Embolization of incidental cerebral aneurysms by using the Guglielmi detachable coil system

Development of a Virtual Stent Deployment Application to Estimate Patient-Specific Braided Stent Sizes

A virtual stent deployment application was developed to estimate the appropriate and patient-specific size of a braided stent for patients who undergo endovascular treatment for intracranial aneurysms. Comparing between the simulated deployed and the actual stents, we evaluated the accuracy of the simulation results. Our results indicated that lengths of the virtual and actual stents matched well despite the actual stent being affected by a geometrical change of the parent artery.Clinical Relevance-Surgeons need to be well-experienced to select an appropriate braided stent size for endovascular treatment of intracranial aneurysms, because the actual length of the deployed stent changes. This simulation will be helpful to make tailor-made surgical planning regardless of the surgeons' individual skill level.

Initial Experience of Coil Embolization for Unruptured Intracranial Aneurysm Combined with Neuroform Atlas and Undersized Flexible Coils

Objective

Intraprocedural rupture (IPR) is a rare complication that can occur during endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs). However, it leads to high morbidity and mortality rates. Others have showed that coil flexibility is a risk factor for IPR. Neuroform Atlas (NA) stents can be deployed with 0.0165-inch microcatheters to enable stent assisted coiling (SAC) with a high likelihood. Undersized flexible coils can be inserted initially during SAC. This study aimed to determine whether SAC using NA and highly flexible coils for UIAs can be conducted without IPR.

Methods

We retrospectively analyzed nine consecutive patients (mean age, 73.2 years; female, n = 6) who underwent SAC for UIAs combined with NA stents and undersized flexible coils between January 2017 and December 2019. Two aneurysms were located at the internal carotid artery (ICA), and one each was located at the ICA-posterior communicating, anterior communicating, middle cerebral, vertebral, vertebra-posterior inferior cerebral and basilar arteries. The mean size of the aneurysms was 4.6 (range, 3.1-8.6) mm. SAC proceeded using the jailing technique. All coils were selected from among the most flexible coils available. We retrospectively assessed technical success rates, aneurysm occlusion at final digital subtraction angiography (DSA), volume embolization ratios (VERs), rates of IPR and symptomatic stroke within 30 days, angiographic findings of aneurysm occlusion at 3 months post-procedure and late adverse events (frequency of aneurysmal rupture, ipsilateral ischemic stroke, and retreated targeted aneurysms).

Results

The technical success rate was 100%. Complete occlusion (CO) was immediate in 8 (89%) patients and a neck remnant persisted in 1 (11%). No IPR or symptomatic stroke developed within 30 days. During a mean follow-up period of 11.8 months, CO persisted in 8 (89%) patients. No late adverse events occurred.

Conclusion

The early clinical and angiographic findings of SAC for UIAs combined with an NA stent and undersized flexible coils were favorable for this series.

Deep learning based detection of intracranial aneurysms on digital subtraction angiography: A feasibility study

BACKGROUND

Digital subtraction angiography is the gold standard for detecting and characterising aneurysms. Here, we assess the feasibility of commercial-grade deep learning software for the detection of intracranial aneurysms on whole-brain anteroposterior and lateral 2D digital subtraction angiography images.

MATERIAL AND METHODS

Seven hundred and six digital subtraction angiography images were included from a cohort of 240 patients (157 female, mean age 59 years, range 20-92; 83 male, mean age 55 years, range 19-83). Three hundred and thirty-five (47%) single frame anteroposterior and lateral images of a digital subtraction angiography series of 187 aneurysms (41 ruptured, 146 unruptured; average size 7±5.3 mm, range 1-5 mm; total 372 depicted aneurysms) and 371 (53%) aneurysm-negative study images were retrospectively analysed regarding the presence of intracranial aneurysms. The 2D data was split into testing and training sets in a ratio of 4:1 with 3D rotational digital subtraction angiography as gold standard. Supervised deep learning was performed using commercial-grade machine learning software (Cognex, ViDi Suite 2.0). Monte Carlo cross validation was performed.

RESULTS

Intracranial aneurysms were detected with a sensitivity of 79%, a specificity of 79%, a precision of 0.75, a F1 score of 0.77, and a mean area-under-the-curve of 0.76 (range 0.68-0.86) after Monte Carlo cross-validation, run 45 times.

CONCLUSION

The commercial-grade deep learning software allows for detection of intracranial aneurysms on whole-brain, 2D anteroposterior and lateral digital subtraction angiography images, with results being comparable to more specifically engineered deep learning techniques.

Delayed Leukoencephalopathy: A Rare Complication after Coiling of Cerebral Aneurysms

BACKGROUND AND PURPOSE

Delayed leukoencephalopathy is a rare complication that occurs after endovascular coiling of cerebral aneurysms. We aimed to describe a clinical picture of delayed leukoencephalopathy and explore potential associations with procedural characteristics.

MATERIALS AND METHODS

We considered endovascular coiling procedures for cerebral aneurysms performed between January 2006 and December 2017 in our institution with follow-up MRIs. We used logistic regression models to estimate the ORs of delayed leukoencephalopathy for each procedural characteristic.

RESULTS

We reviewed 1754 endovascular coiling procedures of 1594 aneurysms. Sixteen of 1722 (0.9%) procedures demonstrated delayed leukoencephalopathy on follow-up FLAIR MR imaging examinations after a median period of 71.5 days (interquartile range, 30-101 days) in the form of high-signal changes in the white matter at locations remote from the coil mass. Seven patients had headaches or hemiparesis, and 9 patients were asymptomatic. All imaging-associated changes improved subsequently. We found indications suggesting an association between delayed leukoencephalopathy and the number of microcatheters used per procedure (P = .009), along with indications suggesting that these procedures required larger median volumes of contrast medium (225 versus 175 mL, OR = 5.5, P = .008) as well as a longer median fluoroscopy duration (123.6 versus 99.3 minutes, OR = 3.0, P = .06). Our data did not suggest that delayed leukoencephalopathy was associated with the number of coils (P = .57), microguidewires (P = .35), and guiding systems (P = .57).

CONCLUSIONS

Delayed leukoencephalopathy after coiling of cerebral aneurysms may have multiple etiologies such as foreign body emboli, contrast-induced encephalopathy, or hypersensitivity reaction to foreign bodies.

Hemodynamics and coil distribution with changing coil stiffness and length in intracranial aneurysms

Purpose

The purpose of this study was to investigate hemodynamics and coil distribution with changing coil stiffness and length using the finite element method (FEM) and computational fluid dynamics (CFD) analysis.

Methods

Basic side-wall and bifurcation type aneurysm models were used. Six types of coil models were generated by changing the coil stiffness and length, based on commercially available embolic coils. Coil embolization was simulated using FEM. CFD was performed to characterize the hemodynamics in the aneurysms after embolization. Coil distribution and velocity reduction in the aneurysms were evaluated.

Results

The median value of radial coil distribution was shifted from the center to the outer side of the aneurysmal dome by changing coil stiffness: harder coils entered the outer side of the aneurysmal dome more easily. Short coils were more distributed at the neck region, since their small size made it easy for them to enter the tighter area. CFD results also indicated that velocity in the aneurysm was effectively reduced when the coils were more distributed at the neck region and the outer side of the aneurysmal dome because of the disturbance in blood inflow.

Conclusions

It is easier for coils to enter the outer side of the aneurysmal sphere when they are harder. If coils are short, they can enter tighter areas more easily. In addition, high coil density at the outer side of the aneurysmal dome and at the neck region is important to achieve effective velocity reduction.

A new combined parameter predicts re-treatment for coil-embolized aneurysms: a computational fluid dynamics multivariable analysis study

Purpose

Coil embolization is a minimally invasive method used to treat cerebral aneurysms. Although this endovascular treatment has a high success rate, aneurysmal re-treatment due to recanalization remains a major problem of this method. The purpose of this study was to determine a combined parameter that can be useful for predicting aneurysmal re-treatment due to recanalization.

Methods

Patient-specific geometries were used to retrospectively analyze the blood flow for 26 re-treated and 74 non-retreated aneurysms. Post-operatively aneurysms were evaluated at 12-month follow-up. The hemodynamic differences between the re-treatment and non-retreatment aneurysms were analyzed before and after coil embolization using computation fluid dynamics. Basic fluid characteristics, rates of change, morphological factors of aneurysms and patient-specific clinical information were examined. Multivariable analysis and logistic regression analysis were performed to determine a combined parameter—re-treatment predictor (RP).

Results

Among examined hemodynamic, morphological, and clinical parameters, slight reduction of blood flow velocity rate in the aneurysm, slight increase of pressure rate at the aneurysmal neck and neck area, and hypertension were the main factors contributing to re-treatment. Notably, hemodynamic parameters between re-treatment and non-retreatment groups before embolization were similar: however, we observed significant differences between the groups in the post-embolization average velocity and the rate of reduction in this velocity in the aneurysmal dome.

Conclusions

The combined parameter, RP, which takes into consideration hemodynamic, morphological, and clinical parameters, accurately predicts aneurysm re-treatment. Calculation of RP before embolization may be able to predict the aneurysms that will require re-treatment.

Risk factors for angiographic recurrence after treatment of unruptured intracranial aneurysms: Outcomes from a series of 178 unruptured aneurysms treated by regular coiling or surgery

BACKGROUND

Long-term stability after intracranial aneurysm exclusion by coiling is still a matter of debate; after surgical clipping little is known.

OBJECTIVE

To study outcome after endovascular and surgical treatments for unruptured intracranial aneurysms in terms of short- and long-term angiographic exclusion and risk factors for recanalization.

METHODS

From 2004 and 2009, patients treated for unruptured berry intracranial aneurysms by coiling or clipping were reviewed. Aneurysmal exclusion was evaluated using the Roy-Raymond grading scale; immediate clinical outcome was also assessed. Clinical outcome, recanalization, risk factors for recurrence and bleeding during the follow-up period were analyzed by groups; "surgery" and "embolization".

RESULTS

From 2004 to 2009, 178 consecutive unruptured aneurysms were treated. The post-procedure angiographic results for "surgery" were: total exclusion 75.6%; residual neck 13.5%; residual aneurysm 10.8%. For "embolization", the results were, respectively: 72%; 20.7%; and 7.2%. Morbidity was 3% for "surgery" and 1.6% for "embolization" (P=0.74); mortality was nil. Mean clinical and angiographic follow-up was 5years. Recurrence rate was of 11.5% for "surgery" vs. 44% for "embolization" with a mean follow-up of 4 and 5.75years, respectively (P=1.10-5). The retreatment rate was 8.4%. Two significant risk factors for recanalization were identified: maximum diameter of the aneurysm sac (P=0.0038) and pericallosal location (P=0.0388). No bleeding event occurred.

CONCLUSION

Both techniques are safe. The rate of aneurismal recurrence was significantly higher for embolization, especially for large diameter aneurysms and pericallosal locations. No bleeding event occurred after recanalization.

Blood Flow Into Basilar Tip Aneurysms

Background and Purpose—

Hemodynamic forces may play a role in the recanalization of coiled aneurysms. The purpose of this study was to investigate the influence of presurgical hemodynamics on the efficacy of coil embolization for basilar tip aneurysms.

Methods—

We identified 82 patients who underwent endovascular coil embolization for basilar tip aneurysms with a follow-up of >1 year. Presurgical hemodynamics were investigated using computational fluid dynamics with 3-dimensional data derived from rotational angiography. During postprocessing, we quantified the rate of net flow entering the aneurysm through its neck and calculated the proportion of the aneurysmal inflow rate to the basilar artery flow rate. In addition, we investigated the correlation between the basilar bifurcation configuration and the hemodynamics.

Results—

Twenty-five of the 82 patients were excluded because of difficult vascular geometry reconstruction. Among the 57 examined patients, angiographic recanalization was observed in 19 patients (33.3%). The proportion of the aneurysmal inflow rate to the basilar artery flow rate and a coil packing density <30% were independent and significant predictors for the recanalization of coiled aneurysms. Additional investigation revealed that a small branch angle formed by the basilar artery and the posterior cerebral artery increased blood flow into the aneurysm.

Conclusions—

The proportion of the aneurysmal inflow rate to the basilar artery flow rate, influenced by the basilar bifurcation configuration, was an independent and significant predictor for recanalization after coil embolization in basilar tip aneurysms.

Endovascular Treatment Using Detachable Coils for Non-Ruptured Intracranial Aneurysm

Detachable coil embolization was performed on 34 non-ruptured cerebral aneurysms in 33 patients. Patients consisted of 28 females and five males, with an age range of 26 to 77 years.

Angiographic examination after coil embolization revealed complete or near-complete occlusion in 24 aneurysms (70.5%) and partial occlusion in three (8.8%). Detachable coil embolization was attempted unsuccessfully in seven aneurysms (20.5%).

Transient ischemic attack occurred in one case with coil migration. The combined mortality/morbidity rate was 0%.

Follow-up Study on Intra-Aneurysmal Embolization for Unruptured Cerebral Aneurysms

We describe follow-up clinical and angiographical results in patients with unruptured cerebral aneurysms treated with IDC or GDC. In 28 patients who underwent intra-aneurysmal occlusion for unruptured aneurysms, there were no permanent neurological deficits in the periprocedural period, while three transient neurological deficits were observed.

On the angiograms obtained immediately after the procedure, complete aneurysmal occlusion was achieved in three patients (10.7%), a small neck remnant was detected in two cases (7.1%), a body filling in 12 cases (42.9%) and both of them were detected in 11 patients (39.3%). On the follow up angiograms (median angiographical follow-up period 15.6 months), 46.4% of incompletely obliterated aneurysms showed aneurysmal recanalization, and a incompletely embolized aneurysm ruptured 15 months after initial embolization.

Detachable platinum coil embolization is a safe treatment for unruptured aneurysms with a lower incidence of peri-procedural morbidity, wheareas follow-up results are less satisfactory in cases involving incompletely obliterated lesions. With this limitation in mind, patients need to be very carefully chosen for GDC embolization and strict follow-up angiography is mandatory when a complete embolization is not achieved.

"Two-coil technique" for embolization of small internal carotid artery aneurysms incorporating the origin of the anterior choroidal artery

PURPOSE

The purpose of this article is to evaluate the efficacy, safety and stability of the "two-coil technique."

MATERIALS AND METHODS

We evaluated a single-center experience by using a two-coil technique, which is a variation of the multiple-microcatheter technique in the treatment of a small internal carotid artery aneurysm with its sac incorporated with the origin of the anterior choroidal artery. Six consecutive patients with small ICA aneurysms with its sac incorporated with origin of the anterior choroidal artery and treated with the two-coil technique were included in this study. We finished the embolization with only two coils introduced via two different microcatheters without any other device assistance in all cases. Embolization status was determined at immediate postoperative and follow-up angiography after six months.

RESULTS

The two-coil technique was technically successful in five of six cases; one case was converted to surgical clipping because of persistent occlusion of the anterior choroidal artery after several attempts. On follow-up study, all five cases showed stable occlusion status without recanalization or residual aneurysm.

CONCLUSIONS

The two-coil technique has potential to be used for coiling small aneurysms, particularly where there is an important branch incorporated into the sac or neck of the aneurysm.

Guidelines for the Management of Patients With Unruptured Intracranial Aneurysms: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this updated statement is to provide comprehensive and evidence-based recommendations for management of patients with unruptured intracranial aneurysms.

METHODS

Writing group members used systematic literature reviews from January 1977 up to June 2014. They also reviewed contemporary published evidence-based guidelines, personal files, and published expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulated recommendations using standard American Heart Association criteria. The guideline underwent extensive peer review, including review by the Stroke Council Leadership and Stroke Scientific Statement Oversight Committees, before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with unruptured intracranial aneurysms. The guidelines address presentation, natural history, epidemiology, risk factors, screening, diagnosis, imaging and outcomes from surgical and endovascular treatment.

Incidence and clinical implications of carotid branch occlusion following treatment of internal carotid artery aneurysms with the pipeline embolization device

BACKGROUND

The use of flow diverters such as the pipeline embolization device (PED) for treatment of intracranial aneurysms carries the risk of side branch occlusion.

OBJECTIVE

To determine the incidence and clinical outcomes associated with supraclinoid internal carotid artery (ICA) branch occlusion after deployment of PEDs for ICA aneurysms.

METHODS

We reviewed patients who underwent endovascular treatment with PEDs for ICA aneurysms between June 2011 and March 2013. Forty-nine patients (43 women, mean age 56.3±1.8 years, 68 aneurysms) in whom PEDs traversed the origin of supraclinoid ICA branches (ophthalmic [OA], posterior communicating [PcommA], and anterior choroidal artery [AChA]) were selected for this study. Follow-up angiograms (mean follow-up, 12.8±0.8 months) were studied to determine the location of PEDs and the patency of ICA branches.

RESULTS

PEDs were placed across the ostia of 49 OAs, 14 PcommAs, and 11 AChAs. Multiple PEDs were deployed in 16 patients. Rate of branch occlusion was 4% (2/49) for the OA, 7.1% (1/14) for the PcommA, and 0% for the AChA. Patients with branch occlusion did not endure new neurological deficits. ICA branch occlusion was not associated with the number of PEDs covering the ostia (P=.76) or the origin of ICA branches from the aneurysm (P=.24).

CONCLUSION

The incidence of major supraclinoid ICA branch occlusion after treatment with PEDs was low. These events were not associated with new neurological deficits nor were they related to the number of PEDs deployed or the origin of ICA branches from the aneurysm.

Temporo-sylvian anastomosis and aneurysm clipping in a case of left M1 aneurysm with progressive evolution after initial embolization; Case report

A giant unrupted middle cerebral artery aneurysm partially thrombosed, previously endovascularly treated after a mild right hemiparesis remitted. After 12 months, in routine check we discovered a reperfusion of the aneurysm and decide ECIC bypass and clipping, with a good outcome

Management strategy of surgical and endovascular treatment of unruptured paraclinoid aneurysms based on the location of aneurysms

OBJECTIVE

Advances in endovascular treatment (EVT) have greatly improved the treatment outcomes of paraclinoid aneurysms. However, EVT had the shortcoming of durability and thromboembolic complications. As well, surgical treatment of paraclinoid aneurysms is still challenging due to the complexity of adjacent structures. The objective of this study is to report our experience with a combined surgical and endovascular treatment of unruptured paraclinoid aneurysms based on the location of aneurysms.

METHODS

A retrospective review was conducted of 185 cases of unruptured paraclinoid aneurysms that underwent surgical or endovascular treatment between September 2008 and August 2012. Thirty-one aneurysms (16.8%) were treated by microsurgery and 154 (83.2%) were treated by EVT. Fifty aneurysms (27.0%) were classified to the dorsal group and 135 (73%) were classified to the non-dorsal group.

RESULTS

Twenty of 50 dorsal group aneurysms (40%) were treated by microsurgery while 124 of 135 non-dorsal group aneurysms (91.9%) underwent an EVT. The rate of complete occlusion was 96.8% in surgical series and 60.4% in EVT (P < 0.001). Recanalization occurred in 9 aneurysms (5.8%) of EVT and 1 aneurysm (3.2%) of surgical series (P = 0.360). In non-dorsal group, transient complications (10 aneurysms (5.4%), P = 0.018) and morbidity at last visiting (6 aneurysms (3.2%), P = 0.021) were more present in surgically treated cases rather than in EVT cases. Diplopia and visual field defect occurred in the non-dorsal group only; in 2 of 11 surgical cases (18.2%) and in 1 of 124 EVT series (0.8%) (P = 0.017). The overall rate of excellent or good clinical outcomes (Glasgow outcome scale 5 or 4) was 98.9%.

CONCLUSION

EVT is a safe and effective treatment for the non-dorsal group. Based on angiographic and clinical aspects, microsurgical clipping has prior efficacy with better outcomes in the dorsal group under proper individualized selection.

Thromboembolic event detected by diffusion weighted magnetic resonance imaging after coil embolization of cerebral aneurysms

Objective

The purpose of this study was to evaluate the occurrence rate of diffusion positive lesions (DPLs), and to assess the peri-procedural risk factors for the occurrence of DPLs in patients who underwent coil embolization of cerebral aneurysms.

Materials and Methods

A total of 304 saccular aneurysms were embolized during a seven-year period from Jan 2007 to Dec 2013. Of these, postoperative diffusion-weighted images were obtained in 186 procedures. There were 100 ruptured aneurysm and 86 unruptured aneurysms. The coiling procedures were as follows: simple coiling in 96, balloon assisted coiling (BAC) in 39, and stent assisted coiling (SAC) in 51 aneurysms. Clinical, angiographic and procedural factors were analyzed in relation to the occurrence of DPLs.

Results

Overall, DPLs were observed in 50.5%. In unruptured aneurysms, DPLs occurred in 23.5% of BAC, 41.9% of SAC and 57.7% of simple coiling (p = 0.08). Among ruptured aneurysms, DPLs occurred in 63.6% of BAC, 62.5% of SAC and 54.3% of simple coiling (p = 0.71). DPLs had a tendency to increase in ruptured aneurysms compared with unruptured aneurysms (57% vs. 43%, p = 0.077). Logistic regression analysis revealed that age > 55 years was the only independent risk factor for the occurrence of DPLs.

Conclusion

DPLs occured more frequently in ruptured aneurysm and at an older age. Although most DPLs are asymptomatic, careful manipulation of cerebral or extracerebral arteries using various endovascular devices is important to reducing the occurrence of DPLs. BAC appeared to reduce occurrence of TE events in patient with unruptured aneurysm.

Thromboembolic Events Associated with Electrolytic Detachment of Guglielmi Detachable Coils and Target Coils : Comparison with Use of Diffusion-Weighted MR Imaging

Objective

The purpose of this study was to retrospectively evaluate and compare the incidence of diffusion-weighted image (DWI) lesions between the Guglielmi detachable coil (GDC) and the Target coil for treating unruptured intracranial aneurysm.

Methods

From 2010 to 2011, consecutive 222 patients with an intracranial aneurysm underwent coil embolization. Inclusion criterias were : 1) unruptured intracranial aneurysm, 2) one or more GDC or Target coils used with or without other coils, 3) DWI examination within 24 hours after coiling, and 4) coiling performed without a balloon or stent.

Results

Ninety patients (92 cases) met the inclusion criteria. DWI lesions were detected in 55 (61.1%) of 90 patients. In the GDC group (n=44), DWI lesions were detected in 31 (70.5%). The average number of DWI lesions was 5.0±8.7 (mean±SD; range, 1-40) in aneurysm-related territory. In the Target coil group (n=48), DWI lesions were detected in 24 (50.0%). The number of DWI lesion was 2.1±5.4 (range, 1-32) in aneurysm-related territory. There was no significant correlation between a number of coils and DWI lesions. No significant differences were also observed in the number of DWI lesions in each group.

Conclusion

The GDC and Target coils, which have an electrolytic detachable system, showed no differences in the incidence of DWI lesion.

Delayed rupture of a basilar artery aneurysm treated with coils: case report and review of the literature

Delayed rupture of a previously unruptured cerebral aneurysm after uneventful saccular coil packing is rare, particularly when the quality of aneurysm occlusion is appropriate (neck remnant or total occlusion). The present report describes the case of a 70-year-old woman with an incidentally detected, asymptomatic, small basilar tip non-thrombosed aneurysm who experienced rupture of the aneurysm 2 years after coiling. Cerebral angiography taken on the day of rupture revealed only small recanalization of the aneurysm neck with no dome-filling. This is the first report of delayed rupture due to minor recurrence of a previously unruptured small asymptomatic cerebral aneurysm after saccular coil packing. A literature review of 26 reports of late bleeding after coil embolization of previously unruptured cerebral aneurysms showed that dome-filling after coil embolization, symptomatic aneurysms and large/giant aneurysms all increase the risk of delayed rupture in previously unruptured aneurysms after saccular coil packing.

Interobserver agreement after pipeline embolization device implantation

BACKGROUND AND PURPOSE

Although flow diversion devices are popular in treatment of aneurysms, angiographic assessment with these devices has rarely been verified by interobserver variability study. The purpose of this study was to determine the interobserver agreement of a 3-point grading system for assessing the angiographic outcome after flow diversion therapy of intracranial, saccular aneurysms and to determine factors affecting such agreement.

MATERIALS AND METHODS

After approval by the institutional review board, 5 independent readers assessed pretreatment and follow-up digital subtraction angiograms from 96 patients treated with the Pipeline embolization device by using a 3-point grading system (complete, near-complete, and incomplete occlusion). "Minor discrepancy" was defined as a difference between any 2 readers of 1 grade, that is, complete vs near-complete or near-complete vs incomplete. "Major discrepancy" was defined as a difference between any 2 readers in which 1 reader noted complete occlusion and the other reader noted incomplete occlusion. We performed statistical analysis for the interobserver agreement by using the intraclass correlation coefficient. Subgroup analyses for discrepancy rate and ICC were performed for previously coiled aneurysms.

RESULTS

The interobserver agreement was excellent (ICC, 0.76; 95% CI, 0.69-0.92). Among 96 cases, there was absolute agreement in 74 (77%), of which 67 had unanimous consensus of "complete" occlusion, 2 "near-complete" occlusion, and 5 "incomplete" occlusion. Discordance between any 2 readers was noted in 22 cases (23%), of which 7 (7.3%) revealed a major discrepancy. Subgroup analysis showed that minor discrepancies were more common among patients previously treated with coils vs those not previously treated with coils (37.5% vs 11.2%; P < .05).

CONCLUSIONS

The observer agreement regarding occlusion after PED therapy is excellent. Only a minority of cases demonstrated discrepancy considered as major in this study.

Endovascular therapy of 500 small asymptomatic unruptured intracranial aneurysms

BACKGROUND AND PURPOSE

Although the natural course of UIAs remains unclear, the risk of aneurysmal SAH due to small (<10 mm) asymptomatic UIAs is low. Endovascular therapy for UIAs has increased because of device development and the need for less invasive treatment. We report the results, safety, and efficacy of endovascular therapy of small asymptomatic UIAs.

MATERIALS AND METHODS

A total of 457 patients with 500 small asymptomatic UIAs (maximum diameter < 10 mm) underwent endosaccular coil embolization at Juntendo University Hospital and affiliated hospitals. We retrospectively evaluated the technical feasibility, immediate and short-to-midterm follow-up anatomic results, procedure-related complications, and clinical outcomes.

RESULTS

Endosaccular coil embolization was completed in 481 aneurysms (96.2%) and attempted in 19 (3.8%). Completed aneurysms were treated with the simple (39.5%), balloon-assisted (51.4%), and double-catheter (9.1%) techniques. Immediate angiographic outcomes were CO for 309 (64.2%) aneurysms, RN for 72 (15.0%), and RA for 100 (20.8%). Procedure-related complications occurred in 38 aneurysms (7.6%): 19 ischemic, 11 hemorrhagic, and 8 others. Permanent morbidity and mortality were 0.8% and 0.2%, respectively. Anatomic outcome of 427 aneurysms followed up for >6 months with conventional catheter or MR angiographies showed recanalization in 72 (16.9%) aneurysms, necessitating retreatment in 9.9% (mean, 31.4 months). No patients had aneurysmal SAH during the clinical follow-up period (mean, 34.7 months).

CONCLUSIONS

In this series, endovascular therapy of small asymptomatic UIAs was highly feasible with low morbidity and mortality rates.

CFD and PIV analysis of hemodynamics in a growing intracranial aneurysm

Hemodynamics is thought to be a fundamental factor in the formation, progression, and rupture of cerebral aneurysms. Understanding these mechanisms is important to improve their rupture risk assessment and treatment. In this study, we analyze the blood flow field in a growing cerebral aneurysm using experimental particle image velocimetry (PIV) and computational fluid dynamics (CFD) techniques. Patient-specific models were constructed from longitudinal 3D computed tomography angiography images acquired at 1-y intervals. Physical silicone models were constructed from the computed tomography angiography images using rapid prototyping techniques, and pulsatile flow fields were measured with PIV. Corresponding CFD models were created and run under matching flow conditions. Both flow fields were aligned, interpolated, and compared qualitatively by inspection and quantitatively by defining similarity measures between the PIV and CFD vector fields. Results showed that both flow fields were in good agreement. Specifically, both techniques provided consistent representations of the main intra-aneurysmal flow structures and their change during the geometric evolution of the aneurysm. Despite differences observed mainly in the near wall region, and the inherent limitations of each technique, the information derived is consistent and can be used to study the role of hemodynamics in the natural history of intracranial aneurysms.

Endovascular treatment of basilar artery trunk aneurysms

BACKGROUND

There has been little reported on the endovascular experience of basilar artery (BA) trunk aneurysms due to its low incidence. The purpose of this study is to report the results of endovascular treatment (EVT) of BA trunk aneurysms.

METHODS

Between 2004 and 2008, eight BA trunk aneurysms were treated by EVT. Five patients presented with subarachnoid hemorrhage, one had intracranial mass effect, and in two of the patients the aneurysms were found incidentally. Four lesions were saccular aneurysms, three of them were found with BA fenestration. Three lesions were dissecting aneurysms and one was a giant fusiform aneurysm. The mean follow-up period of clinical outcome was 17.1 months (range, 6-32 months). Angiographic follow-up data was obtained in six patients for period of a mean of 15.6 months (range, 6-25 months).

RESULTS

Four patients with saccular aneurysms were treated by stent-assisted coil embolization except for one patient that was treated without a stent. Three patients with dissecting aneurysms were treated by a single stent placement. One of these dissecting aneurysms rebled in 4 days after stent placement and was secured by BA occlusion. One giant fusiform aneurysm was treated by bilateral vertebral artery (VA) occlusion after balloon test occlusion. Six patients (75.0%) had excellent or good clinical outcomes, one patient whose aneurysm rebled became vegetative, and one patient with bilateral VA occlusion died. Follow-up angiograms showed that four lesions had complete occlusion and two had neck remnant.

CONCLUSIONS

The endovascular catheterization of these lesions tends to be relatively simple compared to more complex neurosurgical approaches. EVT, especially using a stent, could be a valuable therapeutic method in treating BA trunk aneurysms.

Influence of clinical and anatomic features on treatment decisions for anterior communicating artery aneurysms

OBJECTIVE

The purpose of this study was to analyze the clinical and anatomic features involved in determining treatment modalities for anterior communicating artery (AcoA) aneurysms.

METHODS

The authors retrospectively evaluated 112 AcoA aneurysms with pretreatment clinical features including age, Hunt and Hess grade, medical or neurological comorbidity, and anatomical features including aneurysm size, neck size, dome-to-neck ratio, vessel incorporation, multiple lobulation, and morphologic scoring system. Post-treatment clinical results were classified according to the Glasgow Outcome Scale, and anatomic results in coiled patients were classified according to the modified Raymond scale. Using multivariate logistic regression, the probabilities for decision making between surgical clipping and coil embolization were calculated.

RESULTS

Sixty-seven patients (60%) were treated with surgical clipping and 45 patients (40%) with endovascular coil embolization. The clinical factor significantly associated with treatment decision was age (≥65 vs. <65 years) and anatomical factors including aneurysm size (small or large vs. medium), dome-to-neck ratio (<2 vs. ≥2), presence of vessel incorporation, multiple lobulation, and morphologic score (≥2 vs. <2). In multivariate analysis, older patients (age, >65 years) had significantly higher odds of being treated with coil embolization relative to clipping (adjusted OR=3.78; 95% CI, 1.39-10.3; p=0.0093) and higher morphological score patients (≥2) had a higher tendency toward surgical clipping than endovascular coil embolization (OR=0.23; 95% CI, 0.16-0.93; p=0.0039).

CONCLUSION

The optimal decision for treating AcoA aneurysms cannot be determined by any single clinical or anatomic characteristics. All clinical and morphological features need to be considered, and a collaborative neurovascular team approach to AcoA aneurysms is essential.

Sixteen-year single-surgeon experience with coil embolization for ruptured intracranial aneurysms: recurrence rates and incidence of late rebleeding

Object

Over a 16-year period, 570 patients presenting with acute aneurysmal subarachnoid hemorrhage were successfully treated using endosaccular coil embolization within 30 days of hemorrhage by a single surgeon. Patients were followed to assess the stability of aneurysm occlusion and its longer-term efficacy in protecting against rebleeding.

Methods

Patients were followed for 6 to 191 months (mean 73.7 months, median 67 months) by clinical review, angiography performed at 6 and 24 months posttreatment, and questionnaires sent via the postal service every 5 years. Late rebleeding was defined as > 30 days after treatment.

Results

Stable angiographic occlusion was evident in 74.5% of small, 72.2% of large, and 60% of giant aneurysms. Recurrent filling was found in 119 (26.3%) of 452 aneurysms. Rebleeding was diagnosed in 9 patients (6 treated aneurysms) and occurred between 2 and 114 months posttreatment. It was due to aneurysm recurrence in 6 patients, rupture of a coincidental untreated aneurysm in 2 patients, and rupture of a de novo aneurysm in 1 patient. Rebleeding occurred in 3 (2.5%) of 119 unstable aneurysms and in 3 (0.9%) of 333 stable aneurysms, as seen on initial follow-up angiography studies. Annual rebleeding rates ranged from 0.2% to 0.6% for all causes and from 0.2% to 0.4% for rebleeding of treated aneurysms. No rebleeding was recorded after the first decade, with 138 patients having more than 10 years of follow-up.

Conclusions

Periodic follow-up with angiographic studies after coil embolization is recommended to identify aneurysm recurrence and patients at a high risk of late rebleeding in the medium term. More frequent follow-up is recommended for patients harboring coincidental unruptured aneurysms.

Long-term follow-up study of endovascularly treated intracranial aneurysms

Long-term follow-up studies after endovascular treatment for intracranial aneurysm are still rare and inconclusive. The aim of this study was to assess long-term clinical and angiographic outcome of patients with endovascularly treated aneurysms. The Clinical outcome of all 185 patients with endovascularly treated aneurysms were analyzed and 77 out of 122 surviving patients were examined with MRI and MRA nine to 16 years (mean 11 years) after the initial endovascular treatment. Sixty-three patients were deceased at the time of follow-up. The cause of death was aneurysm-related in 34 (54%) patients. The annual rebleeding rate from the treated aneurysms was 1.3% in the ruptured group and 0.1% in the unruptured group. In long-term follow-up MRA 18 aneurysms (53%) were graded as complete, 11 aneurysms (32%) had neck remnants and five aneurysms (15%) were incompletely occluded in the ruptured group. Occlusion grade was lower in the unruptured group with 20 aneurysms (41%) graded as complete, 11 (22%) had neck remnants and 18 (37%) were incomplete. However, only three aneurysms were unstable during the follow-up period and needed retreatment. Endovascular treatment of unruptured aneurysms showed incomplete angiographic outcome in 37% of cases. However, annual bleeding rate was as low as 0.1%. Endovascular treatment of ruptured aneurysms showed incomplete angiographic outcome in 15% of cases and the annual rebleeding rate was 1.3%.

Long-term follow-up study of endovascularly treated intracranial aneurysms

Long-term follow-up studies after endovascular treatment for intracranial aneurysm are still rare and inconclusive. The aim of this study was to assess the long-term clinical and angiographic outcome of patients with endovascularly treated aneurysms. The clinical outcome of all 185 patients with endovascularly treated aneurysms were analyzed and 77 out of 122 surviving patients were examined with MRI and MRA nine to 16 years (mean 11 years) after the initial endovascular treatment. Sixty-three patients were deceased at the time of follow-up. The cause of death was aneurysm-related in 34 (54%) patients. The annual rebleeding rate from the treated aneurysms was 1.3% in the ruptured group and 0.1% in the unruptured group. In long-term follow-up MRA 18 aneurysms (53%) were graded as complete, 11 aneurysms (32%) had neck remnants and five aneurysms (15%) were incompletely occluded in the ruptured group. The occlusion grade was lower in the unruptured group with 20 aneurysms (41%) graded as complete, 11 (22%) had neck remnants and 18 (37%) were incomplete. However, only three aneurysms were unstable during the follow-up period and needed retreatment. Endovascular treatment of unruptured aneurysms showed incomplete angiographic outcome in 37% of cases. However, the annual bleeding rate was as low as 0.1%. Endovascular treatment of ruptured aneurysms showed incomplete angiographic outcome in 15% of cases and the annual rebleeding rate was 1,3%.

[Middle cerebral artery infarct after aneurysm coiling]

The report concerns a 44-year-old female patient with incidental left middle cerebral artery aneurysm. After endovascular therapy by coiling, a hemiparesis was observed following extubation. Disturbance of speech and disorientation added later. An infarct of the lenticular nucleus was found. The angiography showed an occlusion of a frontal opercular branch of the left middle cerebral artery. The fact-finding board for medical liability should investigate, if the infarct with continuous neurological deficits is explained by improper treatment and if the following management of complication was adequate. A neuroradiologic opinion was requested. Based on that, the board came to the result that no incorrect medical treatment was done.

Endovascular coil occlusion of 152 middle cerebral artery aneurysms: initial and midterm angiographic and clinical results

OBJECT

The object of this study was to evaluate the initial and mid-term angiographic and clinical results after endovascular coil occlusion of middle cerebral artery (MCA) aneurysms at the authors' institution.

METHODS

The authors conducted a retrospective analysis of a consecutive series of 152 MCA aneurysms (73 ruptured) treated by endovascular coiling in 140 patients. Angiographic and clinical data at initial and midterm follow-up as well as procedure-related complications were prospectively registered.

RESULTS

At discharge, favorable clinical outcomes (Glasgow Outcome Scale score of 1 or 2) were obtained in 89.3% of patients (125/140). Seven patients (5%) were in a vegetative state or had died. Complications were encountered in association with 11.8% of the procedures (18/152), and most (13/18) involved thromboembolic events (which led to permanent ischemia in 4 cases and death in 1). The overall procedure-related mortality rate was 0.7%, and the rates of permanent and transient morbidity were 2.6 and 2%, respectively. At a mean follow-up duration of 4.3 years there had been 4 cases of rebleeding: early rebleeding occurred during the initial postoperative period in 3 cases and later in 1. Total or subtotal occlusion was obtained in 84.2% of aneurysms (128/152). At follow-up, this satisfactory occlusion persisted in 83.3% of aneurysms (110/132) at 1 year posttreatment, 79.5% (89/112) at 3 years, and 80.2% (73/91) at 5 years.

CONCLUSIONS

Risks and initial and midterm angiographic and clinical results after endovascular treatment of MCA aneurysms are nearly identical to other locations. Endovascular treatment may thus be proposed as an alternative to surgical clipping at this location. Nevertheless, a longer follow-up period is necessary to determine its efficacy, particularly in cases of unruptured aneurysms.

Endovascular treatment of ACom intracranial aneurysms. Report on series of 280 patients

The immediate and long-term outcomes, complications, recurrences and the need for retreatment were analyzed in a series of 280 consecutive patients with anterior communicating artery aneurysms treated with the endovascular technique. From October 1992 to October 2001 280 patients with 282 anterior communicating artery aneurysms were addressed to our center. For the analysis, the population was divided into two major groups: group 1, comprising 239 (85%) patients with ruptured aneurysms and group 2 comprising of 42 (15%) patients with unruptured aneurysms. In group 1, 185 (77.4%) patients had a good initial pre-treatment Hunt and Hess grade of I-III. Aneurysm size was divided into three categories according to the larger diameter: less than 4 mm, between 4 and 10 mm and larger than 10 mm. The sizes of aneurysms in groups 1 and 2 were identical but a less favorable neck to depth ratio of 0.5 was more frequent in group 2. Endovascular treatment was finally performed in 234 patients in group 1 and 34 patients in group 2. Complete obliteration was more frequently obtained in group 2 unlike a residual neck or opacification of the sac that were more frequently seen in group 1. No peri-treatment complications were recorded in group 2. In group 1 the peri-treatment mortality and overall peri-treatment morbidity were 5.1% and 8.1% respectively. Eight patients (3.4%) in group 1 presented early post treatment rebleeding with a mortality of 88%. The mean time to follow-up was 3.09 years. In group 1, 51 (21.7%) recurrences occurred of which 14 were minor and 37 major. In group 2, eight (23.5%) recurrences occurred, five minor and three major. Two patients (0.8%) presented late rebleeding in group 1. Twenty-seven second endovascular retreatments were performed, 24 (10.2%) in group 1 and three (8.8%) in group 2, seven third endovascular retreatments and two surgical clippings in group 1 only. There was no additional morbidity related to retreatments. Endovascular treatment is an effective method for the treatment of anterior communicating artery aneurysms allowing late rebleeding prevention. Peri-treatment rebleeding warrants caution in anticoagulation management. This is a single center experience and the follow-up period is limited. Patients should be followed-up in the long-term as recurrences may occur and warrant additional treatment.

[Treatment of grade 0 intracranial aneurysms: Retrospective study of 79 cases]

AIM

Without precise international recommendations, despite the advances of the ISUAA study, the superiority of microsurgery or endovascular treatment for unruptured intracranial aneurysm (UIA) over the natural history of this disease has not been proved. In this context, the authors evaluate their experience with the aim of assessing the results and risks of the different therapeutics and comparing them with the natural risk of this disease.

MATERIAL AND METHOD

From January 1993 to July 2000, 79 patients harboring 110 UIAs were treated. These patients were divided retrospectively into two groups. Group A included 45 operated patients. Group B included 37 patients treated with endovascular coiling. The therapeutic choice was not randomized and was approved by a multidisciplinary neurovascular staff.

RESULTS

The two populations were homogeneous in terms of age and sex. In group A, 12 patients presented early complications (26.6 %), with one death. In group B, 15.6 % of the patients presented an ischemic complication. After 1 year of follow-up, morbidity was 11.4 % in group A and 4.8 % for group B. Angiography found a partial recanalization in 12.5 % of the operated patients and in 33 % of the patients treated with endovascular coiling.

DISCUSSION

Many factors are involved in the therapeutic decision: UIA location and size and individual risks. Progress in both surgery and interventional neuroradiology has led to good results conforming with the data reported in the literature but does not demonstrate the superiority of one technique over another.

Immediate anatomic results after the endovascular treatment of unruptured intracranial aneurysms: analysis of the ATENA series

BACKGROUND AND PURPOSE

A precise analysis of the immediate postoperative anatomic results in a large series of unruptured intracranial aneurysms treated by endovascular approach has not previously been presented. This study aimed to assess the efficacy of endovascular treatment of unruptured intracranial aneurysms in light of immediate postoperative anatomic results in a prospective, multicenter study (the Analysis of Treatment by Endovascular Approach of Nonruptured Aneurysms study; ATENA).

MATERIALS AND METHODS

Postoperative anatomic results from digital subtraction angiography (DSA) were evaluated with the Montreal scale by the treating physician and by 2 anonymous, independent, experienced neuroradiologists.

RESULTS

The analysis included 622 patients (449 women, 173 men; age range, 22-83 years; mean age, 51.2 +/- 11.3 years) harboring 694 aneurysms. Evaluation of the postoperative anatomic results by the 2 independent reviewers indicated total occlusions in 437 aneurysms (63.0%), neck remnants in 156 aneurysms (22.5%), and aneurysm remnants in 101 aneurysms (14.6%). Several factors favorably affected the quality of the aneurysm occlusion with treatment, including patient age (< 65 years old; P < .0001), aneurysm diameter (<or= 6 mm; P = .0049), aneurysm dome-to-neck ratio (> 1.5; P = .0388), and endovascular technique (coiling or remodelling compared with stent placement; P = .0001).

CONCLUSIONS

The endovascular treatment of unruptured aneurysms provided satisfactory postoperative occlusion rates, with a high percentage of complete occlusion or neck remnants (85.4%). Postoperative anatomic results were significantly affected by aneurysm size and neck size, but not aneurysm location.

Types of thromboembolic complications in coil embolization for intracerebral aneurysms and management

OBJECTIVE

We describe our clinical experiences and outcomes in patients who had thromboembolic complications occurring during endovascular treatment of intracerebral aneurysms with a review of the literature. The types of thromboembolic complications were divided and the treatment modalities for each type were described.

METHODS

Between August 2004 and March 2009 we performed endovascular embolization with Guglielmi detachable coils for 173 patients with 189 cerebral aneurysms, including ruptured and unruptured aneurysms at our hospital. Sixty-eight patients were males and 105 patients were females. The age of patients ranged from 22-82 years (average, 58.8 years). We retrospectively evaluated this group with regard to complication rates and outcomes. The types of thromboembolic complications were classified into the following three categories: mechanical obstruction, distal embolic stroke, and stent-induced complications, which corresponded to types I, II, and III, respectively. A comparison of the clinical results was made for each type of complication.

RESULTS

Only eight patients had a thromboembolic complication during or after a procedure (4.6%). Of the eight patients, two had a mechanical obstruction as the causative factor; the other three patients had distal embolic stroke as the causative factor. The remaining three patients had stent-induced complications. In cases of mechanical obstruction, recanalization occurred due to the use of intra-arterial thrombolytic agents in one of two patients. Nevertheless, a poor prognosis was seen. In the cases of stent-induced complications, in one of three patients in whom a thrombus developed following stent insertion, a middle cerebral artery territory infarct developed with a poor prognosis despite the use of wiring and an intra-arterial thrombolytic agent. In the cases of distal embolic stroke, all three patients achieved good results following the use of antiplatelet agents.

CONCLUSION

Treatment for thromboemboic complications due to mechanical obstruction and stent-induced complications include antiplatelet and intra-arterial thrombolytic agents; however, this cannot guarantee a sufficient extent of effectiveness. Therefore, active treatments, such as balloon angioplasty, stent insertion, and clot extraction, are helpful.

ENDOVASCULAR TREATMENT OF EXPERIMENTAL ANEURYSMS USING A COMBINATION OF THERMOREVERSIBLE GELATION POLYMER AND PROTECTION DEVICES

OBJECTIVE

We developed a new liquid embolic agent, an aqueous solution of thermoreversible gelation polymer (TGP) for the treatment of cerebral aneurysms. This polymer solution has the unique characteristics that allow it to solidify at a specific temperature without solvent. We performed an experimental aneurysm embolization using this liquid embolic agent with and without different protective devices to evaluate its technical feasibility for the treatment of aneurysms.

METHODS

Fourteen side-wall aneurysms were surgically constructed on 14 common carotid arteries of 7 swine. Embolizations were conducted in combination with balloon protection (balloon group, n = 4), microstent protection (stent group, n = 4), and microcoil and microstent protection (stent-coil group, n = 4). Two aneurysms were used as controls. One control aneurysm was not embolized, and the other received control stent placement only. Angiographic follow-up was performed on day 14 and was followed by histopathological evaluation.

RESULTS

Successful TGP solution delivery was conducted in all cases. Complete aneurysm occlusion was achieved in all cases without TGP migration. Follow-up angiograms demonstrated complete occlusion in the stent and stent-coil groups. A small recurrence was observed in the balloon group. Histopathological findings demonstrated neoendothelialization across the necks of the aneurysms.

CONCLUSION

Experimental aneurysms were safely embolized using TGP. Further modifications related to mechanical stability and long-term safety evaluation results are necessary before clinical application.

Coiling of intracranial aneurysms: a systematic review on initial occlusion and reopening and retreatment rates

BACKGROUND AND PURPOSE

The proportion of incompletely occluded aneurysms after coiling varies widely between studies. To assess overall outcome of coiling, we systematically reviewed the literature to determine initial occlusion, reopening, and retreatment rates of coiled aneurysms according to predefined criteria and subgroups.

METHODS

We searched PubMed and EMBASE (January 1999 to September 2008) for studies of >50 coiled aneurysms. Two reviewers independently extracted data. We grouped studies reporting on only ruptured aneurysms, posterior circulation aneurysms, and studies with large proportions of aneurysms >10 mm to assess possible determinants for incomplete occlusion, reopening, and retreatment.

RESULTS

Forty-six studies totalling 8161 coiled aneurysms met inclusion criteria. Immediately after coiling, 91.2% (95% CI, 90.6% to 91.9%) of the aneurysms were adequately occluded. Aneurysm reopening occurred in 20.8% (95% CI, 19.8% to 21.9%) and retreatment was performed in 10.3% (95% CI, 9.5% to 11.0%). Reopening rate was lower in studies reporting on ruptured aneurysms only compared with all studies (11.4% versus 20.8%; relative risk, 0.55; 95% CI, 0.47 to 0.64) and higher in studies focusing on posterior circulation aneurysms compared with studies with >85% anterior circulation aneurysms (22.5% versus 15.5%; relative risk, 1.5; 95% CI,1.2 to 1.7). Regression analysis showed higher retreatment rates with increasing proportion of aneurysms >10 mm (beta=0.252; 95% CI, 0.073 to 0.432). We could not find a relation between reopening and type of coils used.

CONCLUSIONS

At follow-up, one fifth of all coiled intracranial aneurysms shows reopening of which half is retreated. Possible risk factors for aneurysm reopening are location in the posterior circulation and size >10 mm. To confirm our findings, a meta-analysis on individual well-reported patient data is desirable.

Shape memory polymer foams for cerebral aneurysm reparation: effects of plasma sterilization on physical properties and cytocompatibility

Shape memory polyurethanes (SMPUs) represent promising candidate materials for aneurysm embolization, since they could enable clinical problems still associated with these clinical procedures to be overcome. In this work, we report on the characterization of physicochemical, thermomechanical and in vitro interface properties of two SMPU foams (Cold Hibernated Elastic Memory, CHEM), proposed as a material for embolization devices in minimally invasive procedures. Moreover, because device sterilization is mandatory for in vivo applications, effects on the properties of the foams after plasma sterilization were also evaluated. Both foams (CHEM 3520 and CHEM 5520) showed excellent shape recovery ability (recovery rate, R(r), up to 99%) in conventional shape recovery tests, performed at constant heating rate. Transition temperatures (T(trans)), determined by tandelta peaks in dynamic mechanical analysis (DMA), were 32.2 and 45.1 degrees C, for CHEM 3520 and 5520, respectively. The value of T(trans) affects shape memory ability in the recovery test at 37 degrees C, which simulates the behavior after implantation of the device: in fact, R(r) was significantly higher for lower T(trans) foam (R(r) approximately 82% and R(r) approximately 46%, respectively, for CHEM 3520 and CHEM 5520). After plasma sterilization performed by a Sterrad sterilization system, an increase in open porosity was observed: this is probably due to the sterilization cycle; however, no effects on shape recovery behavior were observed. Furthermore, plasma treatment had no significant effect on L929 cells in in vitro cytotoxicity tests, performed on cell culture medium extracts in contact with foams for up to 7 days. Moreover, direct cytocompatibility tests showed a good colonization and growth from L929 cells on CHEM foams, suggesting the effectiveness of an in vivo healing process. All these results seem to suggest that CHEM foams could be advantageously used for manufacturing devices for mini-invasive embolization procedures of aneurysms.

Clinical and radiogical outcomes of endovascular detachable coil embolization in paraclinoid aneurysms : a 10-year experience

OBJECTIVE

Direct surgical clipping of paraclinoid aneurysms poses technical challenges to even very experienced neurosurgeons, making endovascular treatment an alternative treatment modality in many centers. We have therefore retrospectively evaluated the safety and efficacy of endovascular detachable coil embolization of paraclinoid aneurysms.

METHODS

From June 1997 to June 2007, 65 patients underwent endovascular detachable coiling for 67 paraclinoid aneurysms (of which 9 were ruptured and 58 were unruptured) in our institute. Their medical records, radiological images and readings, and operation records were reviewed retrospectively.

RESULTS

After the initial embolization procedure, complete occlusion was achieved in 29 (43.3%) of the aneurysms treated by endovascular detachable coiling. Six aneurysms required retreatment, with two each requiring one, two, or three additional endovascular procedures. Fifty-five (82.1%) aneurysms were measured by three-dimensional time of flight (TOF) magnetic resonance images (MRI) or transfemoral cerebral angiography (TFCA) at a mean follow-up of 29.7 months (range from 4 to 94 months), with 39 aneurysms (70.9%) showing complete occlusion. Thromboembolic events (3.8%) were the most frequent complication. Rupture did not occur during or after any of the procedures. According to the Glasgow Outcome Scale (GOS), 98.4% of the patients treated by coil embolization had a score of 4 or 5.

CONCLUSION

Our results indicate that endovascular detachable coiling is a safe and effective treatment modality in paraclinoid aneurysms.

Vascular neurosurgery following the International Subarachnoid Aneurysm Trial: modern practice reflected by subspecialization

OBJECT

In this paper the authors' goal was to report on and examine (in the context of a large hospital with good endovascular intervention provisions) the activities of a neurosurgeon with a dedicated vascular interest in the era after the International Subarachnoid Aneurysm Trial in the United Kingdom. They also aimed to establish therapeutic trends and outcomes.

METHODS

The authors reviewed the multidisciplinary team activity of 1 neurosurgeon and 2 interventional radiologists during a period of 22 months (2005-2007). They reviewed 281 aneurysm interventions; the majority was used to treat subarachnoid hemorrhage. Data analysis showed a strong preference for endovascular treatment for acute rupture (86.6 vs 13.4%), with a progressively greater role for open microsurgery in the more elective context (57% endovascular vs 43% surgical). They also reviewed 66 interventions for arteriovenous malformations, of which only 6 were surgical. These data are compared against a sample year from 2001 to 2002 (pre-International Subarachnoid Aneurysm Trial), showing comparable rates of surgically treated aneurysms versus endovascularly treated aneurysms, but an increase overall in the number of patients requiring open surgery.

RESULTS

The authors found that excellent outcomes for microsurgical clipping compared with endovascular therapy can be achieved within the current climate. These and previously published data strongly support a continuing role for vascular neurosurgery as a subspecialist interest in combination with a dedicated endovascular service and a multidisciplinary team.

CONCLUSIONS

Despite a trend to prefer coiling for ruptured aneurysms, the authors have shown that there is still a vital role for open surgery in the management of the ruptured and unruptured aneurysm. They consider the remaining role for surgery for arteriovenous malformations within the modern era of endovascular therapy.

Anatomic results and complications of stent-assisted coil embolization of intracranial aneurysms

SUMMARY

The purpose of this study was to evaluate and report our anatomic results and complications associated with stent-assisted coil embolization of intracranial aneurysms using the Neuroform stent. From September 2003 to August 2007, 127 consecutive patients (ruptured 50, 39.4%; unruptured 77, 60.6%) underwent 129 stent-assisted coil embolization procedures to treat 136 aneurysms at our institution. Anatomic results at follow-up, procedure-related complications, and morbidity/mortality were retrospectively reviewed. Stent deployment was successful in 128 out of 129 procedures (99.2%). Forty-seven patients presented with 53 procedure-related complications (37.0%, 47/127). Thromboembolic events (n=17, 13.4%) were the most common complications, followed by intraoperative rupture (n=8, 6.3%), coil herniation (n=5, 3.9%), and postoperative rupture (n=4, 3.1%). For thromboembolic events, acute intra-procedural instent thromboses were observed in two patients and subacute or delayed in-stent thromboses in three patients. Overall mortality rate was 16.5% (21/127) and procedure-related morbidity and mortality rates were 5.5% (7/127) and 8.7% (11/127) retrospectively. Patients with poor grade subarachnoid hemorrhage (Hunt and Hess grade IV or V; 25/127, 19.7%) exhibited 56% (14/25) overall mortality rate and 24% (6/25) procedure-related mortality rate. Immediate angiographic results showed complete occlusion in 31.7% of aneurysms, near-complete occlusion in 45.5%, and partial occlusion in 22.8%. Sixty nine patients in 70 procedures with 77 aneurysms underwent angiographic followup at six months or later. Mean follow-up period was 13.7 months (6 to 45 months). Complete occlusion was observed in 57 aneurysms (74.0%) and significant in-stent stenosis was not found. Thromboembolism and intra/postoperative aneurysm ruptures were the most common complications and the main causes of procedure-related morbidity and mortality. Patients with poor grade subarachnoid hemorrhage showed poor clinical outcomes. Since most complications were induced by stent manipulation and deployment, it is mandatory to utilize these devices selectively and cautiously. While the follow- up angiographic results are promising, further studies are essential to evaluate safety, efficacy, and durability of the Neuroform stent.

The TEAM trial: safety and efficacy of endovascular treatment of unruptured intracranial aneurysms in the prevention of aneurysmal hemorrhages: a randomized comparison with indefinite deferral of treatment in 2002 patients followed for 10 years

The management of patients with unruptured aneurysms remains controversial. Patients with unruptured aneurysms may suffer intracranial haemorrhage, but the incidence of this event is still debated; endovascular treatment may prevent rupture, but involves immediate risks. Hence, the balance of risks and benefits of endovascular treatment is uncertain. Here, we report the design of the TEAM trial, the first international, randomized, controlled trial comparing conservative management with endovascular treatment. Primary endpoint is mortality and morbidity (modified Rankin Score >/= 3) from intracranial haemorrhage or treatment. Secondary endpoints include incidence of hemorrhagic events, morbidity related to endovascular coiling, morphological results, overall clinical outcome and quality of life. Statistical tests compare between probabilities at 5- and 10-years of 1) mortality from haemorrhage related to the lesion, excluding per-operative complications; 2) mortality from haemorrhage or from complications of treatment; 3) combined disease or treatment related mortality and morbidity in the absence of other causes of death or disability. The study will be conducted in 60 international centres and will enroll 2,002 patients equally divided between the two groups, a size sufficient to achieve 80% power at a 0.0167 significance to detect differences in 1) disease or treatment-related poor outcomes from 7-9% to 3-5%; 2) overall mortality from 16 to 11%. Duration of the study is 14 years, the first three years being for patient recruitment plus a minimum of 10 years of follow-up. The TEAM trial thus offers a means to reconcile the introduction of a new approach with the necessity to acknowledge uncertainties.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN62758344 http://www.controlled-trials.com.

Immediate clinical outcome of patients harboring unruptured intracranial aneurysms treated by endovascular approach: results of the ATENA study

BACKGROUND AND PURPOSE

The management of unruptured intracranial aneurysms remains controversial and the results of endovascular treatment are not precisely known because no prospective data exist. The first prospective multicenter study (ATENA) was conducted in Canada and France to determine clinical outcome and risks of this treatment.

METHODS

Six hundred forty-nine patients harboring a total of 1100 aneurysms from 27 Canadian and French neurointerventional centers were prospectively and consecutively treated by endovascular coil embolization. Of these, 739 unruptured intracranial aneurysms were treated during 700 procedures. Aneurysms were selectively treated in the great majority of cases (98.4%) with coils alone (54.5%), the balloon remodeling technique (37.3%), or stenting (7.8%).

RESULTS

Endovascular treatment failed in 32 aneurysms (4.3%). Technical adverse events with or without clinical modification were encountered in 15.4% of patients and included thromboembolic complications (7.1% per procedure), intraoperative rupture (2.6% per procedure), and device-related problems (2.9% per procedure). Adverse events associated with transient or permanent neurological deficit or death were encountered in 5.4% of cases. The 1-month morbidity and mortality rates were 1.7% and 1.4%, respectively.

CONCLUSIONS

Endovascular treatment of unruptured intracranial aneurysms is feasible in a high percentage of cases with low morbidity and mortality rates.