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Ichiro Yuki, Yuichi Murayama, and Fernando Viñuela

Object. The authors report on a series of 29 patients presenting with acute subarachnoid hemorrhage (SAH) related to the rupture of a vertebrobasilar dissecting aneurysm. Special attention was focused on embolization techniques and immediate and midterm anatomical and clinical outcomes.

Methods. Between March 1994 and January 2003, 29 patients presented with acute SAH caused by the rupture of a vertebrobasilar dissecting aneurysm. Eleven patients (37.9%) had Hunt and Hess Grade I SAH, four (13.8%) Grade II, six (20.7%) Grade III, five (17.2%) Grade IV, and three (10.3%) Grade V. Aneurysms were classified into five groups based on lesion location, and treatment courses were decided. All patients except two were treated by endovascular trapping of the aneurysm with concomitant occlusion of the involved vertebral artery (VA). No technical or clinical complication was observed in 28 patients (97%). Aneurysm perforation occurred during the procedure in one patient (3%). There was evidence of aneurysm recanalization in one patient. One patient with Hunt and Hess Grade IV SAH and two patients with Grade V SAH died. One patient died of respiratory infection 1 year after aneurysm trapping. One patient presented with a recurrent hemorrhage 1 month after treatment and died. Overall morbidity and mortality rates were 13.8 and 17.2%, respectively.

Conclusions. Twenty-nine patients with acute SAH due to rupturing of vertebrobasilar dissecting aneurysms were treated using endovascular techniques. In most cases, endovascular trapping of the aneurysm and concomitant occlusion of the VA was technically and clinically successful.

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Roberto C. Heros

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Ken Uda, Yuichi Murayama, Y. Pierre Gobin, Gary R. Duckwiler, and Fernando Viñuela

Object. The authors present a retrospective analysis of their clinical experience in the endovascular treatment of basilar artery (BA) trunk aneurysms with Guglielmi detachable coils (GDCs).

Methods. Between April 1990 and June 1999, 41 BA trunk aneurysms were treated in 39 patients by inserting GDCs. Twenty-seven patients presented with subarachnoid hemorrhage, six had intracranial mass effect, and in six patients the aneurysms were found incidentally. Eighteen lesions were BA trunk aneurysms, 13 were BA—superior cerebellar artery aneurysms, four were BA—anterior inferior cerebellar artery aneurysms, and six were vertebrobasilar junction aneurysms. Thirty-five patients (89.7%) had excellent or good clinical outcomes; procedural morbidity and mortality rates were 2.6% each. Thirty-six aneurysms were selectively occluded while preserving the parent artery, and in five cases the parent artery was occluded along with the aneurysm. Immediate angiographic studies revealed complete or nearly complete occlusion in 35 aneurysms (85.4%). Follow-up angiograms were obtained in 29 patients with 31 aneurysms; the mean follow-up period was 17 months. No recanalization was observed in the eight completely occluded aneurysms. In 19 lesions with small neck remnants, seven (36.8%) had further thrombosis, three (15.8%) remained anatomically unchanged, and nine (47.3%) had recanalization caused by coil compaction. In one patient (2.6%) the aneurysm rebled 8 years after the initial embolization.

Conclusions. In this clinical series the authors show that the GDC placement procedure is valuable in the therapeutic management of BA trunk aneurysms. The endovascular catheterization of these lesions tends to be relatively simple, in contrast with more complex neurosurgical approaches. Endosaccular obliteration of these aneurysms also decreases the possibility of unwanted occlusion of perforating arteries to the brainstem.

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Yuichi Murayama, Fernando Viñuela, Gary R. Duckwiler, Y. Pierre Gobin, and Guido Guglielmi

Guglielmi detachable coil (GDC) technology is a valuable therapeutic alternative to the surgical treatment of ruptured or incidental intracranial aneurysms. The authors describe their technical and clinical experience in the utilization of the GDC technique in patients who underwent endovascular occlusion for the treatment of incidentally found intracranial aneurysms.

One hundred fifteen patients with 120 incidentally found intracranial aneurysms underwent embolization using the GDC endovascular technique. Ninety-one patients were female and 24 were male. Patient age ranged from 13 to 80 years. In 64 patients the incidental aneurysms were discovered when unrelated nonneurological conditions indicated the need for angiography or magnetic resonance angiography (Group 1). Twenty patients who presented with incidental aneurysms that were discovered during treatment for an acutely ruptured aneurysm were treated in the acute phase of subarachnoid hemorrhage (SAH) (Group 2). Sixteen patients with incidental aneurysms were treated during the chronic phase of SAH (Group 3). Group 4 included 15 patients who had incidental aneurysms associated with brain tumors or arteriovenous malformations.

Angiographic results showed complete or near complete occlusion in 109 aneurysms (91%) and incomplete occlusion in five aneurysms (4%). Unsuccessful GDC embolization was attempted in six aneurysms (5%). One hundred nine patients (94.8%) remained neurologically intact or unchanged from initial clinical status. Five patients (4.3%) deteriorated due to immediate procedural complications (overall immediate morbidity rate). All of these complications occurred in the first 50 patients treated earlier in this series. No clinical complications were observed in the last 65 patients. Follow-up cerebral angiograms were obtained in 77 patients with 79 aneurysms. The median clinical follow-up period was 16.3 months.

No recanalization was observed in the 52 completely occluded aneurysms. Of the 22 aneurysms with small neck remnants, eight (36%) showed further thrombosis, 7 (32%) remained anatomically unchanged, and seven (32%) showed recanalization due to compaction of the coils. In one patient, a partially embolized aneurysm ruptured 3 years postembolization. In Groups 1 and 3, the average length of hospitalization was 3.3 days.

The evolution of the GDC technology has proved to provide safe treatment of incidental aneurysms (a morbidity rate of 0% was achieved in the last 65 patients). The topography of the aneurysm and the clinical condition of the patient did not influence final anatomical or clinical outcomes. The GDC technology also confers a positive economical impact by decreasing hospital length of stay and by eliminating the need for postembolization intensive care unit care.

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Yuichi Murayama, Fernando Viñuela, Gary R. Duckwiler, Y. Pierre Gobin, and Guido Guglielmi

Object. Guglielmi detachable coil (GDC) technology is a valuable therapeutic alternative to the surgical treatment of ruptured or incidental intracranial aneurysms. The authors describe their technical and clinical experience in the use of the GDC technique in patients who underwent endovascular occlusion for the treatment of incidentally found intracranial aneurysms.

Methods. One hundred fifteen patients with 120 incidentally found intracranial aneurysms underwent embolization by means of the GDC endovascular technique. Ninety-one patients were females and 24 were males. Patient age ranged from 13 to 80 years. In 64 patients the incidental aneurysms were discovered when unrelated nonneurological conditions signaled the need for angiography or magnetic resonance angiography (Group 1). Twenty patients who presented with incidental aneurysms that were discovered during treatment for an acutely ruptured aneurysm underwent treatment of both types of aneurysm during the acute phase of subarachnoid hemorrhage (SAH) (Group 2). Sixteen patients with incidental aneurysms were treated during the chronic phase of SAH (Group 3). Group 4 included 15 patients who had incidental aneurysms associated with brain tumors or arteriovenous malformations.

Angiographic results revealed complete or near-complete occlusion in 109 aneurysms (91%) and incomplete occlusion in five aneurysms (4%). Guglielmi detachable coil embolization was attempted unsuccessfully in six aneurysms (5%). One hundred nine patients (94.8%) remained neurologically intact or unchanged from their initial clinical status. Five patients (4.3%) deteriorated as a result of immediate procedural complications. All these complications occurred in the first 50 patients treated in the series. No clinical complications were observed in the last 65 patients. In one patient, a partially embolized aneurysm ruptured 3 years postprocedure. In Groups 1 and 3, the average length of hospitalization was 3.3 days.

Conclusions. The evolution of GDC technology has proved to provide safe treatment of incidental aneurysms (a morbidity rate of 0% was achieved in the last 65 patients). The topography of the aneurysm and the clinical condition of the patient did not influence final anatomical or clinical outcomes. The GDC technology also confers a positive economic impact by decreasing hospital length of stay and by eliminating the need for postembolization intensive care.

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Yuichi Murayama, Fernando Viñuela, Satoshi Tateshima, Joon K. Song, Nestor R. Gonzalez, and Michael P. Wallace

Object. A new embolic agent, bioabsorbable polymeric material (BPM), was incorporated into Guglielmi detachable coils (GDCs) to improve long-term anatomical results in the endovascular treatment of intracranial aneurysms. The authors investigated whether BPM-mounted GDCs (BPM/GDCs) accelerated the histopathological transformation of unorganized blood clot into fibrous connective tissue in experimental aneurysms created in swine.

Methods. Twenty-four experimental aneurysms were created in 12 swine. In each animal, one aneurysm was embolized using BPM/GDCs and the other aneurysm was embolized using standard GDCs. Comparative angiographic and histopathological data were analyzed at 2 weeks and 3 months postembolization.

At 14 days postembolization, angiograms revealed evidence of neck neointima in six of eight aneurysms treated with BPM/GDCs compared with zero of eight aneurysms treated with standard GDCs (p < 0.05). At 3 months postembolization, angiograms demonstrated that four of four aneurysms treated with BPM/GDC were smaller and had neck neointima compared with zero of four aneurysms treated with standard GDCs (p = 0.05). At 14 days, histological analysis of aneurysm healing favored BPM/GDC treatment (all p < 0.05): the grade of cellular reaction around the coils was 3 ± 0.9 (mean ± standard deviation) for aneurysms treated using BPM/GDCs compared with 1.6 ± 0.7 for aneurysms treated using GDCs alone; the percentage of unorganized thrombus was 16 ± 12% compared with 37 ± 15%, and the neck neointima thickness was 0.65 ±0.26 mm compared with 0.24 ±0.21 mm, respectively. At 3 months postembolization, only neck neointima thickness was significantly different (p < 0.05): 0.73 ± 0.37 mm in aneurysms filled with BPM/GDCs compared with 0.16 ± 0.14 mm in aneurysms filled with standard GDCs.

Conclusions. In experimental aneurysms in swine, BPM/GDCs accelerated aneurysm fibrosis and intensified neck neointima formation without causing parent artery stenosis or thrombosis. The use of BPM/GDCs may improve long-term anatomical outcomes by decreasing aneurysm recanalization due to stronger in situ anchoring of coils by organized fibrous tissue. The retraction of this scar tissue may also decrease the size of aneurysms and clinical manifestations of mass effect observed in large or giant aneurysms.

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Motoharu Hayakawa, Yuichi Murayama, Gary R. Duckwiler, Y. Pierre Gobin, Guido Guglielmi, and Fernando Viñuela

Object. The long-term durability of Guglielmi detachable coil (GDC) embolization of cerebral aneurysms is still unknown. The purpose of this study was to evaluate the anatomical evolution of neck remnants in aneurysms treated with GDCs.

Methods. Of 455 aneurysms treated with GDCs from 1990 to 1998 at the University of California at Los Angeles Medical Center, 178 aneurysms (39%) had residual necks postembolization. Long-term follow-up angiograms were obtained in 73 of these aneurysms in 71 patients. The mean duration of angiographic follow up was 17.3 months. Twenty-four of the aneurysms were small with small necks, 24 were small with wide necks, 15 were large, and 10 were giant aneurysms.

In small aneurysms with small necks, postembolization angiography revealed 12 aneurysms (50%) with progressive thrombosis, eight (33%) unchanged, and four (17%) with recanalization. In small aneurysms with wide necks, six (25%) had progressive thrombosis, eight (33%) remained unchanged, and 10 (42%) had recanalization. In large aneurysms, two (13%) were unchanged and 13 (87%) had recanalization. Of the giant aneurysms only one (10%) remained unchanged and nine (90%) had recanalization. Overall, 18 aneurysms (25%) exhibited progressive thrombosis, 19 (26%) remained unchanged, and 36 (49%) displayed recanalization on follow-up angiography. During the last 2 years of the study, the recanalization rate decreased and a higher rate of progressive thrombosis was noted in aneurysms with small necks. These positive changes are related to important new technical developments.

Conclusions. Treatment with GDCs appears to be effective and the results permanent in most small aneurysms with small necks. However, there are important technical limitations in the current GDC technology that prevent recanalization in wide-necked or large or giant aneurysms.

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Satoshi Tateshima, Fernando Viñuela, J. Pablo Villablanca, Yuichi Murayama, Taku Morino, Kiyoe Nomura, and Kazuo Tanishita

Object. The aim of this study was to evaluate axial and secondary flow structures in a wide-necked internal carotid artery—ophthalmic artery aneurysm, one of the most common locations for endovascular coil placement.

Methods. A clear acrylic aneurysm model was manufactured from a three-dimensional computerized tomography angiogram. Intraaneurysm blood flow analysis was conducted using an acrylic aneurysm model together with laser Doppler velocimetry and particle imaging velocimetry. The maximal axial blood flow velocities in the inflow and outflow zones at the aneurysm orifice were noted at the peak systolic phase, measuring 46.8 and 24.9% of that in the parent artery, respectively. The mean size of the inflow zone during one cardiac cycle was 44.3 ± 9.8% (range 35.6–58.7%) the size of the axial section at the aneurysm orifice. In the lower and upper planes of the aneurysm dome, the mean size of inward and outward flow areas were 43.3 ± 6.7% and 43.8 ± 6.8% the size of the axial cross-sectional plane, respectively. The axial flow velocity structures were dynamically altered throughout the cardiac cycle, particularly at the aneurysm orifice. The fastest secondary flow at the opening was also noted at the peak systolic and early diastolic phases. Axial blood flow velocity was slower in the upper axial plane of the aneurysm dome than in the lower one. Conversely, the secondary flow component was faster in the upper plane.

Conclusions. The side-wall aneurysm in this study did not demonstrate a simple flow pattern as was previously seen in ideally shaped experimental aneurysms in vitro and in vivo. The flow patterns of inflow and outflow zones were very difficult to predict based on the limited flow information provided on standard digital subtraction angiography, even in an aneurysm with a relatively simple dome shape.

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Yuichi Murayama, Fernando Viñuela, Akira Ishii, Yih-Lin Nien, Ichiro Yuki, Gary Duckwiler, and Reza Jahan

Object

The Matrix detachable coil is a new bioactive, bioabsorbable coil used in the endovascular embolization of intracranial aneurysms. It has a platinum core covered with a bioactive, bioabsorbable polymer (polyglycolic acid/lactide). The authors report on their initial midterm clinical experience with the first-generation Matrix detachable coil.

Methods

One hundred twelve patients harboring 118 aneurysms were treated using Matrix coils. Forty-nine aneurysms (41.5%) were associated with acute subarachnoid hemorrhage (SAH). Twenty-four lesions (49%) were harbored by patients with Hunt and Hess Grade I, 11 (23.4%) by patients with Grade II, eight (16.3%) by those with Grade III, and six (12.2%) by those with Grade IV. Four aneurysms (3.4%) were harbored by patients who had presented with nonacute SAH. Sixty-five aneurysms (55%) were unruptured. Fifty-seven lesions (48.3%) were small with a small neck, 29 (24.6%) were small with a wide neck, 30 (25.4%) were large, and two (1.7%) were giant. All patients were followed up to obtain angiography and clinical outcome data.

Technical complications occurred in six patients: two thromboembolic complications and four aneurysm perforations. Of these six patients, the status of two deteriorated because of aneurysm perforation and another two because of thrombus formation (morbidity 3.6%). There were five deaths—one due to rerupture after embolization. Angiography follow-up studies of 87 aneurysms were obtained. Seventy aneurysms demonstrated progressive occlusion or a stable neck (80.5%), and 17 had some degree of recanalization (19.5%). The aneurysms originally diagnosed as a neck remnant showed a 15% rate of recanalization.

Conclusions

Matrix coils can be delivered into aneurysms with technical complications similar to those encountered using GDCs. Midterm anatomical outcomes to date have shown moderate improvement in the recanalization rate when compared with those realized using the GDC system. Because of the increased friction associated with the first-generation Matrix coil, the packing density in most aneurysms was less than that achieved with GDCs. Prolonged angiography follow-up evaluations are needed to document long-term efficacy.