Table 1.

Jamieson classification system of pulmonary endarterectomy specimens^23,24

	Description	Frequency, %
Type 1	Semiorganized or organized thrombus beginning in the main or lobar arteries	22.9
Type 2	Organized thrombus and intimal thickening in the proximal to segmental arteries	39.0
Type 3	Intimal thickening and fibrosis in the distal segmental and subsegmental arteries	33.7
Type 4	Distal arteriolar vasculopathy with no intraluminal disease	4.3