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The ultrastructure of plexogenic pulmonary arteriopathy
Author(s) -
Smith Paul,
Heath Donald,
Yacoub Magdi,
Madden Brendan,
Caslin Anthony,
Gosney John
Publication year - 1990
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.1711600204
Subject(s) - myofibroblast , pathology , medicine , pulmonary hypertension , pulmonary artery , lung , internal elastic lamina , myofilament , lung transplantation , pulmonary fibrosis , ground substance , fibrosis , anatomy , cardiology , myocyte , artery , connective tissue
Abstract The lungs from 16 cases of plexogenic pulmonary arteriopathy obtained at heart‐lung transplantation, half of which had primary pulmonary hypertension, were examined by electron microscopy. From these the probable pathogenesis of pulmonary arterial intimal fibrosis in plexogenic pulmonary arteriopathy was deduced. The earliest detectable change was migration of smooth muscle cells from the media; through the internal elastic lamina into the intima. These cells collected beneath the endothelium and lost many of their myofilaments to become myofibroblasts. They were associated with ground substance but scanty collagen fibrils. As the quantity of interstitial collagen increased, the myofibroblasts reverted to a muscular structure, became elongated, and assumed a regular, circumferential orientation. This later stage coincided with the development of plexiform lesions. At both early and later stages, the muscular pulmonary arteries were contracted but not markedly so, and muscular evaginations were not seen. On the other hand, the cellular intimal proliferations developed early and were occlusive. This suggests that occlusion of small pulmonary arterial vessels by myofibroblasts may be at least as important as vasoconstriction in the early elevation of the pulmonary vascular resistance in primary pulmonary hypertension.