Table 2.

Risk of bias of the included studies.

Study	A	B	C	D	E	F	G	H	I	J	Total
Hamid et al., 2007	√	√	√			√				√	5
Xie et al., 2007	√	√	√			√					4
Shibata et al., 2008	√	√	√			√					4
Zhang et al., 2009	√	√	√			√			√	√	6
Li et al., 2012	√	√	√			√				√	5
Ichinomiya et al., 2012	√	√	√			√	√			√	6
Jiang et al., 2012	√	√	√			√			√	√	6
Xi et al., 2012	√		√			√					3
Jiang et al., 2013	√		√						√	√	4
Shang et al., 2013	√	√	√								3
Guan et al., 2013	√	√	√			√				√	5
Wu et al., 2014	√	√	√			√	√			√	6
Kitano et al., 2014	√	√	√			√				√	5
Li et al., 2014	√	√	√			√				√	5
Lu et al., 2014	√		√						√		3
Ye et al., 2016	√	√	√			√					4
Deng et al., 2016	√	√	√							√	4
Min et al., 2017	√	√	√			√					4
Zhang et al., 2018	√	√	√			√			√	√	6

Studies fulfilling the criteria of: A, peer reviewed publication; B, control of temperature; C, random allocation to treatment or control; D, blinded induction of model (group randomly after the induction of ischemia); E, blinded assessment of outcome; F, use of anesthetic without significant intrinsic vascular protection activity; G, appropriate animal model (aged, diabetic, or hypertensive); H, sample size calculation; I, compliance with animal welfare regulations [preoperative anesthesia, postoperative analgesia, nutrition, environment (temperature, humidity, circadian rhythm), and euthanasia]; J, statement of potential conflict of interests.