title: Peter B. Samuels Award. Restenosis after percutaneous transluminal angioplasty.
abstract: BACKGROUND
  Determine the feasibility of studying the natural history of the atherosclerotic plaque following percutaneous transluminal angioplasty (PTA), using duplex scanning.
  
  
  METHODS
  Twenty-three patients with 40 stenoses (>70% and <5 cm in length) in the iliac and femoro-popliteal segments were studied by duplex scanning before PTA, on day 1, weekly for 8 weeks, and at 3 months, 6 months, and 1 year. The following measurements were made: thickness of the plaque, minimal lumen diameter (MLD), and peak systolic velocity ratio (PSVR). A PSVR >2.0 was used to indicate >50% lumen diameter reduction.
  
  
  RESULTS
  Thirty stenoses were available for measurement and analysis. Mean reduction in plaque thickness after angioplasty was greater in echolucent plaques (2.33 +/- 0.9 mm) than echogenic plaques (0.83 +/- 0.6 mm; P < 0.0001). Successful angioplasty (PSVR <2.0) and increase in MLD in echolucent plaques was the result of plaque compression; in echogenic plaques, of wall dilatation. The incidence of restenosis (PSVR >2.0) at 6 months was 12 of 30 (40%) remaining unchanged at 1 year; of the lesions that restenosed, 33% recurred before week 8 and the remainder between weeks 8 and 24, suggesting different mechanisms. During follow-up, all plaques showed "growth"; <2 mm in 17 (57%; group A) and >2 mm in the remaining 13 (43%; group B). The incidence of restenosis (PSVR >2.0) was 4 of 17 (23%) in group A and 8 of 13 (61%) in group B (P <0.05).
  
  
  CONCLUSIONS
  Duplex scanning provides valuable information on both luminal diameter and plaque thickness; it may be used to study the natural history of plaques following angioplasty and also the effects of therapeutic agents aimed at reducing restenosis.
authors.affiliation: Irvine Laboratory for Cardiovascular Investigation and Research, Imperial College School of Medicine at St. Mary's, London, United Kingdom.
authors.forename: G
authors.initials: G
authors.lastname: Ramaswami
authors.forename: S
authors.initials: S
authors.lastname: Dhanjil
authors.forename: A N
authors.initials: AN
authors.lastname: Nicolaides
authors.forename: M
authors.initials: M
authors.lastname: Griffin
authors.forename: A
authors.initials: A
authors.lastname: Al-Kutoubi
authors.forename: T
authors.initials: T
authors.lastname: Tegos
authors.forename: R
authors.initials: R
authors.lastname: Wilkins
authors.forename: J
authors.initials: J
authors.lastname: Lewis
authors.forename: M
authors.initials: M
authors.lastname: Boolell
authors.forename: M
authors.initials: M
authors.lastname: Davies
mesh_terms: D000800:Angioplasty, Balloon; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D003251:Constriction, Pathologic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D015203:Reproducibility of Results; D013997:Time Factors; D018616:Ultrasonography, Doppler, Duplex