Interventional Radiology · Aortic intervention · SVS TEVAR reporting standards

Society for Vascular Surgery Thoracic Aortic Landing Zones

An anatomical zoning system for describing the position of thoracic aortic endograft attachment and seal sites during TEVAR.

Purpose

To standardise the description of thoracic aortic endograft landing sites according to their relationship with the supra-aortic branches and descending thoracic aorta.

Zone	Anatomical boundaries	Key structure or implication
0	Sinotubular junction to the distal margin of the brachiocephalic trunk	Landing here involves the brachiocephalic trunk origin
1	Distal margin of the brachiocephalic trunk to the distal margin of the left common carotid artery	Landing here involves the left common carotid artery origin
2	Distal margin of the left common carotid artery to the distal margin of the left subclavian artery	Landing here involves the left subclavian artery origin
3	Distal margin of the left subclavian artery to approximately 2 cm distally, corresponding to the end of the arch curvature	Proximal descending thoracic aorta immediately beyond the left subclavian artery
4	More than 2 cm distal to the left subclavian artery to approximately the midpoint of the descending thoracic aorta at T6	Proximal half of the descending thoracic aorta
5	Midpoint of the descending thoracic aorta to immediately proximal to the coeliac artery	Distal half of the descending thoracic aorta

How to use it

The landing zone is assigned according to the position of the relevant covered end of the endograft, not merely the location of the aortic lesion.
Zones 0–2 involve progressively distal supra-aortic branch origins: brachiocephalic trunk, left common carotid artery and left subclavian artery.
Zone 3 is the short arch-adjacent segment extending approximately 2 cm beyond the left subclavian artery; zone 4 begins beyond this segment.
The comprehensive SVS/STS aortic-dissection nomenclature extends the anatomical zones distally to zone 11, whereas the thoracic landing-zone sequence shown here ends at zone 5.

Common mistake

Do not confuse zone 2 with a landing site distal to the left subclavian artery: zone 2 involves its origin, whereas zone 3 begins distal to it.

Exam pearl

Remember the arch sequence as 0–brachiocephalic, 1–left carotid, 2–left subclavian, 3–first 2 cm beyond the left subclavian, 4–proximal half and 5–distal half of the descending thoracic aorta.

Viva questions

What is the purpose of the thoracic aortic landing-zone classification?: It standardises the description of the proximal and distal positions of a thoracic aortic endograft in relation to the supra-aortic branches and descending thoracic aorta.
Which landing zone involves the brachiocephalic trunk origin?: Zone 0, extending from the sinotubular junction to the distal margin of the brachiocephalic trunk.
Which supra-aortic branch is involved by a zone 1 landing?: The left common carotid artery origin is involved by a zone 1 landing.
Which supra-aortic branch is involved by a zone 2 landing?: The left subclavian artery origin is involved by a zone 2 landing.
How are zones 3 and 4 distinguished?: Zone 3 is the first approximately 2 cm of the descending thoracic aorta beyond the left subclavian artery. Zone 4 begins more than 2 cm distal to the left subclavian artery and extends to approximately the midpoint of the descending thoracic aorta.
What is the common error when assigning a thoracic aortic landing zone?: The common error is assigning the zone from the lesion location rather than from the position of the covered end of the endograft.