George Kwok Chu Wong

Intracranial Aneurysms: Midterm Outcome of Pipeline Embolization Device—A Prospective Study in 143 Patients with 178 Aneurysms

PURPOSE To evaluate the midterm clinical and angiographic outcomes after pipeline embolization device (PED) placement for treatment of intracranial aneurysms. MATERIALS AND METHODS This prospective nonrandomized multicenter study was approved by the review boards of all involved centers; informed consent was obtained. Patients (143 patients, 178 aneurysms) with unruptured saccular or fusiform aneurysms or recurrent aneurysms after previous treatment were included and observed angiographically for up to 18 months and clinically for up to 3 years. Study endpoints included complete aneurysm occlusion; neurologic complications within 30 days and up to 3 years; clinical outcome of cranial nerve palsy after PED placement; angiographic evidence of occlusion or stenosis of parent artery and that of occlusion of covered side branches at 6, 12, and 18 months; and clinical and computed tomographic evidence of perforator infarction. RESULTS There were five (3.5%) cases of periprocedural death or major stroke (modified Rankin Scale [mRS] > 3) (95% confidence interval [CI]: 1.3%, 8.4%), including two posttreatment delayed ruptures, two intracerebral hemorrhages, and one thromboembolism. Five (3.5%) patients had minor neurologic complications within 30 days (mRS = 1) (95% CI: 1.3%, 8.4%), including transient ischemic attack (n = 2), small cerebral infarction (n = 2), and cranial nerve palsy (n = 1). Beyond 30 days, there was one fatal intracerebral hemorrhage and one transient ischemic attack. Ten of 13 patients (95% CI: 46%, 93.8%) completely recovered from symptoms of cranial nerve palsy within a median of 3.5 months. Angiographic results at 18 months revealed a complete aneurysm occlusion rate of 84% (49 of 58; 95% CI: 72.1%, 92.2%), with no cases of parent artery occlusion, parent artery stenosis (<50%) in three patients, and occlusion of a covered side branch in two cases (posterior communicating arteries). Perforator infarction did not occur. CONCLUSION PED placement is a reasonably safe and effective treatment for intracranial aneurysms. The treatment is promising for aneurysms of unfavorable morphologic features, such as wide neck, large size, fusiform morphology, incorporation of side branches, and posttreatment recanalization, and should be considered a first choice for treating unruptured aneurysms and recurrent aneurysms after previous treatments. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120422/-/DC1.

Intravenous Magnesium Sulphate for Aneurysmal Subarachnoid Hemorrhage (IMASH) A Randomized, Double-Blinded, Placebo-Controlled, Multicenter Phase III Trial

Background and Purpose— Pilot clinical trials using magnesium sulfate in patients with acute aneurysmal subarachnoid hemorrhage have reported trends toward improvement in clinical outcomes. This Phase III study aimed to compare intravenous magnesium sulfate infusion with saline placebo among such patients. Methods— We recruited patients with aneurysmal subarachnoid hemorrhage within 48 hours of onset from 10 participating centers. The patients were randomly assigned to magnesium sulfate infusion titrated to a serum magnesium concentration twice the baseline concentration or saline placebo for 10 to 14 days. Patients and assessors were blinded to treatment allocation. The study is registered at www.strokecenter.org/trials (as Intravenous Magnesium Sulphate for Aneurysmal Subarachnoid Hemorrhage [IMASH]) and www.ClinicalTrials.gov (NCT00124150). Results— Of the 327 patients recruited, 169 were randomized to receive treatment with intravenous magnesium sulfate and 158 to receive saline (placebo). The proportions of patients with a favorable outcome at 6 months (Extended Glasgow Outcome Scale 5 to 8) were similar, 64% in the magnesium sulfate group and 63% in the saline group (OR, 1.0; 95% CI, 0.7 to 1.6). Secondary outcome analyses (modified Rankin Scale, Barthel Index, Short Form 36, and clinical vasospasm) also showed no significant differences between the 2 groups. Predefined subgroups included age, admission World Federation of Neurological Surgeons grade, pre-existing hypertension, intracerebral hematoma, intraventricular hemorrhage, location of aneurysm, size of aneurysm, and mode of aneurysm treatment. In none of the subgroups did the magnesium sulfate group show a better outcome at 6 months. Conclusions— The results do not support a clinical benefit of intravenous magnesium sulfate infusion over placebo infusion in patients with acute aneurysmal subarachnoid hemorrhage.

Flow diverters for treatment of intracranial aneurysms: current status and ongoing clinical trials.

The ultimate treatment goal for intracranial aneurysms is to reconstruct the vessel wall and correct the hemodynamic disturbance. A flow diverter is a stent placed in the parent artery to reduce blood flow in the aneurysm sac to the point of stagnation, gradual thrombosis, and neointimal remodeling to maintain outflow in the side branches and perforators. Here, we review the two commercially available flow diverters, the Pipeline Embolization Device (PED) and the SILK flow diverter (SFD). The rates of severe hemorrhagic complications have been reported to be 2% for the PED and 0.8% for the SFD. The results of studies completed thus far show that endovascular reconstruction with flow diverters is an effective treatment of wide-necked, fusiform, large, and giant unruptured intracranial aneurysms, with 5% to 10% of patients experiencing permanent major morbidity and mortality. The results of ongoing studies may resolve whether flow diverters can replace coil embolization for the treatment of all, or selected, intracranial aneurysms.

Intravenous magnesium sulfate after aneurysmal subarachnoid hemorrhage: a prospective randomized pilot study.

We performed a randomized, double-blind, pilot study on magnesium sulfate (MgSO4) infusion for aneurysmal subarachnoid hemorrhage (SAH). Sixty patients with SAH were randomly allocated to receive either MgSO4 80 mmol/day or saline infusion for 14 days. Patients also received intravenous nimodipine. Episodes of vasospasm were treated with hypertensive and hypervolemic therapy. Neurologic status was assessed 6 months after hemorrhage using the Barthel index and Glasgow Outcome Scale. Incidences of cardiac and pulmonary complications were also recorded. Patient characteristics, severity of SAH, and surgical treatment did not differ between groups. The incidence of symptomatic vasospasm decreased from 43% in the saline group to 23% in patients receiving MgSO4 infusion, but it did not reach statistical significance, P=0.06. For patients who had transcranial Doppler-detected vasospasm, defined as mean flow velocity >120 cm/s and a Lindegaard index >3, the duration was shorter in the magnesium group compared with controls (P<0.01). There was, however, no difference between groups in functional recovery or Glasgow Outcome Scale score. The incidence of adverse events such as brain swelling, hydrocephalus, and nosocomial infection was also similar in patients receiving MgSO4 or saline. In this small pilot study, MgSO4 infusion for aneurysmal SAH is feasible. On the basis of the preliminary data, a larger study recruiting approximately 800 patients is required to test for a possible neuroprotective effect of magnesium after SAH.

The unruptured intracranial aneurysm treatment score A multidisciplinary consensus

Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (vr*) (vr* = 0 indicating excellent agreement and vr* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1–4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1–4.4) for panel members and 4.5 (95% CI 4.3–4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1–4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9–4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (vr*) for both cohorts was 0.026 (95% CI 0.019–0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.

Early risk stratification of patients with major trauma requiring massive blood transfusion

BACKGROUND There is limited evidence to guide the recognition of patients with massive, uncontrolled hemorrhage who require initiation of a massive transfusion (MT) protocol. OBJECTIVE To risk stratify patients with major trauma and to predict need for MT. DESIGNS Retrospective analysis of an administrative trauma database of major trauma patients. A REGIONAL TRAUMA CENTRE: A regional trauma centres in Hong Kong. PATIENTS Patients with Injury Severity Score ≥ 9 and age ≥ 12 years were included. Burn patients, patients with known severe anemia and renal failure, or died within 24h were excluded. MAIN OUTCOME MEASURES Delivery of ≥ 10 units of packed red blood cells (RBC) within 24h. RESULTS Between 01/01/2001 and 30/06/2009, 1891 patients met the inclusion criteria. 92 patients required ≥ 10 units RBC within 24h. Seven variables which were easy to be measured in the ED and significantly predicted the need for MT are heart rate ≥ 120/min; systolic blood pressure ≤ 90 mm Hg; Glasgow coma scale ≤ 8; displaced pelvic fracture; CT scan or FAST positive for fluid; base deficit >5 mmol/L; hemoglobin ≤ 7 g/dL; and hemoglobin 7.1-10 g/dL. At a cut off of ≥ 6, the overall correct classification for predicting need for MT was 96.9%, with a sensitivity of 31.5% and specificity of 99.7%, and an incidence of MT of 82.9%. The area under the curve was 0.889. CONCLUSION A prediction rule for determining an increased likelihood for the need for massive transfusion has been derived. This needs validation in an independent data set.

Craniotomy and clipping of intracranial aneurysm in a stereoscopic virtual reality environment

OBJECTIVEThe release of results of International Subarachnoid Aneurysm Trial in 2003 caused a shift in the paradigm of management of ruptured intracranial aneurysms. The cases selected for microsurgical clipping nowadays are usually those patients with aneurysms that are not suitable for embolization, and are often complex and difficult. We devised an innovative application of operative planning and training for craniotomy and microsurgical clipping of intracranial aneurysms in a stereoscopic virtual reality environment. METHODSPatient-specific Digital Imaging and Communications in Medicine data from computed tomographic angiography of the intracranial circulation and cranium were transferred to the workstation (Dextroscope; Volume Interactions Pte. Ltd., Singapore, Singapore). An aneurysm clip database was loaded into the patient data set. Three-dimensional volume rendering was followed by data coregistration and fusion. RESULTSVirtual head positioning and craniotomy were carried out to simulate the microscopic visualization. Clip selection could be carried out with reference to the angle of application. This allows one to see the exposure and degree of obliteration of an aneurysm with the various angles of approach. CONCLUSIONThe virtual craniotomy and microsurgical clipping application simulated the operative environment. Its role in neurosurgical training is encouraging and should be further developed.

Clipping vs coiling of posterior communicating artery aneurysms with third nerve palsy

The authors investigated the evolution of third nerve palsy in patients with posterior communicating artery aneurysms who underwent coiling vs clipping. There was no statistical difference of complete third nerve palsy recovery in both treatments. Both techniques were of clinical benefit. Older age, diabetes, delayed interventions, and complete third nerve palsy at presentation indicated a poor prognosis for recovery.

Evaluation of cognitive impairment by the Montreal Cognitive Assessment in patients with aneurysmal subarachnoid haemorrhage: prevalence, risk factors and correlations with 3 month outcomes

Objective Identification of patients with aneurysmal subarachnoid haemorrhage (aSAH) with cognitive impairment is important for patient management (medical treatment, cognitive rehabilitation and social arrangements). The Montreal Cognitive Assessment (MoCA) is currently recommended over the Mini-Mental State Examination (MMSE) by the US National Institute of Neurological Disorder, in the chronic post-stroke setting. We hypothesised that the MoCA has a better correlation with functional outcome at 3 months than the MMSE. Methods We carried out a prospective observational study in Hong Kong over a 2 year period, recruiting patients aged 21–75 years with aSAH admitted within 96 h of ictus. The assessments included the modified Rankin Scale, Lawton Instrumental Activity of Daily Living (IADL), Short Form-36, MoCA and MMSE at 3 months after ictus. Analyses were carried out to compare MoCA with MMSE. Results 90 patients completed the 3 month assessments. Cognitive impairment (MoCA <26) was determined in 73% of patients at 3 months. Delayed cerebral infarction explained the 31–38% variance in cognitive outcomes (MMSE and MoCA) at 3 months. MoCA demonstrated good discrimination of favourable neurological and IADL outcomes similar to the MMSE in receiver operating characteristics curve analyses. Conclusions MoCA defined cognitive impairment was common at 3 months after aSAH and MoCA correlated with functional outcomes similar, but not superior, to the MMSE. The study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193).

Aneurysm recurrence after treatment of paraclinoid/ophthalmic segment aneurysms - A treatment-modality assessment

SummaryObject. The treatment of 21 paraclinoid/ophthalmic segment internal carotid artery aneurysms (PCOSAs) over a seven year period in a regional neurosurgical center was reviewed to assess the degree of obliteration and recurrence rate of these aneurysms after treatment by surgical and endovascular methods.Method and result. An assessment of the clinical notes, operation records and cerebral angiograms was made to evaluate the rate of residual and recurrent aneurysms after treatment and at follow-up. In the coiling group, the aneurysm recurrence rate was eight out of fifteen aneurysms (53%). Four recurrences were from previously totally occluded aneurysms. Out of the six surgical cases, five had follow-up angiography performed. All had stable occlusions of their aneurysms including one with subtotal occlusion. Two clipping procedures after previous coiling achieved total occlusion of aneurysm on follow-up angiography.Conclusion. Based on our case series we conclude that PCOSAs frequently recur after primary treatment. GDC coiling was associated with a higher rate of recurrent aneurysms when compared with surgical treatment. A review of the literature on the surgical and endovascular treatment of PCOSAs support this observation.