- Subjects must have previously been judged inoperable due to the obstruction being surgically inaccessible (i.e. distal disease) by an expert multidisciplinary team which must include at least one cardiology or respiratory consultant, and one consultant PEA surgeon. For countries with CTEPH expert centers [including at least a surgeon with sound experience performing Pulmonary Endarterectomy (PEAs)] the expert team will be the local expert centre. For countries without a CTEPH surgical expert center a central adjudication committee will assess the operability of the subjects during the screening period.