Early Experience in the Treatment of Intra-Cranial Aneurysms by Endovascular Flow Diversion: A Multicentre Prospective Study

INTRODUCTION: Flow diversion is a new approach to the endovascular treatment of intracranial aneurysms which uses a high density mesh stent to induce sac thrombosis. These devices have been designed for the treatment of complex shaped and large size aneurysms. So far published safety and efficacy data on this approach is sparse. MATERIAL AND METHODS: Over 8 months, standardized clinical and angiographic data were collected on 70 patients treated with a flow diverter device (SILK flow diverter (SFD)) in 18 centres worldwide. Treatment and early follow up details were audited centrally. SFDs were deployed alone in 57 (81%) or with endosaccular coils in 10 (14%) aneurysms, which included: 44 (63%) saccular, 26 (37%) fusiform shapes and 18 (26%) small, 37 (53%) large, 15 (21%) giant sizes. Treatment outcome data up to 30 days were reported for all patients, with clinical (50 patients) and imaging (49 patients) follow up (median 119 days) data available. RESULTS: Difficulties in SFD deployment were reported in 15 (21%) and parent artery thrombosis in 8 (11%) procedures. Procedural complications caused stroke in 1 and serious extracranial bleeding in 3 patients; 2 of whom developed fatal pneumonias. Delayed worsening of symptoms occurred in 5 patients (3 transient, 1 permanent neurological deficit, and 1 death) and fatal aneurysm bleeding in 1 patient. Overall permanent morbidity rates were 2 (4%) and mortality 4 (8%). Statistical analysis revealed no significant association between complications and variables related to treated aneurysm morphology or rupture status. CONCLUSION: This series is the largest reporting outcome of the new treatment approach and provides data for future study design. Procedural difficulties in SFD deployment were frequent and anti-thrombosis prophylaxis appears to reduce the resulting clinical sequelae, but at the cost of morbidity due to extracranial bleeding. Delayed morbidity appears to be a consequence of the new approach and warrants care in selecting patients for treatment and future larger studies

Prediction of two month modified Rankin Scale with an ordinal prediction model in patients with aneurysmal subarachnoid haemorrhage

Background. Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating event with a frequently disabling outcome. Our aim was to develop a prognostic model to predict an ordinal clinical outcome at two months in patients with aSAH. Methods. We studied patients enrolled in the International Subarachnoid Aneurysm Trial (ISAT), a randomized multicentre trial to compare coiling and clipping in aSAH patients. Several models were explored to estimate a patient's outcome according to the modified Rankin Scale (mRS) at two months after aSAH. Our final model was validated internally with bootstrapping techniques. Results. The study population comprised of 2,128 patients of whom 159 patients died within 2 months (8%). Multivariable proportional odds analysis identified World Federation of Neurosurgical Societies (WFNS) grade as the most important predictor, followed by age, sex, lumen size of the aneurysm, Fisher grade, vasospasm on angiography, and treatment modality. The model discriminated moderately between those with poor and good mRS scores (c statistic = 0.65), with minor optimism according to bootstrap re-sampling (optimism corrected c statistic = 0.64). Conclusion. We presented a calibrated and internally validated ordinal prognostic model to predict two month mRS in aSAH patients who survived the early stage up till a treatment decision.

Angiographic outcomes for the aneurysms treated with SFD.

<p>Angiographic outcomes for the cohort of aneurysms with complete follow up i.e. end of treatment and follow up angiogram.</p><p>Abbreviations: OG1 (complete occlusion); OG2 (neck remnant); OG3 (saccular filling).</p

Clinical complications observed in patients treated with SFD.

<p>Abbreviations: BA (basilar artery), PcomA (posterior communicating artery), CCA (carotid cavernous artery), MCA (middle cerebral artery), AICA (anterior inferior cerebellar artery), COA (carotid ophthalmic artery), S (saccular), F (fusiform), EVT (endovascular therapy).</p

Partially thrombosed aneurysm after treatment with the flow diverter.

<p>CT angiograms showing a residual lumen within a large partially thrombosed fusiform aneurysm of the middle cerebral artery. Follow-up CTA (a) was performed 4 months and (b) 6 months after SFD (arrows) placement. The second follow-up study shows enlargement of the residual aneurysm lumen (arrow heads) and was performed after a new haemorrhage (not shown).</p

Effect of patient and procedure related variables on SFD deployment difficulty, flow disturbance, and delayed neurological complications.

<p>Untoward events reported during and after treatments related to aneurysm shapes, sizes location, and use of coils.</p><p>Deployment difficulty  =  poor opening, poor positioning, or migration of SFD.</p><p>Flow disturbance  =  partial or complete thrombosis of parent artery.</p

Timings and results of angiographic follow up.

<p>Plot of angiographic outcomes against follow up times in weeks.</p