TABLE 2.

University California-San Diego chronic thromboembolic disease (CTED) surgical classification

Level 0	No evidence of CTED in either lung
Level I	CTED starting in the main pulmonary arteries
Level IC	Complete occlusion of one main pulmonary artery with CTED
Level II	CTED starting at the level of lobar arteries, or in the main descending pulmonary arteries
Level III	CTED starting at the level of the segmental arteries
Level IV	CTED starting at the level of the subsegmental arteries

Classification based on the most proximal disease identified. Information from [53].