Surgical problems in the treatment of aneurysms of the posterior circulation

Despite the recent multidisciplinary achievements, surgery for posterior circulation aneurysms remains challenging. Sac dimensions and fundus projection are highly variable and independent factors, which can determine, the operative field being deep and restricted, in some case the failure of the procedure. Other factors the surgeon must cope with are the relationships between aneurysm and surrounding arteries, cranial nerves (oculomotor nerve mainly) and bone structures. Due to the esiguity of the operative field a complete dissection of the sac can be achieved frequently only after the clipping when, by the way, the clip position must be verified in order to avoid perforants closure. Aim of this paper is to perform a retrospective study regarding patients harbouring a posterior circulation aneurysm treated in a public health environment.

Our experience resides on 78 consecutive cases (whose 37 of the basilar artery and 37 with other localizations) successfully clipped by the same surgeon (senior author: RS); 4 additional aneurysms were only explored (whose 3 originated from the basilar artery). The clinical charts of the basilar apex cases were reviewed, the angiographic and intraoperative findings were correlated to the GOS (Glasgow Outcome Scale).

The fundus projection in the basilar apex cases was the main risk factor accounting for a 50% mortality rate in the antero-posterior direction cases.

Posterior circulation aneurysms are intimidating vascular malformations even nowadays; in the future improvements in the endovascular technique could provide an effective alternative to an open surgery approach.