Faculty Bibliography

This article discusses the vascular anatomy of the vertebra-spinal axis and covers such topics as vascular supply to the spine, spinal dura, and paraspinal musculature; vascular supply to the spinal cord; and spinal veins

Dural arteriovenous fistulas are characterized by abnormal arteriovenous shunting localized to the pachymeninges. Fistulae venous drainage is essential to their classification, symptomatology, and treatment. Endovascular therapy is rapidly progressing to an adjunct or even alternative treatment to microsurgical resection. Several techniques, such as transarterial or transvenous embolization with metallic coils, NBCA, or Onyx, have been used successfully in several studies. The long-term clinical and radiographic outcomes of endovascular therapy for the treatment of dural arteriovenous fistulas are satisfactory, and future studies are underway for the refinement of these techniques

Endovascular, endosaccular, coil embolization has emerged as an established therapy for both ruptured and unruptured cerebral aneurysms. However, many aneurysms are not cured using conventional endovascular techniques. Coil embolization often results in incomplete aneurysm occlusion or recanalization in the ensuing months after treatment. The Pipeline embolization device (PED; Chestnut Medical) represents a new generation endoluminal implant which is designed to treat aneurysms by reconstructing the diseased parent artery. Immediately after implantation, the PED functions to divert flow from the aneurysm, creating an environment conducive to thrombosis. With time, the PED is incorporated into the vessel wall as neointimal-endothelial overgrowth occurs along the construct. Ultimately, this process results in the durable complete exclusion of the aneurysm from the cerebrovasculature and a definitive endoluminal reconstruction of the diseased parent artery

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

BACKGROUND AND PURPOSE: Concurrent temporary inflation of a nondetachable balloon in the parent artery has been reported to be useful during endovascular coiling of complex, wide-neck aneurysms, facilitating truer coil reconstruction of the native vessel. Nevertheless, there exists concern that adjunctive use of balloon assistance may lead to increased adverse events during aneurysm coiling. MATERIALS AND METHODS: A literature search of all of the unassisted and balloon-remodeling studies published between 1997 and 2006 was conducted with application of strict selection criteria based on the reporting of complication incidence and outcome. The final cohort was analyzed to determine rates and clinical outcomes of iatrogenic aneurysm rupture and thromboembolism. Additional data were collected on the degree of initial and follow-up aneurysm occlusion rates. RESULTS: A total of 83 potential studies (4973 patients) were identified, from which 23 articles reporting results for 867 traditional-unassisted and 273 balloon-assisted coiled aneurysms met inclusion criteria for the analysis of thromboembolic complications, and 21 articles with 993 routinely coiled and 170 balloon-remodeled aneurysms were eligible for iatrogenic perforation analysis. No statistically significant difference was found in the rates of thromboembolism. Iatrogenic perforation rates were also comparable, though the overall numbers were too few for meaningful statistical analysis. Both initial and follow-up aneurysm occlusion rates were higher in balloon-assisted cases. CONCLUSION: This largest-to-date literature review and meta-analysis did not demonstrate a higher incidence of thromboembolic events or iatrogenic rupture with the use of adjunctive balloon remodeling compared with unassisted coiling. Balloon remodeling appears to result in higher initial and follow-up aneurysm occlusion rates

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

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

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.

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