gms | German Medical Science

Objective: The most employed outcome score for the evaluation of aneurysm treatment is the Glasgow Outcome Score (GOS), but this score solely displays the safety of treatment while disregarding its efficacy (i.e. neck remnant). An incomplete occluded aneurysm, however, is a major cause of distress to the patient, reducing the quality of life (lifelong control or re-treatment, risk of rupture). Consequently, we propose a new outcome scoring system (Grade of Aneuryma Occlusion and Outcome – GAOO score) based on the conventional GOS, now additionally including the degree of aneurysm occlusion.

Methods: We consulted our institutional database and we identified 286 patients in whom at least one unruptured cerebral aneurysm were treated, with either clip or coil. We extracted all specific data necessary for the new assessment (GAOO - combined score: GOS + grade of occlusion): neurological performance and degree of aneurysm occlusion due to the post-procedural rotational angiography (grade of occlusion: complete = A; small remnant ≤ 3mm = B; large remnant > 3mm = C).

Results: GOS, clipping group: 5=98.8% (n=166), 4=1.2% (n=2). GOS, coiling group: 5=95.9% (n=139), 4=4.1% (n=6). GAOO score, clipping group: 5A=79.2% (n=133), 4A=1.2% (n=2), 5B=15.5% (n=26), 5C=4.2% (n=7). GAOO score, coiling group: 5A=64.8% (n=94), 4A=0.7% (n=1), 5B=14.5% (n=21), 4B=2.1% (n=3), 5C=17.9% (n=26). Compared to the GOS, the GAOO score had a significantly higher sensitivity and specificity to predict the treatment efficacy (range from 97.8-100%, and 81.6-100%, resp.). According to the GAOO score significantly more patients achieved the best grade (5A) after clipping than after coiling (79.2% vs 64.8%, p<0.05).

Conclusion: The GAOO score combines the neurological performance and the radiographically confirmed occlusion. The new GAOO score is an easy applicable score to predict precisely the outcome after aneurysm treatment, at least for unruptured cerebral aneurysms.