Management of Drug-eluting Stent Restenosis
Management of Drug-eluting Stent Restenosis
The dramatic reduction of restenosis led to the expanded "off-label" use of DES in the "real-world." As a result, the rate of restenosis became higher compared to the initial DES studies, which targeted "on-label" use of DES. The most widely employed "off-label" use is the DES application to small arteries. Because the original lumen diameter is small, the incidence of restenosis gets higher even with a little late loss. The initial size of the artery is an important factor that impacts the outcome of repeat PCI. In fact, the size of the initial stent was significantly smaller in lesions with recurrent restenosis after SES restenosis. When restenosis develops in the small artery, DES treatment is undesirable because it limits the size of the inner lumen. In these cases, underexpansion needs to be carefully examined and must be avoided. Thus, IVUS use is recommended to identify the underexpansion, as well as size of the vessel to expand the stent as much as possible.
The excellent results of DES prompted the use of DES in one of the most important locations of the coronary artery,ie, the left main. The aforementioned study by Sheiban et al is the only study that reported the outcomes of PCI, CABG, and medical treatment for unprotected left main DES restenosis. After 27.2 ± 15.4 months of follow-up, MACE occurred in 50% of the patients treated medically, 25.4% treated with PCI, and 14.3% after CABG. Due to the small number of studied patients, there were no statistically significant differences found among the treatment strategies. However, if a stent thrombosis took place at the left main coronary artery, it will be inevitably fatal. Therefore, a cautious stance should be taken for repeat DES placement at this location.
The condition of the restenosis at the bifurcation site varies based on the strategy taken at the initial DES implantation. The main branch usually has at least one stent, and some strategies apply another stent implantation for the side branch. In any case, repeat revascularization for the restenosis should be attempted without adding stents to the greatest extent possible, because the double layer of stent strut at the ostium of the side branch raises the risk of obstructing the side-branch flow. In fact, patients who received multiple PES have been shown to have a significant increase in non-Q wave myocardial infarction due to increased rates of side-branch compromise.
Target
Small Arteries
The dramatic reduction of restenosis led to the expanded "off-label" use of DES in the "real-world." As a result, the rate of restenosis became higher compared to the initial DES studies, which targeted "on-label" use of DES. The most widely employed "off-label" use is the DES application to small arteries. Because the original lumen diameter is small, the incidence of restenosis gets higher even with a little late loss. The initial size of the artery is an important factor that impacts the outcome of repeat PCI. In fact, the size of the initial stent was significantly smaller in lesions with recurrent restenosis after SES restenosis. When restenosis develops in the small artery, DES treatment is undesirable because it limits the size of the inner lumen. In these cases, underexpansion needs to be carefully examined and must be avoided. Thus, IVUS use is recommended to identify the underexpansion, as well as size of the vessel to expand the stent as much as possible.
Left Main
The excellent results of DES prompted the use of DES in one of the most important locations of the coronary artery,ie, the left main. The aforementioned study by Sheiban et al is the only study that reported the outcomes of PCI, CABG, and medical treatment for unprotected left main DES restenosis. After 27.2 ± 15.4 months of follow-up, MACE occurred in 50% of the patients treated medically, 25.4% treated with PCI, and 14.3% after CABG. Due to the small number of studied patients, there were no statistically significant differences found among the treatment strategies. However, if a stent thrombosis took place at the left main coronary artery, it will be inevitably fatal. Therefore, a cautious stance should be taken for repeat DES placement at this location.
Bifurcation
The condition of the restenosis at the bifurcation site varies based on the strategy taken at the initial DES implantation. The main branch usually has at least one stent, and some strategies apply another stent implantation for the side branch. In any case, repeat revascularization for the restenosis should be attempted without adding stents to the greatest extent possible, because the double layer of stent strut at the ostium of the side branch raises the risk of obstructing the side-branch flow. In fact, patients who received multiple PES have been shown to have a significant increase in non-Q wave myocardial infarction due to increased rates of side-branch compromise.
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