Keyhole Alternatives to Pterional Craniotomy for the Microsurgical Clipping of Anterior Circulation Aneurysms: Technical Pearls, Surgical Results, and a Case Selection Algorithm.

Background: Despite a recent surge in keyhole approaches to aneurysm clipping, only few studies have compared these approaches, and none have laid any foundation or roadmap for surgeons newly venturing into these procedures.

Objectives: To report a single surgeon's experience of multiple keyhole approaches to these aneurysms, and to highlight the case selection algorithm, technical nuances, and surgical results.

Material and methods: Twenty-four patients (25 aneurysms) underwent aneurysm clipping using either a mini-pterional approach (MPA), lateral supraorbital approach (LSO), or a supraorbital keyhole approach (SOKHA). Intraoperative premature rupture, adequacy of clipping, and immediate postoperative and long-term functional outcomes were recorded.

Results: All but five patients presented with ruptured aneurysms (Hunt and Hess grade 1 in 12 patients, grade 2 in 5 patients, and grade 3 in 2 patients). The anterior communicating artery (A-Comm; n = 14, 56%) was most frequently involved with aneurysms. The MPA was most frequently employed (n = 11, 45.8%), followed by the LSO (n = 9, 37.5%) and the SOKHA (n = 4, 16.7%). An intraoperative rupture (total n = 5, 20.8%) was most frequently seen in the SOKHA group (50%) and the only case of inadequate aneurysm clipping resulted from inadequate clipping ergonomics during the SOKHA for A-Comm aneurysm. Major complications occurred in the supraorbital approaches (one each in the LSO and SOKHA). Irrespective of the approach used, the long-term outcomes were excellent.

Conclusion: In properly selected patients, keyhole approaches-particularly the MPA and the LSO-can provide excellent surgical outcomes. The learning curve in the SOKHA is steeper. A pragmatic case selection algorithm is proposed.