Table 1.

Classification of endoleaks

Type of endoleak	Definition
Type I endoleak	Failure to create an adequate circumferential seal
	• Ia – proximal attachment site
	• Ib – distal attachment site
	• Ic – common iliac artery
Type II endoleak	Backflow of blood from aortic collaterals into the aneurysmal sac
Type III endoleak	Endoleak secondary to structural failure of endograft
	• IIIa – component disconnection
	• IIIb – stent fabric disturbance
Type IV endoleak	Related to graft fabric porosity
Type V endoleak (endotension)	Continued high intrasac pressure following EVAR without evidence of continued aneurysm sac perfusion

Abbreviation: EVAR, endovascular abdominal aortic aneurysm repair.