Definition of the ostium (neck) of an aneurysm revealed by intravascular sonography: an experimental study in canines.

BACKGROUND AND PURPOSE: The major factor influencing the effectiveness of Guglielmi detachable coils (GDCs) in the treatment of saccular aneurysms is the size of the aneurysm's ostium (neck). Current imaging techniques often do not allow accurate assessment of aneurysm neck morphology. The primary purpose of this study was to determine the feasibility of using intravascular sonography to provide this information. METHODS: Lateral and bifurcation aneurysms were created in each of six adult mongrel dogs by using a well-established surgical technique. Aneurysms were evaluated with digital subtraction angiography and intravascular sonography before (n = 12) and after (n = 6) treatment with GDCs. Angiography was performed using standard techniques. Sonography was performed using both a commercially available 2.6F 40-MHz catheter and a preproduction 0.014-inch 40-MHz imaging core wire housed in a Tracker catheter. Angiograms and sonograms were reviewed independently by two observers to assess the clarity and accuracy with which they depicted the size of each aneurysm's ostium. Posttreatment intravascular sonograms were evaluated for the extent to which they depicted the completeness of aneurysm obliteration. Two-dimensional reformatted images were made of the intravascular sonographic pullback sequences. RESULTS: In all instances, intravascular sonography provided clear definition of the aneurysm's neck (ostium) morphology as well as its relationship to the parent artery and adjacent branches, especially when 2D reformatted images were obtained. The position of coils in aneurysms was also clearly defined. CONCLUSION: Intravascular sonography is a novel technique for viewing the ostium (neck) of an aneurysm. It provides information not available with current angiographic methods.     

Endovascular treatment of experimental aneurysms by use of a combination of liquid embolic agents and protective devices

BACKGROUND AND PURPOSE: The use of liquid embolic agents for embolization of cerebral aneurysms has been reported in the neurosurgical literature. The most important limitation of this technique is the relatively poor control of migration of the liquid embolic agent into the parent artery. We performed an experimental aneurysm study using a liquid embolic agent and different protective devices to evaluate the safety and technical feasibility of this endovascular technique. METHODS: Forty lateral aneurysms were surgically constructed on 20 common carotid arteries of swine. Onyx alone was used to obliterate eight aneurysms. Onyx was also used in combination with microcoils (n = 11), microstents (n = 6), balloons inflated proximally to the neck of the aneurysm (n = 6), and across the neck of the aneurysm (n = 7). One control aneurysm was embolized with Guglielmi detachable coils (GDCs) alone. RESULTS: The use of a microballoon across the neck of the aneurysm, a microstent deployed across the neck of the aneurysm, or the deposit of GDCs into the aneurysm allowed faster and more complete filling of the aneurysm with Onyx. However, these protection devices did not totally preclude intractable migration of Onyx into the parent artery (migration rate, 9-33%). CONCLUSION: Although complete occlusion of experimental aneurysms with Onyx is feasible using protective devices, migration of the liquid embolic agent into the parent artery or intracranially remains a difficult challenge. Further experimental studies need to be performed to master this technique and to select those aneurysms that can be safely treated in clinical practice.     

Histopathologic and immunohistochemical comparison of human, rabbit, and swine aneurysms embolized with platinum coils

BACKGROUND AND PURPOSE: The purpose of this study was to clarify the cellular mechanisms of aneurysmal healing by comparing histologic and immunohistochemical findings in experimental rabbit and swine aneurysms to a human aneurysm embolized with platinum coils. METHODS: Swine sidewall aneurysms (n = 5, harvested at 12 weeks) and elastase-induced rabbit aneurysms (n = 6, harvested at 24 weeks) were created and embolized. A single human aneurysm, embolized 6 years before death, was harvested following autopsy. All specimens were processed by using a modified paraffin embedding technique. Tissue was sectioned and stained with hematoxylin and eosin and Masson trichrome. Immunohistochemistry and immunofluorescence were performed with multiple antibodies, including alpha smooth muscle actin, myosin heavy chain, desmin, vimentin, and CD31. RESULTS: The human aneurysm's dome was filled with loose, hypocellular, amorphous tissue. The aneurysm's neck was completely covered with a thin layer of hypocellular tissue. Collagen and myofibroblasts were sparse in both the dome and neck. Rabbit aneurysms' domes were also filled with a loose, hypocellular tissue, amorphous matrix. In 5 of 6 aneurysms, a thin layer of hypocellular tissue ran along the neck. Collagen and myofibroblasts were sparse in the dome. Swine aneurysms were filled with densely infiltrated tissue, including chronic inflammatory tissue and extensive, attenuated collagen fiber bundles associated with myofibroblasts. Thick layers of myofibroblasts entirely bridged the necks. CONCLUSIONS: Absence of collagen deposition and scant myofibroblastic reaction to platinum coil embolization are seen in the rabbit model but not in swine aneurysms. The elastase-induced aneurysm model in rabbits is more suitable than sidewall swine aneurysms for testing of modified devices aimed at improving intra-aneurysmal fibrosis.     

球囊辅助瘤颈成形术治疗颅内宽颈动脉瘤

目的　总结球囊辅助瘤颈成形术在颅内宽颈动脉瘤治疗中应用的临床体会。方法　采用球囊辅助瘤颈成形术对 18例患者 2 0个颅内宽颈动脉瘤进行栓塞治疗 ,先将微导管超选入动脉瘤内 ,再将不可脱卸球囊于动脉瘤颈处充盈覆盖瘤颈 ,电解可脱卸弹簧圈 (GDC)填塞动脉瘤。结果　 17个动脉瘤治疗成功 ,完全填塞的动脉瘤 12个 ,次全填塞 (>90 % ) 4个 ,不完全填塞 (<90 % ) 1个 ,载瘤动脉均保持通畅 ,平均随访 9.4个月 ,临床效果优良。结论　采用球囊辅助瘤颈成形术治疗颅内宽颈动脉瘤是安全、有效的方法     

Can neck size in elastase-induced aneurysms be controlled? A prospective study

BACKGROUND AND PURPOSE: An earlier retrospective study indicated that the neck size of elastase-induced aneurysms could be controlled by adjusting the position of the inflated balloon. We report the current prospective study to confirm our previous work. METHODS: Ninety elastase-induced aneurysms were created in rabbits. Group 1 (n = 62) included cases in which the occlusion balloon resided low, completely within the brachiocephalic/subclavian arteries. Group 2 (n = 28) included cases in which the balloon resided high, within both the common carotid artery and brachiocephalic/subclavian arteries. Follow-up digital subtraction angiography was performed. The aneurysm sizes were measured and compared between groups. The Student t test and the Fisher exact test were used for statistical analysis. RESULTS: The mean aneurysm neck diameter and width for group 1 was significantly larger than that of group 2 (3.4 +/- 1.2 and 2.3 +/- 0.9 mm, P < .001; 3.8 +/- 1.0 and 3.3 +/- 0.9 mm, P < .05, respectively). The proportion of wide-necked aneurysms in group 1 was significantly larger than that in group 2 (29% vs 4%; P < .005). Mean dome-to-neck ratios were 1.2 +/- 0.4 and 1.7 +/- 0.7 for groups 1 and 2 (P < .005). There was no significant difference in aneurysm height between groups 1 and 2 (8.0 +/- 1.7 and 7.5 +/- 2.2 mm; P > .05). CONCLUSION: The neck size of elastase-induced aneurysm models in rabbits can be controlled by adjusting the position of the inflated balloon.     

Delivery of human vascular endothelial growth factor with platinum coils enhances wall thickening and coil impregnation in a rat aneurysm model

BACKGROUND AND PURPOSE: Histopathologic studies indicate that aneurysms treated with Guglielmi detachable coils (GDCs) have avascular centers with fibrosis mostly at the aneurysm periphery. We hypothesized that vascular endothelial growth factor (VEGF) released from a coil promotes clot organization, hyperplasia, and endothelial proliferation to facilitate closure of the aneurysm neck. METHODS: GDC segments were inserted into ligated common carotid arteries (CCAs) of adult male rats for 14 days. Coil segments (4-mm) were unmodified, modified with type I collagen (2.4 mg/mL), or modified with type I collagen and recombinant human VEGF-165 (rhVEGF; 500 microg/mL). CCA segments were harvested and coils removed for scanning electron microscopy (SEM). RESULTS: Collagen/rhVEGF coils (n = 11) resulted in marked reductions in CCA lumen area (0.03 mm(2)) compared with coils (n = 9, 0.21 mm(2), P <.001) and collagen coils (n = 5, 0.13 mm(2), P <.001). Collagen/rhVEGF coils (n = 11) also resulted in marked reductions in CCA diameter (0.19 mm) compared with coils (n = 9, 0.50 mm, P <.001) and collagen coils (n = 5, 0.40 mm, P <.001). Wall thickness was greater for the collagen/rhVEGF coil segments (0.22 mm) compared with coils (0.09 mm, P <.001), and the collagen coils (0.15 mm, P =.06). CCA segments containing collagen/rhVEGF coils also displayed Factor VIII positivity and were completely encapsulated in fibrotic tissue, while the unmodified and collagen coils were essentially smooth, as seen by SEM. CONCLUSION: These results suggest that rhVEGF may be beneficial in promoting endothelialization, clot organization, and tissue integration of the coils. This is the first study to hypothesize that rhVEGF may be useful as a surface modification to GDCs for enhancing their therapeutic effects in the treatment of cerebral aneurysms.     

Intracranial aneurysms treated with Guglielmi detachable coils: midterm clinical and radiological outcome in 97 consecutive Chinese patients in Hong Kong

BACKGROUND AND PURPOSE: Use of Guglielmi detachable coils (GDCs) has proved to be a promising endovascular treatment for intracranial aneurysms. This study aimed to evaluate midterm clinical and radiologic outcomes of this treatment in Hong Kong Chinese patients, 68% of whom had small aneurysms (< or =5 mm). METHODS: We included 97 consecutive patients in whom GDCs were placed with curative intent. The patients presented with subarachnoid hemorrhage (n = 80) or mass effect (n = 17). The aneurysms measured 5 cm +/- 2.8 mm; 68% were < or =5 mm. All patients were followed up clinically for an average of 54.5 +/- 20.9 months and radiologically with sequential digital subtraction angiography at 6 and 18 months. RESULTS: Total occlusion of the aneurysm was successfully achieved in 71.1% of patients after the initial treatment and in 82.5% after subsequent treatments. The retreatment rate was 17.5%. Procedure-related complication and mortality rates were 11.3% and 0%, respectively. The overall mortality was 5%, including mortality due to treatment failure in 1%. Neurologic outcomes were excellent in 77% of patients. Improved neurologic status, unchanged status, and deteriorated status was noted in 61.5%, 22%, and 16.5% of patients, respectively, at the end of the follow-up period. Intrinsic differences existed between Chinese and Western patients regarding the size of the aneurysm at presentation, periprocedural complications, and progression patterns of anatomic outcomes. CONCLUSION: Endovascular coiling with GDCs is a reasonably effective and safe treatment for intracranial aneurysms in this group of Hong Kong Chinese patients, with favorable clinical and radiologic outcomes.     

支架辅助GDC治疗颅内动脉瘤术中并发症的防治

目的 回顾总结血管内支架治疗颅内动脉瘤术中并发症，以提高使用血管内支架结合电解可脱卸弹簧圈(GDC)治疗颅内夹层及宽颈动脉瘤的安全性。方法 105例难治性动脉瘤，首先将冠脉支架跨动脉瘤颈放置，通过支架的网孔将微导管送入动脉瘤腔，填入GDC。结果 6例患者术中出现支架移位，1例发生动脉瘤破裂出血，1例发生大脑中动脉穿支出血，1例发生支架塌陷，1例发生颈内动脉夹层动脉瘤，1例弹簧圈突入小脑后下动脉(PICA)起始部，10例发生血管痉挛，经对症处理，预后良好。结论 在支架植入过程中，联合采用多种措施可减少并发症的发生；支架和GDC联合应用治疗颅内夹层及宽颈动脉瘤安全、有效。     

Balloon-assisted coil embolization of wide-necked aneurysms of the internal carotid artery: medium-term angiographic and clinical follow-up in 22 patients

BACKGROUND AND PURPOSE: The management of broad-necked cerebral aneurysms by Guglielmi detachable coils (GDCs) is technically challenging owing to a variety of factors, including difficulty in defining the aneurysm/parent vessel interface angiographically and problems in achieving complete occlusion, later predisposing the aneurysm to regrowth/recanalization. We sought to determine whether the use of intraluminal balloons to remodel the parent vessel/aneurysm interface during GDC embolization would provide a safe means of improving the efficacy of endovascular treatment of broad-necked aneurysms. METHODS: Twenty-two saccular aneurysms of the internal carotid artery were treated with GDCs by using balloon remodeling techniques. All aneurysms were characterized by wide necks or were small with unfavorable neck/fundus ratios and required balloon assistance for coil embolization. Patients were followed up both clinically and angiographically. RESULTS: By using a microcatheter-mounted nondetachable balloon to provide a temporary barrier across the aneurysmal neck, we were able to deploy GDCs safely within a variety of aneurysms. Among the 22 patients treated, aneurysmal occlusion on follow-up angiography (mean, 19 months) was found in 17 of 20 patients (two patients died and no follow-up studies were available). Observed or suspected thromboembolic events occurred in four of 22 patients, resulting in one permanent deficit. Twenty of the 22 patients had good to excellent clinical outcomes. CONCLUSION: Although balloon-assisted coiling of cerebral aneurysms requires manipulation of a second microcatheter and an inflatable balloon, increasing its technical complexity, we believe that this method has utility in treating broad-necked aneurysms and small aneurysms that are otherwise suboptimally managed by conventional GDC deployment.     

Endovascular treatment of experimental wide neck aneurysms: comparison of results using coils or cyanoacrylate with the assistance of an aneurysm neck bridge device

BACKGROUND AND PURPOSE: Endovascular treatment of wide neck aneurysms often results in incomplete occlusion or aneurysm recurrence. The two goals of the present study were to compare results of coil embolization with or without the assistance of an aneurysm neck bridge device (ANBD) and to explore the use of this instrument to control cyanoacrylate embolization. METHODS: Wide necked bifurcation aneurysms were constructed in 28 dogs. Coil embolization of the aneurysms was performed 2 to 4 weeks later, with (n = 11) or without (n = 10) ANBD assistance. In seven other animals, embolization was performed with cyanoacrylate, injected under the protection of ANBDs. Angiographic results were compared immediately after and at 3 and 12 weeks. Neointima formation at the neck was also compared between groups at 12 weeks. RESULTS: Initial angiographic results and recurrences at 12 weeks were not significantly different in aneurysms coiled with or without ANBDs. Neointimal scores were also similar. The use of one ANBD at the neck was not sufficient to safely deliver cyanoacrylate into aneurysms. Cyanoacrylate embolization led to improved angiographic results (P =.05) and to better neointimal sealing of the neck of the aneurysms at 12 weeks (P =.004). CONCLUSION: ANBDs did not prevent recanalization and recurrences after coil embolization of wide neck aneurysms in this animal study. ANBD-assisted cyanoacrylate embolization was unsafe but could decrease recurrences at 12 weeks.     

Effect of Guglielmi detachable coils on intraaneurysmal flow: experimental study in canines

BACKGROUND AND PURPOSE: Guglielmi detachable coils (GDCs) are effective in preventing rebleeding of ruptured aneurysms. To better understand the mechanism underlying this protective effect, we evaluated blood flow in aneurysms and their parent arteries before and after GDC coil placement. METHODS: An 0.14-inch guidewire containing a combined pressure and thermistor sensor was inserted through a microcatheter into both the parent artery and the dome of surgically created canine aneurysms. Before and after GDC coil placement, intravascular pressures and thermodilution responses where recorded in the parent artery and aneurysmal dome during injections of room-temperature isotonic sodium chloride solution over 4 seconds (5 mL/s) and 2 seconds (20 mL/s) in the parent artery. RESULTS: Before GDC coil placement, similar U-shaped thermodilution curves were present in the parent artery and in the dome of the aneurysm. GDC coil placement reduced intraaneurysmal flow by 61-99.6% (P <.05), prolonged aneurysmal filling and washout (dilution interval increased from 5.16 seconds before coil placement to 26.79 seconds after coil placement, P < 0.05), and caused a dissociation of pressure and flow (shift epsilon was 0.45 seconds before coil placement versus 0.56 seconds after coil placement, P <.05). Flow in the parent artery was not significantly affected by GDC coil placement in the aneurysm. CONCLUSION: In this model, intraaneurysmal blood flow can be evaluated with thermodilution. GDC coil placement significantly reduces blood flow in aneurysms.     

Development of a biologically active Guglielmi detachable coil for the treatment of cerebral aneurysms. Part I: in vitro study

BACKGROUND AND PURPOSE: Stronger cellular adhesion on the surface of endovascular devices promotes accelerated healing of aneurysms. The purpose of this in vitro study was to study the cellular interaction on the surface of bioactive Guglielmi detachable coils (GDCs) after using the surface-modification technology, ion implantation. METHODS: Polystyrene (PS) dishes and platinum plates were used to simulate a GDC surface. They were treated with either simple collagen coating or collagen coating followed with ion implantation. Bovine endothelial cells (2-2.5 x 10(4) cells in 1 mL) were suspended in medium supplemented with 10% fetal bovine serum on the PS dishes or platinum plates. Five days after cell seeding, the strength of cell adhesion was evaluated by trypsin treatment and flow shear stress. The cell detachment from the PS and platinum surfaces was observed microscopically. RESULTS: Five days after cell seeding, both simple collagen-coated surfaces and collagen-coated ion-implanted surfaces showed uniform endothelial proliferation. After trypsin treatment, or under flow shear stress, stronger cell adhesion against chemical and flow shear stress was observed on the ion-implanted collagen-coated surface. In contrast, the endothelial cells were detached easily from the non-ion-implanted collagen-coated surface. CONCLUSION: Ion implantation in combination with protein coating improves the strength of surface cell adhesion when exposed to flow shear stress and proteolytic enzymes. Strong endothelial cell adhesion is reported to be important to achieve earlier endothelialization across the neck of an embolized aneurysm with bioactive GDCs. This new technology may improve long-term anatomic outcome in cerebral aneurysms treated with GDCs.     

Combined stent implantation and endosaccular coil placement for treatment of experimental wide-necked aneurysms: a feasibility study in swine.

PURPOSETo assess the feasibility of combining stent implantation in the parent artery with endosaccular coil placement for the treatment of experimentally created wide-necked aneurysms.METHODSWide-necked aneurysms were surgically created on the common carotid artery in 12 swine. A metal stent was endovascularly implanted across each aneurysm neck and its effect documented anigiographically. If the aneurysm remained patent, a microcatheter was introduced into the aneurysm through the stent mesh. Electrically detachable coils were delivered into the aneurysm sac to produce thrombosis.RESULTSAfter stent implantation, one carotid artery thrombosed and two aneurysms spontaneously occluded. In the other 9 cases, coils were deposited through the stent to occlude the aneurysm. Complete aneurysm packing was possible in all 9 cases. The presence of the stent allowed placement of small coils near the aneurysm neck, thus contributing to the safe occlusion of small remnants in the final stages of aneurysm packing.CONCLUSIONThe combination of stent implantation and coil placement is feasible in the treatment of experimental wide-necked saccular aneurysms. The stent maintains patency of the parent artery while allowing aneurysm occlusion by endosaccular coil placement through the stent''s mesh. Occlusion of small aneurysm remnants is possible with no fear of coil hernation or migration into the parent artery. Long-term studies will be necessary before application to treatment of selected intracranial aneurysms.     

Cerebral aneurysm perforations complicating therapy with Guglielmi detachable coils: a meta-analysis

BACKGROUND AND PURPOSE: The risk of intraprocedural aneurysm perforation in patients with previously ruptured aneurysms tends to be higher than that of patients with previously unruptured aneurysms, but a statistically significant difference has not been shown. Our purpose was to define the rates of occurrence and of morbidity and mortality associated with aneurysmal perforation associated with coil embolization. METHODS: A meta-analysis of the results from 17 published retrospective reports of aneurysm perforations complicating therapy with Guglielmi detachable coils (GDCs) was performed. Rates of perforation and associated morbidity and mortality in previously ruptured and unruptured aneurysms were calculated. The mechanism of perforation was noted. RESULTS: The risk of intraprocedural perforation was significantly higher in patients with ruptured aneurysms compared with patients with unruptured aneurysms (4.1% vs 0.5%; P <.001). The combined risk of permanent neurologic disability and death associated with intraprocedural aneurysm perforation was 38% for ruptured aneurysms and 29% for unruptured aneurysms. The morbidity and mortality rates with perforations caused by coils (39%) and microcatheters (33%) were similar. The morbidity and mortality rate for microguidewire perforations was considerably lower (0%, n = 4) than the rates for coils and microcatheters, but number of cases was too low to indicate statistical significance. CONCLUSION: The risk of aneurysm perforation during GDC therapy is much higher in patients with previously ruptured aneurysms than in those with unruptured aneurysms. The morbidity and mortality rates are substantial for perforations caused by coils and microcatheters, whereas they seem to be much lower for perforations caused by microguidewires.     

Cerebral aneurysms treated by Guglielmi detachable coils: evaluation with diffusion-weighted MR imaging

BACKGROUND AND PURPOSE: The most frequent and serious complications of endovascular treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs) are ischemic lesions caused by thromboembolic events. Diffusion-weighted MR imaging appears to be the most sensitive technique for detecting early ischemic phenomena. We evaluated this technique for the detection of brain changes in patients who underwent GDC treatment of aneurysms. METHODS: Twenty patients with a cerebral aneurysm were studied with diffusion-weighted imaging before and after endovascular treatment with GDCs. Aneurysms were located in the anterior (n = 16) or posterior (n = 4) circulation. Bleeding had occurred in 11 patients. MR studies, including fast fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted sequences, were scheduled before, 2 to 4 hours after, and 48 hours after treatment. MR images, including apparent diffusion coefficient (ADC) maps, were assessed for the presence of acute ischemic stroke lesions. RESULTS: In all patients, the aneurysm was excluded without neurologic worsening. In 18 patients, diffusion-weighted and FLAIR images showed no evidence of recent ischemic lesions after treatment. In one patient, an asymptomatic frontobasal hyperintense signal on diffusion-weighted images with a drop of ADC values corresponding to an acute ischemic lesion was observed. In another patient, multiple silent lesions were seen on diffusion-weighted images after embolization. These silent lesions were not all located in the vascular territory of the aneurysm's parent artery. CONCLUSION: This preliminary study suggests that diffusion-weighted MR imaging is a potentially useful tool for monitoring patients after endovascular treatment of a cerebral aneurysm. While small asymptomatic lesions can be observed on these images after embolization, their exact prevalence should be evaluated in a larger series.     

Evaluation of the stability of aneurysms after embolization using detachable coils: correlation between stability of aneurysms and embolized volume of aneurysms

BACKGROUND AND PURPOSE: The long-term outcome of aneurysmal coil embolization has not been determined. We retrospectively analyzed the results of our cases treated with detachable coils and evaluated the long-term stability of embolized aneurysms. METHODS: This study involved 100 aneurysms in 93 patients who underwent follow-up angiography > or = 3 months after initial treatment between December 1993 and December 1999. The percentage of the coil volume occupying the aneurysm lumen (embolized volume) was used as an index to evaluate the stability of embolized aneurysms. The reliability of the embolized volume was also evaluated by comparing angiographic percentage occlusion. RESULTS: Follow-up angiographic assessment was conducted 12 +/- 8.5 months after initial treatment. Angiographic evaluation of percentage occlusion at initial treatment did not always predict long-term stability of embolized aneurysms. Of 49 aneurysms judged as being totally occluded at initial treatment, 44 remained unchanged and five showed recanalization. The embolized volume of unchanged aneurysms was 30.8 +/- 10.2%, and that of recanalized aneurysms was 19.9 +/- 10.6%. There was a significant difference between these two groups (P=.03). Of 29 subtotally occluded aneurysms, nine had further thrombosis (embolized volume = 31.8 +/- 12.7%), nine remained unchanged (embolized volume = 23.2 +/- 10.3%), and 11 had recanalization (embolized volume = 14.1 +/- 6.1%). The mean embolized volume of 11 recanalized aneurysms was significantly lower than in the thrombosed group and the unchanged group (P=.002 and P <.001, respectively). Large aneurysms tended to have recanalization more frequently (59%) than did small aneurysms (15%). CONCLUSION: There is a significant correlation between embolized volume and stability of embolized aneurysms. Embolized volume is a more objective index than is subjectively angiographic percentage occlusion. In addition to angiographic assessment, measurement of embolized volume could be useful to predict angiographic changes of aneurysms.     

Control of aneurysm volume by adjusting the position of ligation during creation of elastase-induced aneurysms: a prospective study

BACKGROUND AND PURPOSE: Animal models with appropriate volume are crucial for preclinical assessment of aneurysm therapies. Our purpose was to control the aneurysm volume by adjusting the position of ligation during creation of elastase-induced aneurysms in rabbits. MATERIALS AND METHODS: Sixty elastase-induced aneurysms in rabbits were created. Two different methods were used for creation, including group 1 (n=30) by using a lower ligation (from the origin of the right common carotid artery [RCCA] to the ligation point, 10 mm) and group 2 (n=30) by using a higher ligation (from the origin of the RCCA to the ligation point, 15 mm). Aneurysm sizes (neck diameter, width, and height) and volumes in the 2 groups were measured and calculated, and they were compared by using the Student t test. RESULTS: The mean aneurysm neck diameter, width, and height for group 2 were significantly larger than those of group 1 (3.3 +/- 0.8 versus 2.7 +/- 0.6 mm, P<.001; 3.7 +/- 0.7 versus 2.5 +/- 0.7 mm, P<.001; 9.0 +/- 1.7 versus 7.3 +/- 1.9 mm, P<.001, respectively). The aneurysm volume in group 2 was significantly larger than that in group 1 (102.4 +/- 54.8 mm(3) versus 36.6 +/- 26.8 mm(3), P<.001). CONCLUSION: The aneurysm volume of elastase-induced models in rabbits can be controlled by adjusting the position of the ligation. Using a higher ligation can create relatively more voluminous aneurysms, compared with using a lower ligation.     

MR angiography of saccular aneurysms after treatment with Guglielmi detachable coils: preliminary experience.

PURPOSETo review our experience using MR angiography to assess the cerebral vasculature after aneurysmal treatment with Guglielmi detachable coils (GDCs).METHODSForty three-dimensional time-of-flight MR angiographic studies were performed in 23 patients after endovascular aneurysmal therapy with GDCs. Digital subtraction angiographic (DSA) studies were evaluated retrospectively for the following findings: parent artery patency, branch vessel patency, residual flow within the aneurysm, and residual aneurysmal neck. The MR angiographic examinations were inspected for the same findings, as well as for the degree of signal loss surrounding the coil mass. Clinical histories were reviewed to determine the impact of MR angiographic findings on therapy.RESULTSPatency status of the parent artery was correctly identified on 25 of 26 MR angiographic examinations with DSA confirmation. Thirty-four of 37 patent branch vessels were identified by MR angiography. Residual neck was correctly identified in seven studies of six aneurysms, with no false-negative or false-positive results. Intraaneurysmal flow was correctly identified in five of eight studies of six aneurysms with residual flow shown by DSA. Artifact and hemorrhage mimicked residual flow in two of 18 MR angiographic studies of aneurysms with no residual flow shown by DSA. In eight patients, MR angiography provided clinically useful information that affected therapy.CONCLUSIONSMR angiography can identify flow within an aneurysm after treatment with GDCs as well as in the adjacent parent and branch vessels. This technique may be a useful adjunct to DSA in some clinical situations.     

Utility of balloon-assisted Guglielmi detachable coiling in the treatment of 49 cerebral aneurysms: a retrospective, multicenter study

BACKGROUND AND PURPOSE: The management of wide-necked aneurysms or aneurysms with a neck-to-body ratio close to 1 is a difficult challenge for the interventional radiologist because of the risk of coil migration or coil protrusion into the parent vessel. Our objective was to evaluate the efficacy and safety of balloon-assisted coiling as well as the follow-up results of occlusion for those difficult aneurysms in which conventional treatment with Guglielmi detachable coils (GDCs) had failed. METHODS: A nondetachable balloon was used in 49 procedures performed in 44 patients (35 women and nine men) who underwent GDC coiling of aneurysms. Every aneurysm had either a wide neck or a sac diameter/neck size ratio (SNR) of 1.5 or less. RESULTS: In four (8%) of the procedures, balloon placement failed, leaving a total of 45 aneurysms treated with balloon-assisted coiling. Final results consisted of total occlusion in 30 cases (67%), subtotal occlusion in 11 cases (24%), and incomplete occlusion in four cases (9%). We found a correlation between the diameter of the sac and the occlusion rate, but not between the size of the neck or the SNR and the occlusion rate. Two thromboembolic complications occurred, but neither had clinical consequences. No aneurysmal rupture was observed during treatment. Final angiographic follow-up time ranged from 3 months to 5 years (mean, 16 months). CONCLUSION: Balloon-assisted coiling is an important adjunct in the treatment of aneurysms with a wide neck or low SNR. In our experience, this technique allowed safe and efficient treatment of aneurysms when conventional GDC treatment had failed.     

支架结合弹簧圈治疗颅内宽颈动脉瘤急性破裂的可行性和安全性

目的　总结血管内支架结合电解可脱卸弹簧圈 (GDC)治疗颅内宽颈动脉瘤急性破裂的临床体会 ,对其可行性和安全性进行初步探讨。方法　 5 7例急性破裂宽颈动脉瘤 ,均先植入冠脉支架覆盖动脉瘤颈 ,再将微导管通过支架网孔超选进入动脉瘤腔内填塞GDC。结果　 1例因血管扭曲不能植入支架 ,5 6例成功 ,均达到 90 %以上栓塞 ,载瘤动脉通畅 ,所有患者无神经功能障碍出现。结论　血管内支架植入结合GDC填塞是治疗急性破裂宽颈动脉瘤的安全、可行的方法