Angiographic Evaluation of Cranial Venous Outflow Patterns in Patients With and Without Idiopathic Intracranial Hypertension.

BACKGROUND: Several collateral venous pathways exist to assist in cranial venous drainage in addition to the internal jugular veins. The important extrajugular networks (EJN) are often readily identified on diagnostic cerebral angiography. However, the angiographic pattern of venous drainage through collateral EJN has not been previously compared among patients with and without idiopathic intracranial hypertension (IIH). OBJECTIVE: To quantify EJN on cerebral angiography among patients both with and without IIH and to determine whether there is a different EJN venous drainage pattern in patients with IIH. METHODS: Retrospective imaging review of 100 cerebral angiograms (50 IIH and 50 non-IIH patients) and medical records from a single academic medical center was performed by 2 independent experienced neuroendovascular surgeons. Points were assigned to EJN flow from 0 to 6 using an increasing scale (with each patient's dominant internal jugular vein standardized to 5 points to serve as the internal reference). Angiography of each patient included 11 separately graded extrajugular networks for internal carotid and vertebral artery injections. RESULTS: Patients in the IIH group had statistically significant greater flow in several of the extrajugular networks. Therefore, they preferentially drained through EJN compared with the non-IIH group. Right transverse-sigmoid system was most often dominant in both groups, yet there was a significantly greater prevalence of codominant sinus pattern on posterior circulation angiograms. CONCLUSION: Patients with IIH have greater utilization of EJN compared with patients without IIH. Whether this is merely an epiphenomenon or possesses actual cause-effect relationships needs to be determined with further studies.

Onyx extrusion through the scalp after embolization of dural arteriovenous fistula.

A man in his sixties referred with symptoms of episodic left lip numbness and left arm weakness was diagnosed with a Borden type 3 dural arteriovenous fistula (DAVF) on DSA. Successful Onyx embolization of the DAVF was performed via the distal left occipital artery using an ev3 Apollo detachable tip microcatheter. He underwent surgical obliteration for the residual DAVF 3 days later. Three months later during a routine postoperative clinic visit, the patient produced a plastic bag containing multiple small pieces of Onyx cast and the detached tip of the Apollo microcatheter that had extruded out from his scalp through small spontaneous holes about 5 weeks after the embolization procedure. This spontaneous extrusion of Onyx can be alarming to the patient not expecting it; however, prior knowledge and discussion can lessen the anxiety of both the treating physician and the patient dealing with such a situation.

Onyx extrusion through the scalp after embolization of dural arteriovenous fistula.

A man in his sixties referred with symptoms of episodic left lip numbness and left arm weakness was diagnosed with a Borden type 3 dural arteriovenous fistula (DAVF) on DSA. Successful Onyx embolization of the DAVF was performed via the distal left occipital artery using an ev3 Apollo detachable tip microcatheter. He underwent surgical obliteration for the residual DAVF 3 days later. Three months later during a routine postoperative clinic visit, the patient produced a plastic bag containing multiple small pieces of Onyx cast and the detached tip of the Apollo microcatheter that had extruded out from his scalp through small spontaneous holes about 5 weeks after the embolization procedure. This spontaneous extrusion of Onyx can be alarming to the patient not expecting it; however, prior knowledge and discussion can lessen the anxiety of both the treating physician and the patient dealing with such a situation.

Flow failure from intracranial atherosclerotic disease: a rationale for endovascular intervention in a population with recurrent symptoms despite maximal medical therapy.

The Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) trial, the first randomized trial to compare best medical therapies with angioplasty and stenting, was halted prematurely owing to a 30-day stroke rate of 14.7% in the angioplasty and stenting arm compared with 5.8% in the medical management arm. These results have led to a paradigm shift away from interventional therapies and back to dual antiplatelet therapy and aggressive medical therapies only for these patients. However, there appears to be a subset of patients with intracranial atherosclerotic disease (ICAD) who are different from the general SAMMPRIS cohort and are defined by flow failure from severe intracranial arterial stenosis resulting in recurrent ischemic symptoms despite maximal medical therapy. Offering the option of endovascular revascularization seems appropriate in this patient population, given their recurrent ischemic events regardless of aggressive medical therapies. This paper provides a rationale for reconsidering the role of interventional therapies in patients with critical intracranial stenosis and presents four patients with flow failure from ICAD and persistent symptoms of ischemia, regardless of dual antiplatelet and adjuvant medical therapies, who subsequently improved with angioplasty. Consideration of alternative patient populations and treatment paradigms seems to carry particular relevance now as the endovascular treatment of intracranial atheromatous disease is currently receiving intense scrutiny by those medical specialties involved in the care of stroke patients, as well as the public at large.

CT perfusion-guided patient selection for endovascular recanalization in acute ischemic stroke: a multicenter study.

BACKGROUND: The treatment of acute ischemic stroke is traditionally centered on time criteria, although recent evidence suggests that physiologic neuroimaging may be useful. In a multicenter study we evaluated the use of CT perfusion, regardless of time from symptom onset, in patients selected for intra-arterial treatment of ischemic stroke. METHODS: Three medical centers retrospectively assessed stroke patients with a National Institute of Health Stroke Scale of ≥ 8, regardless of time from symptom onset. CT perfusion maps were qualitatively assessed. Patients with defined salvageable penumbra underwent intra-arterial revascularization of their occlusion. Functional outcome using the modified Rankin Score (mRS) was recorded. RESULTS: Two hundred and forty-seven patients were selected to undergo intra-arterial treatment based on CT perfusion imaging. The median time from symptom onset to procedure was 6 h. Patients were divided into two groups for analysis: ≤ 8 h and >8 h from symptom onset to endovascular procedure. We found no difference in functional outcome between the two groups (42.8% and 41.9% achieved 90-day mRS ≤ 2, respectively (p=1.0), and 54.9% vs 55.4% (p=1.0) achieved 90-day mRS ≤ 3, respectively). Overall, 48 patients (19.4%) had hemorrhages, of which 20 (8.0%) were symptomatic, with no difference between the groups (p=1.0). CONCLUSIONS: In a multicenter study, we demonstrated similar rates of good functional outcome and intracranial hemorrhage in patients with ischemic stroke when endovascular treatment was performed based on CT perfusion selection rather than time-guided selection. Our findings suggest that physiologic imaging-guided patient selection rather than time for endovascular reperfusion in ischemic stroke may be effective and safe.

Simulator based angiography education in neurosurgery: results of a pilot educational program.

INTRODUCTION: The use of simulators in medical training has been on the rise over the past decade as a means to teach procedural skills to trainees in a risk free environment. The goal of this study was to pilot a simulator based skills course for inexperienced neurosurgical residents to teach the fundamentals of cervicocerebral catheterization and angiography, with the ultimate goal of defining a universal simulator based curriculum that could be incorporated into neurosurgical resident training in the future. METHODS: Seven neurosurgery residents with no prior angiographic experience served as the pilot participants for this 2 day course. Four neurointerventional trained neurosurgeons served as faculty for instruction and evaluation. The majority of the course focused on hands-on simulator practice with close mentoring by faculty. Participants were evaluated with pre-course and post-course assessments. RESULTS: Post-course written test scores were significantly higher than pre-course scores (p<0.001). Faculty assessments of participants' technical skills with angiography (graded 0-10, with 10 being best) also improved significantly from pre-course to post-course (pre 2.1; post 5.9; p<0.001). Objective simulator recorded assessments demonstrated a significant decrease in the time needed to complete a four vessel angiogram (p<0.001) and total fluoroscopic time (p<0.001). CONCLUSIONS: Participant angiography skills, based on both faculty and simulator assessments, as well as participant knowledge, improved after this didactic, hands-on simulator course. Neuroendovascular simulator training appears to be a viable means of training inexperienced neurosurgery residents in the early learning stages of basic endovascular neurosurgery. Further studies evaluating the translation of procedural skills learned on the simulator to actual clinical skills in the angiography suite is necessary.

Does rural Mississippi have access to emergency neurosurgical care?

Acute neurosurgical emergencies are a potentially devastating occurrence requiring prompt evaluation and intervention by a neurosurgeon. Current consensus for acute subdural hematoma evacuation recommends a maximum time period of four hours from injury to operation; other injuries require prompt evaluation by a neurosurgeon but do not have soundly supported recommendations. Rural hospitals, such as Field Memorial Community Hospital in Centreville, MS, transfer acutely injured neurosurgical patients to centers with neurosurgical capability after initial stabilization. We report our experience with neurosurgical transfer patients and examine times from injury to arrival at neurosurgical care centers after being stabilized and transferred from Field Hospital.