Spinal dural arteriovenous fistula with perimesencephalic subarachnoid haemorrhage

Treatment of Dural Arteriovenous Fistula with Intradural Draining Vein at the Craniocervical Junction: Case Series with Special Reference to the Anatomical Considerations

BACKGROUND

Dural arteriovenous fistulas at the craniocervical junction (CCJ DAVFs) are a rare vascular disease. Endovascular treatment (EVT) and microsurgery are the primary treatment modalities for CCJ DAVFs. However, incomplete treatment or complications may occur after treatment because of the anatomical complexity.

OBJECTIVE

We analyzed the neurosurgical treatment experiences of CCJ DAVFs to recommend suitable classification and treatment options.

METHODS

CCJ DAVFs were anatomically classified into three types according to the feeding arteries and their relationships with the anterior spinal (ASAs) and lateral spinal arteries (LSAs). Type 1 was fed by the radiculomeningeal artery from the vertebral artery and was not associated with the ASA or LSA. Type 2 was fed by the radiculomeningeal artery, and the radicular artery supplied the LSA near the fistula point. Type 3 had the characteristics of type 1 or type 2 CCJ DAVFs, except the ASA also contributed to the fistula.

RESULTS

There were 5, 7, and 4 cases of type 1, type 2, and type 3 CCJ DAVFs, respectively. EVT was attempted in 12 patients, of whom only 1 (type 1) was completely cured without complications. Nine cases had residual lesions after EVT, and two had spinal cord infarction due to occlusion of the LSA. Fourteen patients underwent microsurgical treatment. In all 14 cases, CCJ DAVFs were completely obliterated after microsurgery.

CONCLUSION

In cases of type 1 CCJ DAVF, both microsurgical treatment and EVT may be considered. However, for type 2 and 3 CCJ DAVFs, microsurgery may be a superior treatment modality.

Intraoperative DSA-guided minimal approach for craniocervical junction DAVFs obliteration

BACKGROUND

Dural arteriovenous fistulas (DAVFs) are a group of diseases involving problematic shunts between dural arteries and venous structures such as sinuses, meningeal veins, or even cortical veins. To focus on craniocervical junction dural arteriovenous fistulas (DAVFs), we introduce a minimally invasive technique with midline incision combined with intraoperative digital subtraction angiography (DSA). This hybrid technique can minimize the incision wound to an average of 6 cm which leads to less destruction and lower risk of adverse events.

METHOD

Using this minimally invasive approach, surgical obliteration was achieved in 6 patients with craniocervical junction DAVFs. A minimal midline incision was made over the C1-2 level, measuring approximately 5 to 7 cm in length. C1 hemilaminectomy was performed for DAVF obliteration followed by intraoperative DSA for confirmation of complete obliteration.

RESULTS

Among these 6 patients, the radiculomedullary artery was the most common feeding artery. The mean length of the operation (including DSA performance) was 6.5 ± 1.4 h. None of these cases showed cerebrospinal fluid leakage or exacerbation of neurological symptoms after the operation.

CONCLUSION

Using intraoperative DSA, the minimally invasive technique offers more precise but less destructive access than conventional far lateral suboccipital craniotomy. Most importantly, intraoperative DSA provided verification of complete closure for shunts that could not be examined for indocyanine green (ICG) dye because the microscope did not have a clear line of sight. In our experience, this technique shows encouraging results of fistula obliteration.

The role of venous anatomy in guiding treatment approach for dural arteriovenous fistulas of the craniocervical junction; case series & systematic review

BACKGROUND

Dural arteriovenous fistulas (DAVF) of the craniocervical junction (CCF) are an uncommon entity with the following venous drainage pattern: inferior, superior and mixed. Patients may present with subarachnoid hemorrhage, myelopathy or brainstem dysfunction. CCJ DAVF can be treated with microsurgery or with transarterial and transvenous embolization, depending on the venous drainage pattern. We present our institutional experience of treating CCJ DAVFs along with a systematic review of the literature.

METHODS

Six patients with CCJ DAVF were treated at our institution over five years. Data was collected using electronic medical record review. Systematic review was performed on CCJ DAVF using the PubMed database from 1990 to 2021. We characterized venous drainage patterns, treatment choices, and outcomes to create a classification system.

RESULTS

50 case reports, consisting of 115 patients, were included in our review. 61 (53.0 %) patients had inferior drainage while 32 (27.8 %) patients had superior drainage and 22 (19.2 %) patients had mixed venous drainage. Patients with inferior drainage had the fistulous connection at the foramen magnum while patients with superior drainage had a fistulous connection at C1-C2 (p value = 0.026). Patients with inferior drainage were more likely to present with myelopathy while patients with superior drainage presented with hemorrhage (p value = 0.000).

CONCLUSIONS

Classifying the venous drainage pattern is essential in making treatment decision. Transvenous embolization works best with large superior venous drainage. If endovascular treatment is not an option, then surgical clipping can achieve successful cure. Transarterial embolization is a reasonable option in cases with a large arterial feeder.

Dural arteriovenous fistula of the craniocervical junction along the first cervical nerve: A single-center experience and review of the literature

BACKGROUND

Dural arteriovenous fistulas (DAVFs) of the craniocervical junction (CCJ) are relative rare lesions. Most studies of DAVFs of the CCJ included the fistulas at the foramen magnum, first cervical (C1), and second cervical (C2) level. DAVFs of the CCJ along C1 spinal nerve are rare vascular lesions with distinctive features. Our aim is to review cases of DAVFs of the CCJ along C1 spinal nerve at our institution.

METHODS

From June 2008 and December 2021. We reviewed a consecutive series of intracranial and spinal DAVFs at our institution and collected all patients harboring DAVFs of the CCJ along C1 spinal nerve. Medical charts were retrospectively reviewed regarding patient demographic data (i.e., gender and age), presenting symptoms and signs, treatment methods, and neurological outcome and complications after treatment. All image studies, including cranial computed tomography (CT) scan, cervical magnetic resonance imaging, CT angiography, and digital subtraction angiography (DSA) with rotational CT angiography were analyzed by experienced neuroradiologists. The authors also review of the literature of DAVFs of the C1 spinal nerve.

RESULTS

The authors identified 7 patients, including 5 men (71.4 %) and 2 women (28.6 %) with median age 54 years, range 48-72 years. Subarachnoid hemorrhage (SAH) occurred in 5 (71.4 %) patients, and progressive myelopathy in 2 (28.6 %). All fistulas except one received blood supply from the radiculomeningeal branch of the VA at C1 level. Venous aneurysms, being the source of bleeding, were detected in all fistulas with SAH. All patients except one were treated by surgical management. One fistula was treated by balloon-assisted Onyx embolization. Most patients had good neurological outcome following surgery. Complete obliteration of all fistulas treated by surgery was confirmed by follow-up DSA obtained 1 week after surgery. Two patients developed temporary pain and spasm of the trapezius muscle after the surgery. One patient resulted in poor neurological outcome and died due to sepsis and acute upper gastrointestinal bleeding one month after failed embolization. For patients with SAH, only one patient required ventriculoperitoneal shunt.

CONCLUSIONS

DAVFs of the CCJ along the first spinal nerve are rare and a unique subtype of DAVFs at the CCJ. These fistulas account for 1.74 % of all intracranial and spinal DAVFs in the present study. SAH is the major manifestation of DAVFs at C1 spinal nerve that may be overlooked on routine initial DSA. Rotational CT angiography is useful for clarification of the angioarchitecture of these fistulas, including small feeding artery and venous varix. Surgical treatment by interruption of the intradural draining vein should be the treatment of choice for C1 spinal nerve DAVF.

The relationship between non-aneurysmal spontaneous subarachnoid hemorrhage and basilar tip anatomy

OBJECTIVE

Non-aneurysmal spontaneous subarachnoid hemorrhage (NASAH) has a good prognosis, but its cause has not been clearly identified. In this study, we assessed the clinical and radiological features of NASAH and suggested an anatomical relationship between the basilar tip anatomy and NASAH.

METHODS

From August 2013 to May 2020, 21 patients were diagnosed with NASAH at our institution. We evaluated the clinical features of NASAH. NASAH was classified into a perimesencephalic pattern and aneurysmal pattern according to the distribution of hemorrhage based on initial brain computed tomography. Digital subtraction angiography was used to classify the basilar tip anatomy into symmetric cranial fusion, symmetric caudal fusion, or asymmetric fusion types.

RESULTS

Of the 21 patients, twenty patients had a good clinical outcome (modified Rankin Scale (mRS) 1-2; Glasgow Outcome Scale (GOS) 4-5). These patients showed improvement in mRS and Glasgow Coma Scale (GCS) at the last follow-up (P=.003 and P=.016, respectively). Eighteen patients with NASAH (85.7%) had the caudal fusion type, and only three patients with NASAH (14.3%) had the cranial fusion type. Seven patients with the perimesencephalic pattern (77.8%) had the caudal fusion type, and eleven patients with the aneurysmal pattern (91.7%) had the caudal fusion type.

CONCLUSIONS

In NASAH patients, the caudal fusion tends to occur frequently among patients with basilar tip anatomy. In the case of the caudal fusion, the perforators around the basilar tip would be more susceptible to hemodynamic stress, which could contribute to the occurrence of NASAH.

Subarachnoid Hemorrhage of Unknown Cause: Distribution and Role of Imaging

Subarachnoid hemorrhage of unknown cause represents approximately 10% to 15% of nontraumatic subarachnoid hemorrhages. The key factors in determining the management strategy for a presumed nonaneurysmal subarachnoid hemorrhage are the distribution, location, and amount of subarachnoid blood. Hemorrhage distribution on computed tomography can be categorized as follows: perimesencephalic, diffuse, sulcal, and primary intraventricular. The extent of the workup required in determining the cause of hemorrhage depends on the distribution of blood. The authors review the potential causes, differential diagnoses, and acute and long-term follow-up strategies in patients with subarachnoid hemorrhage of unknown cause.

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

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

Pretruncal Nonaneurysmal Subarachnoid Hemorrhage with Underlying Hemophilia C

BACKGROUND

Pretruncal nonaneurysmal subarachnoid hemorrhage (PNSAH) accounts for 15%-12% of all case of subarachnoid hemorrhage. Its precise etiology is not yet established. Multiple theories and risk factors have been investigated to address the possible cause of this type of hemorrhage including basilar tip dissecting aneurysms, high spinal arteriovenous fistula, venous stenosis/hypertension or venous bleeding. Hereditary coagulopathies and hemophilias have rarely been reported in the literature as a potential cause of PNSAH.

CASE DESCRIPTION

Here, we reported a rare case of PNSAH with negative angiogram and magnetic resonance imaging who was also found to have hemophilia C (factor XI deficiency) confirmed by laboratory investigation. We also included a literature review of hereditary coagulopathies and their role as a possible cause of PNSAH.

CONCLUSIONS

Detailed medical history and physical examination of patients with PNSAH may lead to further hematologic evaluation for this group of patients, as in this case, and may reveal more cases of mild coagulopathy that require treatment.

Spinal Dural Arteriovenous Fistula: Imaging Features and Its Mimics

Spinal dural arteriovenous fistula (SDAVF) is the most common spinal vascular malformation, however it is still rare and underdiagnosed. Magnetic resonance imaging findings such as spinal cord edema and dilated and tortuous perimedullary veins play a pivotal role in the confirmation of the diagnosis. However, spinal angiography remains the gold standard in the diagnosis of SDAVF. Classic angiographic findings of SDAVF are early filling of radicular veins, delayed venous return, and an extensive network of dilated perimedullary venous plexus. A series of angiograms of SDAVF at different locations along the spinal column, and mimics of serpentine perimedullary venous plexus on MR images, are demonstrated. Thorough knowledge of SDAVF aids correct diagnosis and prevents irreversible complications.

Natural history and treatment of craniocervical junction dural arteriovenous fistulas

Dural arteriovenous fistulas (DAVFs) located at the craniocervical junction are rare vascular malformations with distinctive features, and their natural history and the optimal treatment strategy remains unclear. We retrospectively reviewed eight patients with craniocervical junction DAVF who were evaluated at our institution between 2009 and 2012. We also conducted a MEDLINE search for all reports of craniocervical junction DAVF between 1970 and 2013, and reviewed 119 patients from 56 studies. From a total of 127 patients, 46 (37.1%) presented with myelopathy, 53 (43.1%) with subarachnoid hemorrhage (SAH), and four (3.3%) with brainstem dysfunction. SAH was typically mild, most often Hunt and Hess Grade I or II (83.3%), and associated with ascending venous drainage via the intracranial veins (p<0.001). Higher rates of obliteration were observed after microsurgery compared to embolization. Overall, younger age (odds ratio [OR] 1.07; 95% confidence interval [CI] 1.01-1.12; p=0.011), hemorrhagic presentation (OR 0.17; 95% CI 0.06-0.50; p=0.001), and microsurgery (OR 0.23; 95% CI 0.08-0.6; p=0.004) were independently predictive of good outcome at the last follow-up. Microsurgery was the only independent predictor of overall improvement at the last follow-up (OR 4.35; 95% CI 1.44-13.2; p=0.009). Prompt diagnosis and microsurgical management, offering a greater chance of immediate obliteration, may optimize the outcomes for patients with craniocervical junction DAVF. Endovascular treatment is often not feasible due to lesion angioarchitecture, and is associated with a higher risk of lesion recanalization or recurrence. However, long term studies with newer embolic agents such as Onyx (ev3 Endovascular, Plymouth, MN, USA) are yet to be performed.

Dural arteriovenous fistulas at the craniocervical junction: a systematic review

Background

Dural arteriovenous fistulas (DAVFs) at the craniocervical junction are uncommon but clinically important abnormalities.

Objective

To investigate the clinical characteristics of patients with DAVFs at the craniocervical junction and assess angiographic features associated with bleeding at presentation.

Methods

We systematically reviewed the literature and searched PubMed and EMBASE for all relevant English language articles published between 1980 and 2014. The clinical presentation, angiographic characteristics, and treatment were assessed. The clinical differences between a subarachnoid hemorrhage (SAH) group and a non-SAH group were statistically examined.

Results

Fifty-six patients were identified after a review of the literature (mean age 55.6 years; male to female ratio=3:1). Twenty-one patients (37.5%) presented with hemorrhage including SAH and posterior fossa hemorrhage. There was no significant difference in patient age, sex, or location of the DAVF between the SAH group and the non-SAH group. Intracranial venous drainage was significantly associated with SAH (p<0.001). The presence of a varix was significantly associated with SAH (p=0.001). Open surgery had a significantly higher efficacy of initial complete obliteration than embolization (100% vs 71.4%, p<0.01).

Conclusions

DAVFs at the craniocervical junction are rare lesions, which often present with hemorrhage. Intracranial venous drainage and a venous varix are associated with increased risk of SAH. Surgical interruption of the feeding arteries or draining veins is an effective and reliable method for treating DAVFs at the craniocervical junction. Embolization is a feasible alternative to surgery in the treatment of selective DAVFs.

High cervical spinal subdural hemorrhage as a harbinger of craniocervical arteriovenous fistula: an unusual clinical presentation

BACKGROUND CONTEXT

Craniocervical dural arteriovenous fistula (dAVF) is rare as compared with the typical thoracolumbar dAVFs of the spine and usually presents with hemorrhagic manifestation, predominantly intracranial subarachnoid hemorrhage.

PURPOSE

We describe the first case of craniocervical dAVF with initial presentation as neck pain and spinal subdural hemorrhage.

STUDY DESIGN

Case report.

METHODS

We present the case of a 59-year-old woman who presented with sudden onset of neck pain at an outside institution emergency department (ED) and was discharged after negative cervical spine radiographs. Magnetic resonance imaging of the cervical spine performed because of persistent pain demonstrated presence of high cervical spinal subdural hematoma and she was managed conservatively. She subsequently presented to our ED a week later with headache and was found to have an intraventricular hemorrhage on computed tomography scan of the head, which on subsequent workup with an angiography revealed the presence of a craniocervical dAVF.

RESULTS

Surgical obliteration of the fistula was performed with use of intraoperative angiography as an adjunct to confirm complete fistula obliteration. She had an excellent clinical outcome with no deficits at her last follow-up at 9 months.

CONCLUSIONS

Even though hemorrhagic presentation is fairly common in craniocervical dAVFs, there is no report of a craniocervical dAVF presenting with spinal subdural hemorrhage. The present case further highlights the propensity of these vascular lesions to bleed and emphasizes the clinical importance of including these lesions in the differential diagnosis of hemorrhage in the vicinity of foramen magnum region, whether subarachnoid or subdural in location. Physicians treating spinal pathologies should be aware of this entity and clinical presentation, as an angiography needs to be considered in these cases to direct appropriate referral and treatment.

Nonaneurysmal perimesencephalic subarachnoid hemorrhage: diagnosis, pathophysiology, clinical characteristics, and long-term outcome

Patients with nonaneurysmal perimesencephalic subarachnoid hemorrhage (NAPSAH) have no discernible source for the bleeding and generally are considered to have a benign condition. Correctly diagnosing these patients is essential because a missed aneurysm can have catastrophic consequences. Those presenting with NAPSAH have a low risk of complications and better outcome than patients presenting with aneurysmal subarachnoid hemorrhage; however, a limited body of literature suggests that not all of these patients are able to return to their premorbid functional status. Clinical screens of cognitive status, such as the mini-mental status examination, suggest good recovery of these patients, although these tests may lack sensitivity for identifying deficits in this patient population. More comprehensive neuropsychologic testing in some studies has identified deficits in a wide range of cognitive domains at long-term follow-up in patients with NAPSAH. Because these patients often do not lose consciousness (and thus do not have substantial transient global ischemia) and they do not undergo a procedure for aneurysm repair, the cognitive sequelae can be explained by the presence of blood in the subarachnoid space. NAPSAH presents an opportunity to understand the effects of subarachnoid blood in a clinical setting.

Controversies and evolving new mechanisms in subarachnoid hemorrhage

Despite decades of study, subarachnoid hemorrhage (SAH) continues to be a serious and significant health problem in the United States and worldwide. The mechanisms contributing to brain injury after SAH remain unclear. Traditionally, most in vivo research has heavily emphasized the basic mechanisms of SAH over the pathophysiological or morphological changes of delayed cerebral vasospasm after SAH. Unfortunately, the results of clinical trials based on this premise have mostly been disappointing, implicating some other pathophysiological factors, independent of vasospasm, as contributors to poor clinical outcomes. Delayed cerebral vasospasm is no longer the only culprit. In this review, we summarize recent data from both experimental and clinical studies of SAH and discuss the vast array of physiological dysfunctions following SAH that ultimately lead to cell death. Based on the progress in neurobiological understanding of SAH, the terms "early brain injury" and "delayed brain injury" are used according to the temporal progression of SAH-induced brain injury. Additionally, a new concept of the vasculo-neuronal-glia triad model for SAH study is highlighted and presents the challenges and opportunities of this model for future SAH applications.

Spinal dural arteriovenous shunt presenting with intramedullary hemorrhage: case report

The authors report on a 49-year-old man with a thoracic spinal dural arteriovenous shunt (dAVS) in which rupture of a varix caused intramedullary hemorrhage. In the literature, patients with a thoracic dAVS predominantly present with congestive myelopathy; however, the patient featured in this report presented without increased deep tendon reflexes or muscle weakness, but instead with intermittent stabbing chest pain and paresthesia. Magnetic resonance images and angiograms demonstrated tortuous enlargement and the formation of a varix-like structure of the draining veins, features compatible with those of high-flow angiopathy. Recognition of this phenomenon is important in thoracic dAVS because intramedullary hemorrhage dramatically degrades outcome. A high index of clinical suspicion can prevent a similar case of thoracic dAVS from progressing to intramedullary hemorrhage.

[Spinal angiography : Anatomy, technique and indications]

Spinal angiography is a diagnostic modality requiring detailed knowledge of spinal vascular anatomy. The cervical spinal cord is supplied by the vertebral arteries while segmental arteries which are preserved from fetal anatomy, supply the thoracic and lumbar regions. As spinal angiography carries the risk of paraplegia the indications have to be considered very carefully. Nevertheless, spinal angiography should be performed if there is reason to suspect a spinal vascular malformation from magnetic resonance imaging (MRI).

Angiographic characteristics and treatment of cervical spinal dural arteriovenous shunts

Spinal DAVSs of the cervical level are rare lesions. The purpose of this study is to describe the clinical and angiographic characteristics of cervical spinal DAVSs. From a prospectively collected database including 449 cases of brain and spinal DAVSs, lesions located at the cervical level were selected. The clinical presentation, angiographic characteristics, and treatment outcome were assessed. Twelve cases of spinal DAVSs were identified at the level of the cervical spinal canal (male to female ratio = 8:4; mean age = 56.5 years). Five patients (41.7%) presented with hemorrhage including SAH (n = 4) and cerebellar hemorrhage (n = 1). Coincidental spinal DAVSs with cranial DAVSs or brain AVMs were noted in 5 cases (41.7%). The spinal DAVS was the symptomatic lesion in 10 cases and was incidentally discovered during evaluation for SAH from a coincidental lesion in 2 cases. Combined endovascular and surgical resection resulted in symptomatic improvement in 10 patients. In conclusion, DAVSs of the cervical spine are rare lesions which often present with hemorrhage and are frequently associated with complex coincidental vascular lesions. Combined endovascular and surgical treatment will result in good outcome.

Pre-mesencephalic subarachnoid hemorrhage: rupture of tiny aneurysms of the basilar artery perforator

PURPOSE

Subarachnoid hemorrhage (SAH) around the midbrain without evidence of aneurysm, a so-called perimesencephalic SAH, has been considered a typical nonaneurysmal SAH. Recently, we have encountered several patients with SAHs that could have been classified as having perimesencephalic SAH, but a common cause of the bleeding was demonstrated. In this article, we describe clinical and radiologic characteristics of these patients.

METHODS

Clinical and radiologic data from patients with spontaneous SAH (total number 339) who were treated at Seoul National University Bundang Hospital between May 2003 and December 2007 were reviewed.

RESULTS

Of the 13 patients that could be classified as having perimesencephalic SAH, three had common radiologic features that were distinct from others. On computed tomography, the main hemorrhage (hematoma) was found localized in front of the midbrain (interpeduncular and/or peduncular cistern). Angiographically, the cause of the bleeding was not seen on conventional views and rotational angiograms. In three-dimensional reconstructed angiographic images, very small-sized (tiny) aneurysmal lesions were visible at the origin of mesencephalic perforators from the basilar artery. All the aneurysms were positioned at the exact site corresponding to the pre-mesencephalic clots. Follow-up angiography was performed on the three patients and all showed complete disappearance of the lesions at 1 month, 15 months, and 16 months follow-up, respectively.

CONCLUSIONS

Based on our experience, we suggest a subtype of spontaneous SAH that has unique hemorrhage localization (pre-mesencephalic cistern), specific cause (tiny aneurysms at the origin of the mesencephalic perforator), and a common benign clinical course.

Dural arteriovenous fistulas draining into the petrosal vein or bridging vein of the medulla: possible homologs of spinal dural arteriovenous fistulas. Clinical article

OBJECT

Dural arteriovenous fistulas (DAVFs) with leptomeningeal venous reflux generally pose a high risk of aggressive manifestations including hemorrhage. Among DAVFs, there is a peculiar type that demonstrates direct drainage into the bridging vein rather than the dural venous sinus. The purpose of this study was to investigate the characteristics of DAVFs that drain directly into the petrosal vein or the bridging vein of the medulla oblongata.

METHODS

Eleven consecutive cases of DAVFs that drained directly into the petrosal vein and 6 that drained directly into the bridging vein of the medulla were retrospectively reviewed. These cases were evaluated and/or treated at Hospital de Bicêtre in Paris, France, over a 27-year period. A review of previously reported cases was also performed.

RESULTS

Both of these "extrasinusal"-type DAVFs demonstrated very similar characteristics. There was a significant male predominance (p < 0.001) for this lesion, and a significantly higher incidence of aggressive neurological manifestations including hemorrhage or venous hypertension than in DAVFs of the transverse-sigmoid or cavernous sinus (p < 0.001). This finding was considered to be attributable to leptomeningeal venous reflux. Regarding treatment, endovascular embolization (either transarterial or transvenous) is frequently difficult, and surgery may be an effective therapeutic choice in many instances.

CONCLUSIONS

Embryologically, both the petrosal vein and the bridging vein of the medulla are cranial homologs of the spinal cord emissary bridging veins that drain the pial venous network. The authors believe that DAVFs in these locations may be included in a single category with spinal DAVFs because of their similar clinical characteristics.

Onyx embolization of a thoracolumbar perimedullary spinal arteriovenous fistula in an infant presenting with subarachnoid and intraventricular hemorrhage

Identifying a source of spontaneous subarachnoid hemorrhage (SAH) or intraventricular hemorrhage (IVH) in patients with negative results on cranial angiographic imaging can be a diagnostic challenge. The authors present the case of a 14-month-old girl who presented with lethargy and spontaneous SAH and IVH, and later became acutely paraplegic. Except for the SAH and IVH, findings on neuroimages of the brain were normal. Magnetic resonance imaging revealed an intramedullary thoracolumbar spinal cord hemorrhage that was found to be associated with arterialized veins intraoperatively. Catheter-based diagnostic angiography identified a spinal perimedullary macroarteriovenous fistula (macro-AVF) that was completely embolized with Onyx, negating the need for further surgical intervention. The authors believe this to be the first reported case of a thoracolumbar perimedullary macro-AVF presenting with SAH and IVH. In addition, descriptions of Onyx embolization of a spinal AVF in the literature are rare, especially in pediatric patients.

Spinal vascular malformations in non-perimesencephalic subarachnoid hemorrhage

OBJECTIVE

In patients with non-traumatic subarachnoid hemorrhage (SAH) and no evidence for a cerebral aneurysm on angiography, a frequent cause of the hemorrhage is perimesencephalic hemorrhage or other cerebral vascular pathology. In some patients no cause is found. The exact incidence of a spinal vascular malformation (SVM) as the origin for the SAH is not known. We assessed the occurrence of SVM in angiogram-negative, non-perimesencephalic subarachnoid hemorrhage (NPSAH).

METHODS

47 patients (from a consecutive cohort of 632) were identified with an angiogramnegative, non-perimesencephalic subarachnoid hemorrhage and 42 of these were analyzed by performing MR-imaging of the complete spinal neuraxis with additional spinal angiography on indication.

RESULTS

In four patients a spinal vascular malformation was identified as the cause of the SAH, indicating an incidence of 9 % of SVM in NPSAH, and an incidence of 1 % of SVM in all patients with SAH.

INTERPRETATION

Systematic analysis of angiogram-negative, non-perimesencephalic subarachnoid hemorrhage by MR imaging of the complete spinal neuraxis yields a higher incidence of SVM than previously documented. We recommend MR imaging of the complete spinal neuraxis in patients with a non-perimesencephalic subarachnoid hemorrhage in whom no cause for the hemorrhage has been found.

Intracranial subarachnoid hemorrhage resulting from cervical spine dural arteriovenous fistulas: literature review and case presentation

Cervical dural arteriovenous fistulas (dAVFs) are a rare cause of intracranial subarachnoid hemorrhage (SAH) but should be considered when other sources are not found. Subarachnoid hemorrhage caused by dAVF is thought to occur as a result of venous hypertension in most cases. The clinical presentation, acute onset of severe headache, is similar to that in patients with other causes of SAH; however, severe neurological deficits (Hunt and Hess Grade IV and V SAH) have not been reported in SAH caused by cervical dAVFs. Patients with this type of SAH commonly report suboccipital headache, neck pain, and nausea, and thus these hemorrhages can be easily dismissed as perimesencephalic SAH. Vigilant evaluation with 4-vessel cerebral angiography, including selective catherization of both proximal vertebral arteries, should be performed. The practice of unilateral vertebral artery injection with reflux into the contralateral vertebral and posterior inferior cerebellar arteries has the potential to overlook cervical dAVF. Magnetic resonance imaging may be useful to evaluate for other causes of SAH but is probably not sensitive for the identification of a cervical dAVF. Surgical treatment of this lesion has an excellent outcome.

Straight sinus stenosis as a proposed cause of perimesencephalic non-aneurysmal haemorrhage

Perimesencephalic nonaneurysmal haemorrhage (PMNH), a term first coined in 1985, is a diagnosis of exclusion. It is considered a benign form of subarachnoid haemorrhage with a good prognosis and a low risk of rebleeding. Its precise aetiology has not yet been determined. Haemorrhage of venous origin has been proposed as a cause, and has been demonstrated to be associated with venous abnormalities of the basal vein of Rosenthal. We present a patient with PMNH in whom an 80% stenosis at the union of the vein of Galen with the straight sinus is demonstrated. We thus propose hypertensive venous rupture secondary to venous sinus stenosis as an alternative cause for PMNH.

Spinal arteriovenous shunts presenting as intracranial subarachnoid haemorrhage

Background

In approximately 5% of patients with intracranial subarachnoid haemorrhage (SAH), the cause is another than a ruptured aneurysm or perimesencephalic haemorrhage. One of these causes is a spinal arteriovenous shunt (SAVS). The aim of this study was to investigate the characteristics of patients with SAVS who present with intracranial SAH without symptoms and signs suggesting a spinal cause.

Methods

We systematically reviewed the literature and searched the SAH database of the University Medical Center Utrecht, The Netherlands, for patients with SAVS presenting with intracranial SAH and studied the characteristics of patients with SAVS whose clinical presentation mimicked intracranial SAH caused by rupture of a saccular aneurysm.

Results

Thirty-five patients were identified after a review of the literature. In our SAH database, comprising 2142 patients included in the period 1985–2004, we found one patient (0.05%, 95 % CI 0.006–0.3%). SAH due to SAVS occurred at any age (4–72 years). The SAVS was located at the craniocervical junction in 14 patients, at the cervical level in 11, and at the thoracolumbar level in the remaining 11 patients. The majority of patients (n = 26, 72%) had no disabling deficits at discharge or follow-up.

Conclusion

Rupture of a SAVS presenting as intracranial SAH is rare and can occur at any age. The SAVS can be located not only at the craniocervical junction or cervical level but also in the thoracolumbar region. Most patients with SAVS presenting as intracranial SAH have a good recovery.

Dural arteriovenous fistula of the lumbar spine presenting with subarachnoid hemorrhage. Case report and review of the literature

The authors report on a patient presenting with subarachnoid hemorrhage (SAH) that was initially attributed to an aneurysm of the right internal carotid artery. During surgical exploration and placement of a clip, however, it was observed that the aneurysm had not ruptured. Diagnostic workup including spinal magnetic resonance imaging revealed a vascular malformation of the lumbar spinal canal within a subarachnoid hematoma. Spinal angiography demonstrated a spinal dural arteriovenous fistula (DAVF) (Type I spinal arteriovenous malformation) with a feeding vessel arising from the L-4 radicular artery. In the literature, SAH due to spinal DAVFs is rare; only cases of dural fistulas of the craniocervical junction and the cervical spine have been reported. This is the first case of SAH that can be attributed to a lumbar DAVF. Although unusual even in cases of cervical DAVF, SAH as a presenting symptom may occur in spinal DAVF of any location. Nontraumatic SAH should not be prematurely attributed to the rupture of an intracranial aneurysm if the clinical findings and imaging results are inconclusive.