Time for a Time Window Extension: Insights from Late Presenters in the ESCAPE Trial.

BACKGROUND AND PURPOSE: The safety and efficacy of endovascular therapy for large-artery stroke in the extended time window is not yet well-established. We performed a subgroup analysis on subjects enrolled within an extended time window in the Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) trial. MATERIALS AND METHODS: Fifty-nine of 315 subjects (33 in the intervention group and 26 in the control group) were randomized in the ESCAPE trial between 5.5 and 12 hours after last seen healthy (likely to have groin puncture administered 6 hours after that). Treatment effect sizes for all relevant outcomes (90-day mRS shift, mRS 0-2, mRS 0-1, and 24-hour NIHSS scores and intracerebral hemorrhage) were reported using unadjusted and adjusted analyses. RESULTS: There was no evidence of treatment heterogeneity between subjects in the early and late windows. Treatment effect favoring intervention was seen across all clinical outcomes in the extended time window (absolute risk difference of 19.3% for mRS 0-2 at 90 days). There were more asymptomatic intracerebral hemorrhage events within the intervention arm (48.5% versus 11.5%, P = .004) but no difference in symptomatic intracerebral hemorrhage. CONCLUSIONS: Patients with an extended time window could potentially benefit from endovascular treatment. Ongoing randomized controlled trials using imaging to identify late presenters with favorable brain physiology will help cement the paradigm of using time windows to select the population for acute imaging and imaging to select individual patients for therapy.

Enhancing brain lesions after endovascular treatment of aneurysms.

Complications of endovascular therapy of aneurysms mainly include aneurysm rupture and thromboembolic events. The widespread use of MR imaging for follow-up of these patients revealed various nonvascular complications such as aseptic meningitis, hydrocephalus, and perianeurysmal brain edema. We present 7 patients from 5 different institutions that developed MR imaging-enhancing brain lesions after endovascular therapy of aneurysms, detected after a median time of 63 days. The number of lesions ranged from 4-46 (median of 10.5), sized 2-20 mm, and were mostly in the same vascular territory used for access. Three patients presented with symptoms attributable to these lesions. After a median follow-up of 21.5 months, the number of lesions increased in 2, was stable in 1, decreased in 3, and disappeared in 1. The imaging and clinical characteristics suggested a foreign body reaction. We could find no correlation to a specific device, but a possible source may be the generic hydrophilic coating.

Subcortical cystic lesions within the anterior superior temporal gyrus: a newly recognized characteristic location for dilated perivascular spaces.

SUMMARY: Cystic parenchymal lesions may pose an important diagnostic challenge, particularly when encountered in unexpected locations. Dilated perivascular spaces, which may mimic cystic neoplasms, are known to occur in the inferior basal ganglia and mesencephalothalamic regions; a focal preference within the subcortical white matter has not been reported. This series describes 15 cases of patients with cystic lesions within the subcortical white matter of the anterior superior temporal lobe, which followed a CSF signal; were located adjacent to a subarachnoid space; demonstrated variable surrounding signal change; and, in those that were followed up, showed stability. Pathology study results obtained in 1 patient demonstrated chronic gliosis surrounding innumerable dilated perivascular spaces. These findings suggest that dilated perivascular spaces may exhibit a regional preference for the subcortical white matter of the anterior superior temporal lobe. Other features-lack of clinical symptoms, proximity to the subarachnoid space, identification of an adjacent vessel, and stability with time-may help in confidently making the prospective diagnosis of a dilated perivascular space, thereby preventing unnecessary invasive management.

Canadian experience with the pipeline embolization device for repair of unruptured intracranial aneurysms.

BACKGROUND AND PURPOSE: Flow-diverting stents, such as the PED, have emerged as a novel means of treating complex intracranial aneurysms. This retrospective analysis of the initial Canadian experience provides insight into technical challenges, clinical and radiographic outcomes, and complication rates after the use of flow-diverting stents for unruptured aneurysms. MATERIALS AND METHODS: Cases were compiled from 7 Canadian centers between July 2008 and December 2010. Each center prospectively tracked their initial experience; these data were retrospectively updated and pooled for analysis. RESULTS: During the defined study period, 97 cases of unruptured aneurysm were treated with the PED, with successful stent deployment in 94 cases. The overall complete or near-complete occlusion rate was 83%, with a median follow-up at 1.25 years (range 0.25-2.5 years). Progressive occlusion was witnessed over time, with complete or near-complete occlusion in 65% of aneurysms followed through 6 months, and 90% of aneurysms followed through 1 year. Multivariate analysis found previous aneurysm treatment and female sex predictive of persistent aneurysm filling. Most patients were stable or improved (88%), with the most favorable outcomes observed in patients with cavernous carotid aneurysms. The overall mortality rate was 6%. Postprocedural aneurysm hemorrhage occurred in 3 patients (3%), while ipsilateral distal territory hemorrhage was observed in 4 patients (3.4%). CONCLUSIONS: Flow-diverting stents represent an important tool in the treatment of complex intracranial aneurysms. The relative efficacy and morbidity of this treatment must be considered in the context of available alternate interventions.

Long-term clinical and imaging follow-up of complex intracranial aneurysms treated by endovascular parent vessel occlusion.

BACKGROUND AND PURPOSE: Flow-diverting stents are increasingly being used for the treatment of complex intracranial aneurysms, but the indications for their use in lieu of traditional endovascular PVO have yet to be precisely defined. The purpose of this study was to review the clinical and imaging outcomes of patients with intracranial aneurysms treated by PVO. MATERIALS AND METHODS: A total of 28 patients with intracranial aneurysms, treated by PVO between July 1992 and December 2009, were reviewed. Aneurysms arising from peripheral arteries were excluded. Clinical and imaging data were retrospectively analyzed from a prospectively maintained data base. RESULTS: There were 28 patients with 28 aneurysms treated by PVO. Aneurysms of the anterior circulation presenting with mass effect (n = 11) or discovered incidentally (n = 1), and dissecting-type VB aneurysms presenting with subarachnoid hemorrhage (n = 6) faired the best with high obliteration rates (83.3% and 83.6%, respectively) and no permanent major ischemic complications. In contrast, VB aneurysms presenting with mass effect (n = 7) demonstrated the lowest obliteration rate (57.1%), the highest rate of permanent major ischemic complications (28.6%), and a high mortality rate (28.6%). CONCLUSIONS: PVO is a safe and effective treatment for complex intracranial aneurysms of the carotid artery and dissecting-type VB aneurysms presenting with SAH. In contrast, PVO for aneurysms of the VB circulation presenting with mass effect is less efficacious and associated with significant morbidity and mortality. It is hoped that flow diverters may represent a better treatment technique for these most difficult-to-treat lesions.

Transvenous embolization of intracranial dural arteriovenous shunts through occluded venous segments: experience in 51 Patients.

BACKGROUND AND PURPOSE: DAVFs with cortical venous reflux carry a high risk of morbidity and mortality. Endovascular treatment options include transarterial embolization with a liquid embolic agent or transvenous access with occlusion of the involved venous segment, which may prove difficult if the venous access route is thrombosed. The aim of this article is to describe the technique and results of the transvenous approach via thrombosed venous segments for occlusion of DAVFs. MATERIALS AND METHODS: Our study was a retrospective analysis of 51 patients treated with a transvenous approach through an occluded sinus that was reopened by gentle rotational advancement of a 0.035-inch guidewire, which opened a path for a subsequently inserted microcatheter. RESULTS: Of 607 patients with DAVFs, the transvenous reopening technique was attempted in 62 patients in 65 sessions and was successful in 51 patients and 53 sessions. Immediate occlusion was seen in 42 patients; on follow-up, occlusion was seen in 49 patients, whereas 2 patients had reduced flow without cortical venous reflux. No permanent procedure-related morbidity was noted. CONCLUSIONS: The reopening technique to gain access to isolated venous pouches or the cavernous sinus for the treatment of DAVFs is a safe and effective treatment, which should be considered if transarterial approaches fail or are anticipated to result only in an incomplete anatomic cure.

Recanalization rates after endovascular coil embolization in a cohort of matched ruptured and unruptured cerebral aneurysms.

The aim of this study was to retrospectively assess the recanalization rate, factors associated with and time taken for recanalization to occur in a matched ruptured and unruptured aneurysm population that were treated with endovascular coiling.Ruptured and unruptured aneurysms treated between 2002 and 2007 were matched for aneurysm location, diameter and neck size. Recanalization rate, time to recanalize, re-treatment rate and clinical outcome were analysed. Ninety-eight matched ruptured and unruptured aneurysms (49 aneurysms in each group) were studied. 46.8% of aneurysms in the ruptured group achieved complete obliteration on the initial post treatment angiogram versus 34.7% in the unruptured group. The ruptured group had a higher rate of recanalization (40.4% versus 20.4%). 25.5% of aneurysms had significant recanalization in the ruptured group versus 6.1% in the unruptured group (p=0.009). The retreatment rate was higher in the ruptured group (21.3% versus 6%). Ruptured aneurysms took a shorter time to recanalize with a mean time of 5.3±3.8 months versus 12.4±7.7months (p=0.003). Multivariate logistic regression analysis found neck size (p=0.0098), wide neck morphology (p=0.0174), aneurysm diameter (p< 0.0001) and ruptured aneurysms (p=0.0372) were significant predictors of recanalization. The majority of patients in both groups had a good outcome with GOS=5 (85.7% and 83.7%) but two deaths occurred in the ruptured group.Ruptured and unruptured aneurysms showed significant differences in rate, degree and timing of recanalization, thus requiring different protocols for imaging follow-up post endovascular treatment. Earlier and more frequent imaging follow-up is recommended for ruptured aneurysms.

Impact of anatomical variations of the circle of Willis on the incidence of aneurysms and their recurrence rate following endovascular treatment.

AIM: To analyse the impact of anatomical variations of the parent arteries on the incidence and recurrence rate following coil embolization of aneurysms of the anterior (AcoA), posterior communicating artery (PcoA) and basilar artery (BA) tip. METHODS: Two hundred and two (96 AcoA, 67 PcoA, and 29 BA) aneurysms in 200 patients were treated with coil embolization between January 2000 and April 2008. Parent artery variations at each location were classified as: AcoA: A1 aplasia versus hypoplasia versus symmetrical size; PcoA: foetal origin versus medium versus small size, BA: cranial versus caudal versus asymmetrical fusion. The incidence of aneurysms and difference between recurrence rates for each group were recorded on follow-up. RESULTS: AcoA, PcoA, and BA aneurysms were more often associated with embryonically earlier vessel wall dispositions (A1 aplasia, foetal PcoA, asymmetrical fusion). Two of these variations were also associated with aneurysm recurrence following coil embolization: asymmetrical A1 segment (p=0.01), and asymmetrical BA tip (p=0.02). CONCLUSIONS: AcoA, PcoA, and BA tip aneurysms tend to occur more often in anatomically variant parent artery dispositions, some of which are related to aneurysm recurrence following coil embolization. This may relate to a more fragile vessel disposition as it is not fully matured or to altered haemodynamics secondary to the anatomical variations.

Angiographic characteristics and treatment of cervical spinal dural arteriovenous shunts.

Spinal DAVSs of the cervical level are rare lesions. The purpose of this study is to describe the clinical and angiographic characteristics of cervical spinal DAVSs. From a prospectively collected database including 449 cases of brain and spinal DAVSs, lesions located at the cervical level were selected. The clinical presentation, angiographic characteristics, and treatment outcome were assessed. Twelve cases of spinal DAVSs were identified at the level of the cervical spinal canal (male to female ratio = 8:4; mean age = 56.5 years). Five patients (41.7%) presented with hemorrhage including SAH (n = 4) and cerebellar hemorrhage (n = 1). Coincidental spinal DAVSs with cranial DAVSs or brain AVMs were noted in 5 cases (41.7%). The spinal DAVS was the symptomatic lesion in 10 cases and was incidentally discovered during evaluation for SAH from a coincidental lesion in 2 cases. Combined endovascular and surgical resection resulted in symptomatic improvement in 10 patients. In conclusion, DAVSs of the cervical spine are rare lesions which often present with hemorrhage and are frequently associated with complex coincidental vascular lesions. Combined endovascular and surgical treatment will result in good outcome.

Negative CT angiography findings in patients with spontaneous subarachnoid hemorrhage: When is digital subtraction angiography still needed?

BACKGROUND AND PURPOSE: CTA is becoming the frontline modality to reveal aneurysms in patients with SAH. However, in about 20% of SAH patients no aneurysm is found. In these cases, intra-arterial DSA is still performed. Our aim was to evaluate whether negative findings on CTA can reliably exclude aneurysms in patients with acute SAH. MATERIALS AND METHODS: We conducted a retrospective analysis of all negative findings on CTAs performed from 2005 to 2009 in patients with spontaneous SAH. Findings were compared with DSA. CTAs were performed with a 64-section multidetector row CT scanner. RESULTS: One hundred ninety-three patients with SAH and negative findings on CTA who underwent subsequent DSA were identified. The distribution of blood on unenhanced CT was the following: PMH in 93 patients, diffuse aneurysmal pattern in 50, no blood on CT (xanthochromic LP) in 32, and peripheral sulcal distribution in 18. All patients with PMH had negative findings on DSA. One patient with no blood on CT had vasculitis on DSA. Six of 18 (33%) patients with peripheral blood had vasculitis on DSA. Three of these were also diagnosed by CTA. All except 1 patient with diffuse aneurysmal blood had negative findings on DSA. One patient was diagnosed with an aneurysm on DSA (1/50, 0.5%). Repeat delayed DSA performed in 28 of these patients revealed a small aneurysm in 4 (14%). Five patients had a complication of DSA (2.6%); 1 was a clinical stroke (0.5%). CONCLUSIONS: In patients with SAH, negative CTA findings are reliable in ruling out aneurysms in the PMH pattern or no blood on CT. DSA is indicated in the diffuse aneurysmal pattern of SAH, and repeat delayed DSA is required if the initial DSA findings are negative. When the blood is peripheral, CTA should be scrutinized for vasculitis and DSA is recommended for confirmation.

Cranial dural arteriovenous fistula: diagnosis and classification with time-resolved MR angiography at 3T.

BACKGROUND AND PURPOSE: The diagnosis of dural arteriovenous fistula (DAVF) remains one of the few uncontested indications for catheter based cerebral angiography. We report our experience of using a commercially available form of time-resolved MR angiography (trMRA) at 3T for the diagnosis and classification of a cranial DAVF compared with the reference standard of digital subtraction angiography (DSA). MATERIALS AND METHODS: A retrospective review of our patient records identified patients who had undergone trMRA at 3T and DSA for the evaluation of DAVF. The trMRA consisted of whole-head, contrast-enhanced "time-resolved imaging of contrast kinetics" (TRICKS) MRA. Image sets were independently reviewed by 3 readers for the presence, location, and classification of a DAVF. The reported result of the DSA was used as the gold standard against which the performance of the trMRA was measured. RESULTS: Forty patients were identified who had undergone DSA and trMRA for evaluation of DAVF, yielding a total of 42 cases. On DSA, the results of 7 cases were normal, 15 cases were performed for surveillance of a previously cured fistula, and a new fistula (14) or persistent (6) fistula was found in 20 cases. Of these 20 fistulas, on DSA, 13 were Borden I, 2 were Borden II, and 5 were Borden III. In 93% (39/42) of DAVF cases, the 3 readers were unanimous and correct in their independent interpretation of the trMRA, correctly identifying (or excluding) all fistulas and accurately classifying them when encountered. CONCLUSIONS: In this small series, trMRA at 3T seems be a reliable technique in the screening and surveillance of DAVF in specific clinical situations.

Clinical and angiographic follow-up of ruptured intracranial aneurysms treated with endovascular embolization.

BACKGROUND AND PURPOSE: Endovascular embolization is a well-established treatment of ruptured intracranial aneurysms, but concern about its long-term stability and its ability to prevent rehemorrhage are still present. We evaluated the long-term clinical and angiographic follow-up of patients with ruptured cerebral aneurysms treated with coiling, focusing on rehemorrhage and changes in aneurysm morphologic features. MATERIALS AND METHODS: A total of 377 patients with ruptured aneurysms that were treated with endovascular approaches at our institution between 1994 and 2008 were reviewed. Clinical and angiographic data were analyzed from a prospectively collected data base. RESULTS: There were 377 patients with 391 ruptured aneurysms treated for 14 years. Good outcome (Glasgow Outcome Score [GOS], 5) was achieved in 74% of patients, moderate disability or poor outcome in 18%, and 8.8% died. Permanent morbidity or mortality from procedural complications occurred in 2.9%. Complete follow-up was available for 85% of surviving patients, with mean follow-up of 22.3 months. Re-treatment was required in 11% (31 patients). Eight (2.1%) patients had rebleeding, 6 (1.6%) in the hospital within 30 days of treatment, 5 in the first 48 hours. Follow-up imaging was available in 276 aneurysms in 270 patients. Recanalization occurred in 56 of 276 aneurysms (20.3%) regardless of the initial angiographic result, but the risk was higher if a body remnant was left (chi2, 11.791; P = .0006). CONCLUSIONS: Long-term clinical and angiographic follow-up demonstrates the efficacy of endovascular treatment of ruptured intracranial aneurysms. Rebleeding after treatment is rare, with the greatest risk during the first 48 hours after treatment. Initial angiographic results are not a useful predictor of clinical outcome or rehemorrhage.

Intracranial arterial wall imaging using high-resolution 3-tesla contrast-enhanced MRI.

BACKGROUND: Conventional arterial imaging focuses on the vessel lumen but lacks specificity because different pathologies produce similar luminal defects. Wall imaging can characterize extracranial arterial pathology, but imaging intracranial walls has been limited by resolution and signal constraints. Higher-field scanners may improve visualization of these smaller vessels. METHODS: Three-tesla contrast-enhanced MRI was used to study the intracranial arteries from a consecutive series of patients at a tertiary stroke center. RESULTS: Multiplanar T2-weighted fast spin echo and multiplanar T1 fluid-attenuated inversion recovery precontrast and postcontrast images were acquired in 37 patients with focal neurologic deficits. Clinical diagnoses included atherosclerotic disease (13), CNS inflammatory disease (3), dissections (3), aneurysms (3), moyamoya syndrome (2), cavernous angioma (1), extracranial source of stroke (5), and no definitive clinical diagnosis (7). Twelve of 13 with atherosclerotic disease had focal, eccentric vessel wall enhancement, 10 of whom had enhancement only in the vessel supplying the area of ischemic injury. Two of 3 with inflammatory diseases had diffuse, concentric vessel wall enhancement. Three of 3 with dissection showed bright signal on T1, and 2 had irregular wall enhancement with a flap and dual lumen. CONCLUSIONS: Three-tesla contrast-enhanced MRI can be used to study the wall of intracranial blood vessels. T2 and precontrast and postcontrast T1 fluid-attenuated inversion recovery images at 3 tesla may be able to differentiate enhancement patterns of intracranial atherosclerotic plaques (eccentric), inflammation (concentric), and other wall pathologies. Prospective studies are required to determine the sensitivity and specificity of arterial wall imaging for distinguishing the range of pathologic conditions affecting cerebral vasculature.

Management and clinical outcome of posterior fossa arteriovenous malformations: report on a single-centre 15-year experience.

OBJECTIVES: Posterior fossa brain arteriovenous malformations (PFbAVMs) are rare lesions. Management is complicated by eloquence of adjacent neurological structures, multimodality treatment is often necessary, and obliteration is not always possible. We describe a 15-year experience in the management of posterior fossa brain AVMs with a focus on clinical outcome. METHODS: From 1989 to 2004, prospectively collected information on 106 patients with diagnosis of a PFbAVMs was obtained. Clinical and angioarchitectural characteristics, management options and complications are described and reviewed to evaluate their impact on final outcome as measured by the Modified Rankin Score (mRS). RESULTS: Ninety-eight patients were followed for an average of 3.3 years (1-14.6). The male-to-female ratio was 1:1. Ninety-five out of 98 patients (96.9%) were symptomatic at presentation, with 61 (62.2%) intracranial haemorrhages. Sixty-two patients were treated (46 cerebellar, 16 brainstem). Ten haemorrhages occurred in follow-up (4.1%/year). The mRS was obtained in 62 patients and was classified as low (good, mRSor=3). Haemorrhage was the only predictor of poor mRS at presentation (p = 0.0229). A poor clinical outcome was correlated with the presence of AA (p = 0.0276), a poor initial mRS (p<0.0001) and the number of treatments needed (p = 0.0434). Patients were significantly more likely to improve than to deteriorate over time (p = 0.0201). CONCLUSION: The final clinical outcome in PFbAVMs relates directly with the presence of associated aneurysms, number of treatments needed to obliterate the AVM and mRS at presentation. Despite the fact that patients tend to improve after brain AVM haemorrhage, the relationship of MRS at presentation and final outcome suggests that an expedited, more definitive treatment is probably a better choice, especially in patients with good grades after the initial bleeding.

Characterization of aneurysm remnants after endovascular treatment: contrast-enhanced MR angiography versus catheter digital subtraction angiography.

BACKGROUND AND PURPOSE: A substantial percentage of coiled aneurysms are associated with persistent filling of an aneurysmal component due to incomplete initial treatment or re-growth. Traditionally follow-up of coiled aneurysms has consisted of repeated intra-arterial cerebral catheter angiography, an invasive procedure with associated risks. Hence, many authors have advocated the use of non-invasive imaging techniques for this purpose. Our aim was to compare contrast-enhanced MR angiography (CE-MRA) with digital subtraction angiography (DSA) for depiction of aneurysmal remnants of coiled cerebral aneurysms. MATERIALS AND METHODS: Aneurysms coiled between September 2003 and October 2006 were retrospectively reviewed. We included patients meeting the following criteria: 1) residual/recurrent aneurysm measuring 2 mm or greater, and 2) CE-MRA and DSA performed no more than 60 days apart. Three readers were asked to determine which technique was superior for characterization of the aneurysmal remnant: CE-MRA, DSA, or indeterminate. Statistical analysis included most rule and kappa statistics. RESULTS: Of 232 patients who underwent coiling, 44 met the inclusion criteria (33 women and 11 men; 24-72 years of age). Sixteen patients had neck remnants and 28 had body remnants. The first study to identify the remnant was DSA in 35 patients and CE-MRA in 9. In 32 patients (32/44, 73%), the readers indicated that CE-MRA was superior to DSA for remnant characterization. CE-MRA and DSA were thought to be equivalent in 7 (16%), and DSA was preferred in 3 (7%). Two cases (5%) yielded ambiguous results. Of the 28 body remnants, 22 (78.6%) were characterized by remnant protrusion into the coil mass: In 20 of these (91%), the readers preferred CE-MRA over DSA, and in 2 cases (9%), the techniques were thought to be equivalent. CONCLUSION: In patients with known aneurysm remnants, CE-MRA is at least equivalent to DSA for characterization of aneurysmal remnants after coiling. Contrast filling within the coil mass was more clearly seen with CE-MRA than with DSA.

Intrasellar rupture of a paraclinoid aneurysm with subarachnoid hemorrhage: usefulness of MR imaging in diagnosis.

Characterization of paraclinoid aneurysms may be difficult because of the complexity of anatomic structures involved, and differentiation between intradural and extradural lesions is crucial. We report a case of a patient with a unique presentation of a paraclinoid aneurysm with intrasellar hemorrhage in which the presence of intrasellar blood and the relationship of the paraclinoid aneurysmal neck and sac to the dural rings were elegantly demonstrated on MR imaging and were critical in choosing the target lesion for treatment.

Segmental artery exchange technique for stable 4F guiding-catheter positioning in embolization of spinal vascular malformations.

For anatomic and technical reasons, it is often difficult to achieve guiding-catheter stability in the segmental arteries during embolization of spinal vascular lesions. We have developed a segmental artery exchange technique using a thin-walled 4F nontapered catheter that is safe and achieves a stable guiding-catheter position. This catheter accommodates both the flow-guided and variable-stiffness microcatheters, allowing selective catheterization and treatment of spinal vascular lesions.

Endovascular treatment of intracranial aneurysms with matrix coils: immediate posttreatment results, clinical outcome and follow-up.

INTRODUCTION: Endovascular aneurysm repair with coils has become a safe and effective alternative to surgical clipping. Efforts have been made to create coils that will facilitate aneurysm healing and reduce recurrence. The purpose of this study was to review the safety and durability of our aneurysm treatment using Matrix coils. METHODS: A total of 39 aneurysms in 38 patients, aged 30 to 77 years, were treated using Matrix coils in 42 procedures. Two procedures were unsuccessful, and 12 were done using only Matrix coils. Aneurysm volume, packing density and percentage length of Matrix coils were calculated. The treatment results, procedural complication rate and clinical outcome were analyzed. Follow-up examinations were available for 34 procedures with a mean follow-up of 4.9 months (maximum 13.5 months). RESULTS: Angiographic results were similar to those following the use of platinum coils, with complete occlusion or a residual neck in 82.5% of procedures. Six procedures (14%) were complicated with platelet aggregation. Recanalization occurred in 32% of the patients. Nine patients (26%) had major recanalization and were retreated. One patient had a re-bleed 5 months after the treatment resulting in severe disability. The mean packing density of 39.2% in the recanalized aneurysms was similar to that in the nonrecanalized group. CONCLUSION: In our series, treatment with Matrix coils had a complication rate similar to that reported with platinum coils. However, we had a higher percentage of major recanalizations requiring retreatment. We believe that the absorption of the polymer contributes to the failure of formation of a stable scar within the aneurysm.

Acute subarachnoid hemorrhage: using 64-slice multidetector CT angiography to "triage" patients' treatment.

INTRODUCTION: To evaluate the clinical role of CT angiography (CTA) in patients with acute subarachnoid hemorrhage (SAH) for treatment decision-making. METHODS: Consecutive patients with acute SAH had CTA using a 64-slice scanner for initial clinical decision-making. Image processing included multiplanar volume reformatted (MPVR) maximum intensity projections (MIP) and 3D volume-rendered reconstructions. CTAs were used for (1) evaluating the cause of SAH, and (2) triaging aneurysm-bearing patients to the more appropriate management, either surgical clipping or endovascular coiling. CTA findings were confirmed by neurosurgical exploration or catheter angiography (digital subtraction angiography, DSA). Successful coiling provided evidence that triaging to endovascular treatment was correct. RESULTS: Included in the study were 73 patients. CTA findings were confirmed by DSA or neurosurgical operation in 65 patients, and of these 65, 47 had aneurysmal SAH, 3 had vasculitis, 1 had arterial dissection and 14 had no underlying arterial abnormality. The cause of SAH was detected with CTA in 62 out of the 65 patients (95.4%, sensitivity 94%, specificity 100%). CTA revealed the aneurysm in 46 of 47 patients (98%, sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 82.3%), 1 of 3 vasculitides and 1 of 1 dissection. Of the 46 patients with aneurysm, 44 (95.7%) were referred for treatment based on CTA. In 2 patients (2 of 46, 4.4%) CTA was not informative enough to choose treatment requiring DSA. Of the 44 patients, 27 (61.4%) were referred to endovascular treatment and successful coiling was achieved in 25 (25 of 27, 92.6%). CONCLUSION: CTA using a 64-slice scanner is an accurate tool for detecting and characterizing aneurysms in acute SAH. CTA is useful in the decision process whether to coil or clip an aneurysm.