dural arteriovenous fistulas: A systematic review and meta-analysis

BACKGROUND

Craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) are rare and complex vascular malformations that are challenging to diagnose and treat. This study aims to compare surgical and endovascular treatments for CCJ-DAVFs through a systematic review and meta-analysis.

METHODS

A systematic review and meta-analysis was conducted according to the PRISMA guidelines. PubMed, Scopus, and Web of Science databases were searched from inception to July 2024.

RESULTS

Fifteen studies involving 266 patients were included. Of these, 143 (53.8 %) patients underwent surgical treatment alone and 123 (46.2 %) underwent endovascular treatment alone. In the surgical group, the complete obliteration rate at last follow-up was 89.8 %. Retreatment rate was 6.2 %. Periprocedural complications occurred in 21.6 % of cases. In the endovascular group, the complete occlusion rate at last follow-up was 73.6 %. Retreatment rate was 46.7 %. Periprocedural complications occurred in 18.8 % of cases. Comparative meta-analysis revealed that the rate of complete obliteration at last follow-up was significantly higher in the surgical group (OR: 0.24; CI: 0.07 to 0.89, p = 0.03). Surgical treatment had a significantly higher successful treatment rate (OR: 0.24; CI: 0.07 to 0.89, p = 0.03) and lower retreatment rate (OR: 37.13; CI: 6.31 to 218.59, p < 0.01). No significant differences were observed between the groups in terms of periprocedural complications or complete resolution of symptoms.

CONCLUSION

Surgical treatment for CCJ-DAVFs achieves higher rates of complete obliteration with lower retreatment rates compared to endovascular treatment. However, endovascular treatment showed a tendency towards reducing periprocedural complications while increasing the likelihood of complete resolution of symptoms. Individualized treatment plans for CCJ-DAVFs, should be considered according to their anatomical location and potential surgical accessibility. Further studies are required to confirm these findings.

Microvascular anatomy of the lateral spinal artery: Origins, collateral channels, and other anatomical variations

Background

The lateral spinal artery (LSA) corresponds to the posterolateral arterial axis of the craniocervical junction. Although implicated in various pathologies and injury risks during treatments, the existence and anatomical characteristics of the LSA are debated. We aim to demonstrate the characteristics of the LSA, including its origins, collateral channels, and anatomical variations.

Methods

Neurosurgeons performed far-lateral craniotomies and cervical laminectomies on 18 cadaver heads (36 sides). Neurovascular structures associated with the LSA were examined in epidural, subdural, and subarachnoid spaces.

Results

The main origins of the LSA were the V3 segment of the vertebral artery (VA) (n = 18), the V4 segment of the VA (n = 12), and the posterior inferior cerebellar artery (PICA) (n = 6). The PICA originated from V3 in 6 cases; in 5, the main LSA origin was the intradural PICA. In the 30 cases where the PICA originated from V4, only one main LSA originated from the PICA. In addition to the main origin, we identified supplementary origins, averaging 1.7 per case. In 4 cases, the LSA and posterior meningeal artery (PMA) shared an origin at V3. Twenty-seven cases had anastomosis between the LSA and PICA on the pial surface. Collateral channels at the C2 level through posterior radicular arteries were observed in 13 cases.

Conclusion

The main origins of the LSA are around the dural ring of the VA and are associated with the PICA's origin. Other potential channels supplying the LSA were also identified. The LSA and PMA may share an origin from the VA.

Classification, angioarchitecture and treatment outcomes of medullary bridging vein-draining dural arteriovenous fistulas in the foramen magnum region: a multicenter study

PURPOSE

This study aimed to classify medullary bridging vein-draining dural arteriovenous fistulas (MBV-DAVFs) located around the foramen magnum (FM) according to their location and characterize their angioarchitecture and treatment outcomes.

METHODS

Patients with MBV-DAVFs diagnosed between January 2013 and October 2022 were included. MBV-DAVFs were classified into four groups. Jugular vein-bridging vein (JV-BV) DAVF: located in proximity to jugular fossa, Anterior condylar vein (ACV)-BV DAVF: proximity to anterior condylar canal, Marginal sinus (MS)-BV DAVF: lateral surface of FM and Suboccipital cavernous sinus (SCS)-BV DAVF: proximity to dural penetration of vertebral artery.

RESULTS

Twenty patients were included, three JV-BV, four ACV-BV, three MS-BV and ten SCS-BV DAVFs, respectively. All groups showed male predominance. There were significant differences in main feeders between JV (jugular branch of ascending pharyngeal artery) and SCS group (C1 dural branch). Pial feeders from anterior spinal artery (ASA) or lateral spinal artery (LSA) were visualized in four SCS and one MS group. Drainage pattern did not differ between groups. Transarterial embolization (TAE) was performed in three, two, one and two cases and complete obliteration was obtained in 100%, 50%, 100% and 0% in JV, ACS, MS and SCS group, respectively. Successful interventions without major complications were finally obtained in 100%, 75%, 100%, and 40% in JV, ACS, MS and SCS group, respectively.

CONCLUSION

JV-BV DAVFs were successfully treated using TAE alone. SCS-BV DAVFs were mainly fed by small C1 dural branches of vertebral artery often with pial feeders from ASA or LSA, and difficultly treated by TAE alone.

Dural arteriovenous fistulas at the craniocervical junction: a systematic review and meta-analysis

BACKGROUND

The management for craniocervical junction dural arteriovenous fistulas (CCJ-DAVFs) remains controversial and clinically challenging. We systemically summarized the clinical and angiographic outcomes of microsurgery, embolization, and conservative management.

METHODS

Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane, following PRISMA guidelines. A systematic review and meta-analysis were conducted on the clinical characteristics, management approaches, and clinical and angiographic outcomes.

RESULTS

We included 13 articles (166 patients). The weighted mean age was 58.9 years (95%CI: 53.2-64.5), 58.8 years (95%CI: 48.4-69.2), and 63.8 years (95%CI: 60.1-67.5), in microsurgery, embolization, and conservative groups respectively, with an overall male sex predominance (microsurgery [n = 51/77, 66.2%], embolization [n = 44/56, 78.6%], and conservative management [n = 6/8, 75.0%]). Patients were managed with microsurgery (n = 80/172, 46.5%), embolization (n = 79/172, 45.9%), and conservative treatment (n = 13/172, 7.6%). Foramen magnum was the most common location (microsurgery [n = 34/77, 44.2%], embolization [n = 31/56, 55.4%], and conservative treatment [n = 3/8, 37.5%]). Vertebral artery was the primary feeder (microsurgery [n = 58/84, 69.1%], embolization [n = 41/86, 47.6%], and conservative treatment [n = 4/7, 57.1%]). Complete fistula obliteration rates were 74.1% (95%CI:52.3-88.2%) in the microsurgery group and 54.9% (95%CI:30.7-77.0%) in the embolization group. Complications rates were 16.2% (95%CI:6.7-34.5%) in the embolization group, 11.6% (95%CI:3.8-30.4%) in the microsurgery group, and 7.7% (95%CI:1.1-39.1%) in the conservative group. Different rates of good clinical outcomes were observed [microsurgery: 66.4% (95%CI:48.1-80.8%), embolization: 51.9% (95%CI:30.8-72.4%), and conservative: 11.6% (95%CI:4.4-27.4%)].

CONCLUSIONS

In patients with CCJ-DAVFs, each management approach has its own merits based on the fistula and patient characteristics.

Spinal cord infarction: A systematic review and meta-analysis of patient's characteristics, diagnosis accuracy, management, and outcome

Background

Acute spinal cord infarction (SCI) is a rare ischemic vascular lesion. It is difficult to diagnose during the acute phase because the clinical features can vary widely, and the diffusion-weighted imaging of spinal cord magnetic resonance imaging (MRI) often fails to detect any obvious abnormality. The first aim of this study was to describe the SCI patients' characteristics, evaluate the accuracy of its diagnosis tools and management, and then find the strength of the effect of spinal surgical decompression on the patient's outcome.

Methods

A PubMed keyword and Boolean search using ("spinal cord infarction" OR "spinal cord ischemia" AND diagnosis OR management OR outcome) returned 221,571 results by applying filters. We added 17,400 results from Google Scholar. Fourteen studies were included in the quantitative meta-analysis of mean differences.

Results

The Time to Nadir was <6 h (56.1%), 6-12 h (30.7%), 12-72 h (5.4%), and more than 72 h (7.8%). The higher proportion of Owl's eye findings in the MRI was reported at the cervical level (39.6%) and thoracic level (22.9%) P = 0.031. The T2DWI has a moderate accuracy (area under the curve = 0.835) in detecting the T2 hypersignal intensity (T2HSI) at the hyperacute time to NADIR (<6 h). The median modified Rankin Scale (mRS) at admission was 3 (2-3), and after a follow-up duration of 12 months (6-15.5), the median mRS was reported to be 1 (1-2). About 68.9% benefited from medical treatment and physiotherapy, whereas spinal surgical decompression was done in 22.8%. Seventy percent of the overall studies favor spinal surgical decompression, with the estimated average standardized mean difference between medical and surgical treatment being = 1.2083 (95% confidence interval: 1.0250-1.3917).

Conclusion

The T2DWI has moderate accuracy in detecting the T2HSI at the hyperacute time (NADIR <6 h). Even though surgical decompression favored good outcomes, medical treatment with physiotherapy was mostly used for the management of SCI.

Detailed Anatomy of Bridging Veins Around the Foramen Magnum: a Multicenter Study Using Three-dimensional Angiography

BACKGROUND AND PURPOSE

There has been limited literature regarding the bridging veins (BVs) of the medulla oblongata around the foramen magnum (FM). The present study aims to analyze the normal angioarchitecture of the BVs around the FM using slab MIP images of three-dimensional (3D) angiography.

METHODS

We collected 3D angiography data of posterior fossa veins and analyzed the BVs around the FM using slab MIP images. We analyzed the course, outlet, and number of BVs around the FM. We also examined the detection rate and mean diameter of each BV.

RESULTS

Of 57 patients, 55 patients (96%) had any BV. The median number of BVs was two (range: 0-5). The BVs originate from the perimedullary veins and run anterolaterally to join the anterior condylar vein (ACV), inferior petrosal sinus, sigmoid sinus, or jugular bulb, inferolaterally to join the suboccipital cavernous sinus (SCS), laterally or posterolaterally to join the marginal sinus (MS), and posteriorly to join the MS or occipital sinus. We classified BVs into five subtypes according to the draining location: ACV, jugular foramen (JF), MS, SCS, and cerebellomedullary cistern (CMC). ACV, JF, MS, SCS, and CMC BVs were detected in 11 (19%), 18 (32%), 32 (56%), 20 (35%), and 16 (28%) patients, respectively. The mean diameter of the BVs other than CMC was 0.6 mm, and that of CMC BV was 0.8 mm.

CONCLUSION

Using venous data from 3D angiography, we detected FM BVs in most cases, and the BVs were connected in various directions.

Endovascular embolisation of posterior condylar canal dural arteriovenous fistula

We describe a rare case of dural arteriovenous fistula (dAVF) of the posterior condylar canal in a man in his 30s who presented with recent onset headache and neck pain and subsequently acute intracranial haemorrhage. Radiological workup showed a medulla bridging vein draining dAVF of the right posterior condylar canal supplied by a meningeal branch of the right occipital artery. A dilated venous sac was seen compressing over cerebellar tonsil on the right side. There was acute haemorrhage in the posterior fossa and fourth ventricle. He was successfully managed with transarterial endovascular embolisation via a supercompliant balloon microcatheter without any complication. The balloon microcatheter effectively prevented reflux of the liquid embolic agent into the parent artery and vasa nervosa of lower cranial nerves.

Bridging veins at the craniocervical junction: from anatomy to clinical significance in dural arteriovenous shunts

PURPOSE

Bridging veins (BVs) serve as a route of pial venous reflux, and its anatomy is essential to understand the pathophysiology of dural arteriovenous shunts (dAVSs) around the craniocervical junction (CCJ) (from the jugular foramen level to the atlantal level). However, the anatomical variations of the BVs and their proximal connections remained poorly elucidated. This study aimed to radiologically investigate the anatomy of the bridging veins around CCJ and discuss the clinical significance of these BVs in the dAVS.

METHODS

We investigated normal venous anatomy of the BVs from the jugular foramen level to the atlantal level using preoperative computed tomography digital subtraction venography in patients undergoing elective neurosurgery. BVs affected by the dAVSs in the same region were also evaluated. The three types of dAVS, craniocervical junction, anterior condylar, and proximal sigmoid sinus, were investigated.

RESULTS

We identified six BV groups: superolateral, anterolateral, lateral, posterior, inferolateral, and inferoposterior. The superolateral and inferolateral groups, connected with the proximal sigmoid sinus and suboccipital cavernous sinus, respectively, were the largest groups. Each group has a specific downstream venous connection. The association with dVASs was observed only in the inferolateral group, which was typically the sole venous drainage in most dAVSs at the CCJ.

CONCLUSION

We reported detailed anatomy of BVs from the jugular level to the atlantal level, which enhanced our understanding of the pathophysiology of dAVSs in the corresponding region.

Non-Sinus-Type Dural Arteriovenous Fistula at the Foramen Magnum: A Review of the Literature

Dural arteriovenous fistula (dAVF) of the foramen magnum (FM) region is rare. Moreover, the terminology of dAVF is very confusing in this region. In the narrow sense, the FM dAVF is the non-sinus-type dAVF with direct venous reflux to the medulla oblongata or spinal cord via the bridging veins (BVs) of the FM. Previous literature was systematically reviewed to investigate the clinical characteristics, angioarchitecture, and effective treatment of the FM dAVF. From the literature review, almost all the feeders of FM dAVF were dural branches. Spinal pial arteries were rarely involved as the feeder. All lesions had venous reflux to the medulla oblongata via medullary BVs. The FM dAVF is characterized by a significant male predominance and a high incidence of aggressive symptoms. The most common symptom is congestive myelopathy, followed by hemorrhage. The FM dAVF differs from the craniocervical junction (CCJ) arteriovenous fistula (AVF) and is similar to the thoracolumbar spinal dAVF. Direct surgery for the FM dAVF is effective and safe. Endovascular treatment for the FM dAVF may be more effective and has lower complication rates than that for the CCJ AVF.

Treatment of high cervical arteriovenous fistulas in the craniocervical junction region

The craniocervical junction (CCJ) is a complex region. Rarely, arteriovenous fistulas (AVFs) can occur in the CCJ region. Currently, it is accepted that CCJ AVFs should only refer to AVFs at the C1-C2 levels. It is reasonable to assume that high cervical CCJ AVFs are being referred to when discussing CCJ AVFs. High cervical CCJ AVFs can be divided into the following four types: dural AVF, radicular AVF, epidural AVF and perimedullary AVF. Until now, it was difficult to understand high cervical CCJ AVFs and provide a proper treatment for them. Therefore, an updated review of high cervical CCJ AVFs is necessary. In this review, the following issues are discussed: the definition of high cervical CCJ AVFs, vessel anatomy of the CCJ region, angioarchitecture of high cervical CCJ AVFs, treatment options, prognoses and complications. Based on the review and our experience, we found that the four types of high cervical CCJ AVFs share similar clinical and imaging characteristics. Patients may present with intracranial hemorrhage or congestive myelopathy. Treatment, including open surgery and endovascular treatment (EVT), can be used for symptomatic AVFs. Most high cervical CCJ AVFs can be effectively treated with open surgery. EVT remains challenging due to a high rate of incomplete obliteration and complications, and it can only be performed in superselective AVFs with simple angioarchitecture. Appropriate treatment can lead to a good prognosis.

Recurrence Rates Following Treatment of Spinal Vascular Malformations: A Systematic Review and Meta-Analysis

BACKGROUND

Spinal vascular malformations (SVMs), including arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs), are a varied group of vascular lesions that can be subclassified according to localization, vascular structure, and hemodynamics. Early intervention is necessary to halt progression of disease and minimize irreversible dysfunction. We sought to characterize initial treatment success and recurrence rates following interventional treatment of various types of SVMs.

METHODS

A systematic review and meta-analysis were performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. SVMs were categorized into 4 groups: dural AVFs, perimedullary AVFs, intramedullary AVMs, and extradural-intradural AVMs (e.g., epidural, paraspinal). Initial occlusion, recurrence, and complication rates were compared using random-effects analysis.

RESULTS

There were 112 manuscripts included, with a total of 5626 patients with SVM. For treatment, 2735 patients underwent endovascular embolization, 2854 underwent surgical resection, and 37 underwent stereotactic radiosurgery. The initial treatment success and overall recurrence rates following surgical resection of all SVMs were 89.5% (95% CI: 80.5%-98.5%) and 2.3% (95% CI: 0.9%-3.7%), respectively. Those rates following endovascular embolization were 55.9% (95% CI: 30.3%-81.5%) and 27.7% (95% CI: 11.2%-44.2%), respectively. Higher rates of initial treatment success and lower rates of recurrence with surgery were observed in all subtypes compared to embolization. Overall complication rates were higher after embolization for each of the SVM categories.

CONCLUSIONS

Surgical resection of SVMs provided higher rates of initial complete occlusion and lower rates of recurrence than endovascular techniques. Attaining technical success through obliteration must still be weighed against clinical impact and natural history of the specific vascular malformation.

The role of venous anatomy in guiding treatment approach for dural arteriovenous fistulas of the craniocervical junction; case series & systematic review

BACKGROUND

Dural arteriovenous fistulas (DAVF) of the craniocervical junction (CCF) are an uncommon entity with the following venous drainage pattern: inferior, superior and mixed. Patients may present with subarachnoid hemorrhage, myelopathy or brainstem dysfunction. CCJ DAVF can be treated with microsurgery or with transarterial and transvenous embolization, depending on the venous drainage pattern. We present our institutional experience of treating CCJ DAVFs along with a systematic review of the literature.

METHODS

Six patients with CCJ DAVF were treated at our institution over five years. Data was collected using electronic medical record review. Systematic review was performed on CCJ DAVF using the PubMed database from 1990 to 2021. We characterized venous drainage patterns, treatment choices, and outcomes to create a classification system.

RESULTS

50 case reports, consisting of 115 patients, were included in our review. 61 (53.0 %) patients had inferior drainage while 32 (27.8 %) patients had superior drainage and 22 (19.2 %) patients had mixed venous drainage. Patients with inferior drainage had the fistulous connection at the foramen magnum while patients with superior drainage had a fistulous connection at C1-C2 (p value = 0.026). Patients with inferior drainage were more likely to present with myelopathy while patients with superior drainage presented with hemorrhage (p value = 0.000).

CONCLUSIONS

Classifying the venous drainage pattern is essential in making treatment decision. Transvenous embolization works best with large superior venous drainage. If endovascular treatment is not an option, then surgical clipping can achieve successful cure. Transarterial embolization is a reasonable option in cases with a large arterial feeder.

Arteriovenous fistulas in the craniocervical junction region: With vs. without spinal arterial feeders

Objective

Arteriovenous fistulas (AVFs) in the craniocervical junction (CCJ) region are a rare occurrence with special clinical manifestations. This study retrospectively reviewed patients with CCJ AVFs treated at our neurosurgical center, aiming to enhance the understanding of CCJ AVFs.

Methods

A total of 113 patients with CCJ AVFs treated at our neurosurgical center between January 2013 and December 2020 were enrolled. They were grouped as patients with CCJ AVFs with spinal arterial feeders (n = 20) and patients with CCJ AVF without spinal arterial feeders (n = 93). Clinical presentation, angiographic characteristics, intraoperative findings, and treatment outcomes were analyzed.

Results

The patients' median age was 55 years (IQR 47.5-62 years). The proportion of males in the group without spinal arterial feeders was significantly higher (p = 0.001). Subarachnoid hemorrhage (SAH) was the most common clinical presentation, especially in the group with spinal arterial feeders (p < 0.001). There were significant differences in AVF type, fistula location, and direction of the venous drainage between the two groups (p < 0.001). Intervention embolization combined with microsurgery was more common in treating AVFs with spinal arterial feeders (p = 0.006). Spinal arterial feeders did not affect the outcome (p = 0.275).

Conclusions

SAH was the most common presentation of CCJ AVFs in this study. Microsurgery and interventional embolization were optional treatment strategies. The angioarchitecture of CCJ AVFs was essential for selecting treatment strategies.

Spinal Vascular Shunts: Single-Center Series and Review of the Literature of Their Classification

Spinal arteriovenous shunts (sAVSs) are an uncommon disease, constituting 3 to 4% of intradural lesions; 70% of these lesions are spinal arteriovenous fistulas (sAVFs), whereas spinal arteriovenous malformations (sAVMs) are rarer. Both share the problem of their classification due to the heterogeneity of their angioarchitecture. The aim of this study is to report a series of sAVSs treated in the neurosurgery department of the Hospital Nacional Guillermo Almenara during the 2018-2020 period and to present an overview of the current literature on sAVS classification. We reviewed all medical records of patients diagnosed with sAVFs and sAVMs during the 2018-2020 period, and then we analyzed images with Horos v4.0.0, illustrated some cases with Clip Studio Paint v1.10.5, and performed a descriptive statistical analysis with SPSS v25. Twelve patients were included in this study, eight of which were women (67%) and four of which were men (33%); the age range was from 3 to 74 years. Eight sAVSs were sAVFs, whereas four were sAVMs. The most frequent clinical manifestation was chronic myelopathy in seven patients (58%). Of those treated only by embolization, seven (70%) resulted in complete occlusion (five sAVFs and two sAVMs), while three (30%) remained with a residual lesion. At last follow-up, five patients (42%) improved clinically, and the seven remaining (58%) maintained the same neurological state. sAVSs require a detailed study of their angioarchitecture for proper management. The endovascular treatment is safe with acceptable cure rates. The surgical option should not be set aside.

Ischemic complications in the neurosurgical and endovascular treatments of craniocervical junction arteriovenous fistulas: a multicenter study

OBJECTIVE

A recent comparative analysis between neurosurgical and endovascular treatments for craniocervical junction (CCJ) arteriovenous fistulas (AVFs) revealed better treatment outcomes in the neurosurgery group than in the endovascular group. This finding was attributed to the higher than expected rate of ischemic complications in the endovascular group than in the neurosurgery group (26% vs 7.7%, p = 0.037). The aim of the present study was to describe ischemic complications associated with treatments for CCJ AVFs.

METHODS

This descriptive study was authorized by the Neurospinal Society of Japan. Data from 97 consecutive patients with CCJ AVFs who underwent neurosurgical (n = 78) or endovascular (n = 19) treatment between 2009 and 2019 were collected from 29 centers. The primary endpoints were details on ischemic complications and their risk factors. Secondary endpoints were details on other complications.

RESULTS

Among all major complications, ischemic complications were the most common (11% of 97 patients), followed by hemorrhagic complications (7.2%), hydrocephalus (2.1%), and CSF leakage (2.1%). Ischemic complications included 8 spinal, 2 brainstem, and 1 cerebellar infarctions. Iatrogenic occlusion of the anterior or posterior spinal artery from the radiculomedullary or radiculopial arteries caused these complications. Ischemic complications resulted in neurological deficits, including motor paresis, sensory disturbances, and brainstem dysfunction. The modified Rankin Scale score was 3 or higher in 36% of patients with ischemic complications at the final follow-up of 23 months. Risk factors associated with ischemic complications were endovascular treatment (OR 4.3, 95% CI 1.1-16) and spinal feeding arteries (OR 3.8, 95% CI 1.03-14). Most of the other complications were addressed by additional treatment without permanent neurological deficits.

CONCLUSIONS

Among ischemic complications associated with treatments for CCJ AVFs, spinal infarctions were the most common and were mostly attributed to endovascular procedures for CCJ AVFs fed by spinal arteries. These results support the use of neurosurgery as the first-line treatment for CCJ AVFs.