gms | German Medical Science

66th Annual Meeting of the German Society of Neurosurgery (DGNC)
Friendship Meeting with the Italian Society of Neurosurgery (SINch)

German Society of Neurosurgery (DGNC)

7 - 10 June 2015, Karlsruhe

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Computerized angiographic occlusion rating for ruptured clipped aneurysms is superior to subjective occlusion rating

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  • Abdul Rahman Al-Schameri - Department of Neurosurgery, Paracelsus Private Medical University, Salzburg, Austria
  • Gerasimos Baltsavias - University Hospitals of Zurich, Neuroradiology Department, Zurich, Switzerland
  • Manuel Lunzer - Department of Neurosurgery, Paracelsus Private Medical University, Salzburg, Austria
  • Michael Kral - Department of Neurosurgery, Paracelsus Private Medical University, Salzburg, Austria
  • Lukas Machegger - Department of Neuroradiology, Paracelsus Private Medical University, Salzburg, Austria
  • Friedrich Weymayr - Department of Neuroradiology, Paracelsus Private Medical University, Salzburg, Austria
  • Stephan Emich - Department of Neurosurgery, Paracelsus Private Medical University, Salzburg, Austria
  • Camillo Sherif - Department of Neurosurgery (C.S.), Krankenanstalt Rudolfstiftung, Vienna, Austria
  • Bernhard Richling - Department of Neurosurgery, Paracelsus Private Medical University, Salzburg, Austria
  • Peter A. Winkler - Department of Neurosurgery, Paracelsus Private Medical University, Salzburg, Austria

Deutsche Gesellschaft für Neurochirurgie. 66. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). Karlsruhe, 07.-10.06.2015. Düsseldorf: German Medical Science GMS Publishing House; 2015. DocMI.02.02

doi: 10.3205/15dgnc256, urn:nbn:de:0183-15dgnc2566

Published: June 2, 2015

© 2015 Al-Schameri et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.

Outline

Text

Objective: The initial angiographic occlusion rate is the strongest predictor of later rebleeding and retreatment in previously ruptured aneurysms. For coil-embolized aneurysms it was proven that the new method of computerized angiographic occlusion rating (COR) is superior to the actual standard of subjective estimation of occlusion rates (SOR). SOR is limited by unacceptable estimation bias, overestimation of aneurysm occlusion and interobserver variations. In this study, COR was applied to a series of 95 clipped aneurysms, to assess for clinical benefits also for clipped aneurysms.

Method: On pre- and postoperative DSA images SOR were determined by 2 independent observers. COR was measured by 2 blinded investigators. Interobserver variations were determined for SOR and COR. COR results were compared with SOR results and stratified as 100%, 99.9% - 90%, 89.9% - 70%, and _70% occlusion. SOR and COR were evaluated as predictors for retreatment.

Results: With SOR, 75 (78,9%), 12 (12,6%), 7 (7,4%) and 1 (1,1%) and with COR 45 (47,4%), 24 (25,3%), 20(21,0%) and 6 (6,3%) patients had aneurysms stratified to the Groups 0, I, II and III respectively. The interobserver variation was significant with SOR but not with COR. SOR overestimated aneurysm occlusion in 30 (31,6%) patients. Mean values were: SOR 97.5% ± 6.3% and COR 93.5% ± 9.7% (p=< 0.0001). No patient rebled and 4 patients underwent re-treatment during 36 months ± 38, 9; the predictive value (log rank, Kaplan-Meier) of SOR and COR with respect to re-treatment was highly significant for both methods (SOR: chi-square 29.65; p<0.0001, COR:chi-square 35.57, p<0.0001).

Conclusions: The two methods showed remarkable differences in the estimation of the angiographic occlusion rates of clipped aneurysms. The significantly lower interobserver variation of COR versus SOR may indicate a superiority of COR. COR reduced the impact of subjective bias. COR may, therefore, serve as an easily applicable more objective tool for optimized follow-up.