Faculty Bibliography

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

OBJECTIVES: The Pipeline embolization device (PED) (Chestnut Medical Technologies, Inc., Menlo Park, CA) is a new microcatheter-delivered endovascular construct designed to achieve the curative reconstruction of the parent arteries giving rise to wide-necked and fusiform intracranial aneurysms. We present our initial periprocedural experience with the PED and midterm follow-up results for a series of 53 patients. METHODS: Patients harboring large and giant wide-necked, nonsaccular, and recurrent intracranial aneurysms were selected for treatment. All patients were pretreated with dual antiplatelet medications for at least 72 hours before surgery and continued taking both agents for at least 6 months after treatment. A control digital subtraction angiogram was typically performed at 3, 6, and 12 months. RESULTS: Fifty-three patients (age range, 11-77 years; average age, 55.2 years; 48 female) with 63 intracranial aneurysms were treated with the PED. Small (n = 33), large (n = 22), and giant (n = 8) wide-necked aneurysms were included. A total of 72 PEDs were used. Treatment was achieved with a single PED in 44 aneurysms, with 2 overlapping PEDs in 17 aneurysms, and with 3 overlapping PEDs in 2 aneurysms. The mean time between the treatment and last follow-up digital subtraction angiogram was 5.9 months (range, 1-22 months). Complete angiographic occlusion was achieved in 56%, 93%, and 95% of aneurysms at 3 (n = 42), 6 (n = 28), and 12 (n = 18) months, respectively. The only aneurysm that remained patent at the time of the 12-month follow-up examination had been treated previously with stent-supported coiling. The presence of a preexisting endoluminal stent may have limited the efficacy of the PED reconstruction in this aneurysm. No aneurysms demonstrated a deterioration of angiographic occlusion during the follow-up period (i.e., no recanalizations). No major complications (stroke or death) were encountered during the study period. Three patients (5%), all with giant aneurysms, experienced transient exacerbations of preexisting cranial neuropathies and headache after the PED treatment. All 3 were treated with corticosteroids, and these symptoms resolved within 1 month. CONCLUSION: Endovascular reconstruction with the PED represents a safe, durable, and curative treatment of selected wide-necked, large and giant cerebral aneurysms. The rate of complete occlusion at the time of the 12-month follow-up examination approached 100% in the present study. To date, no angiographic recurrences have been observed during serial angiographic follow-up

OBJECTIVE: To demonstrate the curative reconstruction of a giant circumferential basilar trunk aneurysm using the Pipeline embolization device (PED) (Chestnut Medical Technologies, Inc., Menlo Park, CA) alone, without embolization coils. METHODS: A 13-year-old female patient was referred for the treatment of a 4-cm, partially thrombosed, circumferential midbasilar trunk aneurysm. Her presenting symptoms included headache, nystagmus, and left upper-extremity ataxia. Open surgical and conventional endovascular treatment options were thought to be of unacceptably high risk and unlikely to achieve a definitive treatment. The patient underwent PED treatment under a Food and Drug Administration compassionate use exemption. RESULTS: An endovascular construct was built across the affected segment of the basilar trunk with 7 serially placed, telescoping PEDs, which bridged the 29-mm aneurysm neck. Completion angiography demonstrated considerably decreased flow into the aneurysm, with stasis persisting into the venous phase of angiography. No technical complications were encountered. No new neurological symptoms were evident, and the patient's original presenting symptoms resolved completely within 24 hours after the procedure. She was discharged on postoperative Day 3. Computed tomography performed on postoperative Day 5 demonstrated no change in the size of the collective aneurysm-thrombus mass. Conventional angiography performed on postoperative Day 7 showed anatomic reconstruction of the basilar artery and complete occlusion of the circumferential aneurysm. The patient remains neurologically normal. CONCLUSION: The PED provides a safe and definitive constructive treatment option for large, giant, and fusiform/circumferential aneurysms. The PED can achieve complete aneurysm occlusion without embolization coils. When applied judiciously, the PED may be used safely in vascular segments that give rise to eloquent perforators

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

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