Stylianos K. Rammos

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 : Clinical article

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.

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.

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.

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.

Aneurysms Associated with Brain Arteriovenous Malformations

SUMMARY: Brain arteriovenous malformations are frequently associated with the presence of intracranial aneurysms at a higher-than-expected incidence based on the frequency of each lesion individually. The identification of intracranial aneurysms in association with AVMs has increased due to improvement in diagnostic techniques, particularly 3D and superselective conventional angiography. Intracranial aneurysms may confer a higher risk of hemorrhage at presentation and of rehemorrhage in patients with AVMs and therefore may be associated with a more unfavorable natural history. The association of AVMs and intracranial aneurysms poses important therapeutic challenges for practicing neurosurgeons, neurologists, and neurointerventional radiologists. In this report, we review the classification and radiology of AVM-associated intracranial aneurysms and discuss their clinical significance and implications for treatment.

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.

Changing Clinical and Therapeutic Trends in Tentorial Dural Arteriovenous Fistulas: A Systematic Review

BACKGROUND AND PURPOSE: Tentorial dural arteriovenous fistulas are characterized by a high hemorrhagic risk. We evaluated trends in outcomes and management of tentorial dural arteriovenous fistulas and performed a meta-analysis evaluating clinical and angiographic outcomes by treatment technique. MATERIALS AND METHODS: We performed a comprehensive literature search for studies on surgical and endovascular treatment of tentorial dural arteriovenous fistulas. We compared the proportion of patients undergoing endovascular, surgical, and combined endovascular/surgical management; the proportion of patients presenting with ruptured tentorial dural arteriovenous fistulas; and proportion of patients with good neurologic outcome across 3 time periods: 1980–1995, 1996–2005, and 2006–2014. We performed a random-effects meta-analysis, evaluating the rates of occlusion, long-term good neurologic outcome, perioperative morbidity, and resolution of symptoms for the 3 treatment modalities. RESULTS: Twenty-nine studies with 274 patients were included. The proportion of patients treated with surgical treatment alone decreased from 38.7% to 20.4% between 1980–1995 and 2006–2014. The proportion of patients treated with endovascular therapy alone increased from 16.1% to 48.0%. The proportion of patients presenting with ruptured tentorial dural arteriovenous fistulas decreased from 64.4% to 43.6%. The rate of good neurologic outcome increased from 80.7% to 92.9%. Complete occlusion rates were highest for patients receiving multimodality treatment (84.0%; 95% CI, 72.0%–91.0%) and lowest for endovascular treatment (71.0%; 95% CI, 56.0%–83.0%; P < .01). Long-term good neurologic outcome was highest in the endovascular group (89.0%; 95% CI, 80.0%–95.0%) and lowest for the surgical group (73.0%; 95% CI, 51.0%–87.0%; P = .03). CONCLUSIONS: Patients with tentorial dural arteriovenous fistulas are increasingly presenting with unruptured lesions, being treated endovascularly, and experiencing higher rates of good neurologic outcomes. Endovascular treatment was associated with superior neurologic outcomes but lower occlusion rates.

Flow diverters for intracranial aneurysms

Abstract The progressive establishment of endovascular management in treating intracranial aneurysms had lead to continuous technique advancements and development of innovative technologies. Flow diverters are “stent-like” devices currently used for complex unruptured aneurysms allowing endoluminal reconstruction of the parent artery and occlusion of the aneurysm sac. In the present article, we review the development of flow diversion devices through in vitro and in vivo studies to clinical practice and summarize recent clinical data.

Aberrant direct origin of the cerebellar arteries from the internal carotid artery

The persistence of carotid-basilar anastomoses is a well known but rare condition, with the trigeminal artery being the most common. Cerebellar arteries originating directly from the internal carotid artery are considered variants of the persistent trigeminal artery and are less known. The authors present 3 cases of anomalous origin of the cerebellar arteries from the internal carotid artery and a review of the literature to elucidate their etiology and clinical implications. Although these anatomic variants are often an incidental finding, their recognition is important to explain atypical clinical presentations and for preoperative planning of surgical and endovascular procedures.

Thrombosis of a fusiform intracranial aneurysm induced by overlapping neuroform stents: Case report - Commentary

OBJECTIVETo present a case of a true fusiform basilar artery aneurysm that underwent spontaneous thrombosis after placement of two overlapping Neuroform stents (Boston Scientific/Target, Fremont, CA). CLINICAL PRESENTATIONA 45-year-old woman with transient syncopal episodes experienced a fall and presented to the emergency room. Incidentally, a non-contrast head computed tomographic scan and digital subtraction angiography demonstrated an unruptured, fusiform mid-basilar artery aneurysm. INTERVENTIONEndovascular treatment was initiated by using a stent-assisted coil embolization technique with placement of a self-expanding, dedicated intracranial, Neuroform stent in the basilar artery across the aneurysms fusiform neck. Attempts to access the aneurysm for coil embolization resulted in transient migration of the stent into the aneurysm sac. A second Neuroform stent was advanced in telescoping fashion for salvage and stable coverage across the entire aneurysm; therefore, coil embolization was deferred to allow stent endothelialization. After 6 weeks on dual antiplatelet therapy, the patient presented with transient ischemic symptoms suggesting top of the basilar artery syndrome. Subsequent magnetic resonance imaging scans and angiography indicated circumferential thrombus formation in the aneurysm sac but patent flow in the basilar artery. A computed tomographic scan at 6 months and digital subtraction angiography at 12 months confirmed complete thrombosis of the fusiform mid-basilar artery aneurysm with basilar artery reconstruction. CONCLUSIONOverlapping Neuroform stents may induce spontaneous thrombosis of intracranial aneurysms and facilitate parent artery reconstruction through flow remodeling and stent endothelialization. Double stent placement may be a viable option in dissecting or fusiform intracranial aneurysms that are not amenable to open surgical treatment or endovascular coil embolization.