Table 2. Levels of pulmonary thromboembolism, comorbidity and reasons of treatment preferences.

		UCSD classification	Comorbidity	Reasons of treatment preferences
Case 1	71F	III	Rectal cancer	Old age, comorbidity, difficult surgical accessibility
Case 2	53M	III	Protein S deficiency, HTN	Difficult surgical accessibility
Case 3	54M	III	CAD, HTN, DM	Difficult surgical accessibility
Case 4	53F	IV	ESRD, HTN, dyslipidemia	Comorbidities, difficult surgical accessibility
Case 5	76F	III	APS, HTN	Old age, comorbidities, difficult surgical accessibility
Case 6	44F	III	HTN, DM, dyslipidemia	Patient refused PEA, difficult surgical accessibility
Case 7	44F	III	APS	Comorbidity, difficult surgical accessibility
Case 8	55F	III	-	Patient refused PEA, difficult surgical accessibility
Case 9	54F	III	AIHA	Patient refused PEA, difficult surgical accessibility
Case 10	71F	III	HTN	Old age, difficult surgical accessibility
Case 11	66M	IV	-	Patient refused PEA, difficult surgical accessibility

The definition of UCSD classification: level 0: no evidence for CTEPH; level I: disease involved one of the main pulmonary arteries; level II: disease involved the lobar branches or past the takeoff of the upper lobe artery; level III: disease is distal and started from the segmental branches; level IV disease: disease only involved the subsegmental branches.¹⁹

AIHA, autoimmune hemolytic anemia; APS, antiphospholipid syndrome; CAD, coronary artery disease; DM, diabetes mellitus; ESRD, end stage renal disease; HTN, hypertension; PEA, pulmonary endarterectomy; UCSD, University of California, San Diego.