The "edge effect" after implantation of beta-emitting (55Co) stents with high initial activity.
The aim of this study was to evaluate the incidence and the cause of "edge restenosis" after implantation of high activity 41.1 microCi +/- 1.2 microCi = 1520 kBq +/- 44 kBq, beta-emitting (55Co) stents. Proton bombarding in cyclotron has brought the radioactivity. Intravascular ultrasound (IVUS) investigation has been completed in 10 patients. The angiographies performed at 6 month revealed restenosis >50% in 5 cases (50%). The analysis of edges (5 mm distally and proximally to the last stent struts) showed no significant changes in TVV (187.3 +/- 62.60 mm3 and 176.9 +/- 53.5 mm3) but PMV increase significantly (i.e. neointimal proliferation) from 61.9 +/- 31.2 mm3 to 82.2 +/- 43.4 mm3 (p<0.04) and was the major contributor (from 66%) to lumen volume loss (125.4 +/- 40.7 mm3 and 94.7 +/- 22.2 mm3, p<0.02). In conclusion, neither statistically significant positive nor negative remodelling at the "stent edges", were present. Statistically significant increase in plaque +/- media volume (i.e. neointimal hyperplasia) and reduction in lumen volume were found. The cause of "edge restenosis" was especially (from 66%) due to increase in plaque +/- media volume (i.e. neointimal hyperplasia). Probably, main reason for "edge effect"/neointimal hyperplasia was in this trial sharp fall-off in radiation at the edges of the stents.
Cervinka
Pavel
P
Department of Cardiology, Masaryk Hospital, Ustí nad Labem, Czech Republic. cervinkap@iol.cz
St'ásek
Josef
J
Costa
Marco Aurelio
MA
Stursa
Jan
J
Fiser
Miloslav
M
Vodnanský
Petr
P
Kocisová
Michaela
M
Veselka
Josef
J
Pleskot
Miloslav
M
Malý
Jaroslav
J
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001610:Beta Particles; D003037:Cobalt Radioisotopes / Q000008:administration & dosage*; D003327:Coronary Disease / Q000628:therapy*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging* / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015607:Stents; D018084:Ultrasonography, Interventional
D003037:Cobalt Radioisotopes