TY - JOUR T1 - Involvement of the pulmonary micro-vasculature in chronic thromboembolic pulmonary hypertension (CTEPH) JF - European Respiratory Journal JO - Eur Respir J VL - 40 IS - Suppl 56 SP - P1498 AU - Sven Günther AU - Olaf Mercier AU - Xavier Jaïs AU - David Montani AU - Sophie Maitre AU - Jean-François Paul AU - Vincent de Montpréville AU - Elie Fadel AU - Marc Humbert AU - Gérald Simonneau AU - Philippe Dartevelle AU - Peter Dorfmüller Y1 - 2012/09/01 UR - http://erj.ersjournals.com/content/40/Suppl_56/P1498.abstract N2 - Introduction: Pulmonary endarterectomy (PEA) is the treatment of choice for patients with CTEPH. However, a limited subset of CTEPH patients present with persistent PH after PEA.Aims: To assess microvascular lesions and clinical characteristics in CTPEH-patients with persistent PH after PEA.Methods: We analyzed lung histology available from 8/10 patients with persistent PH after PEA and compared them with 10 randomly selected CTEPH-patients with successful PEA.Results: Histopathology from 8 persistent PH patients revealed thrombotic lesions, intimal fibrosis and medial hypertrophy in peripheral small muscular pulmonary arteries of all analyzed lungs. 7/8 persistent PH patients displayed moderate pulmonary venous involvement, including intimal fibrosis of small pre-septal venules, foci of capillary multiplication, and hemosiderosis. All cases presented hypertrophy of bronchiolar systemic arteries. Hemodynamic data, exercise testing and medical history exhibited non-significant but by-trend discriminating values between the persistent PH and the successful PEA group for PVR (1199±154 dynes•s•cm-5 versus 825±98 dynes•s•cm-5), DLCO (63±5% versus 75±4%), 6-minute-walk-distance (6MWD) (272±48m versus 415±31m), history of vascular implants (6/10 versus 0/10), and presence of subpleural septa on chest scanner (6/10 versus 2/10).Conclusion: We report conspicuous remodeling of the pre- and post-capillary microvasculature in CTEPH-patients with persistent PH after PEA. Group-related discrepancies of PVR, DLCO, 6MWD, vascular implant-history, and one radiologic criterion were observed in CTEPH patients with persistent PH, as compared with CTEPH-patients with successfull PEA. ER -