title: Resistance of the internal mammary artery to restenosis: a histomorphologic study of various porcine arteries.
abstract: OBJECTIVE
  Restenosis after percutaneous transluminal angioplasty (PTA) of the internal mammary artery (IMA) grafts is much less pronounced than in other arteries and venous grafts. The aim of the study was to test whether various arteries respond differently to dilatation.
  
  
  METHODS
  PTA of the IMA, carotid, renal and circumflex coronary (RCx) arteries was performed in 9 pigs (balloon to artery ratio of 1:1.5). After 8 weeks, angiography was repeated and vessels prepared for histological analysis. Immunohistochemical staining was done to examine proliferative activity (Ki67) and to identify the vasa vasorum of the adventitia (F VIII-RA).
  
  
  RESULTS
  The intima-media ratio after PTA was lowest in the IMA (0.06), followed by the carotid (0.27) and renal arteries (0.49) and the RCx (0.69). Proliferation of the intima was seen at 287 degrees of the vessel circumference in the RCx, at 286 degrees in the renal and at 166 degrees in the carotid artery. No proliferative activity was seen in the IMA. The intima-adventitia ratio was lower in the IMA than in the RCx and renal arteries (p < 0.05).
  
  
  CONCLUSIONS
  Intima proliferation after PTA varies between the different vessels, with best results seen in the IMA. There are differences in remodeling after PTA between muscular, muscular/elastic and elastic arteries.
authors: 2nd Medical Clinic, Johannes Gutenberg University, Mainz, Germany. horstick@uni-mainz.de
authors: Georg
authors: G
authors: Horstick
authors: Benjamin
authors: B
authors: Bierbach
authors: Peter
authors: P
authors: Schlindwein
authors: Nico
authors: N
authors: Abegunewardene
authors: Markus
authors: M
authors: Vosseler
authors: Fernando
authors: F
authors: Bittinger
authors: Dietmar
authors: D
authors: Becker
authors: Michael
authors: M
authors: Lauterbach
authors: Hans-Anton
authors: HA
authors: Lehr
authors: Oliver
authors: O
authors: Kempski
mesh_terms: D000792:Angiography; D000800:Angioplasty, Balloon / Q000009:adverse effects*; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D000818:Animals; D002339:Carotid Arteries / Q000473:pathology; D016893:Carotid Stenosis / Q000209:etiology* / Q000473:pathology; D049109:Cell Proliferation; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000209:etiology* / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology; D006083:Graft Occlusion, Vascular / Q000209:etiology* / Q000473:pathology; D007150:Immunohistochemistry; D008323:Mammary Arteries / Q000473:pathology*; D008940:Mitotic Index; D023421:Models, Animal; D012077:Renal Artery / Q000473:pathology; D012078:Renal Artery Obstruction / Q000209:etiology* / Q000473:pathology; D013552:Swine; D013997:Time Factors; D016896:Treatment Outcome; D017539:Tunica Intima / Q000473:pathology; D017540:Tunica Media / Q000473:pathology