Perioperative And Delayed Stroke After Surgical Revascularization In Pediatric Moyamoya Arteriopathy

Introduction: Surgical revascularization is the mainstay of management in severe moyamoya arteriopathy (MMA). While perioperative stroke has been characterized, little is known about delayed postoperative stroke. Methods: We retrospectively identified patients diagnosed with MMA between 28 days and 18 years of age seen at our center between 1/2003 and 6/2021 using ICD codes. Those who underwent surgical revascularization either at our or another center were analyzed. Descriptive analysis of patients experiencing perioperative (defined as ≤7 days after surgery) versus delayed postoperative stroke (stroke occurring >7 days after surgery) was conducted. Results: 53 unique patients underwent 68 revascularization surgeries of 95 hemispheres. Median age at time of surgery was 8.3 years. Median time from surgery to final follow-up was 6.6 years. Postoperative stroke occurred in 11 (16%) cases, including 7 (10%) in the perioperative period and 4 (6%) >7 days after surgery. Patients with delayed stroke had a median age of 5.1 years at surgery, and median time to stroke was 87 days. While MMA associated with Trisomy 21 represented only 15% of cases in our sample, these cases accounted for 36% of postoperative strokes. Delayed stroke occurred more frequently in patients with unilateral revascularization. These patients developed infarcts contralateral to the revascularized hemisphere. Conclusions: Delayed stroke following surgical revascularization in patients with MMA occurred less frequently than perioperative stroke in our cohort. Trisomy 21 may be a risk factor for postoperative stroke. Further study is needed to characterize and predict which patients are at risk for delayed stroke.