Abstract TP117: What Have We Learned From the Pre-operative Evaluation of Patients With Moyamoya Disease?

Abstract

Introduction & Hypothesis: Our ability to effectively treat Moyamoya patients revolves around various preoperative imaging modalities used to assess the severity of cerebrovascular reserve compromise; however, not all are necessary for evaluation. We evaluated preoperative conventional angiography, MRI, MRA NOVA, and SPECT and their impact on management of patients with Moyamoya disease. Methods: A prospectively collected database of 36 Moyamoya patients was assessed to evaluate preoperative work-up. Patients were grouped based on MRI findings on presentation; ischemia, hemorrhage, and normal. Patients who did not have all of the pre-operative tests were excluded. Preoperative results were dichotomized as either normal or abnormal. Patients with bilateral disease were assessed individually for each side. Results: Twenty-eight patients (30 total sides) met inclusion criteria: 4 normal, 16 ischemia, and 10 hemorrhage on presentation. All patients had abnormal MR NOVA suggesting reduced CBF in the affected vascular territory. The decision on performing surgery in asymptomatic Moyamoya patients was based on abnormal finding on pre-operative MRA NOVA and/or SPECT and in symptomatic patients based on the presenting symptoms and abnormal MRA/SPECT. All patient underwent STA-MCA bypass surgery for the symptomatic or abnormal side. The two patients with bilateral disease had direct STA-MCA bypass on the symptomatic side and an indirect revascularization on the asymptomatic side. The imaging findings confirmed indication for surgery in all 28 patients. Conclusions: We assessed the impact of SPECT and MR NOVA on evaluation of Moyamoya patients. We confirm that all patients in this series, symptomatic or not, have abnormal CVR. Preoperative imaging can aid in establishing a baseline of CBF and CVR. However, testing did not modify the indication for treatment in Moyamoya patients, even in asymptomatic ones. We suggest to re-evaluate the need for extensive preoperative testing for symptomatic Moyamoya patients and limit the preoperative testing to diagnostic angiogram. Asymptomatic Moyamoya patients benefit from preoperative testing to clarify the need for treatment.