Outcomes of surgical revascularization in a case series of moyamoya patients with severe brain atrophy

OBJECTIVE Patients with advanced moyamoya disease have chronic cerebrovascular insufficiency with superimposed acute ischemic insults, leading to brain atrophy and cognitive decline. The outcomes of revascularization procedures in moyamoya patients with marked brain atrophy are not yet clearly known. METHODS This retrospective study used an approach based on the global cerebral atrophy scale to identify patients with severe brain atrophy from a single-surgeon series of patients with moyamoya disease undergoing revascularization from January 2015 to January 2024. Clinical outcomes (modified Rankin Scale [mRS] score, improvement in symptoms and cognitive function) and radiological outcomes (arterial spin labeling [ASL] perfusion) were studied and compared between direct and indirect revascularization groups. RESULTS Of 153 patients in the series, 16 (mean age 8.9 years) had severe brain atrophy (cortical atrophy score ≥ 8). The presenting symptoms were recurrent transient ischemic attack in 6 patients (37.5%), major stroke in 7 patients (43.75%), and seizure in 3 patients (18.75%). Fourteen patients underwent surgeries for both hemispheres and 2 patients underwent surgery for 1 hemisphere. Of the 30 hemispheres, 17 (56.7%) were treated with direct revascularization and 13 (43.3%) with indirect revascularization. The mean follow-up duration was 38.8 months. The median mRS score improved from 3 (preoperative) to 1.5 (last follow-up), with 11 patients (68.75%) showing improvement in mRS score. Thirteen patients (81.25%) showed improvement in presenting symptoms. Overall, 12 of 16 patients (75%) showed improvement in cognitive function at the last follow-up. The mean preoperative and follow-up ASL scores improved for the lower-perfusion hemispheres from 7.9 to 8.9 and for the higher-perfusion hemispheres from 9.6 to 10.45, respectively. Differences between preoperative and postoperative ASL scores for both groups were statistically significant. There was no significant difference in clinical and radiological outcomes between the direct and indirect revascularization groups. Clinical outcomes were comparable across patient groups based on the distribution of brain atrophy (unilateral/bilateral, predominant left/right side, predominant vascular territory involved). CONCLUSIONS Moyamoya patients with severe brain atrophy showed improvement in paroxysmal symptoms, cognitive function, and overall clinical functioning status, as well as radiological perfusion, after undergoing either direct or indirect revascularization. Comparative efficacy of direct and indirect revascularization in these patients needs further investigation.