title: Experimental directional atherectomy injury in arterial vessels: impact of trauma depth on cellular response.
abstract: This study investigates cellular alterations after directional atherectomy vessel injury (DI) in an experimental model in 50 pigs. Two hundred arteries were excised at eight different times (2 hours to 21 days) after DI and were examined by electron microscopy and immunohistochemistry. The extent of injury varied with the number of repetitive passes of the atherectomy catheter. According to the extent of injury the vessel segments with DI were assigned to three groups: intima injury (group 1), media injury (group 2), and adventitia injury (group 3). A myoproliferative response was found in relation to DI depth, increasing from group 1 (ratio tissue hyperplasia/media: 0.3 +/- 0.2; p < 0.001) to group 2 (ratio tissue hyperplasia/media: 1 +/- 0.5) and group 3. Intense neutrophil infiltration occurred in groups 2 and 3 (peak 12 hours after DI) and was followed by the early occurrence of synthetic smooth-muscle cells (SMC; > 50% of all SMC present). Volume fraction of desmin and actin was transiently reduced in injured media and myoproliferative tissue (7d: 9% vs > 90% normal media). SMC proliferation started in groups 2 and 3 at 48 hours and peaked at 7 days (+500% vs normal media, p < 0.001). After DI was done, vascular response started immediately and depended on injury depth. A transient myoproliferative response resulted, correlating with the extent of vessel trauma.
authors.affiliation: Medical Department I, Klinikum Grosshadern, University of Munich, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Gonschior
authors.forename: F
authors.initials: F
authors.lastname: Gerheuser
authors.forename: G M
authors.initials: GM
authors.lastname: Gonschior
authors.forename: G R
authors.initials: GR
authors.lastname: Maier
authors.forename: B
authors.initials: B
authors.lastname: Mack
authors.forename: A
authors.initials: A
authors.lastname: Nerlich
authors.forename: H A
authors.initials: HA
authors.lastname: Lehr
authors.forename: B
authors.initials: B
authors.lastname: Höfling
mesh_terms: D008841:Actin Cytoskeleton / Q000648:ultrastructure; D000199:Actins / Q000032:analysis; D000818:Animals; D017225:Atherectomy, Coronary / Q000009:adverse effects* / Q000295:instrumentation; D002339:Carotid Arteries / Q000473:pathology; D020212:Carotid Artery Injuries; D003094:Collagen / Q000032:analysis; D003238:Connective Tissue / Q000293:injuries / Q000473:pathology; D003593:Cytoplasm / Q000648:ultrastructure; D003893:Desmin / Q000032:analysis; D004195:Disease Models, Animal; D004547:Elastic Tissue / Q000293:injuries / Q000473:pathology; D004730:Endothelium, Vascular / Q000293:injuries / Q000473:pathology; D005263:Femoral Artery / Q000293:injuries* / Q000473:pathology*; D006965:Hyperplasia; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D009504:Neutrophils / Q000473:pathology; D013552:Swine; D013997:Time Factors; D017539:Tunica Intima / Q000293:injuries / Q000473:pathology; D017540:Tunica Media / Q000293:injuries / Q000473:pathology
chemical_list: D000199:Actins; D003893:Desmin; D003094:Collagen