Additional stenting promotes intimal proliferation and compromises the results of intravascular radiation therapy: an intravascular ultrasound study.
BACKGROUND
Vascular brachytherapy (VBT) reduces in-stent restenosis (ISR). However, additional stenting at the time of radiation may be associated with a worse outcome.


RESULTS
Intravascular ultrasound (IVUS) was performed after VBT and at 6 months follow-up in 79 native artery ISR patients treated with gamma-radiation who participated in the Washington Radiation for In-Stent restenosis Trial (WRIST), Gamma-1, and Angiorad Radiation Technology for In-Stent restenosis Trial in Coronaries (ARTISTIC) trials. Patients were treated with (192)Ir at 14 or 15 Gy at 2 mm from the source. Additional stents were used to treat the ISR lesions in 45 patients; these patients were then compared with the 34 patients treated without restenting. Paired measurements included stent, lumen, and intimal hyperplasia volumes. After the VBT procedure, intimal hyperplasia volume was smaller in the group treated with additional stents (54 +/- 33 mm(3) vs 34 +/- 33 mm(3), P =.012), but minimal lumen area was similar between the 2 groups (4.3 +/- 1.5 mm(2) vs 4.7 +/- 1.4 mm(2) respectively, P = NS). Between the time of the VBT procedure and follow-up, intimal hyperplasia volume increased by 27 +/- 19 mm(3) in the restented group and by 9 +/- 21 mm(3) in the group treated without additional stents (P =.014). At 6 months, intimal volume was similar in the 2 groups, but minimal lumen area was slightly smaller in the group treated with additional stents (3.4 +/- 1.8 mm(2) vs 4.2 +/- 1.7 mm(2), P =.053). Patients treated with additional stents had more target lesion revascularizations than the group treated without additional stents (38% vs 15%, P =.02).


CONCLUSIONS
Additional stenting reduces intimal hyperplasia within the stents acutely. However, it compromises the benefit of VBT by promoting higher intimal regrowth within months after radiation.
Cheneau
Edouard
E
Washington Hospital Center, Washington, DC 20010, USA.
Wu
Zhiyong
Z
Leborgne
Laurent
L
Ajani
Andrew E
AE
Weissman
Neil
N
Pichard
Augusto D
AD
Satler
Lowell F
LF
Kent
Kenneth M
KM
Mintz
Gary
G
Waksman
Ron
R
D001918:Brachytherapy / Q000379:methods*; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D023921:Coronary Stenosis / Q000532:radiotherapy / Q000628:therapy; D019160:Endosonography; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000209:etiology / Q000517:prevention & control; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D015607:Stents / Q000009:adverse effects*; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology*; D018084:Ultrasonography, Interventional
D007496:Iridium Radioisotopes