Edge Restenosis After Implantation of High Activity ³² P Radioactive β-Emitting Stents

Abstract

We compared the results of lesions treated with single radioactive BX stents with an activity of 12 to 21 microCi (group 2, n = 54 lesions) with the results of lesions treated by single radioactive BX stents with an initial activity level of 3 to 12 microCi (group 1, n = 42 lesions). There were no procedural events. At the 6-month follow-up, no myocardial infarctions, deaths, or stent thromboses had occurred. Intrastent binary restenosis was 0% in group 1 versus 4% in group 2 (n = 2, both at the ostium of the right coronary artery, P = NS). Intrastent neointimal hyperplasia was significantly lower in group 2 than in group 1. The intralesion (intrastent plus peri-stent) restenosis rate was 38% in group 1 versus 30% in group 2 (P = NS). Conclusions-Single (32)P radioactive stents with an initial activity level of 12 to 21 microCi reduced intrastent neointimal hyperplasia compared with stents of 3 to 12 microCi, but they did not solve the problem of edge restenosis, even if a nonaggressive stent implantation strategy was used.

Vascular Responses at Proximal and Distal Edges of Paclitaxel-Eluting Stents

“…18 In patients treated with radioactive stents, edge stenosis has proved to be an important clinical problem, occurring in 30% of patients. 8,19 TAXUS II confirmed that no edge effect greater than that found with a BMS occurs with either MR or SR paclitaxel-eluting stents. As reported previously, the term "edge effect" is used to connote an effect greater than would be seen with BMS.…”

“…As reported previously, the term "edge effect" is used to connote an effect greater than would be seen with BMS. 8,19 In fact, there was a slight but nonsignificant decrease in edge stenosis compared with BMS. Edge stenosis (diameter stenosis Ͼ50%) rates for BMS were 3.4% (proximal) and 3.1% (distal), whereas for the SR and MR groups, the rates were 1.6% and 2.3% at the proximal and distal edges, respectively.…”

“…6,7 However, initial enthusiasm in the use of radioactive stents has been limited by the occurrence of stenosis in the segments adjacent to the proximal and distal edge of the stent (so-called edge stenosis). 8,9 Recently, stent-based local drug delivery with a number of pharmacological agents has been demonstrated to reduce in-stent neointimal hyperplasia. Randomized clinical safety and feasibility trials with sirolimus-and paclitaxel-eluting stents have shown very promising results, with prevention of in-stent restenosis in de novo coronary and in-stent restenosis lesions.…”

Persistent Inhibition of Neointimal Hyperplasia After Sirolimus-Eluting Stent Implantation

“…1,2,3 Histological follow-up in the porcine model, however has indicated that late neointimal hyperplasia can recur at 90 and 180 days (Andrew J. Carter, DO, unpublished data, 2001). Thus, there are sufficient concerns about delayed healing with consequent risks of late restenosis 4 and thrombosis, 5 late malapposition, 6 edge effect, 7 and, on the other hand, delayed restenosis, 8 to warrant additional late follow-up catheterization. The objective of this study was to determine angiographic, intravascular ultrasound (IVUS), and clinical outcome up to 2 years after implantation of sirolimus-eluting stents in de novo coronary lesions.…”

7-Hexanoyltaxol–Eluting Stent for Prevention of Neointimal Growth

“…Animal studies have demonstrated several important similarities in histological characteristics between antiproliferative drug-eluting stents and intracoronary radiation therapy, which raises the concern of potential negative edge effects, 18 unhealed dissections, 19 or late stent-vessel wall malapposition. 20 In this study population, however, none of those morphological complications were detected at 6-month follow-up.…”