Hemoglobin Concentration May Influence the Incidence of Postoperative Transient Neurological Events in Patients With Moyamoya After Extracranial-intracranial Arterial Bypass: A Retrospective Single Center Experience.

Abstract

Moyamoya is a rare condition characterized by cerebral angiographic findings of intracranial carotid artery stenosis with abnormal net-like vessels in the brain, and often presents as transient ischemic attacks or intracranial hemorrhage. Revascularization in the form of extracranial-intracranial (EC-IC) artery bypass has demonstrated efficacy in preventing ischemic attacks and intracranial hemorrhage, although it is associated with a relatively high rate of perioperative ischemic and hemorrhagic stroke. This retrospective analysis aims to evaluate the possible association between postoperative hemoglobin (Hgb) concentration and early postoperative transient neurological events (TNEs) experienced at our center. Consecutive patients undergoing EC-IC bypass between January 1, 2017 and August 31, 2019 were identified, resulting in a study population of 24 patients with 34 individual cases for different cerebral hemispheres. Postoperative Hgb level was evaluated upon arrival to the intensive care unit (ICU) and the primary outcome was the occurrence of TNEs within 24-hours after surgery. The incidence of TNEs within 24 hours postoperatively was 12% (n=4). Statistically significant differences were demonstrated between patients who did and did not experience TNEs in the postoperative period: total Hgb value (mean 9.4 vs. 11.3 g/dL, respectively; P=0.012) and percentage of patients with Hgb <10 g/dL (75% vs. 20%, respectively; P=0.048). Patients with a postoperative Hgb value <10 g/dL upon arrival to the ICU were significantly more likely to experience TNEs (odds ratio, 12; 95% confidence interval, 1.053-136.794; P=0.045). This study reports a possible association between postoperative Hgb level and the occurrence of TNEs within the first 24 hours after surgery in patients undergoing EC-IC for moyamoya.