Table 3. Comparison of TEVAR and IARS protocols ¹⁷ .

TEVAR vs. ICAARs protocol
TEVAR	ICAARS
Aorta divided into 12 zones: Zone 0 : proximal edge of covered endograft Zone 1 : proximal transverse aorta Zone 2- distal transverse aorta Zone 3 :  <   2 cm within the origin of the left subclavian artery without covering it Zone 4 : proximal end of endograft >   2 cm distal to left subclavian artery within proximal descending thoracic aorta Zone 5 : distal descending thoracic aorta but proximal to celiac artery Zone 6 : celiac segment and proximal juxtavisceral segment Zone 7 : SMA segment and juxtavisceral segment Zone 8 : covering at least 1 renal artery Zone 9 : infrarenal arteries Zone 10 : common iliac arteries Zone 11: external iliac arteries	Aorta divided into 14 zones: Zone 1: aortic root to ascending aorta Zone 2: proximal transverse aorta Zone 3: distal transverse aorta Zone 4: distal to left common carotid to include left subclavian Zone 5: distal to left subclavian to spindle Zone 6: distal to spindle to proximal descending aorta Zone 7: proximal descending to distal descending Zone 8: distal descending aorta to juxtavisceral Zone 9: juxtavisceral including celiac artery but supra renal Zone 10: juxtarenal and SMA Zone 11: proximal infrarenal to mid infrarenal Zone 12: midinfrarenal to distal infrarenal including IMA Zone 13: distal infrarenal to suprailiac aorta Zone 14: suprailiac proximal to bifurcation
Measures diameter of aorta at centerline and estimation of irregularities and tortuosity	Allows for measurements of aneurysms that overlap to include thoracoabdominal aorta or includes continuation of abdominal aorta into its bifurcation into common iliac arteries
Utilized to determine candidates of revascularization through measurement of aneurysm pre- and postoperatively	Describes morphology of aneurysm (saccular, fusiform, juxtavisceral, apple-on-a-stick, aortoiliac)
Focus on aortic arch and lower sections of abdominal aorta	Focus includes sinus region, isthmus descending sections of aorta

Abbreviations: ICAARS, International College of Angiology Aortic Research Schema; IMA, inferior mesenteric artery; SMA, superior mesenteric artery; TEVAR, thoracic endovascular aortic repair.