Perimedullary Venous System Research Articles

An isolated Sinus Intracranial Dural Arteriovenous Fistula with Unusual Drainage Pattern

Isolated sinus dural arteriovenous fistulas (DAVFs) involve a dural sinus with occlusion on both sides of the diseased sinus segment. Because of venous drainage refluxing from the isolated sinus into the cortical veins, all isolated sinus DAVFs are Borden type III or Cognard type Ⅲ/Ⅳ. Venous drainage typically involves temporo-occipital cortical veins or the superior petrosal sinus and tributaries of the petrosal vein. However, drainage veins involving the perimedullary venous system are extremely rare. Here, we present a case of Cognard type V isolated sinus DAVF successfully treated with balloon catheter and Onyx.

Early Diagnosis of Spinal Dural Arteriovenous Fistula

Spinal dural arteriovenous fistulas (SDAVF) are rare and most commonly affect men aged >50 years. Patients with SDAVF develop an abnormal vascular dural shunt between the dural branch of a segmental artery and a subdural radicular vein that drains the perimedullary venous system, leading to venous hypertension and secondary congestive myelopathy. Most SDAVFs are located in the thoracolumbar region, and usually patients present with slowly progressive paraparesis and urinary disturbances. SDAVF is diagnostically challenging; this condition may be misdiagnosed as lumbar spinal stenosis or myelitis. Clinicians should be aware of fluctuating symptoms in the early stages to avoid misdiagnosis of SDAVF. Claudication is associated with various activities including walking, bathing, drinking, and singing. On T2-weighted magnetic resonance imaging of the spinal cord, SDAVFs show a high signal intensity with a low signal intensity peripherally and dilated spinal cord veins in the subarachnoid space.

Spinal Epidural Fistulas–A Separate Entity to Dural Fistulas with Different Angioarchitecture and Treatment Approach

Spinal epidural arteriovenous fistulas (SEAVFs) are the rarest variety of spinal vascular malformation and are often misdiagnosed as type 1 spinal dural fistula. This retrospective study highlights the salient anatomic differentiating points of these entities and also highlights the importance of a planned endovascular treatment approach using different routes of access. Efficacy of the endovascular treatment at 3 months follow-up was also studied. We retrospectively reviewed 11 treated patients with SEAVF. Existence of epidural arteriovenous fistula in all these patients was confirmed by spinal angiography. The Aminoff-Logue Scale score was assigned both before and after the procedure. The statistical results were expressed as percentages, and the preprocedure scale was compared with the postprocedure scale at 3 months by using a nonparametric Wilcoxon signed-rank test. The patients ranged in age from 7 to 53 years, with male predominance. Paraparesis was the commonest symptom, and 1 patient had congestive cardiac failure caused by a large fistula. Location was mostly dorsolumbar with intradural venous reflux into the perimedullary venous system (Castilla type A) noted in 3/11(27%) patients, and the remaining 73% patients had Castilla type B1 with an enlarged epidural venous sac. Therapeutic embolization was performed from arterial, venous, or combined routes. The 3-month postprocedure clinical assessment showed statistically significant (P < 0.004) improvement in the Aminoff-Logue Scale score. The differentiating points between SEAVF compared with type 1 spinal dural fistula are emphasized. The study also highlights the importance of a good angiographic assessment to best access the fistula by arterial, venous, percutaneous, or combined routes. Endovascular treatment resulted in statistically significant clinical improvement at 3 months follow-up.

Chapter 3 - Neurovascular anatomy: Spine

The arterial supply of the spinal cord is provided by the spinal branch of the cervical, thoracic, and lumbar intersegmental arteries. While supply is initially provided at each embryonic segment, only a few prominent anterior radiculomedullary arteries remain at the adult stage, including the arteries of the cervical and lumbosacral enlargements as well as a constant upper thoracic contributor. The spinal cord is surrounded by the vasocorona, an arterial network that includes several longitudinal anastomotic chains, notably the anterior and posterior spinal arteries, which respectively supply the central and peripheral components of the intrinsic vascularization. The intrinsic venous circulation is also divided into central and peripheral components. The perimedullary venous system includes several longitudinal anastomotic chains interconnected by the coronary plexus. The radiculomedullary veins loosely follow the spinal nerve roots on their way to the epidural plexus. Their point of passage through the thecal sac forms an important valve-like structure, the antireflux mechanism.

Cervical spinal dural fistulas leading to remote thoracolumbar myelopathy: A diagnostic pitfall.

Spinal dural arteriovenous fistulas (SDAVFs) are abnormal connections between 1 or more radiculomeningeal arteries and a single radiculomedullary vein draining into the perimedullary venous system. SDAVFs present in older patients with a progressive myelopathy caused by diffuse spinal venous hypertension. The discrepancy between the focal nature of the arteriovenous shunt and the extent of the induced myelopathy is a classic feature of SDAVFs related to the coexistence of diffuse spinal venous drainage impairment. We describe 3 cases of cervical SDAVFs (at C1, C4, and C7) presenting with a myelopathy that spared the cervical spinal cord and, in 2 instances, the upper thoracic cord. This is to our knowledge the first observations of cervical SDAVFs with MRI showing absent or subtle flow voids and presenting remote thoracolumbar myelopathy without cervical cord involvement. A considerable distance may separate low-flow spinal arteriovenous fistulas from the spinal cord damage they produce. These observations emphasize the importance of performing a complete spinal angiogram when investigating a vascular myelopathy of any location and extent.

The arrow-tipped loop is a marker of radiculomedullary vein thrombosis linked to the anti-reflux mechanism—angiographic anatomy and clinical implications

This article proposes that the "arrow-tipped" loop or anastomosis classically described as an anatomic variant represents in fact a pathological phenomenon resulting from the partial thrombosis of a radiculomedullary vein (RMV) with a duplicated origin (double-rooted RMVs). The arrow-tip loop concept proposed in this report is illustrated with angiographic observations of patients with underlying pathologies of the spinal venous system, three cases of spinal arteriovenous fistulas, and one case of spinal venous insufficiency. In each clinical case, the presence of arrow-tip loops was associated with diffuse alteration of the perimedullary venous system, including the lack of detectable RMVs. The angiographic appearance of the arrow-tip loops suggested partially thrombosed double-rooted RMVs, with rootlets originating either from the anterior or posterior spinal veins, or from both. While a thrombosed single-rooted RMV typically becomes anatomically and angiographically undetectable, double-rooted MRVs keep a flowing proximal segment made of their two rootlets of origin. This residual proximal segment takes the appearance of an arrow-tip loop, which therefore be seen as an indicator of spinal venous thrombosis.

Filum terminale arteriovenous fistulas: the role of endovascular treatment

The authors describe the clinical presentation, imaging features, and management of patients presenting with filum terminale arteriovenous fistulas (FTAVFs) and the role of transarterial treatment in their management. The authors retrospectively reviewed data obtained in 10 patients with FTAVFs diagnosed between January 1990 and December 2011. Most patients (70%) were male, and the age of the population ranged from 31 to 72 years (mean 58.2 years). Clinical presentation was progressive paraparesis and sensory loss in the lower extremities in 9 cases, back pain in 7, radicular pain in 3, bowel/bladder disturbance in 5, and impotence in 1. The duration of symptoms varied between 2 and 24 months. Initial MRI studies showed intramedullary increased T2 signal, swollen cord, and dilated perimedullary veins in all patients. One patient had syringomyelia, presumably caused by venous hypertension transmitted by the perimedullary venous system. Embolization was attempted in 7 patients and was curative in 6 patients. Surgery was performed in the other 4 patients in whom embolization was unsuccessful or deemed not feasible. There was no treatment-related complication in either group. Symptoms, venous congestion in the cord, and syringomyelia improved on follow-up in all patients. Embolization should be considered the treatment of choice for FTAVFs and can effectively treat the majority of patients presenting with an FTAVF. In a smaller group of patients in whom the angioarchitecture is unfavorable, open surgery is recommended.

Spinal dural arteriovenous fistula presenting with paraplegia following lumbar puncture

Spinal dural arteriovenous fistulas are rare lesions with an annual incidence of 1 per 100,000 population. In patients with this disease, an abnormal vascular dural shunt exists between a dural branch of a segmental artery and a subdural radicular vein that drains the perimedullary venous system, leading to venous hypertension and secondary congestive myelopathy. Generally, patients present with progressive paraparesis, urinary disturbances, and gait ataxia. In this report the authors describe a 61-year-old woman with a spinal dural arteriovenous fistula who developed an acute paraplegia after a nontraumatic lumbar puncture. The possible underlying mechanisms and treatment options are discussed.

Spinal Dural Fistulas without Swelling and Edema of the Cord as Incidental Findings

SDAVFs cause hypertension and hence outflow obstruction in the perimedullary venous system resulting in swelling and edema of the cord followed by dysfunction. Clinical presentation is usually with gradual progressive paraparesis, numbness, and sphincter problems. MR imaging typically demonstrates the dilated perimedullary veins and the swelling and edema of the cord. During the past few years, we incidentally found an SDAVF on MR imaging with dilated perimedullary veins but without swelling and edema of the cord in 5 patients with unrelated presenting clinical symptoms. Spinal angiography confirmed the presence of an SDAVF in all 5 patients. Although the indication was considered questionable, eventually all 5 fistulas were endovascularly or surgically treated, resulting in normalization of the MR images.

E-003 Localization of spinal dural arteriovenous fistula: diagnosis and implications

PurposeSpinal Dural Arteriovenous Fistula (SDAVF) is a rare acquired lesion that can impair spinal cord function. Early diagnosis is very important since the symptoms can be reversed if treated prior...

Dural arteriovenous fistula with spinal perimedullary venous drainage

The purpose of this study was to investigate the characteristics of six patients with dural arteriovenous fistula (DAVF) with drainage directly into the perimedullary venous system. In five patients with subarachnoid hemorrhage (SAH), cerebral angiography revealed a DAVF with spinal venous drainage located at the petrosal sinus in one, at the tentorium in one, and at the craniocervical junction in four. In the patient with myelopathy, angiographic exploration began with a spinal angiogram. Bilateral vertebral angiography initially failed to demonstrate the fistula, and a tentorial DAVF was established with carotid artery angiography. Patients had no myelopathy when the venous drainage was limited to the cervical cord; myelopathy was present when the venous drainage descended toward the conus medullaris. Diagnosis of a DAVF presenting with myelopathy is more challenging than of those presenting with SAH.

Tentorial Dural Arteriovenous Fistula Presenting with Quadriparesis: Case Report and Review of the Literature

Tentorial dural arteriovenous fistulas (TDAVFs) draining into the spinal venous system are rare lesions. The clinical presentation can be devastating and the diagnosis delayed because of the initial nonspecific imaging and laboratory findings. We report a case of a 20-year-old woman with a rapidly progressive myelopathy, who was found to have a left TDAVF, fed by a single arterial feeder with drainage into the perimedullary venous system. The fistula was surgically clipped. The patient showed neurologic improvement at her 3-month follow-up but still had significant weakness of all 4 extremities. Early diagnosis is key as the neurologic symptoms are reversible with appropriate treatment. We review the relevant literature, imaging characteristics, and treatment modalities for TDAVF.

Intracranial dural arteriovenous fistula associated with progressive cervical myelopathy and normal venous drainage of the thoracolumbar cord: case report and review of the literature

Background Intracranial dural arteriovenous malformations draining into the perimedullary venous system are rare lesions. In these cases, the selective spinal catheterization of all vessels with potential of causing that malformation was negative, and additional cerebral angiography usually reveals the fistula. Because of venous congestion of the cord caused by the DAVF, a delayed drainage or stagnation of contrast material in the artery of Adamkiewicz was considered as a compelling angiographic disorder so far. Case Description We report about a 58-year-old patient with a DAVF of the right posterior fossa draining into the cervical and upper thoracic plexus of medullary veins, followed by progressive cervical myelopathy and a normal venous drainage of the artery of Adamkiewicz. Because of the failing endovascular treatment option, the neurosurgical intervention was performed. The fistula was explored and clipped without any complications. Immediately after operation, the patient reported an improvement of his neurological deficits. Conclusion About 38 cases of intracranial DAVFs draining into the perimedullary venous system are reported, but to our knowledge, this is the second one with a normal drainage of the artery of Adamkiewicz. The pathophysiological mechanisms, diagnostic procedures, and treatment modalities are discussed.