Spinal Cord Arteriovenous Malformations Research Articles

Dissecting pseudoaneurysm in a spinal cord AVM treated by flow diversion: Technical note.

We report the case of a 29-year-old woman presenting with severe back pain and S1-radiculopathy. Digital subtraction angiography revealed a spinal cord arteriovenous malformation complicated by acute feeder dissection and pseudoaneurysm (PA) formation causing mass effect. After conservative management with limited angiographic and clinical improvement, selective treatment of the PA by flow diversion (FD) led to occlusion and shrinkage with the resolution of clinical symptoms. FD may be a feasible treatment option for spinal artery aneurysms in selected patients with favorable anatomy. The need for antiplatelet therapy is a limitation of its use with currently available devices.

CyberKnife Radiosurgery for Spinal Intramedullary Arteriovenous Malformations: A Single-Center Experience

Intramedullary spinal AVM (ISAVM, glomus type) is a type of spinal cord arteriovenous malformation, which is a rare disease known often to have a complex vascular supply interfering with that of the spinal cord, and is in complex anatomical relations with cord structures and nerve roots. Though microsurgical and endovascular treatment has mainly been the standard options, in high-risk cases with these treatments, stereotactic radiotherapy (SRT) might be the option of choice. We retrospectively reviewed 10 consecutive patients with ISAVM who received SRT using CyberKnife® (Accuray, Inc., Sunnyvale, CA) at the Japanese Red Cross Medical Center (Tokyo, Japan) from 2011/1-2022/3. No case in this series suffered from hemorrhage after applying SRT. One case experienced neurological impairment ten years after SRT, which we attributed to venous congestion due to the remaining lesion. No case of radiation myelopathy was observed in this series. In one case, the nidus volume reduction and loss of flow voids were obvious, though improvement in the neurological outcome was not apparent. No radiological changes were observed in the other nine patients. Even in lesions without radiological changes, no hemorrhagic events were observed for an average period of 4 years. SRT may be a feasible option in treating ISAVM, especially for lesions in which microsurgical resection and endovascular treatment are inapplicable. To ascertain the safety and efficacy of this approach, further studies with more patients and longer follow up is required.

A Classification Proposal for Spinal Vascular Lesions.

A Classification Proposal for Spinal Vascular Lesions.

Embolization for Perimedullary Arteriovenous Fistulae: Pioneering Experience in Peru

Background Perimedullary arteriovenous fistulae, or type IV spinal cord arteriovenous malformations, are very rare and not well-known lesions. This paper aims to present our endovascular experience with these lesions. Methods We report our experience with 4 patients with perimedullary arteriovenous fistulae, subtypes b and c (macrofistulae), exhibiting severe neurological impairment. The patients were treated with endovascular embolization. Results Complete fistula eradication was achieved in all of them. One complication occurred. We discuss the natural history, pathophysiology, clinical presentation, prognosis and embolization techniques, along with the angiographic and clinical outcomes. Conclusion Our experience with endovascular embolization as an upfront treatment allowed us to eradicate these lesions in a safe and effective way, arresting the clinical worsening and reversing partially or completely the neurological injury in most of our cases.

Spinal cord arterio-venous shunts: From classification to therapeutic management.

Spinal Cord Arterio-Venous shunts (SCAVSs) are a rare disease. The aim of this paper is to describe how we classify and consider management of SCAVSs in relation to the location of the shunt focusing mainly on intradural SCAVSs. The anatomical features of the SCAVSs together with data provided by MRI and CT scans allow identification of four types of SCAVSs: paraspinal, epidural, dural and intradural ones. Clinical and neuroradiologic characteristics are described for each entity as well as the therapeutic endovascular management at our institution between 2002 and 2020. The therapeutic management of SCAVSs, and in particular of intradural shunts, remains mainly based on endovascular treatment as a first-choice approach. Understanding properly the lesional and regional vascular anatomy is mandatory to plan an appropriate therapeutic strategy and obtain good clinical results stable at long term follow up.

Combined surgical and endovascular approach to treat a ventrally located perimedullary arteriovenous fistula

Perimedullary arteriovenous fistulae (PMAVFs) (also called type IV spinal cord arteriovenous malformations) are rare lesions. They are located in the subarachnoid space or just under the pia. The shunt occurs between the anterior spinal artery (ASA) and/or posterior spinal artery (PSA) and a network of perimedullary veins. The aim of the treatment, surgical or endovascular, is to occlude the fistula. This article presents a unique treatment strategy of a demanding strictly ventral PMAVF in the lower thoracic cord. A posterior surgical approach with spinal cord rotation followed by direct puncture of a distally located arterial feeder was achieved. Precise identification of the fistula with superselective contrast injections was obtained and accurate catheterization of the venous pouch with a microcatheter was performed. Complete occlusion of the PMAVF was achieved with coils.

Radiosurgical Ablation Of Intramedullary Spinal Cord AVM

Radiosurgical Ablation Of Intramedullary Spinal Cord AVM

Possibilities of endovascular embolization of spinal cord arteriovenous malformations using neurophysiological monitoring and provocative pharmacological tests

The study objective is to evaluate the results of pharmacologic provocative tests with neurophysiological intraoperative monitoring application during spinal cord arteriovenous malformation (AVM) embolization. Materials and methods . In the period from 2016 to 2018, 38patients with spinal cord AVM of different types (according the J. Anson and R. Spetzler classification) underwent endovascular surgery at the Federal Neurosurgical Center (Novosibirsk, Russia). Fifteen of these patients were operated using pharmacologic provocative tests with neurophysiological intraoperative monitoring of motor (MEP) and somatosensory evoked potentials (SSEP). Aminoff and Logue Disability Scale was used to estimate neurological deficit before and after surgery, additionally Medical Research Council Muscle Scale was used to estimate motor deficit. Results. In 15 patients, 37provocative samples with propofol and 38 samples with lidocaine with simultaneous registration of MEP and SSEP were performed. In the early postoperative period, a significant improvement in motor function was achieved in 2 patients, 3 showed a noticeable improvement, and 10 patients remained without dynamics. Urinary function improved in 2 patients, and in 13 remained unchanged. In 4 patients, the pharmacological test with propofol was positive, which was manifested by a decrease in the amplitudes of the MEP, and among the samples with lidocaine in 10 cases, a decrease in the amplitudes of the MEP was noted, with a simultaneous decrease in the amplitudes of the SSEP during 3 samples. In all patients, the decrease in the amplitudes of the evoked potentials was transient in nature and disappeared after a change in the place of administration of the pharmacological agent. This did not allow us to determine the sensitivity of the method for predicting persistent postoperative neurological deficit. To predict the development of motor deficiency in the early postoperative period, the specificity of lowering the amplitude of the MEP during the pharmacological test was: 57 % to reduce by 50 %; 87 % for a reduction of 80 % and 93 % for the complete disappearance of MEP. For the prognosis in the distant period (3 months after endovascular treatment), the specificity of decreasing the amplitude of the MEP by 50, 80 and 100 % was 46, 85 and 100 %, respectively. Conclusion. The use of neurophysiological monitoring and provocative tests is a safe method that allows you to make the optimal tactical decision in the endovascular treatment of spinal cord AVM. As a provocative test, it is recommended to use two pharmacological drugs (propofol and lidocaine). A 80 % decrease in MVP amplitudes or the disappearance of MVPs are more accurate criteria for the clinical outcome of spinal cord AVM embolization. The specificity of MVP in detecting an increase in motor deficiency in the early and long-term postoperative periods was maximum (93 and 100 %, respectively), if the disappearance of MVP was chosen as a criterion of pathology.

Clinical and angiographic results of long-term follow-up of patients after endovascular treatment for spinal arteriovenous malformations

Objective – to evaluate long-term results of treatment of patients with arteriovenous malformations AVM of the spinal cord. Materials and methods. A retrospective analysis of clinical and angiographic data of the results of treatment of patients with spinal AVM for the period from 2005 to 2019 was conducted. In SO «Scientific-Practical Center of Endovascular Neuroradiology NAMS of Ukraine» 47 patients were operated on endovascular method. The age of patients ranged from 11 to 62 years (middle age is 45.3 years). There were 29 men (61.7 %), 18 women (38.3 %). Liquid cyanoacrylate embolizant was used for endovascular intervention. The operations were performed with transfemoral access. Accoding the classification proposed by Anson and Spetzler in 1992 patients with type I were 31 (65.9 %), with ІІ type – 8 (17.0 %), with ІIІ type – 5 (10.6 %), with IV type – 3 (6.4 %). Magnetic resonance tomography and spinal angiography were used for diagnostics AVM.Results. Total exclusion of AVM from the bloodstream was achieved in 22 (46.8 %) cases. Out of the 31 (65.9 %) patients with type I AVM, 17 (54.8 %) had an early transient deepening of the neurological deficit. In this group, complete dissection of arteriovenous fistula was achieved in 16 (51.6 %) patients. In 8 (17.0 %) patients with type II AVM, complete exclusion of AVM was achieved in 5 (62.5 %) cases. In this case, 6 (75.0 %) patients were observed early postoperative deepening of neurological symptoms. In 5 (10.6 %) patients with type III AVM, total exclusion was achieved in 1 (20.0 %) case. Transient deepening of neurological deficit was noted in 3 (60.0 %) patients. In 3 (75.0 %) patients with type IV AVM, total embolization was achieved in 1 (33.0 %) observation. Neurological impairment occurred in 1 (33.0 %) patient. In all groups there were no fatalities.Conclusions. Angiography is the gold standard of diagnosis and dynamic monitoring of patients with spinal cord AVM. The use of endovascular treatment of AVM can stop the further progression of neurological deficits, which, however, is not always associated with the total exclusion of AVM. The best neurological improvement and total exclusion were achieved in patients with type I AVM. Radicality, efficacy and deepening of neurological deficiency depend on angioarchitectonics of AVM. The main condition for carrying out embolization is to achieve a safe level of catheterization of the afferent.

Spinal Cord Tolerance Guided by Stereotactic Radiosurgical Treatment of Intramedullary Arteriovenous Malformations

Spinal cord toxicity resulting in neurological deficits remains the most feared complication of spinal region stereotactic radiosurgery (SRS). In treating vertebral body disease, a radiation dose gradient can typically be established between tumor and spinal cord. This is difficult for intramedullary spinal cord arteriovenous malformations (iSCAVMs), which can be integrated throughout the cord. Here we report outcomes of cord tolerance in treatment of integrated iSCAVMs. A retrospective cohort of 17 consecutive patients with integrated iSCAVMs treated once with frameless robotic surgery, SRS between 2007 and 2018 was accrued. Clinical outcomes, dose prescriptions, and target dose-volume histogram (DVH) parameters were acquired. Volumes of interest (VOIs) comprising the proper AVM and cord were registered on treatment planning software. A cord minus AVM (CmA) structure representing independent spinal cord was generated by Boolean subtraction of the respective proper AVM from the cord. Various dose quantifiers were extracted from DVHs, statistical univariate analysis was performed, and Task Group 101 (TG101) constraints were interpolated to two-fraction regimens with α/β of 2-3 Gray (Gy) using Wolfram Mathematica (Wolfram Research, Champaign, IL). Among the 17 patients analyzed (eight male and nine female), all had CmA volumes smaller than cord, confirming the integrated nature of their iSCAVMs. Nine had a nidus in the C-spine; six in the T-spine; and two in the L-spine or lower. Median age at diagnosis was 23, ranging from 9 to 56 years. Nine patients had no prior intervention, while eight had prior embolization(s) and/or microsurgery. Median follow-up time was 40 months. Ten patients (59%) experienced Grade (G) 0 neurological toxicity post-treatment, seven (41%) experienced G1, and zero experienced G2+. Three patients were prescribed three fractions to 21 or 24 Gy. The rest received two fractions (20-22 Gy). Max dose (Dmax) to cord and CmA ranged from 2278-2874 cGy and 2000-2659 cGy, respectively. All patients had Dmax to cord and CmA greater than TG101 constraints. All patients received minimum dose to hottest 0.03 cc volume (D0.03) to cord greater than constraints; 15 patients (88%), to CmA. All patients received minimum dose to hottest 0.35 cc volume (D0.35) to cord greater than threshold; 13 patients (76%), to CmA. At significant level of 0.05, one-tailed binomial test suggests max monthly G2+ toxicity rate of 0.4% in exceeding tolerances. No neurologic toxicity beyond Grade 1 was experienced by any patient, all of whom received Dmax to spinal cord tissue (both independent and integrated with AVM) beyond recommended constraints. Further, all patients exceeded volumetric constraints to cord. Most exceeded volumetric constraints to CmA, as well. Novel tolerance data from rare iSCAVMs may influence current cord constraints to avoid limiting appropriate treatment of more common vertebral metastases.

Natural History and Treatment of Symptomatic Spinal Cord Arteriovenous Malformations

Spinal cord arteriovenous malformations (AVMs) are an important, albeit uncommon, etiology for myelopathy. They can cause spinal cord compression,

A Descriptive Analysis of Spinal Cord Arteriovenous Malformations: Clinical Features, Outcomes, and Trends in Management

Spinal arteriovenous malformations (AVM) are an abnormal interconnection of vasculature in the spine than can lead to significant neurologic deficit if left untreated. The objective of this study was to characterize how patients with spinal AVM initially presented, what treatment options were used, and their overall outcomes on a national scale. The MarketScan database was queried to identify adult patients diagnosed with a spinal AVM from 2007 to 2015. Trends in management, postoperative complication rates, and costs were determined. In total, 976 patients were identified with having a diagnosis of a spinal AVM. Patients were more commonly treated with an open incision than an embolization (40.1% vs. 15.4%). The overall complication rate was 33.61%. Spinal AVM admissions have been stable over the past decade, and mean cost of hospitalization has risen from of $48,700 in 2007 to $71,292 in 2015. Patients who underwent open surgery had a greater complication rate than those treated with embolization (31.15% vs. 18.25%, P< 0.005); however, this may be strongly influenced by complexity of spinal AVM pathology and not treatment modality. Costs of spinal AVM management continue to rise, even when treatment modalities have reduced length of stay significantly. Open surgery may lead to more postoperative complications and a greater length of stay than endovascular approaches. Further studies should look to identify the efficacy of endovascular approaches for spinal cord AVMs, particularly in complex spinal AVM traditionally treated with open surgery and to isolate factors leading to the elevated hospitalization costs.

Diagnostic accuracy and efficiency of combined acquisition of low-dose time-resolved and single-phase high-resolution contrast-enhanced magnetic resonance angiography in a single session for pre-angiographic evaluation of spinal vascular disease.

Background/PurposeThe purpose of this study was to evaluate the utility and efficacy of combined low-dose, time-resolved (TR) and single-phase high-resolution (HR) contrast-enhanced MRA (CE-MRA) as a pre-angiographic study for spinal vascular disease.Materials and methodsSeventeen consecutive patients with suspected spinal vascular disease were retrospectively reviewed. All patients underwent combined low-dose TR CE-MRA and three-dimensional single-phase HR CE-MRA at 3 Tesla, followed by conventional spinal digital subtraction angiography (DSA) within 90 days. Six patients underwent additional spinal MRA and DSA for treatment follow-up. Spinal lesions were analyzed in terms of presence, disease type, laterality, spinal level, and number of arterial feeders.ResultsLow-dose TR CE-MRA helped proper localization of subsequent HR CE-MRA in two patients with high or low level of the lesion. For initial detection of spinal vascular disease, sensitivity, specificity and accuracy of CE-MRA were 93.3% (n = 14/15), 100% (n = 3/3), and 94.4% (n = 17/18), respectively. In characterization of dural arteriovenous fistula (AVF), perimedullary AVF, spinal cord arteriovenous malformation (AVM), and extraspinal AVM, CE-MRA correctly characterized in 86.7% (n = 13/15) among the positive findings, and in 88.9% (n = 16/18) among the several patients including negative results. CE-MRA showed matched per-case localization of arterial feeders within 1 vertebral level in 80% (n = 12/15), and matched per-lesion localization in 78.3% (n = 18/23).ConclusionCombined low-dose TR CE-MRA and single-phase HR CE-MRA at 3 Tesla was an effective and accurate non-invasive tool for the pre-angiographic evaluation of spinal vascular diseases in a single session.

Volumetric T2-weighted MRI improves the diagnostic accuracy of spinal vascular malformations: comparative analysis with a conventional MR study

BackgroundTo date, very little study of the importance of a volumetric T2-weighted MR sequence in the evaluation of spinal vascular malformations (SVMs) has been carried out.ObjectiveTo determine the utility and...

Differences in the Electrophysiological Monitoring Results of Spinal Cord Arteriovenous and Intramedullary Spinal Cord Cavernous Malformations

Spinal arteriovenous malformations (SAVMs) and intramedullary spinal cord cavernous malformations (ISCCMs) have a very low incidence of disease. The purpose of this study was to compare the differences in electrophysiologic monitoring in these 2surgeries. The study included 109 patients (SAVMs, n= 55; ISCCMs, n = 54) recruited from November 2012 to January 2016. All patients underwent electrophysiologic monitoring during the entire operation, including somatosensory-evoked potentials, motor-evoked potentials, and electromyography. We used an amplitude reduction of >80% as warning criterion for motor-evoked potentials and an amplitude reduction of more than 50% and latency prolongation of more than 10% as warning criteria for somatosensory-evoked potentials. In our study, the sensitivity and specificity of intraoperative monitoring during SAVM surgery were 77.3% and 87.1%, respectively. The sensitivity and specificity of intraoperative monitoring during ISCCM surgery were 68.8% and 83.3%, respectively. We found that 21 patients with SAVM showed permanent changes, 17 had immediate postoperative impairment, 8 recovered before discharge, and 5 showed neurologic deficits at long-term follow-up. Of the 17 patients with ISCCMs showing permanent changes, 11 had immediate postoperative impairment, 5recovered before discharge, and 2 had long-term residual neurologic deficits. Electrophysiological monitoring provides effective guidance during operation on spinal vascular malformations. Electrophysiologic monitoring revealed that surgical resection of SAVMs resulted in more permanent changes and postoperative dysfunction when compared with ISCCMs. The incidence of both false-positive and -negative results suggests that electrophysiologic monitoring cannot fully predict the complete function of the patients.

Study and therapeutic progress on spinal cord perimedullary arteriovenous fistulas.

Spinal cord perimedullary arteriovenous fistulas (PMAVFs) are rare and belong to type IV spinal cord arteriovenous malformations (AVMs). Little is known regarding the treatment and prognosis of spinal cord PMAVFs. In the present study the relevant literature from PubMed was reviewed, and it was found that these fistulas can occur at all ages but are more common in children. In children, most spinal cord PMAVFs are large and with high flow, begin with bleeding and are frequently associated with hereditary hemorrhagic telangiectasia. However, in adults, most spinal cord PMAVFs are small and with low flow and begin with progressive spinal cord dysfunction. The early diagnosis of spinal cord PMAVFs is generally difficult, and symptoms can be very severe at the time of diagnosis. Digital subtraction angiography remains the gold standard; however, computed tomography angiography and magnetic resonance angiography are also promising. Spinal cord PMAVFs can be treated by endovascular embolization, surgical removal or a combination of the two methods. Most spinal cord PMAVFs show good outcomes after the appropriate treatment, and the prognosis is primarily associated with the blood flow of the PMAVF. For high-flow spinal cord PMAVFs, endovascular embolization is more effective and can lead to a good outcome; however, for low-flow spinal cord PMAVFs, surgical removal or the combination with endovascular embolization is the optimal choice. The prognosis for low-flow types is slightly worse than for high-flow spinal cord PMAVFs in children, but the outcome is acceptable.

Type III Spinal Cord Arteriovenous Malformation With Good Postsurgical Outcome

Type III Spinal Cord Arteriovenous Malformation With Good Postsurgical Outcome

Chapter 17 - Radiosurgical ablation of spinal cord arteriovenous malformations

Spinal cord arteriovenous malformations (SCAVMs) are rare entities that account for less than 20% of spinal masses. These lesions represent a unique clinical challenge, in that surgical or endovascular treatment is often associated with devastating functional consequences. Over the past few decades, radiosurgery has become a well-established treatment modality for SCAVMs, and may be a first-line treatment in many patients afflicted with this devastating disease. This chapter summarizes the data available regarding radiosurgical treatment of SCAVMs.

Microsurgical Resection of Cervical Spinal Cord Arteriovenous Malformations: Report of 6 Cases

To summarize the experience in microsurgical resection of cervical spinal cord arteriovenous malformation (AVM). Six patients undergoing microsurgical resection of cervical intramedullary AVM in the Third Affiliated Hospital of Sun Yat-sen University, China, between March 2005 and March 2015 were reviewed retrospectively, and their clinical manifestations, imaging data, surgical treatment, and results of long-term follow-up were analyzed. Of the 6 patients who underwent AVM resection, 2 had compact AVMs and 4 had diffuse AVMs. All 6 patients were reexamined with spinal magnetic resonance imaging within 48 hours after surgery, and 1 patient was examined with digital subtraction angiography. The average patient age was 40.7 ± 10.4 years (range, 29-60 years). Three patients had chronic onset, of whom 2 developed sensory disturbances and 1 had muscle weakness. The other 3 patients had acute onset, including 1 with sudden quadriplegia, 1 with idiopathic severe headache and altered consciousness, and 1 with idiopathic neck pain. The average duration of follow-up was 48.5 ± 38.9 months (range, 15-119 months). One patient experienced complete recovery, and the other 5 patients showed improvement. No patient exhibited deterioration. Microsurgical resection of cervical intramedullary AVMs has obtained satisfactory clinical results. Preoperative magnetic resonance angiography, computed tomography angiography, and digital subtraction angiography are useful for evaluating the angioarchitecture, which is key to the success of surgery. Intraoperative indocyanine green fluorescence angiography is an important aid in the surgical treatment of spinal AVMs.

Stereotactic radiosurgery for intramedullary spinal arteriovenous malformations

Spinal cord arteriovenous malformations (AVM) are rare lesions associated with recurrent hemorrhage and progressive ischemia. Occasionally a favorable location, size or vascular anatomy may allow management with endovascular embolization and/or microsurgical resection. For most, however, there is no good treatment option. Between 1997 and 2014, we treated 37 patients (19 females, 18 males, median age 30years) at our institution diagnosed with intramedullary spinal cord AVM (19 cervical, 12 thoracic, and six conus medullaris) with CyberKnife (Accuray, Sunnyvale, CA, USA) stereotactic radiosurgery. A history of hemorrhage was present in 50% of patients. The mean AVM volume of 2.3cc was treated with a mean marginal dose of 20.5Gy in a median of two sessions. Clinical and MRI follow-up were carried out annually, and spinal angiography was repeated at 3years. We report an overall obliteration rate of 19% without any post-treatment hemorrhagic events. In those AVM that did not undergo obliteration, significant volume reduction was noted at 3years. Although the treatment paradigm for spinal cord AVM continues to evolve, radiosurgical treatment is capable of safely obliterating or significantly shrinking most intramedullary spinal cord AVM.