Zilver stent versus Carotid Wallstent for endovascular treatment of idiopathic intracranial hypertension.

BACKGROUND: Venous sinus stenting (VSS) is a promising treatment option for medically refractory idiopathic intracranial hypertension (IIH). There are no published studies comparing the performance of different types of stents employed in VSS procedures. In this study we aimed to compare the safety and efficacy outcomes of the Zilver 518 (Cook Medical, Bloomington, Indiana, USA) and the Carotid Wallstent (Boston Scientific, Marlborough, Massachusetts, USA) devices. METHODS: Records of patients with IIH who underwent VSS between January 2015 and February 2022 at a single referral center were retrospectively reviewed. Patients treated with the Zilver stent or Carotid Wallstent were included in the study. Stent model and size data, pre- and post-treatment pressure gradients, technical and safety outcomes, and pre- and post- stenting papilledema, headache, and tinnitus severity were collected. The χ2 and Fisher-Freeman-Halton tests were used for categorical data and the Student's t-test and Mann-Whitney U test were employed to examine the differences in non-categorical variables. RESULTS: A total of 81 procedures (28 (34.5%) with the Zilver stent and 53 (65.5%) with the Carotid Wallstent) were performed in 76 patients. The mean procedure time was significantly shorter with the Zilver stent (22.56±10.2 vs 33.9±15 min, p=0.001). The papilledema improvement and resolution rates did not significantly differ between groups (94.7% vs 94.5%, p>0.99 for improvement; 78.9% vs 67.5%, p=0.37 for resolution). The tinnitus improvement and resolution rates in the Zilver stent group were significantly higher than those of the Carotid Wallstent group (100% vs 78.9%, p=0.041; 90% vs 63.1%, p=0.03, respectively). Additionally, the Zilver stent provided a significantly higher rate of headache resolution and improvement than the Carotid Wallstent (84.6% vs 27.6%, p=0.001 for resolution; 92.3% vs 72.3%, p=0.043 for improvement). One patient from the Carotid Wallstent group underwent re-stenting due to in-stent stenosis and refractory papilledema. No significant in-stent stenosis was observed in the Zilver stent group. CONCLUSION: Stent choice may affect VSS outcomes. The Zilver stent provided better clinical outcomes than the Carotid Wallstent, with significantly shorter procedure times. Larger studies are needed to determine the efficacy of available venous stents for IIH.

The Lateral Mesencephalic Vein: Surgical Anatomy and Its Role in the Drainage of Tentorial Dural Arteriovenous Fistulae.

BACKGROUND: The lateral mesencephalic vein (LMV) represents an important connection between the infratentorial and supratentorial compartments. It joins the basal vein of Rosenthal and the petrosal system. In our experience with management of tentorial dural arteriovenous fistulas (DAVFs) we have often noted involvement of the lateral mesencephalic vein (LMV) in the venous drainage of these fistulas. METHODS: We reviewed the clinical and angiographic findings of 26 patients with tentorial DAVFs to study the incidence and pattern of drainage through the LMV. In addition, we reviewed the pertinent literature on the anatomy of the LMV. RESULTS: The LMV was involved in the venous drainage of 31% (8/26) of patients with tentorial DAVFs. The direction of venous drainage through the LMV is more commonly from the infratentorial to the supratentorial compartment. There were no specific clinical symptoms/signs associated with tentorial DAVFs involving the LMV compared with those without LMV involvement. When involved in DAVF drainage, the LMV could be invariably identified on noninvasive imaging studies. We present illustrative clinical/angiographic cases and provide a detailed review of the pertinent clinical anatomy of this important but often neglected intracranial vein. CONCLUSIONS: The LMV is a constant venous anastomosis between the supratentorial and infratentorial compartments. Detailed knowledge of the most common variations of the LMV surgical and radiological anatomy has important clinical implications. The vein is an important anatomic landmark during surgery of midbrain lesions. It is often involved in the tentorial DAVF drainage, and it is critical in understanding some "unexpected" venous complications during surgery for posterior fossa lesions.

Successful rheolytic mechanical thrombectomy of cerebral venous thrombosis in a pediatric patient.

Thrombosis of the deep cerebral venous system is associated with a significant risk of morbidity and mortality in the pediatric population. Anticoagulation is the mainstay of current treatment of cerebral venous thrombosis (CVT). Systemic or local delivery of thrombolytics may be used in cases of inexorable progression of CVT and neurological compromise. Mechanical thrombectomy has been described in adult patients with CVT and may offer the added advantage of accelerated thrombolysis in the face of rapid clinical deterioration. In this report the authors describe the use of rheolytic mechanical thrombectomy in a pediatric patient with extensive dural sinus and deep CVT.

Anterior communicating artery aneurysm rupture after intravenous thrombolysis for acute middle cerebral artery thromboembolism: case report.

BACKGROUND AND IMPORTANCE: The use of intravenous recombinant tissue plasminogen activator (IV rtPA) has become an integral part of modern acute ischemic stroke management; however, its use has been associated with the development of intracranial hemorrhage in 6.4% of patients. It is possible that underlying and unsuspected vascular lesions, such as cerebral aneurysms, may lead to intracranial hemorrhage after IV rtPA thrombolysis. CLINICAL PRESENTATION: We present a previously unreported case of a 51-year-old woman who presented with subarachnoid hemorrhage from an acutely ruptured anterior communicating artery aneurysm after IV rtPA treatment for acute left middle cerebral artery thromboembolism. The patient underwent mechanical thromboembolectomy of the left middle cerebral artery occlusion with resultant TIMI (Thrombolysis In Myocardial Infarction) grade I recanalization, followed by coil embolization of the anterior communicating artery aneurysm. The patient never improved neurologically, and she ultimately died. CONCLUSION: Screening to identify patients at risk for development of hemorrhagic complications from underlying structural vascular lesions before the use of IV rtPA with computed tomography angiography should be considered.

The putative role of the venous system in the genesis of vascular malformations.

Recent clinical and experimental evidence has challenged the traditional concept of the venous system as a "passive" element in the genesis and evolution of intracranial vascular malformations. The authors review the clinical and experimental evidence linking the venous system and its anomalies to the genesis of various intracranial vascular malformations, including dural arteriovenous fistulas, cavernous malformations, parenchymal arteriovenous malformations, and capillary telangiectasia. They also describe the potential significance of different associations of these vascular anomalies.

Schwannoma of the vagus nerve, a rare middle mediastinal neurogenic tumor: case report.

Schwannoma originating from the vagus nerve within the mediastinum is a rare, usually benign tumor. A 44-year old male was presented with chest pain. Chest radiography, CT scan and MRI showed a well circumscribed mass, 5 x 4 cm located in the aortopulmonary window. The mass was found at surgery to be in close proximity with the aortic arch and the left pulmonary hilum, alongside the left vagus nerve. The encapsulated tumor was completely resected through a left thoracotomy incision and it was found to be a benign schwannoma in pathology. The patient is free of recurrence 6 years after surgery.

Developmental venous anomalies: current concepts and implications for management.

Developmental venous anomalies (DVAs), formerly known as venous angiomas, have become the most frequently diagnosed intracranial vascular malformation. DVAs are currently considered congenital cerebrovascular anomalies with mature venous walls that lack arterial or capillary elements. They are composed of radially arranged medullary veins, which converge in an enlarged transcortical or subependymal collector vein, and have characteristic appearances (caput medusae) on magnetic resonance imaging and angiography. DVAs were once thought to be rare lesions with substantial potential for intracerebral hemorrhage and considerable morbidity. The prevalence of incidental and asymptomatic DVAs has been more apparent since the advent of magnetic resonance imaging; recent cohort studies have challenged the once-held view of isolated DVAs as the cause of major neurological complications. The previously reported high incidence of intracerebral hemorrhage associated with DVAs is currently attributed to coexistent, angiographically occult cavernous malformations. Some patients may still have noteworthy neurological morbidity or die as a result of acute infarction or hemorrhage directly attributed to DVA thrombosis. DVAs can coexist with cavernous malformations and arteriovenous malformations. Such combination or transitional forms of malformations might suggest common pathways in pathogenesis. Recent data support a key role for DVAs in the pathogenesis of mixed vascular malformations.

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 catheterization 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.