Endovascular treatment of extracranial vertebral artery stenosis

Table 1 Recommendations from The American Heart Association/American Stroke Association guideline for vascular imaging of vertebral artery disease[21]

Size of treatment effect	Indications	Recommended imaging study	Level of evidence (A,B,C1)
Class 1 (benefit>>>risk)
1	-With symptoms referable to posterior circulation and subclavian steal syndrome	Noninvasive imaging	C
2	-With asymptomatic bilateral carotid occlusions or-Unilateral carotid artery occlusion and incomplete circle of Willis	Noninvasive imaging	C
3	-With symptoms of posterior cerebral ischemia or -With symptoms of cerebellar ischemia	Noninvasive imaging (MRA or CTA rather than Doppler US)	C
Class 2a (benefit>>risk)
1	-With symptoms of posterior cerebral ischemia or -With symptoms of cerebellar ischemia	Serial noninvasive imaging	C
2	-Revascularization candidates with symptoms of posterior cerebral ischemia or -Revascularization candidates with symptoms of cerebellar ischemia	-Noninvasive imaging -DSA (if noninvasive imaging fails)	C
3	-Patients undergone vertebral artery revascularization	-Serial noninvasive imaging	C

¹Level of evidence C indicates that very limited populations were evaluated and it depends on consensus opinion of experts, case studies or standard of care. MRA: Magnetic resonance angiography; CTA: Computed tomography angiography; Doppler US: Doppler ultrasonography; DSA: Digital subtraction angiography.

Table 2 Review of the long term results of previous studies on endovascular stent treatment of extracranial vertebral artery stenosis

Studies	Stent type	Number of patients	Number of treated stenoses	Rate of complication (%)		Follow-up
				Technical	Clinical	Period (mo)	Rate of significant restenosis2 (%)
Lin et al[74]	Bare stent	58	67	0	7	11	25
Albuquerque et al[11]	Bare stent	33	33	3	0	16	43
Chastain et al[12]	Bare stent	50	55	2	0	6	10
Weber et al[75]	Bare stent	38	38	2	1	11	38
Cloud et al[76]	Bare stent	14	14	0	0	20	9
SSYLVIA1 study[77]	Bare stent	18	18	-	-	6	43
Akins et al[78]	Bare stent	7	7	0	0	36	43
Taylor et al[79]	Bare stent	44	48	0	0	7	48
Hatano et al[80]	Bare stent	117	117	0	0	6	10
Lin et al[81]	Bare stent	80	90	0	0	12	28
Jenkins et al[16]	Bare stent	32	38	0	0	10	3
Karamehev et al[82]	Bare stent, DES	10	12	0	0	34	10
Lin et al[27]	DES	11	11	0	0	8	0
Zhou et al[30]	DES	86	92	0	0	12	17
Gupta et al[83]	DES	27	27	0	2	6	7
Akins et al[78]	DES	5	5	0	0	17	0
Edgell et al[84]	DES	5	5	0	0	15	0
Vajda et al[85]	DES	48	52	0	0	7	12
Lugmayr et al[86]	DES	7	8	0	0	6	63

¹Stenting of symptomatic atherosclerotic lesions in the vertebral or intracranial arteries;

²significant restenosis indicates that it is equal or higher than 50% stenosis. DES: Drug-eluting stents.