Role of microsurgery for treatment of posterior circulation aneurysms in the endovascular era.

[OBJECTIVE] Several studies have reported that the outcomes of endovascular treatment were superior to those of microsurgical treatment for posterior circulation aneurysms. Thus, this study compared outcomes of endovascular and microsurgical treatment for posterior circulation aneurysms and assess the usefulness of microsurgery in these patients.

[METHODS] Outcomes were retrospectively evaluated after endovascular and microsurgical treatment of 621 posterior circulation aneurysms. The 621 aneurysms included 187 treated by surgical clipping and 434 treated by endovascular coiling.

[RESULTS] In patients with unruptured aneurysms the rates of residual lesions and retreatment were significantly lower in those who underwent microsurgical than endovascular treatment. However immediate postoperative and 6 month follow-up Glasgow outcome scale (GOS) scores did not differ significantly in the two groups. In patients with ruptured aneurysms, the rates of residual lesions and retreatment were significantly lower in the microsurgery than in the endovascular treatment group. Even so immediate postoperative and 6 month follow-up GOS scores did not differ significantly in the two groups.

[CONCLUSIONS] Endovascular treatment has increasingly become an alternative modality for microsurgery in posterior circulation aneurysm, whereas the indication for microsurgery is greatly reduced. However, the absolute number of microsurgery is maintained showing that it is a still valuable technique, as advances in endovascular or stent-assisted coiling have not solved many of the challenges inherent in the management of complex aneurysms. Hence, the advantages and limitations of both modalities must be carefully concerned in posterior circulation aneurysm to obtain favorable outcome.