Analysis of branch artery orifice angulation: Feasibility of the shelf technique for the treatment of wide-neck bifurcation aneurysms.

Background and Purpose: The aim of this study was to investigate the feasibility of the shelf technique by analyzing the angle between the two branch orifices and to present its safety and effectiveness compared with that of the double-stent technique.
Materials and Methods: Patients with complex wide-neck bifurcation aneurysms (WNBAs) who underwent stent-assisted coiling (SAC) were reviewed. The study sample was divided into two groups: single SAC (shelf technique) and double SAC. The angle between the lines connecting the superior and inferior points of each branch orifice (α angle) was measured by two neurointerventional radiologists in both groups. The inter- and intraobserver repeatability and consistency of the α angle were assessed. The effect of the α angle on the feasibility of using the shelf technique to treat WNBA was analyzed. Technical and clinical success rates were investigated by comparing both groups.
Results: Forty-eight patients (32 shelf technique and 16 double-stent technique) were included. There was excellent agreement between the intra- and interobserver repeatability and consistency of α angle measurements. The α angle was smaller in the shelf technique group than in the double-SAC group (p < 0.001). The technical and clinical success rates of both groups were similar based on long-term follow-up (p > 0.05).
Conclusion: WNBA treatment with the shelf technique is safe and effective. The α angle is a useful parameter to evaluate the performance of the shelf technique. The shelf technique is more suitable for WNBAs with a narrow α angle.