UPDATE ON MANAGEMENT OF IN-STENT RESTENOSIS

In-stent restenosis (ISR) is a common and frequently resistant problem . The pathophysiology of in-stent and nonstent restenosis is different , the former resulting primarily from intimal hyperplasia, while the l atter is predominantly a consequence of negative late remodeling. Pred ictors of ISR are patient and lesion related. Wizen approaching a pati ent with stent restenosis, false or pseudo-restenosis must be consider ed. Angiography frequently Sails to reveal pseudo-restenosis, and cons equently, intravascular ultrasound can be essential in guiding the mos t effective strategy. Because of spontaneous neointimal regression, pa tients with asymptomatic stent restenosis often call be followed and t reated medically. The mechanical approaches to ISR include balloon ang ioplasty alone, debulking plus PTCA, and restenting. For focal lesions (<10 mm in length) balloon angioplasty at moderately high pressures i s often effective. Following balloon dilatation, stent expansion and p laque extrusion equally account for the gain in lumen area. For more d iffuse disease, debulking plus balloon angioplasty is preferred althou gh no randomized data are available. Only restenting is associated wit h a gain in MLD that is comparable to the original stent implant and i s not associated with reintrusion of neointima-INSTANT restenosis. Des pite aggressive debulking with or without further stenting, diffuse st ent restenosis often is resistant to purely mechanical treatment. Nonm echanical approaches, such as localized radiation therapy, will be req uired to effectively treat this difficult subset of patients.