The Barrow Ruptured Aneurysm Trial: 6-year results.

OBJECT: The authors report the 6-year results of the Barrow Ruptured Aneurysm Trial (BRAT). This ongoing randomized trial, with the final goal of a 10-year follow-up, compares the safety and efficacy of surgical clip occlusion and endovascular coil embolization in patients presenting with subarachnoid hemorrhage (SAH) from a ruptured aneurysm. The 1- and 3-year results of this trial have been previously reported. METHODS: In total, 500 patients with an SAH met the entry criteria and were enrolled in the study. Of these patients, 471 were randomly assigned to the treatments: 238 to surgical clipping and 233 to endovascular coiling. Six patients who died before treatment and 57 patients with nonaneurysmal SAHs were excluded, leaving a total of 408 patients who underwent clipping (209 assigned) or coiling (199 assigned). Whether to treat patients within the assigned group or to cross over patients to the other group was at the discretion of the treating physician; 38% (75/199) of the patients assigned to coiling were crossed over to clipping and 1.9% (4/209) assigned to clipping were crossed over to coiling. The outcome data were collected by a dedicated nurse practitioner. The primary outcome analysis was based on the assigned treatment group; poor outcome was defined as a modified Rankin Scale (mRS) score > 2 and was independently adjudicated. Six years after randomization, 336 (82%) of 408 patients who had been treated were available for examination. RESULTS: On the basis of an mRS score of > 2, and similar to the results at the 3-year follow-up, no significant difference in outcomes (p = 0.24) was detected between the 2 treatment groups. Complete aneurysm obliteration at 6 years was achieved in 96% (111/116) of the clipping group and in 48% (23/48) of the coiling group (p < 0.0001). In the period between the 3- and 6-year follow-ups, 3 additional patients assigned to coiling and none assigned to clipping received retreatment, for overall retreatment rates of 4.6% (13/280) for clipping and 16.4% (21/128) for coiling (p < 0.0001). When aneurysm location was considered, the 6-year results continued to match the previously reported results, with no difference in outcome for anterior circulation aneurysms at most time points. Of the anterior circulation aneurysms assigned to coiling treatment, 42% (70/168) were crossed over to clipping treatment. The outcomes for posterior circulation aneurysms continued to favor coiling. The randomization process was unexpectedly skewed, with 18 of 21 treated aneurysms of the posterior inferior cerebellar artery (PICA) being assigned to clipping, but even when PICA aneurysms were removed from the analysis, outcomes for the posterior circulation aneurysms still favored coiling. CONCLUSIONS: Although BRAT was statistically underpowered to detect small differences, these results suggest little difference in outcome between the 2 treatments for anterior circulation aneurysms. This was not the case for the posterior circulation aneurysms, where coil embolization appeared to provide a sustained advantage over clipping. Aneurysm obliteration rates in BRAT were significantly lower and retreatment rates significantly higher in the patients undergoing coiling than in those undergoing clipping. However, despite the fact that retreatment rates were higher after coiling, no recurrent hemorrhages were known to have occurred in patients undergoing coiling in BRAT who were followed up for 6 years. Sufficient questions remain about the relative benefits of the 2 treatment modalities to warrant further well-designed randomized trials.

The Barrow Ruptured Aneurysm Trial: 3-year results.

OBJECT: The authors report the 3-year results of the Barrow Ruptured Aneurysm Trial (BRAT). The objective of this ongoing randomized trial is to compare the safety and efficacy of microsurgical clip occlusion and endovascular coil embolization for the treatment of acutely ruptured cerebral aneurysms and to compare functional outcomes based on clinical and angiographic data. The 1-year results have been previously reported. METHODS: Two-hundred thirty-eight patients were assigned to clip occlusion and 233 to coil embolization. There were no anatomical exclusions. Crossovers were allowed based on the treating physician's determination, but primary outcome analysis was based on the initial assignment to treatment modality. Patient outcomes were assessed independently using the modified Rankin Scale (mRS). A poor outcome was defined as an mRS score>2. At 3 years' follow-up 349 patients who had actually undergone treatment were available for evaluation. Of the 170 patients who had been originally assigned to coiling, 64 (38%) crossed over to clipping, whereas 4 (2%) of 179 patients assigned to surgery crossed over to clipping. RESULTS: The risk of a poor outcome in patients assigned to clipping compared with those assigned to coiling (35.8% vs 30%) had decreased from that observed at 1 year and was no longer significant (OR 1.30, 95% CI 0.83-2.04, p=0.25). In addition, the degree of aneurysm obliteration (p=0.0001), rate of aneurysm recurrence (p=0.01), and rate of retreatment (p=0.01) were significantly better in the group treated with clipping compared with the group treated with coiling. When outcomes were analyzed based on aneurysm location (anterior circulation, n=339; posterior circulation, n=69), there was no significant difference in the outcomes of anterior circulation aneurysms between the 2 assigned groups across time points (at discharge, 6 months, 1 year, or 3 years after treatment). The outcomes of posterior circulation aneurysms were significantly better in the coil group than in the clip group after the 1st year of follow-up, and this difference persisted after 3 years of follow-up. However, while aneurysms in the anterior circulation were well matched in their anatomical location between the 2 treatment arms, this was not the case in the posterior circulation where, for example, 18 of 21 posterior inferior cerebellar artery aneurysms were in the clip group. CONCLUSIONS: Based on mRS scores at 3 years, the outcomes of all patients assigned to coil embolization showed a favorable 5.8% absolute difference compared with outcomes of those assigned to clip occlusion, although this difference did not reach statistical significance (p=0.25). Patients in the clip group had a significantly higher degree of aneurysm obliteration and a significantly lower rate of recurrence and retreatment. In post hoc analysis examining only anterior circulation aneurysms, no outcome difference between the 2 treatment cohorts was observed at any recorded time point. CLINICAL TRIAL REGISTRATION NO.: NCT01593267 ( ClinicalTrials.gov ).

The Barrow Ruptured Aneurysm Trial.

OBJECT: The purpose of this ongoing study is to compare the safety and efficacy of microsurgical clipping and endovascular coil embolization for the treatment of acutely ruptured cerebral aneurysms and to determine if one treatment is superior to the other by examining clinical and angiographic outcomes. The authors examined the null hypothesis that no difference exists between the 2 treatment modalities in the setting of subarachnoid hemorrhage (SAH). The current report is limited to the clinical results at 1 year after treatment. METHODS: The authors screened 725 patients with SAH, resulting in 500 eligible patients who were enrolled prospectively in the study after giving their informed consent. Patients were assigned in an alternating fashion to surgical aneurysm clipping or endovascular coil therapy. Intake evaluations and outcome measurements were collected by nurse practitioners independent of the treating surgeons. Ultimately, 238 patients were assigned to aneurysm clipping and 233 to coil embolization. The 2 treatment groups were well matched. There were no anatomical exclusions. Crossing over was allowed, but primary outcome analysis was based on the initial treatment modality assignment. Posttreatment care was standardized for both groups. Patient outcomes at 1 year were independently assessed using the modified Rankin Scale (mRS). A poor outcome was defined as an mRS score > 2 at 1 year. The primary outcome was based on the assigned group; that is, by intent to treat. RESULTS: One year after treatment, 403 patients were available for evaluation. Of these, 358 patients had actually undergone treatment. The remainder either died before treatment or had no identifiable source of SAH. A poor outcome (mRS score > 2) was observed in 33.7% of the patients assigned to aneurysm clipping and in 23.2% of the patients assigned to coil embolization (OR 1.68, 95% CI 1.08-2.61; p = 0.02). Of treated patients assigned to the coil group, 124 (62.3%) of the 199 who were eligible for any treatment actually received endovascular coil embolization. Patients who crossed over from coil to clip treatment fared worse than patients assigned to coil embolization, but no worse than patients assigned to clip occlusion. No patient treated by coil embolization suffered a recurrent hemorrhage. CONCLUSIONS: One year after treatment, a policy of intent to treat favoring coil embolization resulted in fewer poor outcomes than clip occlusion. Although most aneurysms assigned to the coil treatment group were treated by coil embolization, a substantial number crossed over to surgical clipping. Although a policy of intent to treat favoring coil embolization resulted in fewer poor outcomes at 1 year, it remains important that high-quality surgical clipping be available as an alternative treatment modality.

Incidence and pattern of direct blunt neurovascular injury associated with trauma to the skull base.

OBJECT: Skull base fractures are often associated with potentially devastating injuries to major neural arteries in the head and neck, but the incidence and pattern of this association are unknown. METHODS: Between April and September 2002, 1738 Level 1 trauma patients were admitted to St. Joseph's Hospital and Medical Center in Phoenix, Arizona. Among them, a skull base fracture was diagnosed in 78 patients following computed tomography (CT) scans. Seven patients had no neurovascular imaging performed and were excluded. Altogether, 71 patients who received a diagnosis of skull base fractures after CT and who also underwent a neurovascular imaging study were included (54 men and 17 women, mean age 29 years, range 1-83 years). Patients underwent CT angiography, magnetic resonance angiography, or digital subtraction angiography of the head and craniovertebral junction, or combinations thereof. RESULTS: Nine neurovascular injuries were identified in six (8.5%) of the 71 patients. Fractures of the clivus were very likely to be associated with neurovascular injury (p < 0.001). A high risk of neurovascular injury showed a strong tendency to be associated with fractures of the sella turcica-sphenoid sinus complex (p = 0.07). CONCLUSIONS: The risk of associated blunt neurovascular injury appears to be significant in Level 1 trauma patients in whom a diagnosis of skull base fracture has been made using CT. The incidence of neurovascular trauma is particularly high in patients with clival fractures. The authors recommend neurovascular imaging for Level 1 trauma patients with a high-risk fracture pattern of the central skull base to rule out cerebrovascular injuries.

Assessment of the reproducibility of postprocessing dynamic CT perfusion data.

BACKGROUND AND PURPOSE: Commercially available software programs for the conversion of dynamic CT perfusion (CTP) source data into cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps require operators to subjectively define parameters that are used in subsequent postprocessing calculations. Our purpose was to define the variability of CBV, CBF, and MTT values derived from CTP maps generated from the same source data postprocessed by three different CT technologists (CTTs). METHODS: Raw data derived from dynamic CTP examinations performed in 20 subjects were postprocessed seven times by three experienced CTTs. Parenchymal regions of interest derived from each map (CBV, CBF, and MTT) were compared. The CBF maps generated by each technologist were also qualitatively assessed. Decisions made by each analyzer during postprocessing were assessed. RESULTS: The intraclass correlation coefficients were 0.73 (95% CI, 0.64-0.81), 0.87 (0.83-0.91) and 0.89 (0.85-0.93), for the CBV, CBF, and MTT parenchymal regions of interest, respectively. All individual correlation coefficients between data sets were significant to a P value <.05. Measurement error, made solely on the basis of different technologists postprocessing the same source data and expressed as the coefficients of variation, were 31%, 30%, and 14% for CBV, CBF, and MTT, respectively. The selection of the arterial input function (AIF) region of interest, venous function region of interest, and preenhancement interval were very reproducible. The technologists differed significantly with respect to the selection of the postenhancement image (PoEI) (P <.01). A retrospective review of the individual CBF maps indicated that variance in the PoEI selection accounted for much of the variation in the qualitative appearance of the CBF maps generated by different technologists. The PoEI was selected to demarcate the baseline of the AIF time-attenuation curve. It is likely that this method of PoEI selection significantly contributed to intra- and interanalyzer variability. CONCLUSION: There is a high degree of correlation between parenchymal regions of interest derived from CBV, CBF, and MTT maps generated from the same dynamic CTP source data postprocessed by different operators. The level of agreement, however, may not be sufficient to incorporate quantitative values into clinical decision making. Quantitative differences between parenchymal regions of interest were not infrequently manifest as significant differences in the qualitative appearance of the CBF maps. It is likely that, with optimization of postprocessing parameter selection, the degree of variability may be substantially reduced.

Distinction between paraclinoid and cavernous sinus aneurysms with computed tomographic angiography.

OBJECTIVE: To examine the reliability of using the optic strut as a landmark in computed tomographic (CT) angiography, to differentiate between intradural and extradural (cavernous sinus) aneurysms involving the paraclinoid segment of the internal carotid artery (ICA). METHODS: Microanatomic dissections were performed with five cadaveric heads (10 sides), to establish the relationships of the optic strut to the cavernous sinus and the ICA. Results from these anatomic studies were compared with intraoperative and CT angiographic findings for four patients with nine intracranial aneurysms involving the paraclinoid segment of the ICA. RESULTS: The inferior boundary of the optic strut accurately localized the point at which the ICA pierced the oculomotor membrane (proximal dural ring) and exited the cavernous sinus. The optic strut and its relationship to the ICA could be well observed on CT angiograms. During surgery, six of six aneurysms that arose distal to the optic strut were identified intradurally and were successfully clipped. Conversely, all aneurysms that arose proximal to the optic strut were observed to lie within the cavernous sinus. An aneurysm at the optic strut was within the clinoid segment or interdural, between the proximal and distal rings. CONCLUSION: The optic strut, as identified with CT angiography, provided a reliable anatomic landmark for accurate discrimination between intradural and extradural (cavernous sinus) aneurysms.