Peter B. Samuels Award. Restenosis after percutaneous transluminal angioplasty.
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.
Ramaswami
G
G
Irvine Laboratory for Cardiovascular Investigation and Research, Imperial College School of Medicine at St. Mary's, London, United Kingdom.
Dhanjil
S
S
Nicolaides
A N
AN
Griffin
M
M
Al-Kutoubi
A
A
Tegos
T
T
Wilkins
R
R
Lewis
J
J
Boolell
M
M
Davies
M
M
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