title: [Cellularity and ultrastructural characteristics of human atherectomy specimens: comparison between restenosis and primary stenotic tissue of coronary and peripheral lesions].
abstract: Restenosis in patients treated by angioplasty is clinically and angiographically defined. The question remains to which extent each restenotic lesion can be attributed to residual plaque material and/or neointimal tissue formation post primary intervention. In an effort to reveal distinct anatomical characteristics which may allow conclusions to pathogenetic mechanisms involved in restenosis, histopathologic and electron microscopic examinations of human restenotic tissue were performed. To compare tissue samples from clinically restenotic lesions with those from untreated primary lesions for cell number and ultrastructural characteristics, a total of 64 percutaneously excised tissue specimens from coronary (n = 9) and femoral lesions (n = 18) of 27 patients treated by directional atherectomy were analyzed. Semiquantitative assessment of plaque slices for cell number (12 fields of view/lesion; magnification x500) revealed a spectrum of 11.7 to 35.3 cell nuclei/field of view (C/F) for clinical restenoses (n = 10) and of 0.9 to 28.2 C/F for primary lesions (n = 17). When comparing tissue specimens from restenotic origin with those of native lesions, there was a highly significant (p < 0.001) difference in cell number (ave: 22.2 +/- 7.1 versus 8.6 +/- 7.9 C/F; x +/- SD). Hypercellularity (mean cell density defined with > 20 C/F) was observed in 6/10 restenoses, hypocellularity (< 10 C/F) in 0/10 restenoses. For primary lesions, hypocellularity was found in 10/17 lesions, but hypercellularity in 2/17 lesions. Ultrastructural analysis of hypocellular lesions by transmission electron microscopy revealed large extracellular matrix fields with infrequently embedded smooth muscle cells (SMCs). These cells were characterized by a microfilament-rich intermediate phenotype, thereby indicating decreased metabolic activation.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Medizinische Klinik I, Klinikum Grosshadern, Ludwig-Maximilians-Universität München.
authors.forename: G
authors.initials: G
authors.lastname: Bauriedel
authors.forename: B
authors.initials: B
authors.lastname: Höfling
authors.forename: C
authors.initials: C
authors.lastname: Grünwaldt
authors.forename: T
authors.initials: T
authors.lastname: Beinert
authors.forename: U
authors.initials: U
authors.lastname: Welsch
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D017225:Atherectomy, Coronary; D002452:Cell Count; D003324:Coronary Artery Disease / Q000473:pathology* / Q000601:surgery; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D005263:Femoral Artery / Q000473:pathology; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D012008:Recurrence; D012086:Reoperation
vernacular_title: Zellularität und ultrastrukturelle Charakteristika humaner Atherektomiezylinder: Vergleich zwischen Restenose- und Primärstenosegewebe koronarer und peripherer Läsionen.