gms | German Medical Science

59th Annual Meeting of the German Society of Neurosurgery (DGNC)
3rd Joint Meeting with the Italian Neurosurgical Society (SINch)

German Society of Neurosurgery (DGNC)

1 - 4 June 2008, Würzburg

Partially thrombosed giant aneurysms of the posterior fossa. Pathophysiology, imaging, and treatment strategies

Partiell thrombosierte Riesenaneurysmen in der hinteren Schädelgrube. Pathophysiologie, Bildgebung und Behandlungsstrategien

Meeting Abstract

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  • corresponding author F.J. Hans - Neurochirurgische Universitätsklinik, RWTH Aachen, Aachen
  • T. Krings - Abteilung für Neuroradiologie, RWTH Aachen, Aachen

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocP 062

The electronic version of this article is the complete one and can be found online at:

Published: May 30, 2008

© 2008 Hans et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: Within the group of giant and large aneurysms the subgroup of the so-called “partially thrombosed” aneurysms can be differentiated according to clinical and neuroimaging findings. The present study was carried out to determine the site of bleeding of these aneurysms and what implications concerning their pathomechanism can be drawn from these findings.

Methods: 9 patients aged 2 to 71 (mean 39) years who exhibited a partially thrombosed aneurysm that had recently bled were included. Images (MRI including T1 pre- and postcontrast and T2 weighted images in multiple planes, CT and digital subtraction angiography), patients' charts and treatment strategies were reviewed.

Results: MRI showed an onion-skin appearance of the thrombus and rim enhancement of the aneurysm wall (either partial or complete) in all nine patients, and a perifocal edema in 7 patients. The acute hemorrhage was typically crescent-shaped and located at the periphery of the aneurysm, distant from the perfused lumen of the aneurysm within the thrombosed part of the aneurysm. In those aneurysms where only coiling of the lumen was performed (n=2) early compaction was noted, parent vessel occlusion by endovascular means (n=3) and surgical means (n=2) led to stable and complete occlusion, in two patients, a conservative management was adopted. Patients in whom a parent vessel occlusion was performed improved on follow-up whereas the other patients remained unchanged from their clinical status.

Conclusions: The current denomination “partially thrombosed” intracranial arterial aneurysms leads to the presumption that thrombus is present endoluminal whereas in fact the site of hemorrhage is within the vessel wall. A more accurate nomination would, therefore, be “aneurysms with intramural hemorrhage”. The enhancing wall and the edematous reaction of the adjacent brain parenchyma might be a sign for an inflammatory pathomechanism which is reinforced by histological and pathophysiological studies. This disease should be regarded as a clinical entity separate from saccular or non-thrombosed giant or large aneurysms. Following our retrospective analysis, we think that parent vessel occlusion should be performed in these diseases, either by surgical or endovascular means to reduce mass effect.