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.

"Live cadavers" for training in the management of intraoperative aneurysmal rupture.

OBJECT: Intraoperative rupture occurs in approximately 9.2% of all cranial aneurysm surgeries. This event is not merely a surgical complication, it is also a real surgical crisis that requires swift and decisive action. Neurosurgical residents may have little exposure to this event, but they may face it in their practice. Laboratory training would be invaluable for developing competency in addressing this crisis. In this study, the authors present the "live cadaver" model, which allows repetitive training under lifelike conditions for residents and other trainees to practice managing this crisis. METHODS: The authors have used the live cadaver model in 13 training courses from 2009 to 2014 to train residents and neurosurgeons in the management of intraoperative aneurysmal rupture. Twenty-three cadaveric head specimens harboring 57 artificial and 2 real aneurysms were used in these courses. Specimens were specially prepared for this technique and connected to a pump that sent artificial blood into the vessels. This setting created a lifelike situation in the cadaver that simulates live surgery in terms of bleeding, pulsation, and softness of tissue. RESULTS: A total of 203 neurosurgical residents and 89 neurosurgeons and faculty members have practiced and experienced the live cadaver model. Clipping of the aneurysm and management of an intraoperative rupture was first demonstrated by an instructor. Then, trainees worked for 20- to 30-minute sessions each, during which they practiced clipping and reconstruction techniques and managed intraoperative ruptures. Ninety-one of the participants (27 faculty members and 64 participants) completed a questionnaire to rate their personal experience with the model. Most either agreed or strongly agreed that the model was a valid simulation of the conditions of live surgery on cerebral aneurysms and represents a realistic simulation of aneurysmal clipping and intraoperative rupture. Actual performance improvement with this model will require detailed measurement for validating its effectiveness. The model lends itself to evaluation using precise performance measurements. CONCLUSIONS: The live cadaver model presents a useful simulation of the conditions of live surgery for clipping cerebral aneurysms and managing intraoperative rupture. This model provides a means of practice and promotes team management of intraoperative cerebrovascular critical events. Precise metric measurement for evaluation of training performance improvement can be applied.

Endovascular management of intracranial dural arteriovenous fistulae.

Endovascular embolization is the primary therapeutic modality for intracranial dural arteriovenous fistulae. Based on access route, endovascular treatment can be schematically divided into transarterial, transvenous, combined, and direct/percutaneous approaches. Choice of access route and technique depends primarily on dural arteriovenous fistulae angioarchitecture, pattern of venous drainage, clinical presentation, and location. Individualized endovascular approaches result in a high degree of cure with a reasonably low complication rate.

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.

Conversion of external ventricular drains to ventriculoperitoneal shunts after aneurysmal subarachnoid hemorrhage: effects of site and protein/red blood cell counts on shunt infection and malfunction.

OBJECT: The purpose of this study was to determine the incidence of shunt infection in patients with subarachnoid hemorrhage (SAH) after converting an external ventricular drain (EVD) to a ventriculoperitoneal (VP) shunt using the existing EVD site. The second purpose was to assess the risk of shunt malfunction after converting the EVD to a permanent shunt irrespective of the cerebrospinal fluid (CSF) protein and red blood cell (RBC) counts. METHODS: Data obtained in 80 consecutive adult patients (18 men and 62 women, mean age 60.8 years, range 33-85 years) who underwent direct conversion of an EVD to a VP shunt for post-SAH hydrocephalus between August 2002 and March 2007 were retrospectively reviewed. In each patient, the existing EVD site was used to pass the proximal shunt catheter. In no patient was VP shunt insertion delayed based on preoperative RBC or protein counts. RESULTS: The mean period of external ventricular drainage before VP shunt placement was 14.1 days (range 3-45 days). No patient suffered ventriculitis. The mean perioperative CSF protein level was 124 mg/dl (range 17-516 mg/dl). The mean and median perioperative RBC values in CSF were 14,203 RBCs/mm(3) and 4600 RBCs/mm(3) (range 119-290,000/mm(3)), respectively. No patient was lost to follow-up. The mean follow-up duration was 24 months (range 2-53 months). Three patients (3.8%) had shunt malfunction related to obstruction of the shunt system after 15 days, 2 months, and 18 months, respectively. There were no shunt-related infections. No patient suffered a clinically significant hemorrhage from ventricular catheter placement after VP shunt insertion. CONCLUSIONS: In adult patients with aneurysmal SAH, conversion of an EVD to a VP shunt can be safely done using the same EVD site. In this defined patient population, protein and RBC counts in the CSF do not seem to affect shunt survival adversely. Thus, conversion of an EVD to VP shunt should not be delayed because of an elevated protein or RBC count.

Successful endovascular treatment of a ruptured mycotic intracavernous carotid artery aneurysm in an AIDS patient.

INTRODUCTION: As the medical treatment for human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) continues to advance, the HIV-related aneurysms may pose a clinical problem of increasing magnitude. The authors report on a successfully treated ruptured mycotic intracavernous carotid artery aneurysm case in an AIDS patient. METHODS: This 41-year-old AIDS patient presented with severe epistaxis. His head CT revealed acute blood in the left sphenoid sinus with bony erosion of the lateral wall (Fig. 1). The cerebral angiogram demonstrated a quite irregularly shaped intracavernous carotid artery aneurysm with proximal arterial stenosis (Fig. 2). RESULTS: After balloon test occlusion, this aneurysm was trapped endovascularly with detachable balloons (Fig. 3). The blood culture was positive for Aspergillus. The patient died 2 years later from other AIDS-related causes. CONCLUSION: The cerebral aneurysms in HIV/AIDS patients can be generally categorized into two groups: the mycotic aneurysms from bacterial or fungal infections and the HIV-associated aneurysms as a distinct entity. To plan appropriate interventions, a high degree of clinical suspicion must be exercised to promptly recognize the mycotic nature of many HIV-related aneurysms.