Impact of flow and angioarchitecture on brain arteriovenous malformation outcome after gamma knife radiosurgery: the role of hemodynamics and morphology in obliteration.

BACKGROUND: Few studies have evaluated the relationship between brain arteriovenous malformations (bAVMs) angioarchitecture and the response to Gamma Knife Stereotactic Radiosurgery (GKSR). METHODS: A prospectively enrolled single-center cohort of patients with bAVMs treated by GKSR has been studied to define independent predictors of obliteration with particular attention to angioarchitectural variables. Only patients older than 18 years old (y.o.), who underwent baseline digital subtraction angiography (DSA) and clinico-radiological follow-up of at least 36 months, were included in the study. RESULTS: Data of 191 patients were evaluated. After a mean follow-up of 80 months (range 37-173), total obliteration rate after first GKSR treatment was 66%. Mean dose higher than 22 Gy (P = .019, OR = 2.39, 95% CI 1.15-4.97) and flow rate dichotomized into high vs non-high (P < .001, OR = 0.23, 95% CI 0.11-0.51) resulted to be independent predictors of obliteration. Flow-surrogate angioarchitectural features did not emerge as independent outcome predictors. CONCLUSIONS: Flow rate seems to be associated in predicting outcome after GKSR conferring high-flow AVM a lower occlusion rate. Its role should be considered when planning radiosurgical treatment of bAVM, and it could be added to other parameters used in GKRS outcome predicting scales.

Safety and feasibility of lumbar drainage in the management of poor grade aneurysmal subarachnoid hemorrhage.

The use of lumbar drain (LD) in the aneurysmal subarachnoid hemorrhage (aSAH) has been described to reduce cerebral vasospasm and delayed cerebral ischemia (DCI), with a lack of studies referring to high grade population. The purpose of our study is to assess safety and feasibility of LD in the poor grade aSAH population subjected to endovascular aneurysm occlusion. Twenty-four consecutive poor grade aSAH patients, defined as grade IV and V according to World Federation of Neurological Surgeons (WFNS) classification, subjected to endovascular aneurysm occlusion, were retrospectively reviewed. Details of CSF drainage via LD and related complications were analyzed. Ventriculo-lumbar pressure gradient (VLPG) lower than 6 mmHg was considered in order to start LD use. Good outcome was defined as modified Rankin Scale (mRS) 0-2. LD was started within 72 h since aSAH in 17 cases (70.8%), and in 7 cases (29.2%) it was delayed due to contraindications. The mean LD length was of 13.8 days. The median VLPG during drainage was 2 mmHg (IQR: 0-4). No cases of brain or spinal hemorrhage, permanent neurological worsening due to brain herniation were noted. Three cases (12.5%) of CSF infection and a related death (4.2%) were reported. The use of LD, in association with external ventricular drain (EVD), seems to be safe and feasible in the poor grade aSAH population. VLPG monitoring seems to play a key role in avoiding potentially severe complications.

Hemorrhagic burden in poor-grade aneurysmal subarachnoid hemorrhage: a volumetric analysis of different bleeding distributions.

BACKGROUND: Volumetric assessment of aneurysmal bleeding has been evaluated in few studies and emerged as a promising outcome predictor. There is a lack of studies evaluating its impact in the poor-grade population. METHODS: Retrospective review of 63 consecutive poor-grade aneurysmal subarachnoid hemorrhage (aSAH) patients, defined as grade IV and V according to the World Federation of Neurological Surgeons (WFNS) classifications. Global intracranial bleeding volume was calculated with its subarachnoid, intracerebral (ICH), and intraventricular (IVH) portions by means of analytical software. Univariate and multivariate analyses were performed in order to identify independent predictors of outcome. Good outcome was defined as modified Rankin Scale (mRS) 0-2 and mortality as mRS 6. The cutoff values of bleeding volumes were derived by receiver operating curve (ROC) analysis. RESULTS: Mean follow-up was of 12.5 (± 1.5) months. Thirty (47.7%) patients achieved good outcome, whereas 19 (30.2) patients out of 63 died. Global intracranial bleeding resulted as an independent predictor of good outcome (cutoff 24 mL). Furthermore, ICH relative percentage of global volume (10% of total) and pure SAH (64% of total) emerged respectively as independent predictors of worsened and improved outcome. Global bleeding volume (cutoff 51 mL) along with global cerebral edema showed to independently predict mortality in the examined poor-grade aSAH population. CONCLUSIONS: Volumetric assessment of aneurysmal bleeding has the potential for identifying cutoff values that independently predict outcome. Further insights into the relative importance of different bleeding volumes may be implicated in better tailoring the management of this dismal aSAH population.

Comparison of 3D TOF-MRA and 3D CE-MRA at 3T for imaging of intracranial aneurysms.

PURPOSE: To compare 3T elliptical-centric CE MRA with 3T TOF MRA for the detection and characterization of unruptured intracranial aneurysms (UIAs), by using digital subtracted angiography (DSA) as reference. MATERIALS AND METHODS: Twenty-nine patients (12 male, 17 female; mean age: 62 years) with 41 aneurysms (34 saccular, 7 fusiform; mean diameter: 8.85 mm [range 2.0-26.4mm]) were evaluated with MRA at 3T each underwent 3D TOF-MRA examination without contrast and then a 3D contrast-enhanced (CE-MRA) examination with 0.1mmol/kg bodyweight gadobenate dimeglumine and k-space elliptic mapping (Contrast ENhanced Timing Robust Angiography [CENTRA]). Both TOF and CE-MRA images were used to evaluate morphologic features that impact the risk of rupture and the selection of a treatment. Almost half (20/41) of UIAs were located in the internal carotid artery, 7 in the anterior communicating artery, 9 in the middle cerebral artery and 4 in the vertebro-basilar arterial system. All patients also underwent DSA before or after the MR examination. RESULTS: The CE-MRA results were in all cases consistent with the DSA dataset. No differences were noted between 3D TOF-MRA and CE-MRA concerning the detection and location of the 41 aneurysms or visualization of the parental artery. Differences were apparent concerning the visualization of morphologic features, especially for large aneurysms (>13 mm). An irregular sac shape was demonstrated for 21 aneurysms on CE-MRA but only 13/21 aneurysms on 3D TOF-MRA. Likewise, CE-MRA permitted visualization of an aneurismal neck and calculation of the sac/neck ratio for all 34 aneurysms with a neck demonstrated at DSA. Conversely, a neck was visible for only 24/34 aneurysms at 3D TOF-MRA. 3D CE-MRA detected 15 aneurysms with branches originating from the sac and/or neck, whereas branches were recognized in only 12/15 aneurysms at 3D TOF-MRA. CONCLUSION: For evaluation of intracranial aneurysms at 3T, 3D CE-MRA is superior to 3D TOF-MRA for assessment of sac shape, detection of aneurysmal neck, and visualization of branches originating from the sac or neck itself, if the size of the aneurysm is greater than 13 mm. 3T 3D CE-MRA is as accurate and effective as DSA for the evaluation of UIAs.

Carotid artery stenosis: intraindividual correlations of 3D time-of-flight MR angiography, contrast-enhanced MR angiography, conventional DSA, and rotational angiography for detection and grading.

PURPOSE: To compare three-dimensional (3D) time-of-flight (TOF) MR angiography, contrast-enhanced MR angiography, digital subtraction angiography (DSA), and rotational angiography for depiction of stenosis. MATERIALS AND METHODS: The study had Ethics Committee approval, and each patient gave written informed consent. Forty-nine patients (18 women, mean age, 67.2 years +/- 9.1 [+/- standard deviation], and 31 men, mean age, 63.1 years +/- 8.0) with symptomatic stenosis of internal carotid artery (ICA) diagnosed at duplex ultrasonography underwent transverse 3D TOF MR angiography with sliding interleaved kY acquisition and coronal contrast-enhanced MR angiography, followed by DSA and rotational angiography within 48 hours. MR angiography was performed at 1.5-T with a cervical coil. Contrast-enhanced MR angiograms were obtained after a bolus injection of 20 mL of gadobenate dimeglumine. Maximum ICA stenosis on maximum intensity projection and source images was quantified according to NASCET criteria. Correlations for 3D TOF MR angiography, contrast-enhanced MR angiography, DSA, and rotational angiography were determined by means of cross tabulation, and accuracy for detection and grading of stenoses were calculated. Data were evaluated with analysis of variance, Wilcoxon signed rank test, and McNemar test, all at significance of P < .05. RESULTS: Ninety-eight ICAs were evaluated at contrast-enhanced MR angiography, DSA, and rotational angiography, and 97 were evaluated at 3D TOF MR angiography. Correlations for contrast-enhanced MR angiography, 3D TOF MR angiography, and DSA relative to rotational angiography were r2 = 0.9332, r2 = 0.9048, and r2 = 0.9255, respectively. Lower correlation (r2 = 0.8593) was noted for contrast-enhanced MR angiography and DSA. Respective sensitivity and specificity for detection of hemodynamically relevant stenosis relative to rotational angiography were 100% and 90% for contrast-enhanced MR angiography, 95.5% and 87.2% for 3D TOF MR angiography, and 88.6% and 100% for DSA. Four of 31 severe stenoses were underestimated at DSA, and three were underestimated at contrast-enhanced MR angiography. Three severe stenoses were underestimated at 3D TOF MR angiography, and one was misclassified as occluded. Of 13 moderate (50%-69%) stenoses, one was overestimated at contrast-enhanced MR angiography, two were underestimated and three overestimated at 3D TOF MR angiography, and two were underestimated at DSA. CONCLUSION: DSA results in an underestimation of ICA stenosis compared with rotational angiography. Contrast-enhanced MR angiography correlates best with rotational angiography.

Spinal dural arteriovenous fistulae: analysis of outcome in relation to pretreatment indicators.

OBJECTIVE: The outcome of treatment for a spinal dural arteriovenous fistula is unpredictable. In this study, we reviewed the outcome of patients treated for this condition, in relation to pretreatment indicators. METHODS: We reviewed the records of 37 consecutive patients treated either surgically or endovascularly in our department between 1989 and 2002. RESULTS: At follow-up, 78% of the patients reported improvement. Those with motor symptoms had the best outcome: improvement was achieved in more than 60% of the patients, amounting to 1 or 2 points on the Aminoff scale. Sensory disorders improved in 43% of cases, pain in 61%, and sphincter impairment in only 37%. Patients with a fistula in the lower thoracic region did better than those with fistulae in other locations. CONCLUSION: The clinical state before treatment is certainly relevant in predicting outcome. Age and duration of the symptoms before treatment have no direct relation to the chances of improvement with treatment, particularly when motor improvement is considered. The modality of onset of symptoms and location of the fistula play significant roles, also: a fistula in the lower thoracic segment was associated with more severe symptoms but tended to improve more (83%, P = 0.04) after treatment. Midthoracic and lumbar fistulae showed a lower incidence of improvement (<50%).