A single-center, long-term study of spinal dural arteriovenous fistulas with multidisciplinary treatment

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.

Extravertebral low back pain: a scoping review

BACKGROUND

Low back pain (LBP) is one of the most common reasons for consultation in general practice. Currently, LBP is categorised into specific and non-specific causes. However, extravertebral causes, such as abdominal aortic aneurysm or pancreatitis, are not being considered.

METHODS

A systematic literature search was performed across MEDLINE, Embase, and the Cochrane library, complemented by a handsearch. Studies conducted between 1 January 2001 and 31 December 2020, where LBP was the main symptom, were included.

RESULTS

The literature search identified 6040 studies, from which duplicates were removed, leaving 4105 studies for title and abstract screening. Subsequently, 265 publications were selected for inclusion, with an additional 197 publications identified through the handsearch. The majority of the studies were case reports and case series, predominantly originating from specialised care settings. A clear distinction between vertebral or rare causes of LBP was not always possible. A range of diseases were identified as potential extravertebral causes of LBP, encompassing gynaecological, urological, vascular, systemic, and gastrointestinal diseases. Notably, guidelines exhibited inconsistencies in addressing extravertebral causes.

DISCUSSION

Prior to this review, there has been no systematic investigation into extravertebral causes of LBP. Although these causes are rare, the absence of robust and reliable epidemiological data hinders a comprehensive understanding, as well as the lack of standardised protocols, which contributes to a lack of accurate description of indicative symptoms. While there are certain disease-specific characteristics, such as non-mechanical or cyclical LBP, and atypical accompanying symptoms like fever, abdominal pain, or leg swelling, that may suggest extravertebral causes, it is important to recognise that these features are not universally present in every patient.

CONCLUSION

The differential diagnosis of extravertebral LBP is extensive with relatively low prevalence rates dependent on the clinical setting. Clinicians should maintain a high index of suspicion for extravertebral aetiologies, especially in patients presenting with atypical accompanying symptoms.

Surgical evolution in spinal dural arteriovenous fistula treatment-a 7 years monocentric experience

Accounting for 70% of all spinal vascular malformations, spinal dural arteriovenous fistulas (SDAVF) are the most common type of malformation. Interruption of the fistulous arterialized vein point is the goal of surgical treatment. The aim of the study was to compare open surgery (laminectomy) versus minimal invasive surgery (MIS) in SDAVF treatment. Between March 2013 and March 2020, we retrospectively collected 21 consecutive adult patients with SDAVF. Since March 2017, MIS has been routinely used for surgical treatment. Pre- and post-operative clinical evaluations used Aminoff-Logue score (ALS). Complication rate was noted. Post-operative occlusion of the malformation was confirmed by digital subtraction angiography (DSA) in all patients. MIS was compared to open surgery in terms of efficacy and complications with statistical evaluation. Standard laminectomy was performed in 12 patients and MIS technique in 9 patients. No difference was noted on pre-operative parameters. ALS and MRI signs of myelopathy were improved in all cases except for 1 patient in each group. All SDAVFs were excluded based on post-operative DSA. Significant differences were noted between the 2 groups in terms of perioperative blood loss (p<0.001), post-operative pain visual analog scale values (p<0.001), and first time out of bed (p<0.001). Wrong level surgery occurred in one patient in each group; patients were re-operated using the same technique. No infection or cerebrospinal fluid (CSF) leak was noted. In our experience, MIS is a safe alternative to open laminectomy for SDAVF treatment. MIS contributes to patient comfort and minimizes blood loss without increasing complication rate.

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.

Imaging characteristics, misdiagnosis and microsurgical outcomes of patients with spinal dural arteriovenous fistula: a retrospective study of 32 patients

Background

Spinal dural arteriovenous fistula (SDAVF) is an extremely rare spinal vascular malformation. As SDAVF exhibits no specific clinical manifestations nor diverse imaging results, it is easily misdiagnosed, resulting in delayed treatment and irreversible neurological damage. Most patients were initially misdiagnosed, but there were few reports on reducing misdiagnosis.

Methods

A total of 32 consecutive patients, who presented to our institution (Shanghai Deji Hospital) with SDAVF between June 2013 and January 2016 were retrospectively analyzed. Data were collected on demographics, clinical presentation, imaging findings, follow-up, and clinical outcomes. The Aminoff-Logue scale (ALS) was used to assess clinical outcomes.

Results

Of the 32 enrolled patients (3 females, mean age 59.1±3.8 years), 23 patients (71.9%) were misdiagnosed as acute myelitis (11 patients), intramedullary tumors (6 patients), lumbar disc herniation (4 patients), and other conditions (2 patients). All patients underwent surgical procedures under electrophysiological monitoring. Fistulas were found in all 32 patients and were successfully occluded. The mean follow-up period was 19.22±8.21 months (ranging from 2 weeks to 30 months). One year later, 20 patients underwent magnetic resonance imaging (MRI), and 14 showed no T2 edema, and the edema was relieved in 6 patients. A total of 10 patients underwent enhancement MRI and no enhancement signs were detected. Among the 27 patients with long-time follow-up, the fistula had no residual or recurrence, 21 patients showed decreased ALS scores (P<0.05). Six patients exhibited nonsignificant improvement. No aggravating patient was found. Prognosis differed significantly between patients with ALS <6 and those with ALS ≥6 (P<0.05).

Conclusions

Spinal angiography should be performed with full intubation, and microcatheter angiography can reduce misdiagnosis. SDAVF must be differentiated from acute myelitis, intramedullary tumor, and other spinal vascular malformations. Microsurgical treatment is effective with a low recurrence rate.

[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.

Far Lateral Approach for Disconnection of Craniocervical Junction Dural Arteriovenous Fistula Presented with Myelopathy and Hydrocephalus

We report a case of craniocervical junction dural arteriovenous fistula (dAVF) presented with myelopathy and normal pressure hydrocephalus, and was treated with hybrid approach of embolization and surgical disconnection. A 68-year-old gentleman presented with 1 year history of unsteady gait and sphincter disturbance. Magnetic resonance imaging (MRI) showed abnormally enlarged and tortuous vessels over right cerebellomedullary cistern. Digital subtraction angiogram (DSA) showed Cognard's type-V dAVF at craniocervical junction. Catheter embolization was performed via external carotid artery and finally surgical disconnection was done with far lateral approach ( Fig. 1 ). Postoperative DSA showed no more arteriovenous shunting ( Fig. 2 ). Clinically the patient improved after a course of rehabilitation. Dural AVF at craniocervical junction is rare and its clinical presentation can be highly variable from subarachnoid hemorrhage to brainstem dysfunction. Identification of the exact fistula site is essential in surgical planning. Surgery is effective and safe to achieve complete obliteration and good clinical outcome. 123456

The link to the video can be found at: https://youtu.be/xI48stSlWpY .

Spinal Dural Arteriovenous Fistula: Diagnosis, Outcomes, and Prognostic Factors

OBJECTIVE

Typically, the clinical presentation of a spinal dural arteriovenous fistula (SDAVF) will be insidious, with patients' symptoms regularly attributed to other conditions. Although previous studies have characterized the neurologic outcomes after treatment for SDAVFs, little is known about the pretreatment patient characteristics associated with poor and/or positive patient outcomes. We sought to characterize the pretreatment patient demographics, diagnostic history, and neurologic outcomes of patients treated for SDAVFs and to identify the patient factors predictive of these outcomes.

METHODS

The medical records of patients who had been treated for SDAVFs from 2006 to 2018 across 1 healthcare system were retrospectively analyzed. Neurologic status was assessed both before and after intervention using the Aminoff-Logue scales for gait and micturition disturbances.

RESULTS

Of 46 total patients, 16 (35%) had a documented misdiagnosis. Patients with a history of misdiagnosis had had a significantly longer symptom duration before treatment compared with those without a misdiagnosis (median, 2.3 vs. 0.9 years; P = 0.018). A shorter symptom duration before intervention was significantly associated with both improved motor function (median, 0.8 vs. 3.1 years; P = 0.001) and improved urinary function (median, 0.8 vs. 2.2 years; P = 0.040) after intervention.

CONCLUSIONS

Misdiagnosis has been relatively common in patients with SDAVFs and contributes to delays in treatment. Delays in diagnosis and treatment of SDAVFs appear to be associated with worse clinical outcomes for patients who, ultimately, receive treatment.

Massive subarachnoid hemorrhage during type iv spinal arteriovenous malformation embolization. An endovascular procedure complication

Spinal arteriovenous malformations are rare diseases with a low prevalence and a complex diagnosis that usually requires the several neuroscience disciplines collaboration. Multidisciplinary approach requires fluid communication, favorable work environment and a correct social relationship, thus avoiding the conflict of interest appearance. We reported a 31 years old female referred to our department with progressive asymmetric spastic paraparesia for 10 months of evolution and occasional bladder dysfunction. With the diagnosis of a type IV arteriovenous malformation, a scheduled embolization was performed resulting in a massive subarachnoid hemorrhage due to the ASA laceration requiring an emergency bifrontal craniectomy. We discuss the neurosurgeońs role in complications during endovascular spinal vascular pathology treatment.

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.

Comparison of Endovascular Embolization and Surgery in the Treatment of Spinal Intradural Dorsal Arteriovenous Fistulas

BACKGROUND

We compared the outcomes of endovascular embolization and surgery and investigated the factors affecting the clinical outcomes of spinal intradural dorsal arteriovenous fistulas (SIDAVFs).

METHODS

The medical records of 26 patients who had undergone endovascular embolization or surgery for SIDAVFs from 2004 to 2014 were retrospectively reviewed. The recurrence rate and clinical outcomes for each treatment modality were compared. Multivariate analysis was used to identify significant factors influencing the clinical outcomes using the Aminoff and Logue (AL) score.

RESULTS

Of the 26 patients, 14 (56%) had undergone endovascular embolization and 11 (44%) had undergone surgery as the initial treatment. Embolization was applied as the primary treatment for most patients. Surgery was chosen for patients with difficult superselection (n = 5), multiple feeders (n = 2), or easy surgical accessibility (n = 4). Of the 14 patients who had undergone embolization as initial treatment, 5 (36%) had developed a recurrence within an average of 29.6 months (range, 2-87). One patient with recurrent SIDAVF was treated with repeat embolization and four with surgery. None of patients in the surgical group developed recurrence. Embolization as the initial treatment resulted in significantly greater recurrence compared with surgery (odds ratio, 2.222; 95% confidence interval, 1.369-3.608; P = 0.046). Surgery resulted in better clinical outcomes than embolization (P = 0.021). The final AL score was also strongly affected by the preoperative AL score, micturition score, and recurrence (P = 0.000, P = 0.000, and P = 0.011, respectively).

CONCLUSIONS

Our results have shown that surgery results in a low recurrence rate and superior clinical outcomes. A multidisciplinary and ordered decision is crucial for the treatment choice to ensure better outcomes, especially for patients with a definite neurologic deficit at diagnosis.

Timing, severity of deficits, and clinical improvement after surgery for spinal dural arteriovenous fistulas

OBJECTIVE

Spinal dural arteriovenous fistulas (dAVFs) are rare vascular abnormalities caused by arteriovenous shunting. They often form at the dural root sleeve between a radicular feeding artery and draining medullary vein causing venous congestion and edema, decreased perfusion, and ischemia of the spinal cord. Treatment consists of either surgical ligation of the draining vein or selective embolization via an endovascular approach. There is a paucity of data on which modality provides more durable and effective outcomes.

METHODS

The authors performed a retrospective review of a prospectively maintained database by the senior author to assess clinical outcomes in patients undergoing surgical treatment of spinal dAVFs. Preoperative and postoperative motor and Aminoff-Logue Scale (ALS) scores were collected.

RESULTS

A total of 41 patients with 44 spinal dAVFs were identified, with a mean patient age of 64 years. The mean symptom duration was 14 months, with weakness (82%), urinary symptoms (47%), and sensory symptoms (29%) at presentation. The fistula locations were as follows: 30 thoracic, 9 lumbar, 3 sacral, and 2 cervical. Five patients had normal motor and ALS scores at presentation. Among the remaining 36 patients with motor deficits or abnormal gait and micturition at presentation, 78% experienced an improvement while the remaining 22% continued to be stable. There was a trend toward improved outcomes in patients with shorter symptom duration; mean symptom duration among patients with clinical improvement was 13 months compared with 22 months among those without improvement. Additionally, rates of improvement were higher for lower thoracic and lumbosacral dAVFs (85% and 83%) compared with those in the upper thoracic spine (57%). No patient developed recurrent fistulas or worsening neurological deficits.

CONCLUSIONS

Surgery is associated with excellent outcomes in the treatment of spinal dAVFs. Early diagnosis and treatment are critical, with a trend toward improved outcomes. No patient in this study had fistula recurrence or worsening of symptoms. Among patients with abnormal motor or ALS scores, 78% improved after surgery. Therapeutic embolization is an option for some lesions, but for cases with unfavorable anatomy where embolization is not feasible, surgery is a safe option associated with high success.

Three-Dimensional Endoscopic Magnification for Treatment of Thoracic Spinal Dural Arteriovenous Fistulas: Technical Note

BACKGROUND

Treatment of thoracic spinal dural arteriovenous fistulas (DAVFs) by microsurgery has recently been approached using minimally invasive spine surgery (MISS). The advantages of such an approach are offset by difficult maneuverability within the tubular retractor and by the creation of "tunnel vision" with reduced luminosity to a remote surgical target.

OBJECTIVE

To demonstrate how the pitfalls of MISS can be addressed by applying 3-D endoscopy to the minimally invasive approach of spinal DAVFs.

METHODS

We present 2 cases of symptomatic thoracic DAVFs that were not amenable to endovascular treatment. The DAVFs were excluded solely via a minimally invasive approach using a 3-D endoscope.

RESULTS

Two patients underwent exclusion of a DAVF following laminotomy, one through a midline 5-cm incision and the other through a paramedian 3-cm incision using minimally invasive nonexpandable tubular retractors. The dura opening, intradural exploration, fistula exclusion, and closure were performed solely under endoscopic 3-D magnification. No incidents were recorded and the postoperative course was marked by clinical improvement. Postoperative imaging confirmed the exclusion of the DAVFs. Anatomical details are exposed using intraoperative videos.

CONCLUSION

When approaching DAVFs via MISS, replacing the microscope with the endoscope remedies the limitations related to the "tunnel vision" created by the tubular retractor, but at the expense of losing binocular vision. We show that the 3-D endoscope resolves this latter limitation and provides an interesting option for the exclusion of spinal DAVFs.

[Spinal dural arteriovenous fistulas. A series of clinical cases and an analysis of the literature data]

Spinal dural arteriovenous fistulas (SDAVFs) are the most common vascular malformation of the spinal cord, causing segmental lesions of the spinal cord due to venous ischemia. Functional outcomes of treatment in SDAVF patients are favorable, but the rate of improvement varies from 25 to 100%, which complicates prediction of the treatment outcome.

AIM

the study aim was to identify a relationship between fistula localization and clinical manifestations and evaluate the effect of disease duration and severity of neurological impairments on immediate and long-term treatment outcomes, based on analysis of the literature and own data.

MATERIAL AND METHODS

In September 2016, we performed a PubMed search for publications using keywords 'spinal arteriovenous fistula', 'treatment', and 'outcome'. We selected publications containing information on the patient's age, fistula location, disease duration, and evaluation of symptom severity (Aminoff-Logue scale) preoperatively, postoperatively, and at least 3 months after surgery. The analysis also included data on patients operated on at the clinic. A total of 187 patients were included in the analysis.

RESULTS

The fistula was most often located at the T6, T7, and T9 level, with motor disorders being more severe for fistulas located at or below the T9 vertebra. Surgical isolation of the fistula improved the functional state of patients, with patients under the age of 60 years having a better prognosis for recovery of impaired functions. Motor disorders significantly regressed in the early postoperative period in all patients, but in the long-term period, there was worsening of motor disorders in patients with a better baseline functional state.

Open and endovascular treatment of spinal dural arteriovenous fistulas: a 10-year experience

OBJECTIVE Vascular malformations of the spine represent rare clinical entities with profound neurological implications. Previously reported studies on management strategies for spinal dural arteriovenous fistulas (sDAVFs) appeared before the advent of modern liquid embolic agents. Authors of the present study review their institutional experience with endovascularly and surgically treated sDAVFs. METHODS The authors performed a retrospective, observational, single-center case series on sDAVFs treated with endovascular embolization, microsurgical occlusion, or both between 2004 and 2013. The mode, efficacy, and clinical effect of treatment were evaluated. RESULTS Forty-seven patients with spinal arteriovenous malformations were evaluated using spinal angiography, which demonstrated 34 Type I sDAVFs (thoracic 20, lumbar 12, and cervical 2). Twenty-nine of the patients (85%) were male, and the median patient age was 63.3 years. Twenty patients underwent primary endovascular embolization (16 Onyx, 4 N-butyl cyanoacrylate [NBCA]), and 14 underwent primary surgical clipping. At a mean follow-up of 36 weeks, according to angiography or MR angiography, 5 patients treated with endovascular embolization demonstrated persistent arteriovenous shunting, whereas none of the surgically treated patients showed lesion persistence (p = 0.0237). Thirty patients (88%) experienced some resolution of their presenting symptoms (embolization 17 [85%], surgery 13 [93%], p = 1.00). CONCLUSIONS Microsurgical occlusion remains the most definitive treatment modality for sDAVFs, though modern endovascular techniques remain a viable option for the initial treatment of anatomically amenable lesions. Treatment of these lesions usually results in some clinical improvement.

Concomitant origin of the anterior or posterior spinal artery with the feeder of a spinal dural arteriovenous fistula (SDAVF)

Background/objective

The concomitant origin of the anterior spinal artery (ASA) or the posterior spinal artery (PSA) from the feeder of a spinal dural arteriovenous fistula (SDAVF) is rare and the exact incidence is not known. We present our experience with the management of SDAVFs in such cases.

Methods

In 63 patients with SDAVF between 1993 and 2015, the feeder origin of the SDAVF was evaluated to determine whether it was concomitant with the origin of the ASA or PSA. Embolization was attempted when the patient did not want open surgery and an endovascular approach was regarded as safe and possible. The outcome of the procedure was evaluated as complete, partial, or no obliteration. The clinical outcome was evaluated by Aminoff–Logue (ALS) gait and micturition scale scores.

Results

Nine patients (14%) had a concomitant origin of the ASA or PSA with the feeder. There were two cervical, five thoracic, and two lumbar level SDAVFs. A concomitant origin of the feeder was identified with the ASA (n=7) and PSA (n=2). Embolization was performed in four patients and open surgery was performed in five. Embolization resulted in complete obliteration in three patients and partial obliteration in one. Using the ALS gait and micturition scale, the final outcome improved in six while three cases remained in an unchanged condition over 2–148 months.

Conclusions

The concomitant origin of the ASA or PSA with the feeder occurs occasionally. Complete obliteration of the fistula can be achieved either by embolization or open surgery. Embolization can be carefully performed in selected patients who are in a poor condition and do not want to undergo open surgery.

Surgical and Endovascular Treatment for Spinal Arteriovenous Malformations

Spinal arteriovenous malformation (AVM) is a broad term that constitutes diverse vascular pathologies. To date, various classification schemes for spinal AVM have been proposed in literature, which helped neurosurgeons understand the pathophysiology of the disease and determine an optimal treatment strategy. To discuss indications and results of surgical and endovascular interventions for spinal AVM, this article refers to the following classification proposed by Anson and Spetzler in 1992: type I, dural arteriovenous fistula (AVF); type II, glomus intramedullary AVM; type III, juvenile malformations; and type IV, perimedullary AVF. In general, complete obliteration of the fistula is a key for better outcome in type I dural and type IV perimedullary AVFs. On the other hand, in type II glomus and type III juvenile malformations, functional preservation, instead of pursuing angiographical cure, is the main goal of the treatment. In such cases, reduction of the shunt flow can alleviate clinical symptoms. Proper management of spinal AVM should start with neurological examination and understanding of angioarchitectures, which provide critical information that guides the indication and modality of intervention. Finally, close collaboration of the microsurgical and endovascular teams are mandatory for successful treatment.

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.

Spinal Dural Arteriovenous Fistula: A Review

Spinal dural arteriovenous fistula (SDAVF) is a rare disease, the etiology of which is not entirely clear. It is the most common vascular malformation of the spinal cord, comprising 60-80 % of the cases. The clinical presentation and imaging findings may be nonspecific and misleading, often mistaking it for other entities like demyelinating or degenerative diseases of the spine.This chapter describes the imaging findings, clinical signs, and symptoms of this disease and also the available treatment options according to the current literature.Angiography is still considered the gold standard for diagnosis; however, MRI/MRA is increasingly used as a screening tool. Modern endovascular techniques are becoming increasingly more effective in treating SDAVF offering a less invasive treatment option; however, they still lag behind surgical success rates which approach 100 %. The outcome of both treatment options is similar if complete obliteration of the fistula is obtained and depends mainly on the severity of neurological dysfunction before treatment.Heightened awareness by radiologists and clinicians to this rare entity is essential to make a timely diagnosis of this treatable disease. A multidisciplinary treatment approach is required in order to make appropriate treatment decisions.

Comparison of surgical and endovascular approach in management of spinal dural arteriovenous fistulas: A single center experience of 27 patients

Background:

Spinal dural arteriovenous fistula (SDAVF) is a rare spinal vascular malformation with an annual incidence of 5-10 cases per million. The data on efficacy, recurrence rates and complications of endovascular versus surgical treatment of SDAVF is limited.

Methods:

We conducted a retrospective chart review of 27 adult patients with a diagnosis of SDAVF and who underwent treatment at Duke University Hospital between January 1, 1993 and December 31, 2012. We compared the outcome measures by Aminoff–Logue score (ALS) in patients who underwent treatment with endovascular embolization versus surgical ligation of fistula. We compared complication rates, recurrence rates as well as data on long-term follow up in these patients.

Results:

Out of 27 patients in the study, 10 patients underwent endovascular embolization (Onyx was used in 5 patients and NBCA in 5 patients) as the first line therapy. Seventeen patients underwent surgical ligation as initial therapeutic modality. Patients in both groups showed significant improvement in clinical status (ALS) after treatment. One patient in endovascular group developed spinal infarction due to accidental embolization of medullary artery. Three patients in embolization group had recurrence of fistula during the course of follow up requiring surgical ligation. Two patients in surgical group developed local wound infection. None of the patients in surgical group had recurrence of fistula during the course of follow up.

Conclusions:

Endovascular embolization and surgical ligation are effective treatment strategies for SDAVF. Our observations show that surgical ligation may offer permanent cure without any recurrence. Endovascular approach is associated with higher incidence of recurrence, especially with use of onyx.

Absence of abnormal vessels in the subarachnoid space on conventional magnetic resonance imaging in patients with spinal dural arteriovenous fistulas

Spinal dural arteriovenous fistula (DAVF) is an uncommon condition that can be difficult to diagnose. This often results in misdiagnosis and treatment delay. Although conventional MRI plays an important role in the initial screening for the disease, the typical MRI findings may be absent. In this article, the authors present a series of 4 cases involving patients with angiographically proven spinal DAVFs who demonstrated cord T2 prolongation on conventional MRI but without abnormal subarachnoid flow voids or enhancement. These cases suggest that spinal DAVF cannot be excluded in symptomatic patients with cord edema based on conventional MRI findings alone. Dynamic Gd-enhanced MR angiography (MRA) was successful in demonstrating abnormal spinal vasculature in all 4 cases. This limited experience provides support for the role of spinal MRA in patients with abnormal cord signal and symptoms suggestive of DAVF even when typical MRI findings of a DAVF are absent.

Surgical treatment of Type I spinal dural arteriovenous fistulas

Object

Type I spinal dural arteriovenous fistulas (SDAVFs) are low-flow vascular shunts fed by radicular arteries in patients who most often present with myelopathy. Although some fistulas are amenable to endovascular embolization, nearly all can be treated with direct microsurgical obliteration.

Methods

The authors reviewed their experience in treating 214 craniospinal arteriovenous malformations and/or fistulas over the last 8 years. Of these, 19 were spinal (9%), of which 15 (79%) were Type I SDAVFs. The authors reviewed the patients' epidemiological characteristics, presenting symptoms, and SDAVF angioarchitecture in all cases. They subsequently analyzed surgical obliteration rates and outcomes of all 11 patients who underwent fistula microsurgical obliteration.

Results

In all patients who underwent microsurgical treatment, complete angiographic obliteration of the fistula was achieved. At follow-up, 10 (91%) of 11 patients exhibited improvement, 1 patient (9%) was the same, and no patients were worse. Specifically, 8 (73%) of 11 patients had improvement in strength and sensation, 5 (71%) of 7 had improvement of bowel/bladder function, and 3 (60%) of 5 had improvement of preoperative paresthesias. There were no wound infections, CSF leaks, or permanent neurological deficits.

Conclusions

Microsurgical treatment of SDAVF provides direct access to the fistula point, allowing for high obliteration rates with excellent long-term improvement of preoperative deficits and limited periprocedural complications.