Risk factors and a novel cerebral infarction extent scoring system for postoperative cerebral ischemia in patients with ischemic Moyamoya disease

Abstract

Postoperative cerebral ischemic complication is the most common complication of revascularization surgery for patients with moyamoya disease (MMD). This retrospective study was conducted on 63 patients with ischemic MMD. Postoperative ischemia occurred in 15 of the 70 revascularization operations performed for patients after surgical revascularization, translating to an incidence of 21.4%. Univariate analysis revealed that onset infarction (p = 0.015), posterior cerebral artery involvement (p = 0.039), strict perioperative management (p = 0.001), interval time between transient ischemic attack (TIA) or infarction presentation and operation (p = 0.002) and preoperatively cerebral infarction extent score (CIES) (p = 0.002) were significantly associated with postoperative cerebral ischemia. Multivariate analysis revealed that strict perioperative management (OR = 0.163; p = 0.047), and preoperatively CIES (OR = 1.505; p = 0.006) were independently associated with postoperative cerebral ischemia-related complications. After comprehensive improvement of perioperative management protocol, the incidence of symptomatic infarction declined to 7.4% (4 out of 54). Analysis of the area under the receiver operating characteristic curve (AUROC) indicated CIES was a predictor for both postoperative ischemia and high follow-up modified Rankin Scale scores. In summary, strict perioperative management and CIES were identified as independent risk factors for postoperative ischemic complications in ischemic MMD, demonstrating that comprehensive and individualized perioperative management improve postoperative outcomes in patients with MMD. Furthermore, application of CIES to evaluate pre-existing cerebral infarction can improve the management of patients.

Figure 1

Schematic diagrams of CIES. (A) Diagrams showed no infarction preoperatively. CIES = 0 point, (B) diagrams indicated infarction (gray area) on the right temporal lobe, affecting about 1/3 of the lobe. CIES = 1. (C) Diagrams indicated infarction (gray area) on the right temporal lobe, affecting about 2/3 of the lobe, CIES = 2. (D) Diagrams indicated infarction (gray area) on the right temporal lobe, affecting about whole lobe. CIES = 3.

Figure 2

Protocol tree of perioperative management of patients with ischemic Moyamoya disease. BP: Blood pressure. PaCO₂ partial pressure of carbon dioxide, SBP systolic blood pressure.

Figure 3

MR images obtained pre and postoperatively represent ischemic lesions. (A–C) T2-weighted, T1-weighted and diffused weighted MR images showed preoperative infarction in bilateral of temporal lobe and occipital lobe (white arrowheads). CIES = 7 point. (D) Diffused weighted MR images showed acute cerebral infarction in left temporal and occipital lobe postoperatively.

Figure 4

Multivariate analysis of postoperative ischemic complications. CIES cerebral infarction extent scoring system, TIA transient ischemic attack, PCA posterior cerebral artery.

Figure 5

Preoperative, postoperative and follow-up mRS based on the high or low CIES. (A) Comparison of preoperative mRS between low (< 7) and high (≥ 7) CIES subgroups (ns: not significant, Mann–Whitney U test). (B) Comparison of discharge mRS between low and high CIES subgroups (***p < 0.001, Mann–Whitney U test). (C) Comparison of follow-up mRS between low and high CIES subgroups (***p < 0.001, Mann–Whitney U test. (D) The difference of incidence of postoperative ischemic complications between low and high CIES subgroups. (E,F) AUROC for CIES as a predictor for postoperative ischemia (E) or a high follow-up mRS score (F).