Clinical results after the multidisciplinary treatment of spinal arteriovenous fistulas

Surgery versus endovascular treatment for spinal dural arteriovenous fistulas: a multicenter experience and systematic literature review

Surgery and endovascular therapy are the primary treatment options for spinal dural arteriovenous fistula (SDAVF). Due to the absence of a consensus regarding which therapy yields a superior outcome, we conducted a comparative analysis of the surgical and endovascular treatment of SDAVF through a multicenter case series and a systematic literature review. Patients with SDAVF, surgically or endovascularly treated at four neurosurgical centers from January 2001 to December 2021, were included in this study. Level of SDAVF, primary treatment modality, baseline and post-procedural neurological status were collected. The primary outcomes were failure, complication rates, and a newly introduced parameter named as therapeutic delay. A systematic review of the literature was performed according to PRISMA-P guidelines. The systematic review identified 511 papers, of which 18 were eligible for analysis, for a total of 814 patients, predominantly male (72%) with a median age of 61 and mainly thoracic SDAVFs (65%). The failure rate was significantly higher for endovascular therapy (20%) compared to surgery (4%) (p < 0.01). Neurological complications were generally rare, with similar rates among the two groups (endovascular 2.9%; surgery 2.6%). Endovascular treatment showed a statistically significantly higher rate of persistent neurological complications than surgical treatment (2.9% versus 0.2%; p < 0.01). Both treatments showed similar rates of clinical improvement based on Aminoff Logue scale score. The multicenter, retrospective study involved 131 patients. The thoracic region was the most frequent location (58%), followed by lumbar (37%). Paraparesis (45%) and back pain (41%) were the most common presenting symptoms, followed by bladder dysfunction (34%) and sensory disturbances (21%). The mean clinical follow-up was 21 months, with all patients followed for at least 12 months. No statistically significant differences were found in demographic and clinical data, lesion characteristics, or outcomes between the two treatment groups. Median pre-treatment Aminoff-Logue score was 2.6, decreasing to 1.4 post-treatment with both treatments. The mean therapeutic delay for surgery and endovascular treatment showed no statistically significant difference. Surgical treatment demonstrated significantly lower failure rates (5% vs. 46%, p < 0.01). In the surgical group, 2 transient neurological (1 epidural hematoma, 1 CSF leak) and 3 non-neurological (3 wound infections) complications were recorded; while 2 permanent neurological (spinal infarcts), and 5 non-neurological (inguinal hematomas) were reported in the endovascular group. According to the literature review and this multicenter clinical series, surgical treatment has a significantly lower failure rate than endovascular treatment. Although the two treatments have similar complication rates, endovascular treatment seems to have a higher rate of persistent neurological complications.

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.

[Clinical outcomes following microsurgery and endovascular embolization in the management of spinal dural arteriovenous fistula: A meta-analysis study]

OBJECTIVE

To compare the clinical effect of microsurgery and endovascular embolization in the treatment of spinal dural arteriovenous fistula (SDAVF) by meta-analysis.

METHODS

A systematic review was performed to retrieve all relevant literature about surgical treatment or endovascular embolization of SDAVF up to December 2019 through PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials Results, CNKI, Wanfang Data, and SinoMed. The Chinese and English key words included: "SDAVF", "spinal dural arteriovenous fistula", "spinal AVM", "spinal vascular malformation and treatment". The included studies were evaluated using the Newcastle-Ottawa scale. The early failure rate, long-term recurrence, neurological recovery, and complications were evaluated and the clinical effects of the two methods in the treatment of SDAVF were compared by using RevMan 5.3 software. And a further subgroup analysis of the therapeutic effect of endovascular embolization with different embolic agents was conducted.

RESULTS

A total of 46 studies involving 1 958 cases of SDAVF were included, in which 935 cases were treated by microsurgery and 1 023 cases were treated by endovascular embolization. The funnel plot demonstrated that there was no publication bias. The results of meta-analysis showed that the incidence of early surgical failure was lower than that of endovascular embolization (OR=0.20, 95%CI: 0.13-0.30, P < 0.05), and the long-term recurrence was also lower than that of endovascular embolization (OR=0.36, 95%CI: 0.22-0.58, P < 0.05). The improvement of neurological function in the surgical patients is significantly higher than that in the patients treated with endovascular embolization (OR=2.86, 95%CI: 1.36-5.99, P < 0.05). There was no significant difference in the occurrence of complications in these two groups (OR=1.52, 95%CI: 0.88-2.64, P=0.14). In the cases of endovascular embolization, the risk of treatment failure or recurrence was higher with Onyx glue than with n-butyl 2-cyanoacrylate (NBCA), and the difference was statistically significant (OR=4.70, 95%CI: 1.55-14.28, P < 0.05).

CONCLUSION

Although the treatment of dural arteriovenous fistulas by intravascular embolization has been widely used, the clinical effect of microsurgery is still better than that of endovascular embolization. Large scale and high-quality randomized controlled trials are required to validate the efficacy and safety of endovascular treatment in SDAVF patients.

Treatment of Spinal Arteriovenous Malformation and Fistula

With the rapid advancements in endovascular therapy over previous decades, the treatment of spinal arteriovenous malformations (AVMs) continues to evolve. The decision to use endovascular versus surgical therapy largely depends on the type of lesion and its anatomic location. Recent studies demonstrate that endovascular treatment is effective for extradural arteriovenous fistulas (AVFs), intradural ventral (perimedullary) AVMs, and intramedullary spinal AVMs. Treatment of intradural dorsal (dural) AVFs remains largely surgical because of lower recurrence rates, although recent studies demonstrate equivocal outcomes. Extradural-intradural (juvenile) AVMs and conus AVMs remain difficult-to-treat lesions.

Radiation exposure in the endovascular therapy of cranial and spinal dural arteriovenous fistula in the last decade: a retrospective, single-center observational study

PURPOSE

This study aims to determine local diagnostic reference levels (DRLs) in the endovascular therapy (EVT) of patients with cranial and spinal dural arteriovenous fistula (dAVF).

METHODS

In a retrospective study design, DRLs and achievable dose (AD) were assessed for all patients with cranial and spinal dAVF undergoing EVT (I) or diagnostic angiography (II). All procedures were performed at the flat-panel angiography-system Allura Xper (Philips Healthcare). Interventional procedures were differentiated according to the region of fistula and the type of procedure.

RESULTS

In total, 264 neurointerventional procedures of 131 patients with dAVF (94 cranial, 37 spinal) were executed between 02/2010 and 12/2020. The following DRLs, AD, and mean values could be determined: for cranial dAVF (I) DRL 507.33 Gy cm2, AD 369.79 Gy cm2, mean 396.51 Gy cm2; (II) DRL 256.65 Gy cm2, AD 214.19 Gy cm2, mean 211.80 Gy cm2; for spinal dAVF (I) DRL 482.72 Gy cm2, AD 275.98 Gy cm2, mean 347.12 Gy cm2; (II) DRL 396.39 Gy cm2, AD 210.57 Gy cm2, mean 299.55 Gy cm2. Dose levels of EVT were significantly higher compared to diagnostic angiographies (p < 0.001). No statistical difference in dose levels regarding the localization of dAVF was found.

CONCLUSION

Our results could be used for establishing DRLs in the EVT of cranial and spinal dAVF. Because radiation exposure to comparably complex interventions such as AVM embolization is similar, it may be useful to determine general DRLs for both entities together.

Outcomes following surgical versus endovascular treatment of spinal dural arteriovenous fistula: a systematic review and meta-analysis

Although surgical resection is associated with a complete cure in most cases of spinal dural arteriovenous fistulas (SDAVF), there has been an increasing trend towards embolisation. We performed a systematic review and meta-analysis comparing surgical resection with endovascular treatment in terms of success of treatment, rate of recurrence and complications. A literature search was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Strength of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation Working Group system. Surgical outcomes such as initial treatment failure, late recurrence, neurological improvement and complications were compared between the two approaches. We included 57 studies with 2029 patients, of which 32 studies with 1341 patients directly compared surgery (n=590) and embolisation (n=751). Surgery was found to be associated with significantly lower odds of initial treatment failure (OR: 0.15, 95% CI 0.09 to 0.24, I² 0%, p<0.001) and late recurrence (OR 0.18, 95% CI 0.09 to 0.39, I² 0%, p<0.001). The odds of neurological improvement following surgery were also significantly higher compared with embolisation alone (OR: 2.73, CI:1.67 to 4.48, I² :49.5%, p<0.001). No difference in complication rates was observed between the two approaches (OR 1.78, 95% CI 0.97 to 3.26, I² 0%, p=0.063). Onyx was associated with significantly higher odds of initial failure/late recurrence as compared with n-butyl 2-cyanoacrylate (OR: 3.87, CI: 1.73 to 8.68, I² :0%, p<0.001). Surgery may be associated with superior outcomes for SDAVFs in comparison to endovascular occlusion. Newer embolisation agents like Onyx have not conferred a significant improvement in occlusion rate.

Intracranial subarachnoid hemorrhage resulting from non-cervical spinal arteriovenous lesions: Analysis of possible cause of bleeding and literature review

Subarachnoid hemorrhage (SAH) or intraventricle hemorrhage (IVH) with negative cerebral digital subtraction angiography (DSA) results, which are due to non-cervical spinal arteriovenous lesions, are uncommon. In this article we presented three cases from our hospital and nineteen cases from prior published literature and discussed clinical features, possible mechanisms underlying the hemorrhage and therapeutic strategies for managing this unusual entity. Our analysis revealed that headache was the most common initial symptom. Almost 60% of patients had symptoms related to the spinal cord at admission. Intramedullary arteriovenous malformations (AVM) were the most common type of malformation, and the thoracic segment was the most common location of the non-cervical spinal arteriovenous lesions. More than half of the patients had additional aneurysms. Surgery was chosen as the primary treatment modality in this series. Therefore, we speculate that thoracolumbar spinal arteriovenous lesions are an unusual cause of intracranial SAH with negative cerebral DSA results. If non-cervical spinal AVMs were associated with DSA-negative SAH, the pattern of hemorrhage could be manifested as the blood in supratentorial cisterns, the fourth ventricle or no copious blood around the foramen magnum as well (somewhat paradoxically), it depends on the timing of detection and image evaluation. The formation and the rupture of associated aneurysms were the most likely immediate cause of the intracranial SAH. If non-cervical spinal AVMs were not associated with DSA-negative SAH and all cases were genuine cases of 'SAH-of-unknown origin', the spinal AVM could be considered as incidental finding. Magnetic resonance imaging (MRI) of the complete spinal neuraxis is recommended to either exclude or identify a spinal lesion in these patients. Catheter-based spinal angiography remains the gold standard for the diagnosis of spinal vascular diseases. The decision regarding a therapeutic strategy is based on the angioarchitecture and on the type of spinal arteriovenous lesions.

Recurrence Rates After Surgical or Endovascular Treatment of Spinal Dural Arteriovenous Fistulas: A Meta-analysis

BACKGROUND

There is an increasing tendency to treat spinal dural arteriovenous fistulas (SDAVFs) endovascularly despite the lack of clear evidence favoring embolization over surgery.

OBJECTIVE

To compare the initial failure and recurrence rates of primary treatment of SDAVFs by surgery and endovascular techniques.

METHODS

A meta-analysis using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) standard was performed. All the English literature from 2004 onward was evaluated. From each article that compared the 2 treatment modalities, the odds ratio (OR) was calculated. Combined ORs were calculated with Review Manager 5.3 of The Cochrane Collaboration.

RESULTS

A total of 35 studies harboring 1112 patients were assessed. Initial definitive fistula occlusion was observed in 588 of 609 surgical patients (96.6%; 95% confidence interval [CI], 94.8-97.8) vs 363 of 503 endovascularly treated patients (72.2%; 95% CI, 68.1-75.9; P < .001). The combined OR from 18 studies that assessed both treatment modalities (730 patients) was 6.15 (95% CI, 3.45-11.0) in favor of surgical treatment. Late recurrence (13 studies, 480 patients) revealed an OR of 3.15 (95% CI, 1.66-5.96; P < .001) in favor of surgery. In a subgroup, recurrence was reported in 10 of 22 patients (45%) treated with Onyx vs 8 of 35 (23%) treated with n-butyle-2-cyanoacrylate (OR, 2.51; 95% CI, 0.75-8.37; P = .13).

CONCLUSION

Although hampered by inclusion of poor quality studies, this meta-analysis shows a definite advantage of primary surgical treatment of SDAVF over endovascular treatment in initial failure rate and late recurrences. The often-used argument that endovascular techniques have improved and therefore outweigh surgery is not supported by this meta-analysis.

The Preventive Effect of Endovascular Treatment for Recurrent Hemorrhage in Patients with Spinal Cord Arteriovenous Malformations

BACKGROUND AND PURPOSE

Spinal cord AVMs represent rare and insufficiently studied pathologic entities. Embolization is thought to play an important role in the management of spinal cord AVMs. Factors for recurrent hemorrhage and the impact of endovascular treatment on prevention of recurrent hemorrhage remain to be confirmed. We aimed to assess recurrent hemorrhagic incidence of spinal cord AVMs and its prevention by endovascular treatment.

MATERIALS AND METHODS

We reviewed 80 patients with spinal cord AVMs by spinal cord angiography who had hemorrhage before the first endovascular treatment at New York University Medical Center, Beth Israel Medical Center, or Roosevelt Hospital in New York. We compared the baseline and radiologic characteristics of patients with and without recurrent hemorrhage by the log-rank test and the Cox proportional hazards model.

RESULTS

We observed recurrent hemorrhage in 35 (44%) patients (1/41 patients with endovascular treatment and 34/39 patients without endovascular treatment). The median length of total follow-up was 659 days (interquartile range, 129-2640 days), and the median length from first-to-recurrent hemorrhage was 369 days (interquartile range, 30-1596 days). The log-rank test revealed that endovascular treatment and venous thrombosis reduced recurrent hemorrhage, and associated aneurysm was related to recurrent hemorrhage. Even in multivariate analysis, the endovascular treatment reduced (hazard ratio, 0.027; P < .0001) and associated aneurysm increased (hazard ratio, 3.4; P = .044) the risk of recurrent hemorrhage.

CONCLUSIONS

Endovascular embolization is the first choice of treatment for spinal cord AVMs and is effective in preventing recurrent hemorrhage.