Multiple Ulcerations in Plaque Behind Stent Struts Resulting in Late Stent Malapposition After Gamma Brachytherapy for In-Stent
- Volume 15 - Issue 11 - November, 2003
- Posted on: 8/1/08
- 0 Comments
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Intracoronary stents reduce restenosis compared with conventional balloon angioplasty.1,2 However, in-stent restenosis remains an important clinical problem.3,4 Recently, randomized trials have demonstrated that intracoronary vascular brachytherapy (VBT) reduces recurrence after the treatment of in-stent restenosis.5–7 On the other hand, undesired effects of VBT such as late thrombosis and edge effect are also reported.6–8 Late stent malapposition is one of undesired effects of VBT. This case report describes multiple late stent malappositions after gamma VBT.
Case Report. A 57-year-old male with previous stent placement in the mid- and distal right coronary artery (RCA) was admitted due to exertional angina in November 2000. Coronary angiogram revealed a total occlusion at the previously stented segment in the mid-RCA (Figure 1A). There were no significant stenosis in the left anterior descending artery and the left circumflex artery. After written informed consent had been obtained, the patient was enrolled in a randomized trial to compare two doses of gamma VBT (14 Gy vs. 17 Gy) for the treatment of in-stent restenosis (SCRIPPS IV). The occlusion was successfully crossed with a Choice PT guidewire (Boston Scientific, Maple Grove, Minnesota) and dilated with a 3.0 mm Ranger balloon catheter (Boston Scientific) inflated at 12 ATM. After successful dilation, a noncentered, 3.7 French CHECKMATE radiation catheter (Cordis, Miami Lakes, Florida) was inserted and a ribbon with 22 radioactive 192Ir seeds (Best Industries, Springfield, Virginia) was delivered and positioned to cover the treated site (Figure 1B). The precise prescribed radiation dose was unknown (either 14 or 17 Gy to a 2 mm radial distance), because this blinded study is still ongoing. The final angiogram demonstrated a good result (Figure 1C). Intravascular ultrasound (IVUS) was not used in the procedure. After the procedure, the patient was given oral aspirin (325 mg/day) and clopidogrel (75 mg/day) for 6 months.
In May 2001, the patient underwent angiography because of recurrent angina. It demonstrated the recurrence of in-stent restenosis of 70% severity in the mid-RCA with luminal irregularity (Figure 1D). A 0.014´´ Balance Middle Weight guidewire (Guidant, Temecula, California) was placed across the lesion into the distal RCA. IVUS imaging was performed in the mid-RCA using a 40-MHz Atlantis IVUS catheter (Boston Scientific). IVUS image revealed a significant stenosis (minimal lumen cross-sectional area [3.8 mm2]). It also revealed multiple ulcerations in plaque behind stent struts, resulting in multiple stent malapposition (Figure 2A, B). Balloon angioplasty using a 3.0-mm Quantum balloon catheter (Boston Scientific) inflated at 18 atm was performed. The final angiogram demonstrated a good result without the luminal irregularity (Figure 1E). The final IVUS imaging showed a good lumen without stent malapposition (Figure 2C).