Roham Moftakhar

Thromboembolic complications with Pipeline Embolization Device placement: impact of procedure time, number of stents and pre-procedure P2Y12 reaction unit (PRU) value.

Background Thromboembolic events after Pipeline Embolization Device (PED) placement remain a feared complication among neuroendovascular surgeons. This study aimed to investigate potential risk factors for thromboembolic events in patients undergoing PED placement. Methods Medical records of patients who underwent PED placement from April 2011 to August 2013 were reviewed. Variables including pre-procedure P2Y12 reaction unit (PRU) value, procedure time, number of PEDs deployed and perioperative neurovascular complications were recorded. Multivariate analysis was performed to identify risk factors for perioperative thromboembolic complications. Results Seventy-four patients were identified. Six patients (8.1%) had changes in neurological status after PED placement including five (6.8%) thromboembolic complications and one (1.4%) delayed intracranial hemorrhage; 50.9% of patients had diffusion-weighted imaging (DWI) changes on post-procedural MRI. Longer procedure time (>116 min) and multiple PED placements (>1) were statistically significant risk factors for symptomatic thromboembolic events (p<0.01). A pre-procedural PRU value >208 had an OR of 11.32 (95% CI 0.06 to 212.57) for symptomatic thromboembolic complications, but the result was not statistically significant. Conclusions DWI changes on MRI occurred at a much higher rate than new neurological symptoms following PED placement. Longer procedure time and multiple PED deployment are associated with higher risks of new neurological changes due to thromboembolic events. There was a trend for an increased risk of a symptomatic thromboembolic event in patients with pre-procedural PRU values >208. Reloading (clopidogrel 600 mg) patients with preoperative PRU >208 was safe and may have a protective effect on thromboembolic events.

Noninvasive Measurement of Intra-Aneurysmal Pressure and Flow Pattern Using Phase Contrast with Vastly Undersampled Isotropic Projection Imaging

BACKGROUND AND PURPOSE: Currently, more reliable parameters to predict the risk of aneurysmal rupture are needed. Intra-aneurysmal pressure gradients and flow maps could provide additional information regarding the risk of rupture. Our hypothesis was that phase contrast with vastly undersampled isotropic projection reconstruction (PC-VIPR), a novel 3D MR imaging sequence, could accurately assess intra-aneurysmal pressure gradients in a canine aneurysmal model when compared with invasive measurements. MATERIALS AND METHODS: A total of 13 surgically created aneurysms in 8 canines were included in this study. Pressure measurements were performed in the parent vessel, aneurysm neck, and 5 regions within the aneurysmal sac with a microcatheter. PC-VIPR sequence was used to obtain cardiac-gated velocity measurements in a region covering the entire aneurysm. The velocity and pressure gradient maps derived from the PC-VIPR data were then coregistered with the anatomic DSA images and compared with catheter measurements. RESULTS: In 7 of the bifurcation aneurysms, the velocity flow maps demonstrated a recirculation flow pattern with a small neck-to-dome pressure gradient (mean, +0.5 mm Hg). In 1 bifurcation aneurysm, a flow jet extending from the neck to the dome with significantly greater pressure gradient (+50.2 mm Hg) was observed. All sidewall aneurysms had low flow in the sac with intermediate pressure gradients (mean, +8.3 mm Hg). High statistical correlation existed between PC-VIPR aneurysmal pressures and microcatheter pressure measurements (R = 0.82, P < .01). CONCLUSION: PC-VIPR can provide anatomic as well as noninvasive quantitative and qualitative hemodynamic information in the canine aneurysm model. The PC-VIPR intra-aneurysmal pressure measurements correlated well with catheter measurements.

Feasibility and Safety of Pipeline Embolization Device in Patients With Ruptured Carotid Blister Aneurysms

BACKGROUND Treatment of internal carotid ruptured blister aneurysms (IC-RBA) presents many challenges to neurosurgeons because of the high propensity for rebleeding during intervention. The role of a Pipeline Embolization Device (PED) in the treatment of this challenging aneurysm subtype remains undefined despite theoretical advantages. OBJECTIVE To present a series of 11 patients treated with a PED and to discuss the management and results of this novel application of flow diverters. METHODS Medical records of patients who presented with IC-RBA from May 2011 to March 2013 were retrospectively reviewed at 6 institutions in the United States. All relevant data were independently compiled. RESULTS A total of 12 IC-RBAs in 11 patients were treated during the study period. Nine (75%) were treated with a single PED; 1 was treated with 2 PEDs; 1 was treated with coils and 1 PED; and 1 was treated with coils and 2 PEDs. Three (27%) had major perioperative complications: middle cerebral artery territory infarction, vision loss, and death. Seven patients demonstrated complete obliteration of the aneurysm in postoperative imaging. Early clinical outcomes were favorable (modified Rankin Scale score, 0-2) in all 10 survivors. CONCLUSION This study demonstrates the feasibility and safety of using the PED to treat IC-RBA with fair initial results. The proper introduction and management of antiplatelet regimen are key for successful results. Bleeding complications related to dual antiplatelet therapy were similar to those in previous studies of stent-assisted coiling for the same population. Larger cohort analysis is needed to define the precise role of flow diverters in the treatment of IC-RBA.

Solitaire flow restoration thrombectomy for acute ischemic stroke: Retrospective multicenter analysis of early postmarket experience after FDA approval

BACKGROUND The promising results of the Solitaire Flow Restoration (FR) With the Intention for Thrombectomy (SWIFT) trial recently led to Food and Drug Administration (FDA) approval of the Solitaire FR stent retriever device for recanalization of cerebral vessels in patients with acute ischemic stroke. OBJECTIVE To report the early postmarket experience with this device since its FDA approval in the United States, which has not been previously described. METHODS We conducted a retrospective analysis of consecutive acute ischemic strokes cases treated between March 2012 and July 2012 at 10 United States centers where the Solitaire FR was used as a single device or in conjunction with other intraarterial endovascular approaches. RESULTS A total of 101 patients were identified (mean age, 64.7 years; mean admission National Institutes of Health Stroke Scale [NIHSS] score, 17.6). Intravenous thrombolysis was administered in 39% of cases; other endovascular techniques were utilized in conjunction with the Solitaire FR in 52%. Successful recanalization (Thrombolysis in Myocardial Infarction 2/3) was achieved in 88%. The rate of symptomatic intracranial hemorrhage within the first 24 hours was 15%. In-hospital mortality was 26%. At 30 days, 38% of patients had favorable functional outcome (modified Rankin scale score ≤2). Severity of NIHSS score on admission was a strong predictor of poor outcome. CONCLUSION Our study shows that a variety of other endovascular approaches are used in conjunction with Solitaire FR in actual practice in the United States. Early postmarket results suggest that Solitaire FR is an effective tool for endovascular treatment of acute ischemic stroke.

The Pipeline Embolization Device for the treatment of posterior circulation fusiform aneurysms: lessons learned at a single institution

OBJECT Vertebrobasilar fusiform aneurysms (VFAs) are rare lesions characterized by abnormal dilation and tortuosity of the vertebral and/or basilar arteries. Untreated, these aneurysms have a tendency to progress, often resulting in neurological symptoms or rupture leading to subarachnoid hemorrhage. The microsurgical treatment of these lesions can be difficult due to their location and the circumferential involvement of the arteries. These features make microsurgical treatment prone to high morbidity. The Pipeline Embolization Device (PED) has gained popularity for the treatment of aneurysms of the internal carotid artery. Its use in the posterior circulation has been limited, likely due to a fear of perforating artery occlusion. METHODS The authors retrospectively reviewed their database of patients treated with the PED and identified 12 patients who had VFAs. The clinical features, complications, and outcomes of these patients were analyzed. RESULTS At an average follow-up of 11 months, the mean modified Rankin Scale score was 1.9. Complete aneurysm occlusion was seen in 90% of the patients with radiographic follow-up. Three patients suffered new neurological deficits postoperatively. One of these patients died, while the remaining 2 demonstrated significant clinical improvement at follow-up. CONCLUSIONS With attention to the anatomy of perforating arteries, staged contralateral vertebral artery sacrifice, and adequate platelet inhibition, PED may be an effective treatment option-alone or in a hybrid construct with stents of less coverage for VFAs-with an acceptable complication rate.

Clinical, radiological, and genetic similarities between patients with Chiari Type I and Type 0 malformations

OBJECT Although Chiari Type I (CM-I) and Type 0 (CM-0) malformations have been previously characterized clinically and radiologically, there have been no studies focusing on the possible genetic link between these disorders. The goal of this study was to identify families in whom CM-0 and CM-I co-occurred and to further assess the similarities between these disorders. METHODS Families were ascertained through a proband with CM-I. Detailed family histories were obtained to identify first-degree relatives diagnosed with CM-0. Several criteria were used to exclude individuals with acquired forms of CM-I and/or syringomyelia. Individuals were excluded with syndromic, traumatic, infectious, or tumor-related syringomyelia, as well as CM-I due to a supratentorial mass, hydrocephalus, history of cervical or cranial surgery unrelated to CM-I, or development of symptoms following placement of a lumbar shunt. Medical records and MR images were used to characterize CM-I and CM-0 individuals clinically and radiologically. RESULTS Five families were identified in which the CM-I proband had a first-degree relative with CM-0. Further assessment of affected individuals showed similar clinical and radiological features between CM-0 and CM-I individuals, although CM-I patients in general had more severe symptoms and skull base abnormalities than their CM-0 relatives. Overall, both groups showed improvement in symptoms and/or syrinx size following craniocervical decompression surgery. CONCLUSIONS There is accumulating evidence suggesting that CM-0 and CM-I may be caused by a common underlying developmental mechanism. The data in this study are consistent with this hypothesis, showing similar clinical and radiological features between CM-0 and CM-I individuals, as well as the occurrence of both disorders within families. Familial clustering of CM-0 and CM-I suggests that these disorders may share an underlying genetic basis, although additional epigenetic and/or environmental factors are likely to play an important role in the development of CM-0 versus CM-I.

Treatment of a Ruptured Vertebrobasilar Fusiform Aneurysm Using Pipeline Embolization Device

Treatment options of ruptured vertebrobasilar fusiform aneurysms (VFA) are limited and often carry significant mortality and morbidity. We report the use of Pipeline Embolization Device (PED) to successfully treat a patient with a ruptured vertebrobasilar fusiform aneurysm (VFA) who presented with subarachnoid hemorrhage (SAH). A 73 year-old man with a history of cardiac stent placement seven days earlier presented with Hunt-Hess II SAH. He was taking aspirin and clopidogrel. Computed tomography angiogram revealed a large vertebrobasilar fusiform aneurysm. Microsurgical treatment options are technically challenging and carry high risk. He underwent endovascular treatment of the ruptured VFA using overlapping PEDs. Five PEDs were placed in a telescoping fashion to reconstruct the affected portions of the left vertebral and basilar arteries. An additional 2-mm blister aneurysm in the right vertebral artery was also discovered during the conventional cerebral angiography and was treated with one additional PED. The patient remained neurologically intact after the procedure. He was continued on aspirin and clopidogrel. Follow-up magnetic resonance imaging at three months demonstrated patency of the stents without any evidence of ischemic change. Follow-up conventional cerebral angiogram at six months demonstrated thrombosis of the VFA and reconstruction of the vertebrobasilar system. The patient remained clinically well. An endovascular approach using PEDs can be a safe and effective treatment option for ruptured VFA in selected cases.

Microsurgical anatomy of the supracerebellar transtentorial approach to the posterior mediobasal temporal region: technical considerations with a case illustration.

OBJECTIVE Surgical access to the posterior portion of the mediobasal temporal lobe presents a formidable challenge to neurosurgeons, and much controversy still exists regarding the selection of the surgical approach to this region. The supracerebellar transtentorial (SCTT) approach to the posterior mediobasal temporal region can be used as an alternative to the subtemporal or transtemporal approaches. The aim of this study was to demonstrate the surgical anatomy of the SCTT approach and review the gyral, sulcal, and vascular anatomy of the posterior mediobasal temporal lobe. The use of this approach in the resection of a ganglioglioma located in the left posterior parahippocampal gyrus is illustrated. METHODS The SCTT approach to the posterior parahippocampal gyrus was performed on three silicone-injected cadaveric heads. The gyral, sulcal, and arterial anatomy of the posterior mediobasal temporal lobe was studied in six formalin-fixed injected hemispheres. RESULTS The SCTT approach provided a direct path to the posterior mediobasal temporal lobe and exposed the posterior parahippocampal gyrus as well as the adjacent gyri in all of the cadaveric specimens. Through this approach, gross total resection of the ganglioglioma was possible in our patient. CONCLUSION The SCTT approach provided a viable surgical route to the posterior mediobasal temporal lobe in the cadaveric studies. This approach provides an advantage over the subtemporal and transtemporal routes in that there is less temporal lobe retraction.

Outcome following intracranial hemorrhage associated with novel oral anticoagulants

The emergence of dabigatran, rivaroxaban and apixaban has changed the approach to anticoagulation for patients worldwide. Continued approval of novel oral anticoagulants (NOAC) for non-valvular atrial fibrillation and venous thromboembolism will result in increasing use of these medications over warfarin. Morbidity and mortality of anticoagulant related intracranial hemorrhage (ICH) is relatively high and there is concern that outcomes may be worse with NOAC as there is a lack of specific antidotes for these agents with a greater risk for hematoma expansion. Unfortunately, the evidence supporting effective reversal strategies is lacking. Therefore, to gain further insight into the outcome after the management of NOAC related ICH, we present our experience with two patients with NOAC-induced ICH.

Evaluation of a Metal Artifacts Reduction Algorithm Applied to Postinterventional Flat Panel Detector CT Imaging

BACKGROUND AND PURPOSE: Flat panel detector CT images are degraded by streak artifacts caused by radiodense implanted materials such as coils or clips. A new metal artifacts reduction prototype algorithm has been used to minimize these artifacts. The application of this new metal artifacts reduction algorithm was evaluated for flat panel detector CT imaging performed in a routine clinical setting. MATERIALS AND METHODS: Flat panel detector CT images were obtained from 59 patients immediately following cerebral endovascular procedures or as surveillance imaging for cerebral endovascular or surgical procedures previously performed. The images were independently evaluated by 7 physicians for metal artifacts reduction on a 3-point scale at 2 locations: immediately adjacent to the metallic implant and 3 cm away from it. The number of visible vessels before and after metal artifacts reduction correction was also evaluated within a 3-cm radius around the metallic implant. RESULTS: The metal artifacts reduction algorithm was applied to the 59 flat panel detector CT datasets without complications. The metal artifacts in the reduction-corrected flat panel detector CT images were significantly reduced in the area immediately adjacent to the implanted metal object (P = .05) and in the area 3 cm away from the metal object (P = .03). The average number of visible vessel segments increased from 4.07 to 5.29 (P = .1235) after application of the metal artifacts reduction algorithm to the flat panel detector CT images. CONCLUSIONS: Metal artifacts reduction is an effective method to improve flat panel detector CT images degraded by metal artifacts. Metal artifacts are significantly decreased by the metal artifacts reduction algorithm, and there was a trend toward increased vessel-segment visualization.