Single-Center Case Series of Simple Proximal Clipping for Large Thrombosed Vertebral Artery Aneurysms: Preservation of Perforating Arteries and Long-Term Outcomes.

BACKGROUND: Surgical proximal parent artery occlusion (PAO) is one of the treatments for partially thrombosed vertebral artery aneurysms (PTVAs). However, whether long-term changes in size and perforating arteries through the blind end can be truly preserved remain unknown. OBJECTIVE: To evaluate the efficacy and safety of surgical proximal PAO for PTVAs, focusing on the transition in size and preservation of perforating arteries. METHODS: We retrospectively reviewed 14 consecutive cases of unruptured large PTVAs. The cases were treated with surgical proximal PAO without trapping or thrombectomy. Preservation of the perforating arteries was confirmed through intraoperative indocyanine green video angiography. The aneurysm size was evaluated by measuring the maximum diameter on axial T2-weighted magnetic resonance images. Post-treatment outcomes were assessed using the modified Rankin Scale at the last follow-up examination. RESULTS: Thirteen patients (excluding 1 with morbidity) had a mean follow-up time of 33.2 months (range, 12-60 months) and a mean reduction rate of 71% (range, 32%-95%). Only 1 patient (7.2%) experienced postoperative stroke, and 13 patients (92.8%) showed no worsening of the modified Rankin Scale score at the final follow-up examination. The symptoms were improved in 5 of the 6 symptomatic patients (83.3%). In 10 patients (71.4%), a perforating branch that could not be identified on preoperative imaging was identified intraoperatively. CONCLUSION: Surgical proximal PAO without trapping or thrombectomy for PTVAs allows long-term reduction of aneurysm size and improves treatment safety by preserving the perforating artery, especially in cases wherein direct reconstruction is not feasible.