title: Frequency and determinants of black holes in sirolimus-eluting stent restenosis.
abstract: BACKGROUND
  In-stent neointimal hyperplasia typically has a homogenous echoreflective appearance during intravascular ultrasound (IVUS) imaging. However, the neointimal hyperplasia of some brachytherapy failure lesions contains a very echolucent, dark zone that has been termed black hole. We sought to investigate the frequency and determinants of black holes (BH) after sirolimus-eluting stent (SES) implantation.
  
  
  METHODS
  A prospective, consecutive series of 33 intrastent SES restenosis (> 50% neointimal hyperplasia with a minimal lumen area < 4.0 mm2) was studied with IVUS. Patients were divided into 2 groups: 8 patients with BH versus 25 patients without BH.
  
  
  RESULTS
  Fifty percent of the BH cases occurred in saphenous vein graft lesions. BH tissue was noticed in 8% of all patients with in-stent restenosis. Three patients in each group had previous vascular brachytherapy failure (p = 0.1). Compared to non-BH cases, a greater proportion of BH cases occurred after SES treatment of bare-metal stent restenosis (75% vs. 32%; p = 0.035). BH cases presented earlier (89.9 +/- 34.3 vs. 161.3 +/- 78.8 days; p = 0.001) with more severe in-stent restenosis, as indicated by greater absolute and relative amounts of neointimal hyperplasia (41.3 +/- 10.0 vs. 26.9 +/- 19.5 mm3; p = 0.012, and 19.6 +/- 6.8 vs. 10.4 +/- 7.9%; p = 0.0001, respectively).
  
  
  CONCLUSIONS
  Echolucent restenotic tissue (black hole) is more often observed in SES restenosis after treatment of saphenous vein graft lesions or treatment of bare-metal stent restenosis. It occurs earlier and is more severe than typical SES failures.
authors.affiliation: Cardiovascular Research Foundation and Columbia University Medical Center, New York, New York, USA.
authors.forename: Jose de Ribamar
authors.initials: Jde R
authors.lastname: Costa
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.forename: Stéphane G
authors.initials: SG
authors.lastname: Carlier
authors.forename: Kenichi
authors.initials: K
authors.lastname: Fujii
authors.forename: Koichi
authors.initials: K
authors.lastname: Sano
authors.forename: Masashi
authors.initials: M
authors.lastname: Kimura
authors.forename: Kaoru
authors.initials: K
authors.lastname: Tanaka
authors.forename: Joanna
authors.initials: J
authors.lastname: Lui
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Moses
authors.forename: Martin B
authors.initials: MB
authors.lastname: Leon
mesh_terms: D000368:Aged; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D023921:Coronary Stenosis / Q000628:therapy*; D004867:Equipment Design; D005260:Female; D006083:Graft Occlusion, Vascular / Q000628:therapy; D006801:Humans; D015994:Incidence; D008297:Male; D008670:Metals; D008875:Middle Aged; D011446:Prospective Studies; D012501:Saphenous Vein / Q000637:transplantation; D020123:Sirolimus / Q000008:administration & dosage*; D015607:Stents / Q000009:adverse effects*; D018084:Ultrasonography, Interventional
chemical_list: D008670:Metals; D020123:Sirolimus