The Mini-Spheno-Supraorbital Craniotomy for Treatment of Ruptured Anterior Circulation Aneurysms

Objective:Yasargil introduced the pterional approach mainly for clipping of anterior circulation (AC) aneurysms. We implemented the mini-spheno-supraorbital (MSS) craniotomy, changing the shape and reducing the size of the classical pterional craniotomy. The literature on clipping ruptured AC aneurysms through reduced-in-size craniotomies is sparse. This study aims to describe the technique and present our experience in clipping ruptured AC aneurysms through the MSS approach. Materials and methods: The MSS craniotomy was used in 114 cases of clipping ruptured AC aneurysms. A single burr hole was placed at the "keyhole" and an ellipsoid bone flap in the spheno-supraorbital region was raised. The tabula interna was thinned circumferentially, the roof of the orbit was flattened. Among aneurysm clipping, the lamina terminalis and the subarachnoid basal cisterns were opened. The imaging modality, the severity of the subarachnoid hemorrhage (SAH) according to Hunt & Hess (H&H), the size of the bone flap, the surgery duration and the aneurysm obliteration rate seen at the postoperative DSA were examined. Results:Out of all patients in the study, 71% had exclusively CT-angiogram as initial imaging and suffered low-grade (H&H I°) SAH (71%). The mean size of the bone flap was 1.6 x 4.5 cm (1.3 x 4.3 - 2 x 8.5 cm). The approach allowed adequate 360°-dissection, sufficient proximal and distal control, brain relaxation though laminoterminotomy and opening of the basal cisterns. The mean duration from skin incision to clip application was 130 minutes (64-236 mins). Total obliteration rate was 97.3%. Conclusion:The MSS craniotomy is feasible in terms of safety and speed for clipping of ruptured AC aneurysms especially in lower-grade SAH.