Faculty Bibliography

BACKGROUND: The Pipeline embolization device (PED) is a new endoluminal construct designed to exclude aneurysms from the parent cerebrovasculature. We report the very late (>1 year) thrombosis of a PED construct placed for the treatment of a left vertebral aneurysm. CLINICAL PRESENTATION: A patient with an occluded right vertebral artery and a large, fusiform intracranial left vertebral artery aneurysm was treated with PED and coil reconstruction. A durable, complete occlusion of the aneurysm was confirmed with control angiography at 1 year. The patient remained neurologically normal for 23 months until he experienced a transient visual disturbance followed weeks later by a minor brainstem stroke. INTERVENTION: Imaging evaluation showed thrombosis of the PED construct with complete occlusion of the left vertebral artery. After this stroke, he was initially treated with dual antiplatelet therapy and was then converted to warfarin. The patient remained neurologically stable for 5 months until he experienced progressive basilar thrombosis that ultimately resulted in a fatal stroke. CONCLUSION: The PED represents a promising new endovascular technology for the treatment of cerebral aneurysms; however, as an investigational device, long-term follow-up data are sparse at this point. The etiology of the very late thrombosis of the PED construct in this case remains unknown; however, this report underscores the need for a continued, careful systematic evaluation and close long-term follow-up of treated patients

BACKGROUND AND PURPOSE: Aneurysm treatment by intrasaccular packing has been associated with a relatively high rate of recurrence. The use of mesh tubes has recently gained traction as an alternative therapy. This article summarizes the midterm results of using an endoluminal sleeve, the PED, in the treatment of aneurysms. MATERIALS AND METHODS: A total of 19 wide-neck aneurysms were treated in 18 patients: 10 by implantation of PEDs alone and 9 by a combination of PED and coils. Angiographic and clinical results were recorded immediately and at 6 months following treatment. RESULTS: Immediate angiographic occlusion was achieved in 4 and flow reduction, in another 15 aneurysms. Angiography at 6 months demonstrated complete occlusion in 17 and partial filling in 1 of 18 patients. There was no difference between coil-packed and unpacked aneurysms. Of 28 side branches covered by > or =1 device, the ophthalmic artery was absent immediately in 1 and at 6 months in another 2 cases. One patient experienced abrupt in-stent thrombosis resulting in a transient neurologic deficit, and 1 patient died due to rupture of a coexisting aneurysm. All giant aneurysms treated with PED alone were demonstrated by follow-up cross-sectional imaging to have involuted by 6 months. CONCLUSIONS: Treatment of large, wide-neck, or otherwise untreatable aneurysms with functional reconstruction of the parent artery may be achieved with relative safety using dedicated flow-modifying devices with or without adjunctive use of intrasaccular coil packing

INTRODUCTION: We present the use of the Pipeline embolization device (PED) to achieve reconstruction of the right anterior circulation in a patient with a dolichoectatic internal carotid artery (ICA) and middle cerebral artery (MCA) and an associated symptomatic, large, carotid-ophthalmic segment aneurysm. CLINICAL PRESENTATION: A 36-year-old man presented with progressive right eye vision loss followed by sudden severe headache. Subsequent neuroimaging revealed a large right carotid-ophthalmic segment aneurysm and diffuse ectasia of the supraclinoid ICA and proximal MCA. A coil embolization of the aneurysm was performed without stent support. Over the next year, the patient experienced increasing headache and progressive bitemporal vision loss. Serial MRI showed progressive coil compaction and recanalization of the aneurysm. TREATMENT: The right anterior circulation was reconstructed with a total of six PEDs that extended from the distal M1 segment of the MCA proximally into the distal cavernous segment of the ICA. Follow-up angiography at 1 and 4 months demonstrated progressive complete occlusion of the aneurysm and a reorganization of blood flow to the anterior cerebral and anterior choroidal arteries. MRI and radiographic imaging provided evidence of progressive contraction of the intra-aneurysmal thrombus. The patient's headaches resolved and serial visual field examinations have demonstrated gradual improvement after treatment. CONCLUSION: Extensive cerebrovascular reconstructions that are not possible using commercially available endovascular devices can be achieved with Pipeline. The safety, efficacy and long term implications of such reconstructions are currently being defined

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

BACKGROUND: The objective of this study was 2-fold: (1) document the presence and degree of vascularity in gliomas of different pathologic grades and (2) determine whether the presence of abnormal vascularity, determined by catheter angiography, correlates with a shortened survival. METHODS: As part of a protocol for radiographic data acquisition that was used in a computer-assisted, stereotactic system, all patients who underwent biopsy or resection of a newly diagnosed glioma between 1994 and 2000 at our institution routinely underwent preoperative catheter angiography. The presence and degree of tumor vascularity were recorded and then correlated with survival and pathologic grade. The confounding effects of age, KPS, adjuvant treatment, and extent of resection on survival were considered. RESULTS: Two hundred thirty-one patients were included in this study. The mean follow-up of survivors was 7.8 years. Tumor vascularity correlated with a shortened survival (proportional hazards RR for survival, 0.69; 95% CI, 0.58-0.82). This correlation persisted after correction for age, KPS score, adjuvant therapy, and extent of resection (RR, 0.81; 95% CI, 0.68-0.97). Abnormal vascularity was present in 25 (30%) of 82 low-grade (WHO grade 2) gliomas. Overall, the extent of vascularity (none [120 patients, 52%], blush [63 patients, 27%], neovessels [25 patients, 11%], and arteriovenous shunting [23 patients, 10%]) correlated with worse WHO tumor grade (P < .0001). CONCLUSIONS: The presence of abnormal vascularity correlates with both a shortened survival and higher grade of malignancy. These findings underscore the importance of antiangiogenesis factor investigation and drug development for the treatment of gliomas, regardless of their pathologic grade

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

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