Comparison Between Minipterional Craniotomy Associated With Focused Sylvian Fissure Opening and Standard Pterional Approach With Extended Sylvian Fissure Dissection for Treatment of Unruptured Middle Cerebral Artery Aneurysms

Background: In our institution, standard pterional craniotomy (PC) with an extended Sylvian fissure opening (ESFO) represented the standard approach for unruptured middle cerebral artery (MCA) aneurysm clipping until 2014, when we progressively started to prefer minipterional craniotomy (MPC) associated with a focused Sylvian fissure opening (FSFO). In the present study, we compared our results in terms of the efficacy of clipping and the rate of complications with these 2 different techniques.

Methods: We included patients with small- and medium-size unruptured MCA aneurysms from January 2008 to December 2018 with follow-up of >12 months. The clinical and radiologic data were reviewed from the medical records. The outcomes were measured in terms of efficacy (aneurysmal exclusion rate) and safety (intracranial complication rate).

Results: Overall, 134 patients who had presented with unruptured MCA aneurysms <1.5 cm were treated at our institution from January 2007 to December 2018: PC and ESFO were used in 73 patients and MPC and FSFO in 61. The demographics and angioarchitectural features were comparable between the 2 groups, except for age, which was older in the FSFO group. The aneurysm exclusion rate was not different between the 2 groups. The intracranial complication rate was, overall, significantly lower in the FSFO group (P < 0.001), especially for the rate of postoperative seizures. Finally, the FSFO group had had shorter postoperative hospitalization and better short- and long-term clinical outcomes.

Conclusions: The association between MPC and FSFO should represent the standard of treatment of unruptured MCA aneurysms in all referral cerebrovascular centers, allowing for the achievement of the same efficacy of standard PC with ESFO and minimizing the complications.