Table 1.

Advantages and disadvantages associated with clipping and coil embolization.

	Advantages		Disdvantages
clipping	Surgery is superior to intravascular therapy because:		Surgery is inferior to intravascular therapy because:
	1.	Long-term therapeutic effects are clear	1.	General anesthesia is required
	2.	Accompanying lesions can be treated at the same time	2.	Conserving perforators near an aneurysm is occasionally difficult
	3.	Vascular anatomy can be accurately ascertained macroscopically	3.	Cerebral compression is required
	4.	Intraoperative bleeding can be effectively dealt with	4.	Blocking circulation may be necessary
			5.	Skills differ between surgeons and institutions
embolization	Intravascular therapy is superior to surgery because:		Intravascular therapy is inferior to surgery because:
	1.	General anesthesia is unnecessary (?)	1.	Additional angiographies may be needed within a short period of time
	2.	Systemic complications are not an issue	2.	Long-term prognosis is unknown
	3.	Perforators near an aneurysm can be conserved	3.	Embolization may not be possible depending on shape, size or location
	4.	Brain compression is unnecessary	4.	A risk of cerebral infarction or parent vessel occlusion is present
	5.	Cost is less than surgery (?)	5.	Dealing with intraoperative bleeding is difficult
			6.	Skills differ between surgeons and institutions