Therapeutic strategy and effect of different approaches for microsurgical treatment of basilar artery bifurcation aneurysms

Objective To investigate the strategy and effect of microsurgical treatment of basilar artery bifurcation aneurysms with different surgical approaches. Methods We retrospectively reviewed the clinical data of 43 patients with basilar artery bifurcation aneurysms who underwent microsurgical clipping at Department of Neurosurgery, the Second Xiangya Hospital, Central South University from April 2011 to April 2018. Of all 43 cases, 32 cases had ruptured basilar aneurysms and 11 cases had unruptured basilar aneurysms. According to the different morphological and anatomical locations of aneurysms, 17 cases underwent infraorbital approach, 26 cases underwent transsyvian approach (including the transorbirozygomatic approach, the 'half-half’ approach which combined the subtemporal approach with pterion approach and the simple pterion approach) to conduct microsurgical clipping. Intraoperative monitoring was performed using the combination of multiple technologies. Clinical and imaging follow-up was conducted over 6 months post surgery. Results Of all 43 cases with basilar artery bifurcation aneurysms, 38 cases were completely clipped, 4 cases were partially clipped, and 1 case was wrapped. There were 2 cases (4.7%) of hemiplegia after operation, 1 case (2.3%) of coma, 14 cases (32.6%) of oculomotor nerve palsy and no death during perioperative period. Thirty-seven patients (86.4%) were followed up for 25.0±10.1 months (range: 6 months to 4 years). Among them, 35 patients underwent radiographic review without aneurysm residual and 1 patient with partial clipping was treated with second-stage interventional embolization. In 1 case with wrapped aneurysm, the significantly enlargement of aneurysm was not observed in the follow-up image. Of 14 cases with oculomotor nerve palsy after operations, 11 were followed up and 8 of them improved significantly afterwards. Glasgow′s outcome scale(GOS) showed that grade V was reported in 34, grade IV in 1 case, grade III in 1 case, grade II in 0 and grade I in 1 case who died from severe pulmonary infection at 42 days post operation. Conclusions The superior treatment of the basilar artery bifurcation aneurysm could be achieved through subtemporal and transsyvian approach. Preoperative evaluation of anatomical and morphological characteristics of aneurysm seems important for the choice of surgical approach. The application of various assistive techniques during surgery is an important part of ensuring the safety of surgery. Key words: Intracranial aneurysm; Basilar artery; Microsurgery; Treatment outcome