Neurosurgical versus endovascular treatment of spinal dural arteriovenous fistulas: a multicenter study of 195 patients

OBJECTIVE

The purpose of the present study was to compare the treatment success rates of primary neurosurgical and endovascular treatments in patients with spinal dural arteriovenous fistulas (dAVFs).

METHODS

Data from 199 consecutive patients with thoracic and lumbosacral spinal dAVFs were collected from 18 centers. Angiographic and clinical findings, the rate of initial treatment failure or recurrence by procedures, risk factors for treatment failure, complications, and neurological outcomes were statistically analyzed.

RESULTS

Spinal dAVFs were frequently detected in the thoracic region (81%), fed by a single feeder (86%), and shunted into an intradural vein via the dura mater. The fistulous connection between the feeder(s) and intradural vein was located at a single spinal level in 195 patients (98%) and at 2 independent levels in 4 patients (2%). Among the neurosurgical (n = 145), and endovascular (n = 50) treatment groups of single dAVFs (n = 195), the rate of initial treatment failure or recurrence was significantly higher in the index endovascular treatment group (0.68% and 36%). A multivariate analysis identified endovascular treatment as an independent risk factor with significantly higher odds of initial treatment failure or recurrence (OR 69; 95% CI 8.7-546). The rate of complications did not significantly differ between the two treatment groups (4.1% for neurosurgical vs 4.0% for endovascular treatment). With a median follow-up of 26 months, improvements of ≥ 1 point in the modified Rankin Scale (mRS) score and Aminoff-Logue gait and Aminoff-Logue micturition grades were observed in 111 (56%), 121 (61%), and 79 (40%) patients, respectively. Independent risk factors for lack of improvement in the Aminoff-Logue gait grades were multiple treatments due to initial treatment failure or recurrence (OR 3.1) and symptom duration (OR 1.02).

CONCLUSIONS

Based on data obtained from the largest and most recently assessed multicenter cohort, the present study shows that primary neurosurgery is superior to endovascular treatment for the complete obliteration of spinal dAVFs by a single procedure.

Nationwide survey of pediatric intracranial arteriovenous shunts in Japan: Japanese Pediatric Arteriovenous Shunts Study (JPAS)

The authors performed a nationwide study in Japan to evaluate the annual detected rate of pediatric intracranial arteriovenous (AV) shunts such as brain AV malformations (BAVMs), pial AV fistulas (PAVFs), vein of Galen aneurysmal malformations (VGAMs), and dural AV fistulas (DAVFs). These rates were revealed for the first time and showed that VGAM, DAVF, and PAVF were relatively common but that BAVMs were extremely rare in neonates and infants.

Angioarchitecture of arteriovenous fistulas at the craniocervical junction: a multicenter cohort study of 54 patients

OBJECTIVE The aim of this retrospective multicenter cohort study was to assess the details of the angioarchitecture of arteriovenous fistulas (AVFs) at the craniocervical junction (CCJ) and to determine the associations between the angiographic characteristics and the clinical presentations and outcomes. METHODS The authors analyzed angiographic and clinical data for patients with CCJ AVFs from 20 participating centers that are members of the Japanese Society for Neuroendovascular Therapy (JSNET). Angiographic findings (feeding artery, location of AV shunt, draining vein) and patient data (age, sex, presentation, treatment modality, outcome) were tabulated and stratified based on the angiographic types of the lesions, as diagnosed by a member of the CCJ AVF study group, which consisted of a panel of 6 neurointerventionalists and 1 spine neurosurgeon. RESULTS The study included 54 patients (median age 65 years, interquartile range 61-75 years) with a total of 59 lesions. Five angiographic types were found among the 59 lesions: Type 1, dural AVF (22 [37%] of 59); Type 2, radicular AVF (17 [29%] of 59); Type 3, epidural AVF (EDAVF) with pial feeders (8 [14%] of 59); Type 4, EDAVF (6 [10%] of 59); and Type 5, perimedullary AVF (6 [10%] of 59). In almost all lesions (98%), AV shunts were fed by radiculomeningeal arteries from the vertebral artery that drained into intradural or epidural veins through AV shunts on the dura mater, on the spinal nerves, in the epidural space, or on the spinal cord. In more than half of the lesions (63%), the AV shunts were also fed by a spinal pial artery from the anterior spinal artery (ASA) and/or the lateral spinal artery. The data also showed that the angiographic characteristics associated with hemorrhagic presentations-the most common presentation of the lesions (73%)-were the inclusion of the ASA as a feeder, the presence of aneurysmal dilatation on the feeder, and CCJ AVF Type 2 (radicular AVF). Treatment outcomes differed among the angiographic types of the lesions. CONCLUSIONS Craniocervical junction AVFs commonly present with hemorrhage and are frequently fed by both radiculomeningeal and spinal pial arteries. The AV shunt develops along the C-1 or C-2 nerve roots and can be located on the spinal cord, on the spinal nerves, and/or on the inner or outer surface of the dura mater.

Long-term treatment outcome of venous-predominant arteriovenous malformation

OBJECTIVE

Treatment strategies for venous-predominant arteriovenous malformation (vp-AVM) remain unclear due to the limited number of cases and a lack of long-term outcomes. The purpose of this study was to report the authors' experience with treatment outcomes with a review of the pertinent literature in patients with vp-AVM.

METHODS

Medical and radiological data from 1998 to 2011 were retrospectively evaluated. The degree of the arteriovenous (AV) shunt was categorized into 2 groups, a high- and low-flow AV shunt based on the angiographic findings.

RESULTS

Sixteen patients with a mean age of 45.3 years (range 16-78 years) and a mean follow-up of 79.9 months (range 25-264 months) were examined. Symptomatic lesions were noted in 13 patients: intracranial hemorrhage (ICH) in 9, seizure in 1, and headache in 3. A high-flow shunt was observed on angiography in 13 patients. Among these 13 patients, 12 patients were symptomatic. Nine patients presenting with ICH underwent hematoma removal with additional Gamma Knife surgery (GKS; n = 4), GKS only (n = 2), or conservative treatment (n = 3). The 3 asymptomatic patients received conservative treatment, and 1 rebleeding episode was observed. Seven of 8 patients who underwent GKS as an initial or secondary treatment modality experienced a marked reduction in the AV shunt on follow-up angiography, but complete obliteration was not observed.

CONCLUSIONS

Poor lesion localization makes a vp-AVM challenging to treat. Symptomatic patients with a high-flow shunt are supposedly best treated with GKS, despite the fact that only 87.5% of the vp-AVMs treated this way showed a reduction in the malformation volume, and none were cured.

The role of percutaneous embolization techniques in the management of dural sinus malformations with atypical angioarchitecture in neonates: report of 2 cases

Dural sinus malformations (DSMs) are rare congenital malformations that can be midline or lateral in location. Midline DSMs have been reported to have a worse prognosis than lateral DSMs and have traditionally been more difficult to manage. The authors report 2 unusual manifestations of midline DSMs and their management with percutaneous transfontanelle embolization. The first patient (Case 1) presented at 21 days of life with a large midline DSM and multiple highflow dural and pial arteriovenous shunts. The child developed congestive cardiac failure and venous congestion with intracranial hemorrhage and seizures within a few weeks. The second patient (Case 2) presented with a large midline DSM found on prenatal imaging that was determined to be a purely venous malformation on postnatal evaluation. This large malformation resulted in consumptive coagulopathy and apneic episodes from brainstem compression. The patient in Case 1 was treated initially with endovascular embolization and eventually with curative percutaneous-transfontanelle embolization. The patient in Case 2 was treated with percutaneous transfontanelle embolization in combination with posterior fossa decompression and cranial expansion surgery.

Microvascular anatomy of spinal dural arteriovenous fistulas: arteriovenous connections and their relationships with the dura mater

OBJECT The microvascular anatomy of spinal dural arteriovenous fistulas (AVFs), especially the relationships of the vessels with the dura mater, has yet to be angiographically demonstrated in detail and proven histologically. METHODS From January 2012 through April 2014, a total of 7 patients with spinal dural AVFs in the thoracic region underwent open microsurgical obliteration at Tokyo Metropolitan Neurological Hospital. The microvascular anatomy of spinal dural AVFs was comprehensively assessed by using advanced microangiography, including 3D computer graphics and intraoperative indocyanine green video angiography, and by histological findings. RESULTS The 2 microangiography techniques revealed the spatial course and in vivo blood flow of the meningeal vessels and their relationships with the dura mater in sufficient detail. The meningeal branch of the intercostal artery split into multiple meningeal vessels on the outer dural surface adjacent to the root sleeve. After crossing the dura mater to the inner dural surface, these vessels gathered and joined a single intradural draining vessel. On the inner dural surface, the single draining vessel was fed by the surrounding multiple meningeal vessels, which appeared to be caput medusae. Histological findings revealed that the structure of the meningeal branch of the intercostal artery corresponded to that of a normal artery. The structure of intradural draining vessels corresponded to that of a vein modified by retrograde arterial inflow. On the inner dural surface, more than 1 meningeal artery gathered and joined with the proximal radiculomedullary vein. CONCLUSIONS Spinal dural AVFs are located on the inner dural surface, where multiple direct AV connections between more than 1 meningeal feeding artery and a single proximal radiculomedullary vein occur at the site where the vein connects to the dura mater.