Table 1.

Characteristics of included studies

Study	Race	Number of surgery patients	Age (mean ± sd., or range)	Type of study	Onset symptoms	Adverse postoperative events (number)	Preoperative possible risk factors	Quality
Meng 2018 [5]	Asian	500	37.5 ± 9.4	Retrospective	IS; HS; NS	IS (62)	age, male sex, ischemic presentation, hypertension, diabetes, Suzuki stage, PCA involvement, surgery type	High
Peicong 2017 [7]	Asian	87	54.0 ± 3.7	Retrospective	IS; HS	IS (5) + HS (1)	diabetes, PCA involvement	High
Meng 2017 [6]	Asian	121	35.4 ± 7.5	Prospective	IS; NS	IS (7) + HS (2)	age, male sex, diabetes, hypertension, PCA involvement, Suzuki stage, surgery type	High
Wonhyoung 2016 [8]	Asian	194	37.2 ± 11.4	Retrospective	IS; HS; NS	IS (43)	Infarction, TIA, PCA involvement, surgery type	High
Antonucci 2015 [9]	Caucasian	31	18–67	Retrospective	IS; NS	IS (8)	Infarction	High
Tackeun 2015 [10]	Asian	201	38.3 ± 11.6	Retrospective	IS; NS	IS (4) + HS (1)	age, male sex, Suzuki stage	Fair
Gross 2013 [11]	Caucasian	45	39.2 ± 12.2	Prospective	IS; HS; NS	IS (5) + HS (1)	age, Infarction, surgery type	High
Xiangyang 2012 [12]	Asian	470	36.8 (18–59)	Prospective	IS; HS; NS	IS (43) + HS (17)	age TIA, PCA involvement, male sex, infarction, Suzuki stage	High

IS ischemic stroke, HS hemorrhagic stroke, NS nonspecific symptom, sd. standard deviation