Faculty Bibliography

UNLABELLED:Abstract: BACKGROUND AND PURPOSE/OBJECTIVE:To summarize the theoretical background and existing technical achievements of flow modification techniques in the treatment of intracranial aneurysms. The evolution of the concept of flow modification for aneurysm treatment is overviewed within the published literature on application of stents for aneurysms. The newest achievements using dedicated flow modifying devices is discussed. Reconstruction of laminar flow within intracranial arteries harboring aneurysms is feasible. Reorientation of flow using dedicated flow modifying devices is a highly effective technique in the treatment of large, broad neck, otherwise untreatable aneurysms.

OBJECTIVE: The Pipeline embolization device (PED; Chestnut Medical, Menlo Park, CA) is a new endovascular construct designed to exclude aneurysms from the parent cerebrovasculature. We report the results of the first two human implantations of this device in North America. CLINICAL PRESENTATION: Two patients presenting with large, symptomatic, circumferential, fusiform intracranial vertebral artery aneurysms were treated with the PED. In both cases, more traditional open microneurosurgical and neuroendovascular treatment strategies had either failed or were associated with unacceptably high risk. INTERVENTION: Three PEDs were placed across the aneurysms in each of the patients to achieve reconstruction of a new parent vessel through the center of a circumferential aneurysm. In the first patient, who had previously been treated with stent-supported coil embolization, the PED construct alone was sufficient to achieve parent vessel reconstruction and exclusion of the recurrent aneurysm. In the second patient, a microcatheter was jailed within the saccular portion of the aneurysm and the parent vessel was reconstructed with three telescoped PEDs. Although the PED construct dramatically reduced flow into the aneurysm, the lesion remained patent. Coiling of the saccular portion of the aneurysm was subsequently performed via the jailed microcatheter. Follow-up angiography performed 72 hours after the procedure demonstrated occlusion of the aneurysm with cylindrical reconstruction of the affected vascular segment. Neither patient has experienced any complication in the periprocedural period (30 d) or during subsequent long-term (>1 year) follow-up. CONCLUSION: The PED represents an important advance in the endovascular therapy of cerebral aneurysms, targeting primary parent vessel reconstruction rather than endosaccular occlusion as a means by which to achieve exclusion of the aneurysm and definitive anatomic reconstruction of the parent artery

PURPOSE: To report a wide-necked renal artery aneurysm treated successfully with stent-assisted Gugliemi detachable coil occlusion, assisted by three-dimensional (3-D) angiography. CASE REPORT: A 56-year-old woman with history of hypertension presented with a 2.5-cm wide-necked saccular aneurysm involving her distal right renal artery. A balloon-expandable stent was positioned across the neck of the aneurysm and multiple Gugliemi detachable coils were deployed through a microcatheter inserted through the interstices of the stent into the aneurysm sac, guided by 3-D angiography. Follow-up 3-D angiography at 6 months revealed a patent renal artery with continued exclusion of the aneurysm and preservation of renal blood flow. CONCLUSION: Stent-assisted coil occlusion assisted by 3-D angiography is a potential renal-sparing endovascular approach to treating wide-necked renal artery aneurysms with complex vascular anatomy

BACKGROUND AND PURPOSE: Despite availability of an approved drug to treat acute cerebral ischemia, most patients with stroke do not realize a good outcome. A method that would rapidly increase or restore cerebral perfusion before irreversible cell death should improve patient outcomes. MATERIALS AND METHODS: We recently had the opportunity to treat 6 middle-aged-to-elderly patients who presented with signs and symptoms of acute cerebral ischemia, by mechanically removing their (predominantly) middle cerebral artery clots by using a new retrieval device that had been previously approved by the US Food and Drug Administration for intravascular retrieval of foreign bodies. During a 2-month period, the 6 patients were treated in 5 separate institutions. No patient had an unsuccessful attempt at clot removal. The cases were collected by personal communication with each operator. RESULTS: In all instances, use of the device resulted in rapid clot removal. Each patient had a large improvement in National Institutes of Health Stroke Scale score. Two of the 6 patients had experienced failure of another clot retrieval device, and 3 patients required no systemic thrombolytics, reducing the likelihood of one of the most feared complications of stroke therapy, intracranial hemorrhage. SUMMARY: We believe that use of this device may result in improved outcomes for patients with acute ischemic stroke. In our limited experience, it provided a rapid, safe, and effective means for achieving revascularization

OBJECTIVE: The purposes of this article are to summarize recent developments and concerns in endovascular aneurysm therapy leading to the adjunctive use of endoluminal devices, to review the published literature on stent-supported coil embolization of cerebral aneurysms, and to describe our experience with this technique in a limited subgroup of problematic complex aneurysms over a medium-term follow-up period. METHODS: Between January 2003 and June 2004, 28 individuals among 157 patients with cerebral aneurysms we evaluated were identified as harboring aneurysms with exceptionally broad necks. Out of these 28 patients, 16 were treated with a combination of stents and detachable coils, preserving the parent artery. Recorded data included patient demographics, the clinical presentation, aneurysm location and characteristics, procedural details, and clinical and angiographic outcome. RESULTS: Over an 18-month period, 16 patients with large cerebral aneurysms additionally characterized by neck sizes between 7 and 14 mm were treated, using combined coil embolization of the aneurysm with stent reconstruction of the aneurysm neck. Thirteen out of the 16 aneurysms were occluded at angiographic reevaluation between 11 and 24 months (mean angiographic follow-up, 17.5 mo). There were no treatment-related deaths or clinically evident neurological complications. Thirteen patients experienced excellent clinical outcomes, with good outcomes in two patients and a poor visual outcome in one patient (mean clinical follow-up, 29 mo). A single technical complication occurred, involving transient nonocclusive stent-associated thrombus, which was treated uneventfully with abciximab. CONCLUSION: Stent-supported coil embolization of large, complex-neck cerebral aneurysms seems to provide superior medium-term anatomic reconstruction of the parent artery compared with historic series of aneurysms treated exclusively with endosaccular coils. In the near future, increasingly sophisticated endoluminal devices offering higher coverage of the neck defect will likely enable more definitive endovascular treatment of complex cerebral aneurysms and further expand our ability to manipulate the vascular biology of the parent artery

Spinal cord arteriovenous malformations are rare lesions that represent one-tenth of the brain arteriovenous malformations. Depending on their location and relationship to the dura, these lesions are divided into four categories. Their clinical manifestations may vary from mild symptoms to severe motor deficits. Spinal angiography remains the 'gold standard' for diagnosing spinal cord vascular lesions. Although the type of shunting remains difficult to determine by the magnetic resonance imaging, it is well analyzed by spinal angiography. The cure of the shunting is not by itself a therapeutic goal, but the objective is the creation of a new hemodynamic equilibrium between the lesion and the spinal cord to decrease the risk of hemorrhage and prevent the progression of the spinal cord ischemia. The endovascular tools seem to be a reasonable therapeutic option for the treatment of the majority of the spinal cord arteriovenous malformations

BACKGROUND Ruptured intracranial aneurysms are associated with a high risk of permanent neurological impairment or death. Evidence suggests that detachable coils can be used to treat ruptured aneurysms safely and effectively; however, data regarding their long-term efficacy is sparse. OBJECTIVE To determine the frequency of late rebleeding of ruptured intracranial aneurysms after treatment with detachable coils. DESIGN AND INTERVENTION In this retrospective study that was conducted over 8 years, 393 consecutive patients (70% female, 30% male) with a ruptured aneurysm were treated with a detachable coil and followed up to determine the incidence of late rebleeding-defined as recurrent hemorrhage from a coiled aneurysm >1 month after coiling. Using angiography, treatment outcomes were classified as complete occlusion (98-100%), near-complete occlusion (90-98%) or incomplete occlusion (<90%). Patients were followed up clinically 6 weeks after initial discharge, and underwent angiographic follow-up at 6 months and 18 months. Further appropriate treatment was undertaken if incomplete occlusion was discovered at any time during the follow-up period. At the time of initial coiling, the mean patient age was 52.9 years (range 2581 years). In total, 63% of patients were classified as Hunt and Hess (HH) Stroke Scale I-II, 21% were HH III and 16% were HH IV-V. The majority of treated ruptured aneurysms were located in the anterior communicating artery (n = 123), the basilar tip (n = 85) or the posterior communicating artery (n = 68). OUTCOME MEASURES The primary outcome was the number of patients to experience late rebleeding after coiling of a ruptured aneurysm. A secondary outcome was the number of patients to require follow-up treatment for aneurysms. RESULTS Clinical data was available for 392 of the 393 patients. The total follow-up duration was 18,708 months, or 1,559 patient-years (mean 47.7 months, range 0-120 months). During follow-up, 70 patients (17.8%) died; deaths were attributed to various factors including subarachnoid hemorrhage (n=23), unrelated causes (n=21) and procedural complications of coiling (n = 11). Mortality associated with late rebleeding was 0.76% (n=3), giving an annual late-rebleeding mortality rate of 0.19% (95% Cl 0.04-0.60%). The late-rebleeding incidence was 1.27% (n=5), giving an annual late-rebleed rate of 0.32% (95% Cl 0.12-0.78%). The median size of the original aneurysm in patients with late rebleeding was 17 mm, compared with 8 mm in patients without late rebleeding (P=0.0017). Late rebleeding occurred in 3 of 366 (0.82%) patients with complete initial aneurysm occlusion, and 2 of 27 patients (7.41%) with incomplete initial occlusion (P=0.04). Additional treatment was required for 53 (13%) coiled aneurysms during the follow-up period. There was no significant difference in the median ages and gender ratios between patients who experienced late rebleeding and those who did not. CONCLUSION Coiling of ruptured aneurysms is associated with a very low rate of rebleeding. Angiographic follow-up reveals incomplete initial occluded aneurysms that might require additional treatment

OBJECTIVE: To examine the relationship between the degree of handedness and hemispheric language dominance in patients with epilepsy. METHODS: The authors examined the relationship between degree of handedness and hemispheric language dominance in 174 epilepsy surgery candidates using the intracarotid amobarbital procedure and results from a modified version of the Edinburgh Handedness Inventory. RESULTS: The incidence of atypical language dominance increased linearly with the degree of left-handedness, from 9% in strong right-handers (laterality quotient [LQ] = +100) to 46% in ambidextrous individuals and 69% in strong left-handers (LQ = -100). CONCLUSIONS: The incidence of atypical language dominance depends not only on the direction but also on the degree of handedness. In addition, direction of language dominance varies with hemisphere of seizure focus and degree of handedness. A familial history of sinistrality may have an additional effect on the likelihood of atypical dominance

We report the case of a patient with an acute middle cerebral artery occlusion emergently revascularized with a Neuroform self-expanding stent

OBJECTIVE AND IMPORTANCE/OBJECTIVE:Locked-in syndrome is a state of preserved consciousness in the setting of quadriplegia, anarthria, and usually also includes lateral gaze palsy. It is most commonly associated with upper brainstem infarction variably sparing the third cranial nerve nucleus. There are likely many etiologies that contribute to this clinical syndrome. These are incompletely understood, and the syndrome remains a rare but devastating complication that can occur after neurosurgical and neurovascular interventions. Advanced magnetic resonance imaging techniques such as perfusion and diffusion tensor imaging may help to elucidate the mechanism behind locked-in syndrome. To the authors' knowledge, there are no reports in the literature of perfusion and diffusion tensor findings in patients with this syndrome. A postprocedural case of locked-in syndrome is described with abnormalities on perfusion and diffusion tensor imaging in the absence of any changes in conventional magnetic resonance imaging. CLINICAL PRESENTATION/METHODS:A 57-year-old man who presented with acute onset headache, ataxia, and other nonspecific symptoms was found on imaging to have a giant fusiform basilar artery aneurysm. INTERVENTION/METHODS:A saphenous vein graft bypass between the proximal right external carotid artery and P2 segment of the right posterior cerebral artery followed immediately by endovascular embolization of the aneurysm sac and distal left vertebral artery was performed. CONCLUSION/CONCLUSIONS:Postprocedural angiography demonstrated patency of the bypass graft, and diffusion weighted imaging showed no evidence for acute brainstem infarction. Nevertheless, despite technically successful procedures and the absence of abnormalities on conventional magnetic resonance imaging, the patient developed quadriplegia and anarthria and remained in a locked-in state until he expired. Abnormalities were, however, seen on both perfusion and diffusion tensor imaging, where hypoperfusion, increased mean diffusivity, and decreased fractional anisotropy were observed in the ventral brainstem. The findings suggested a disruption of pontine white matter tracts. Advanced imaging techniques may allow us to image important microstructural changes that were previously not discernable and assist in the evaluation of patients with complex neurological sequelae such as locked-in syndrome.