Perimedullary arteriovenous fistulas in pediatric patients: clinical, angiographical, and therapeutic experiences in a series of 19 cases

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.

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.

Role of the Cervical Anterior Spinal Artery in the Endovascular Treatment of Vascular Diseases: Bystander, Accomplice, Victim, or Friend?

The cervical anterior spinal artery (ASA) is a very important artery arising from the intracranial vertebral artery (VA). It can play different roles in endovascular treatment (EVT) of spinal vascular diseases. The current understanding of these roles is incomplete; therefore, we performed this review. We found that cervical ASA can be involved in many spinal vascular diseases, such as arteriovenous fistula (AVF), arteriovenous malformation (AVM), and aneurysm, and can serve as a collateral channel in proximal VA occlusion. In AVF and AVM, when the cervical ASA is involved, it often plays the role of an accomplice or victim because it acts as the feeder or as a bystander that does not provide blood flow to the AVF and AVM. In cervical ASA aneurysm, the ASA is a victim. During EVT of VA aneurysms or stenoses, the cervical ASA ostia can be covered or occluded, resulting in ASA ischemia. In this situation, the ASA is a victim. In VA occlusion or the subclavian steal phenomenon, the cervical ASA can serve as a collateral channel to provide blood flow to the posterior circulation. In this case, the ASA plays the role of a friend. According to the role of the cervical ASA in spinal vascular diseases, EVT should be determined “case by case.” Most importantly, when EVT is performed to treat these diseases, the cervical ASA axis must be preserved. Therefore, understanding the role of the cervical ASA in spinal vascular diseases is crucial.

Treatment options and long-term outcomes in pediatric spinal cord vascular malformations: a case report and review of the literature

A 16-month-old female was admitted for prolonged fever, gait ataxia, and neurogenic bowel and bladder. Neurological exam was significant for decreased sensory and motor functions in bilateral lower extremities. Initial MRI showed a thoracic spine hematoma and diagnostic angiogram revealed a large AVM and aneurysm. The patient underwent surgical resection of the hematoma and AVM, as well as clipping and later endovascular coiling of the aneurysm. Due to significant hemorrhage perioperatively, she developed spastic paraplegia improved by baclofen and onabotulinumtoxin A injections. The aims of this paper were to conduct a systematic review of the literature on pediatric spinal cord vascular malformations and analyze trends in treatment options and long-term neurological outcomes. PubMed searches were conducted using keywords "pediatric spinal vascular malformation" and "pediatric spinal AVM", yielding 34 results after abstract screening and cross-reference. Endovascular embolization was determined to have better long-term outcomes, with 10/19 (52.6%) patients with postoperative complications associated with open vascular surgeries. Open versus endovascular surgical decisions can be difficult with unique spinal AVM pathologies in pediatric patients. Important considerations such as size, location, neurological deficits, and risk of rupture are important factors to consider in treating these patients. We recommend endovascular treatment as a first-line approach due to lower risk of hemorrhage and postoperative deficits.

[Perimedullary arteriovenous fistula. Case report and literature review]

Arteriovenous fistula is a common vascular abnormality of spinal cord and meninges. This disease is more common in young men. Clinical manifestation includes progressive sensitive and motor disorders. However, acute symptoms including impaired consciousness, head or back pain are also possible. The authors describe a rare case. A 15-year-old boy experienced acute depression of consciousness accompanied by headache, vomiting, weakness in the upper limbs and sensitive disorders. The patient was hospitalized to the intensive care unit and examined for subarachnoid hemorrhage. MRI of the head and cervical spine and direct invasive angiography were performed. Perimedullary AVF of cervical spinal cord was diagnosed. Complete clinical regression was observed within a month. Microsurgical removal of AVF was performed in scheduled fashion. Postoperative follow-up period was over 6 months.

De novo arteriovenous shunts after endovascular cure of cerebrospinal macro arteriovenous fistulas. A role for the vasa vasorum?

BACKGROUND AND PURPOSE

Macro-arteriovenous fistulas (MAVFs) are arteriovenous shunts draining into a giant venous ectasia. They can be treated by surgery or embolisation. Angiographic controls are usually performed rapidly after treatment in order to prove the cure of the lesion but no long term angiographies are generally scheduled. We wanted to control the stabilities of such lesions at follow-up.

METHOD

Clinical history and imaging of ninety-five patients with high flow shunts draining into venous ectasias (MAVFs, Vein of Galen malformations and dilatations) were reviewed.

RESULTS

De novo arteriovenous shunts related to angiogenesis involving vasa vasorum developed in three patients with MAVFs at various intervals. Genetic underlying conditions as HHT or RASA 1 mutations were suspected in each patient.

CONCLUSIONS

Neo-angiogenesis can occur after cure of MAVFs. Long term imaging follow-ups should be considered as the natural history of such recurrent shunts is currently unknown.

The role of spinal angiography in the evaluation and treatment of pediatric spinal vascular pathology: a case series and systematic review

OBJECT

While it has been extensively studied in adults, the role of spinal angiography in children with suspected spinal vascular malformations is not fully characterized. With special implications regarding technique, radiation dose, and pathology, we sought to review our single-center experience with pediatric spinal vascular pathology and use a systematic review of the literature to further identify its role in pediatrics.

METHODS

A retrospective chart review was conducted under IRB approval for all patients age 0-18 years old who underwent spinal angiography at our institution between 2007 and 2018 for concern for spinal vascular pathology. A simultaneous systematic review was conducted via dedicated search terms in two distinct databases and reviewed to identify all studies referring to spinal angiography or angiograms in pediatric patients.

RESULTS

Six patients were included. Three patients (50%) had vascular malformations confirmed on diagnostic angiography and underwent subsequent endovascular treatment. Two patients (33.3%), one with hematomyelia and one with spinal cord infarction, had negative diagnostic angiograms. One patient (16.7%) had a spinal tumor and underwent angiography for further evaluation preoperatively. Spinal angiography was used to aid in diagnosis, preoperative planning, and treatment in these cases. It was demonstrated to be safe in this patient population, with no untoward events, minimal radiation dose, and possible therapeutic applications in select cases. The systematic review identified 11 studies regarding pediatric spinal angiography. These ranged from single case reports to case series of up to 38 patients and highlighted the role of spinal angiography in diagnosis, endovascular treatment, preoperative planning, and postoperative follow-up.

CONCLUSIONS

Spinal angiography may be used in a variety of scenarios to better understand the architecture of vascular spinal lesions and facilitate endovascular intervention. While its application in both adult and pediatric pathology is limited to select cases, spinal angiography remains a key diagnostic procedure when approaching vascular lesions or tumors of the spine, assessing for etiology of spinal cord infarcts, and in the evaluation of unexplained hemorrhage in the spinal canal.

Pediatric perimedullary arteriovenous fistula: clinical features and endovascular treatments

Objective

Pediatric spinal perimedullary arteriovenous fistula (PMAVF) is rare but may cause permanent disability. We aim to summarize the clinical features of pediatric PMAVFs and our clinical experience in their treatment and to evaluate the effect of endovascular treatment in a large cohort.

Methods

From 2008 to 2017, 51 PMAVFs in pediatric patients (<14 years' old) treated with endovascular techniques were retrospectively reviewed, including 24 type IVb (47.1%) and 27 type IVc (52.9%) lesions. Clinical features, radiological findings, treatment, and outcomes were evaluated.

Results

Thirty-eight boys and thirteen girls were included, and the mean age at presentation was 5.6±4.1 years. Acute neurological deterioration was identified in 33 patients, and 21 of those patients (63.6%) suffered from bleeding. The annual bleeding rate before treatment was 2.55%. After transarterial embolization with coils and glue, 46 PMAVFs (90.2%) were completely occluded, and five (9.8%) were obliterated by supplementary microsurgery. During a follow-up period of 6 to 119 months (mean 58.4±16.7 months), the patients’ clinical states were improved in 42 cases (82.4%), stationary in nine cases (17.6%), and aggravated in none. Type IVc patients had a longer preoperative period, more chronic symptoms, a lower cure rate by embolization, and less improvement of symptoms than type IVb patients had (P<0.05).

Conclusions

Pediatric PMAVF is a special subgroup of intradural arteriovenous shunt that should be treated early. Endovascular embolization is safe and effective in the treatment of pediatric PMAVFs.

Clinical presentation and treatment paradigms in patients with hereditary hemorrhagic telangiectasia and spinal vascular malformations

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder that causes angiodysplasia and results in mucocutaneous telangiectasias and arteriovenous malformations of organs. Although central nervous system vascular malformations can occur anywhere along the neuraxis, spinal vascular malformations are rare. We present our experience with the presentation and management of spinal vascular malformations in patients with HHT. Of the more than 800 patients with the diagnosis of HHT screened at our institution from 1995 through 2017, four patients with spinal vascular malformations (age range 1 month-77 years; 2 male, 2 female) were identified, three of whom came to clinical attention after significant neurological deterioration from previously unknown malformations. A review of the literature including our patients demonstrated 29 total spinal arteriovenous fistulas (AVFs) in 28 HHT patients (69% male). The lesions were located predominantly in the thoracic spine (65.5%). Three lesions were not treated, 17 were treated with embolization, 6 were surgically resected, and 3 were treated with embolization and surgery. In 14 cases, the patients presented with hemorrhage of the AVF. Overall, 79% of patients achieved complete or near-complete occlusion, with 75% reporting improvement in neurological function. Discovery of spinal lesions often occurs after neurological decline because current screening protocols do not include evaluation of the patient for spinal lesions. Most patients benefit from intervention, which is tailored to the characteristics of the patient and their malformation. Given the often-severe neurological deficit encountered at presentation, we favor a protocol that screens HHT patients for spinal vascular malformations.

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.

An unusual cause of vertigo and headache in childhood

Spinal perimedullary arteriovenous fistulas (PMAVFs) are rare entities among vascular malformations of the spinal cord. Due to progressive myelopathy, spastic paresis, sensory disturbance, and bowl and bladder dysfunction can be the presenting symptoms. Cervical spinal arteriovenous fistulas (AVFs) are even rarer. These lesions differ from the ones in the thoracolumbar region and have an even wider mode of presentation. We report on a 9-year-old boy with a cervical PMAVF manifesting with headache and vertigo.

Pediatric spinal arteriovenous malformations and fistulas: a single institute's experience

OBJECTIVE

Pediatric spinal vascular diseases are extremely rare. We aimed to evaluate their clinical characteristics and treatment outcomes in our institute.

DESIGN

A total of 10 patient files were retrospectively reviewed, including 3 cases of intramedullary arteriovenous malformations (AVMs), 6 cases of perimedullary arteriovenous fistulas (AVFs), and 1 case of epidural AVF. Clinical features, radiological findings, treatment results, and clinical outcomes were evaluated. The median durations of the radiologic and clinical follow-ups were 17.7 and 107.9 months, respectively.

RESULTS

The male to female ratio was 1:1, with a median age at diagnosis of 9 years. All AVMs were juvenile type, all perimedullary AVFs were high flow types (three type IVb and three type IVc), and one epidural AVF was associated with intradural venous drainage. Most cases (90 %) were located in the cervical spine and conus medullaris. Acute neurological deterioration was identified in five patients; however, bleeding was identified in only one patient. Two cases were surgically treated, seven cases underwent embolization, and one case underwent radiosurgery. Three cases were completely obliterated, and their clinical states were improved (n = 2; 66.7 %) and stationary (n = 1; 33.3 %). Meanwhile, seven cases were incompletely obliterated, and their clinical states were improved (n = 2; 28.6 %), stationary (n = 3; 42.8 %), and aggravated (n = 2; 28.6 %).

CONCLUSIONS

Pediatric spinal AVMs and AVFs were mostly complex and high flow types, and complete obliteration could not be satisfactorily achieved. Incompletely treated lesions should be closely followed up because they may worsen.

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.

Spinal arteriovenous fistulae in patients with hereditary hemorrhagic telangiectasia: A case report and systematic review of the literature

BACKGROUND

Although rare, spinal arteriovenous malformations (AVMs) are thought to be more prevalent in the hereditary Hereditary Hemorrhagic Telangiectasia (HHT) population.

METHODS

We report a case of a spinal AVM in a 37-year-old female with HHT treated with endovascular embolization. In addition, we report findings from a systematic review of the literature on the clinical characteristics, angioarchitecture, and clinical outcomes of HHT patients with spinal AVMs.

RESULTS

The patient is a 37 year-old female with definite HHT who presented with a one-year history of progressive gait difficulty. The spinal fistula was incidentally detected on chest computed tomography (CT). Spinal angiography demonstrated a large perimedullary arteriovenous fistula was supplied by a posterolateral spinal artery. The fistula was treated with detachable coils. The patient made a complete neurological recovery. Our systematic review yielded 25 additional cases of spinal AVMs in HHT patients. All fistulae were perimedullary (100.0%). Treatments were described in 24 of the 26 lesions. Endovascular-only treatment was performed in 16 cases (66.6%) and surgical-only treatment was performed in five cases (20.8%). Complete or near-complete occlusion rates were 86.7% (13/15) for endovascular treated cases, 100.0% (4/4) for surgery and 66.6% (2/3) for combined treatments. Overall, 80.0% of patients (16/20) reported improvement in function following treatment, 100.0% (5/5) in the surgery group and 84.6% (11/13) reported improvement in the endovascular group.

CONCLUSIONS

Spinal fistulae in HHT patients are usually type IV perimedullary fistulae. Both endovascular and surgical treatments appeared to be effective in treating these lesions. However, it is clear that endovascular therapy has become the preferred treatment modality.

Cervical perimedullary arteriovenous shunts: a study of 22 consecutive cases with a focus on angioarchitecture and surgical approaches

BACKGROUND

Reports of cervical perimedullary arteriovenous shunt (PMAVS) are limited, and treatment strategies have not been established.

OBJECTIVE

To describe angioarchitecture and optimal treatment strategies for cervical PMAVS.

METHODS

We treated 22 patients with cervical PMAVS between 2000 and 2012 (8 women and 14 men; age, 9-80 years). According to the classification, our patients included type IVa (4 patients), type IVb (16 patients), and type IVc (2 patients). Seventeen patients presented with subarachnoid hemorrhage.

RESULTS

A total of 41 shunting points were localized in 22 patients, of which 34 points were located ventral or ventrolateral to the spinal cord. The anterior spinal artery (ASA) contributed to the shunts in 16 patients. Aneurysm formation was identified in 8 patients. Endovascular treatment was attempted in 3 patients, resulting in complete obliteration in 1 patient (type IVc). Overall, 21 patients underwent open surgery. An anterior approach with corpectomy was elected for 2 patients; the other 19 patients underwent the posterior approaches using indocyanine green videoangiography, intraoperative angiography, endoscopy (8 patients), and neuromonitoring. Twenty patients were rated as having a good recovery at 6 months after surgery. No recurrence was observed in any patients during the follow-up (mean, 59.7 months).

CONCLUSION

Shunting points of the cervical PMAVS were predominantly located ventral or ventrolateral to the spinal cord and were often fed by the ASA. Even for ventral lesions, posterior exposure assisted with neuromonitoring and endoscopy, and intraoperative angiography provided a view sufficient to understand the relationships between the shunts and the ASA and contributed to good surgical outcomes.

Endovascular treatment of spinal vascular lesion in Japan: Japanese Registry of Neuroendovascular Therapy (JR-NET) and JR-NET2

A subgroup analysis of spinal vascular lesions in the Japanese Registry of Neuroendovascular Therapy (JR-NET) and JR-NET2, retrospective registry studies conducted in 2005–2009, was performed to understand the current status of treatment in Japan. Of 201 spinal lesions enrolled, 98 analyzable cases of spinal dural arteriovenous fistula (SDAVF), 43 of spinal perimedullary arteriovenous fistula (SPAVF), and 23 of spinal intramedullary arteriovenous malformation (SIAVM) were assessed. Treatment was radical in the majority (83.6%) of SDAVF, palliative in the majority (70.6%) of SIAVM, and radical and palliative in a similar number of cases of SPAVF. Total occlusion was achieved in 26 (54.2%) SDAVF cases, 9 (29.0%) SPAVF, and 4 (23.5%) SIAVM. Treatment-related complications occurred in 3 (3.1%) SDAVF cases, 7 (16.3%) SPAVF, and 1 (4.3%) SIAVM. Post-treatment neurological improvement was achieved in 49 (50.0%) of SDAVF cases, 15 (34.9%) SPAVF, and 5 (21.7%) SIAVM. The modified Rankin Scale (mRS) of 0, 1, or 2 on postoperative day 30, the primary endpoint, was achieved in 62 (63.3%) SDAVF cases, 26 (60.5%) SPAVF, and 12 (52.2%) SIAVM. The mRS of 0–2 on postoperative day 30 was correlated with pre-symptomatic mRS of 0–2 [P < 0.0001, odds ratio (OR): 42.88, 95% confidence interval (CI): 14.83–123.97] and postoperative neurological improvement (P = 0.046, OR: 2.57, 95% CI: 1.02–6.48). In Japan, endovascular treatment of spinal vascular lesions was administered safely. Good mRS on postoperative day 30 was highly correlated with good pre-symptomatic mRS, suggesting necessity of early diagnosis and treatment.

Vascular diseases of the spinal cord

Vascular disease affecting the spinal can cause substantial neurologic morbidity. Several vascular spinal cord ailments present as neurologic emergencies, and should thus be recognizable to the practicing neurologist. We review the epidemiology, presentation, management strategies, and prognosis of various pathologies, including infarction, dural arteriovenous fistula, arteriovenous malformation, cavernous malformation, compressive epidural hematoma, vasculitis, and genetic abnormalities.

Spinal Pial (Type IV) Arteriovenous Fistulae

BACKGROUND:

Demographics, hemorrhage risk, and results of surgical and endovascular treatment of spinal pial (type IV) arteriovenous fistulae (AVFs) across a large patient group have not been previously reported.

OBJECTIVE:

To report demographics, hemorrhage rates, and treatment results for these AVFs.

METHODS:

We performed a pooled analysis via the PubMed and Embase databases through November 2012. Individualized patient data were extracted and analyzed using Cox proportional hazards regression to obtain hazard ratios for hemorrhage risk factors and pooled for baseline demographics and treatment results.

RESULTS:

We extracted information on 213 patients from 28 studies. Only 1% of lesions were incidental; 93% of patients presented with neurologic deficits and 36% with hemorrhage. Patients with type IVa lesions were significantly older (mean age, 46.9 years) and demonstrated a male sex predilection (68% male). Patients with type IVc lesions were significantly younger (mean age, 18.7 years), had no sex predilection, and had the highest prevalence of syndromic conditions (29% of cases). The annual hemorrhage rate was 2.5% (95% confidence interval [CI]: 1.4%-4.7%), increasing to 5.6% for hemorrhagic fistulae (95% CI: 3.0%-10.7%; hazard ratio: 6.31; 95% CI: 0.69-57.4; P = .10). Patient sex, fistula location, and fistula subclass were not significant risk factors for hemorrhage. The surgical obliteration rate was 88%; 68% of patients improved, 26% were the same, and 6% were worse. The endovascular obliteration rate was 74%; 75% of patients improved, 14% were the same, and 11% were worse.

CONCLUSION:

We demonstrate the utility of the Anson-Spetzler a-c subclassification and underscore the efficacy of surgical and endovascular spinal AVF treatment.

Pediatric perimedullary arteriovenous fistula of the conus medullaris supplied by the artery of Desproges-Gotteron

The cone artery, or artery of Desproges-Gotteron, is sometimes seen arising from the internal iliac artery. The authors describe a case of a symptomatic perimedullary arteriovenous fistula (AVF) of the conus medullaris in an 8-year-old boy who presented with a protracted history of urinary difficulty and severe sudden-onset right lumbosciatic pain that evolved to severe paraparesis with compromise of the sphincter muscles. The spinal AVF, which was supplied by the cone artery and a thoracic radiculomedullary artery that joined at the fistula site in a large partially thrombosed varix, was completely occluded with Onyx liquid embolic. The patient's clinical condition improved rapidly after embolization. As shown in this patient, urgent endovascular embolization of spinal AVFs can be very rewarding, even in patients with severe neurological presentation. The artery of Desproges-Gotteron appears to be a rare arterial variation. To the authors' knowledge, this is the first pediatric case of a conal AVF supplied by this artery.

Communicating hydrocephalus caused by an unruptured perimedullary arteriovenous fistula in the lumbar region of an infant

Spinal arteriovenous malformations are rare in children, although perimedullary arteriovenous fistulas (PMAVFs) may account for up to 24% of spinal arteriovenous malformations in this age group. Reported presentations of PMAVFs have included progressive or acute myelopathic symptoms, pain, hematomyelia, and subarachnoid hemorrhage. No known reports of an unruptured PMAVF causing communicating hydrocephalus have been previously published. A 17-month-old girl presented to the authors' clinic with a 6-month history of back and leg pain, gait regression, constipation, and marked lumbar hyperlordosis due to a PMAVF. A brain MRI study also demonstrated advanced hydrocephalus. The patient underwent embolization with Onyx of 2 feeding arteries from the right L-1 and 1 feeding artery from the left L-1 lumbar arteries. Postembolization follow-up imaging demonstrated a reduction in size of the L-1 pedicles and no residual supply of the fistula. Three-year clinical follow-up showed normal bowel and bladder function with significant improvements in the patient's back pain, gait, and hyperlordosis. The patient's ventricular enlargement improved without direct management of her hydrocephalus. To the authors' knowledge, this is the first reported case of communicating hydrocephalus caused by an unruptured PMAVF. The authors postulate that the origin of hydrocephalus was either central venous hypertension caused by the high-flow fistula or a change in fluid dynamics reducing CSF resorption through arachnoid granulations in the lumbar region of the spinal cord. The exact role that spinal arachnoid granulations play in CSF resorption is not currently known. Regardless of pathogenesis, initial treatment should focus on management of the fistula with additional hydrocephalus management only when necessary.

Spinal arteriovenous fistulas in children with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant angiodysplasia with high penetrance and variable expression. The manifestations of HHT are often age related, and spinal arteriovenous fistula (AVF) may be the initial presentation of HHT in young children. Because spinal AVFs are rarely reported, however, screening is not incorporated into current clinical recommendations for the treatment of patients with HHT. The authors describe 2 cases of children younger than 2 years of age with acute neurological deterioration in the context of a spinal AVF and in whom HHT was subsequently diagnosed. One patient presented with intraventricular and subarachnoid hemorrhage and the other with acute thrombosis of an intramedullary varix. These cases highlight the potential for significant neurological morbidity from a symptomatic AVF in very young children with HHT. Given the lack of data regarding the true incidence and natural history of these lesions, these cases raise the question of whether spinal cord imaging should be incorporated into screening recommendations for patients with HHT.

Endovascular embolization for symptomatic perimedullary AVF and intramedullary AVM: a series and a literature review

INTRODUCTION

Perimedullary arteriovenous fistula (AVF) has shunt on the spinal cord surface and it can be treated with surgery, or endovascular embolization. Intramedullary arteriovenous malformation (AVM) has its nidus in the cord and is difficult to treat either by surgery or endovascular technique. We report our experience with endovascular embolization in the treatment of perimedullary AVF and intramedullary AVM.

METHODS

Four consecutive cases of spinal perimedullary AVF and six intramedullary AVM were retrospectively reviewed. These cases were evaluated and treated at Beijing Tiantan Hospital, China, over a 2-year period. A review of previously reported cases was also performed.

RESULTS

There was no significant difference in the presentations (P = 0.348), level of lesions (P = 0.350), arterial suppliers (P = 0.801), and associated vascular anomalies between perimedullary AVF and intramedullary AVM, except for age (P = 0.014) and treatment modalities (P = 0.003). The patients with perimedullary AVFs were younger in our cases; the age at onset of symptoms averaged 25.8 years compared to 31.7 years for intramedullary AVMs. There was a significant male predominance for both lesions, and a significantly higher incidence of subarachnoid hemorrhage than in spinal dural AVFs. Regarding treatment, endovascular coil embolization is frequently used in perimedullary AVF and liquid embolic agent is an effective therapeutic choice in intramedullary AVM.

CONCLUSION

Perimedullary AVF and intramedullary AVM are dissimilar with dural AVF in clinical characteristics. Our experience suggests that the endovascular treatment of spine perimedullary AVFs and intramedullary AVMs is feasible and effective. Endovascular treatment for intramedullary AVMs is still challenging, the main problem is acute ischemia injury of the spinal cord.

Perimedullary arteriovenous fistulas in children: report on six cases

BACKGROUND

Perimedullary arteriovenous fistulas (PMAVFs) are rare spinal lesions and even more uncommon in children.

OBJECTIVE

The aim of this study was to document rare occurrences of this type of arteriovenous malformation in six children treated at our institution.

METHODS

The clinical data, radiological findings, and treatment in six cases of PMAVFs were reviewed. Six patients with PMAVFs were managed at our institution over a 5-year period. The patients (four girls and two boys), ranging in age from 6 to 15 years, presented with initially fluctuating, and eventually permanent and progressive, sudden-onset paraparesis, sensory disturbances, and sphincter dysfunction. The duration of symptoms before diagnosis ranged from 1 week to 13 years.

RESULTS

All the patients underwent magnetic resonance imaging and spinal selective angiography, which demonstrated the characteristic imaging of an arteriovenous fistula. Embolization of the arteriovenous fistula was initially attempted in three patients with successful occlusion of the fistula in two. For the remaining cases, open surgery was performed, with complete occlusion of the fistula. There was no morbidity, regardless of the treatment performed. All the patients experienced neurological improvement after treatment.

CONCLUSIONS

No specific clinical or radiological characteristic of PMAVFs in the pediatric population was observed when our series was compared with a general series. Early diagnosis and timing of the therapeutic intervention seemed to avoid the development of irreversible ischemic myeloradiculopathy and prevented hemorrhage. Treatment for PMAVFs is difficult to standardize because these are extremely rare lesions with different angioarchitecture configurations.

Pediatric high-flow, cervical spinal, macro-arteriovenous fistula, treated with the endovascular cotton candy glue injection technique

A 3-year-old boy presented to our hospital with progressive neurological deficits. Spinal magnetic resonance imaging (MRI) revealed a perimedullary macro-arteriovenous fistula (PMAVF) resulting in a large venous pouch within the parenchyma of the lower cervical spinal cord. Transarterial varix embolization of the fistula from the venous side was performed using N-butyl cyanoacrylate with tantalum powder. Postembolization angiography confirmed obliteration of the fistula, and MRI revealed thrombosis and reduction in size of the venous component. The patient's clinical symptoms were reduced dramatically following the intervention, and no neurological complications occurred due to the treatment. The prognosis of spinal PMAVF depends primarily on the presence of medullar signs and symptoms and on time to treatment. The volume of the venous pouch after the intervention was markedly reduced, and complete clinical recovery was obtained. Urgent endovascular intervention, as seen in this case, is considered first-line therapy and aims to decrease the risk of neurological sequela.