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Treatment of Intracranial Aneurysms with Hydrogel Coated Expandable Coils

  • Thorsteinn Gunnarsson (a1), Paula Klurfan (a2), Karel G. terBrugge (a2) and Robert A. Willinsky (a2)



Coiling of intracranial aneurysms with platinum coils sometimes results in relatively poor angiographic results which may be is related to low packing volumes achieved. Hydrogel coated expandable coils (HydroCoil®) have been shown to achieve better aneurysm volume filling which may potentially result in lower recanalization rates. Currently there is limited clinical data on their safety and efficacy in aneurysm treatment.


We analyzed data from a prospectively collected database on patients treated at the Toronto Western Hospital. The analysis included the patients' characteristics, aneurysm size, packing, procedure related complications, recanalization and clinical outcome.


Twenty-nine aneurysms were treated with HydroCoils only or in combination with other coils. The average calculated filling of the aneurysm volume was 74-76%. On the immediate post treatment angiograms, 44% of the berry type aneurysms were completely obliterated, 33% had a residual neck and, in 20%, a residual aneurysm was seen. Follow-up imaging was available in 23 cases. On imaging follow-up (from 2 days to 11 months) one dissecting aneurysm had recanalized. There were six technical/medical complications with no clinical consequences. Two clinically significant procedural related complications occurred.


HydroCoils can be used effectively to treat intracranial aneurysms. The volume expansion allows for much greater packing than described for bare platinum coils, which may result in better long-term results. The recanalization rate is low but the limited follow-up does not allow for any conclusion regarding the long-term outcome. The complication rate is similar to larger current series using bare platinum coils.

RÉSUMÉ: Contexte:

Le traitement des anévrismes intracrâniens avec des microspires de platine donne parfois des résultats angiographiques peu satisfaisants qui sont peut-être dus au faible remplissage obtenu. Les microspires expansibles enduites d'hydrogel (HydroCoil,) permettent un meilleur remplissage de la cavité de l'anévrisme, ce qui est susceptible de diminuer le taux de reperméabilisation. Il existe peu de données cliniques au sujet de leur sécurité et de leur efficacité dans le traitement des anévrismes.


Nous avons analysé les données d'une base de données accumulées de façon prospective sur des patients traités au Toronto Western Hospital. Les caractéristiques des patients, la taille de l'anévrisme, l'entassement des microspires, les complications suite à l'intervention, la reperméabilisation et l'issue clinique ont été analysés.


Vingt-neuf anévrismes ont été traités au moyen d'HydroCoils seulement ou combinés à d'autres microspires. Le remplissage calculé moyen du volume anévrismal a été de 74 à 76%. Àl'angiographie effectuée immédiatement après le traitement, 44% des anévrismes ampullaires étaient complètement oblitérés, 33% avaient un collet résiduel et un anévrisme résiduel était visible chez 20% des patients. L'imagerie effectuée au cours du suivi, soit de 2 jours à 11 mois après l'intervention, était disponible chez 23 patients. Un anévrisme disséquant était reperméabilisé. Il y a eu 6 complications techniques ou médicales sans conséquences cliniques et deux complications reliées à l'intervention qui étaient significatives au point de vue clinique.


Les HydroCoils peuvent être utilisés efficacement pour traiter les anévrismes intracrâniens. Leur expansion permet de les entasser beaucoup plus que les microspires de platine nus, ce qui est susceptible de donner de meilleurs résultats à long terme. Dans cette étude, le taux de reperméabilisation est faible. Cependant, le suivi est trop court et ne permet pas de tirer des conclusions sur l'issue à long terme. Le taux de complication était semblable à celui de plus grandes séries de cas traités au moyen de microspires de platine nues.

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