Background and Purpose: Surgical revascularization is known to reduce subsequent incidence of ischemic and hemorrhagic stroke with low morbidity in moyamoya disease. However, repeat bypass surgery is required for a certain subgroup of patients, although the information on indication, surgical technique, and outcome is limited. Therefore, this study was aimed to precisely analyze clinical features, surgical technique, and long-term outcome of repeat bypass surgery for refractory moyamoya disease.
Methods: This study included totally 20 surgeries for18 patients who underwent repeat bypass surgery because previous surgery was inadequate in 10 surgeries (Group A) or because the posterior cerebral artery was further involved after surgery in 10 (Group B). There were 7 males and 11 females. Their age ranged from one to 69 years. Precise radiological examinations were performed before surgery, using MRI, cerebral angiography, and SPECT. In Group A, all patients who previously underwent inadequate surgery repeated headache attack, TIA, or hemorrhagic stroke, and underwent repeat bypass surgery targeted to the non-revascularized area, using STA-MCA anastomosis and/or indirect synangiosis as appropriate. On the other hands, occipital artery to posterior cerebral artery (OA-PCA) anastomosis and/or indirect bypass was required in Group B who developed disease progression in the PCA.
Results: All 18 patients successfully underwent repeat bypass surgery. Postoperative course was uneventful. Postoperative examinations revealed good revascularization in the operated hemispheres and the improvement of cerebral hemodynamics. Headache attack and TIA disappeared within 6 months at the latest after surgery. During follow-up periods, one (5.6% per person) of 18 patients died of recurrent hemorrhagic stroke two years after repeat bypass surgery.
Conclusion: Repeat bypass surgery is feasible and effective to reduce further incidence of headache attack, TIA, and ischemic and hemorrhagic stroke. Through precise radiological analysis, surgical procedures should be planned to yield maximal therapeutic effects.