A patient returns months or years after a coronary stent was placed, reporting chest pain that feels familiar. The culprit, on repeat angiography, is tissue regrowth inside the previously treated segment — a condition known as in-stent restenosis (ISR). In-stent restenosis treatment is a distinct area of interventional cardiology because the problem occurs inside a metal scaffold that is already in place, which limits and shapes the tools available. This article reviews what ISR is, how it is typically assessed, and the general categories of treatment an interventional cardiology team may consider.
What Is In-Stent Restenosis and Why Does It Happen?
In-stent restenosis is the renarrowing of a coronary artery segment that has already been treated with a stent, generally caused by excessive tissue growth (neointimal hyperplasia) within or around the stent struts. It is commonly reported as a possibility following any coronary stent placement, though rates and presentation vary by stent type, vessel size, and individual patient factors. ISR can present as recurrent angina (chest pain), and because new or worsening chest pain can also signal other serious conditions, patients experiencing this should seek immediate medical care or contact a healthcare provider promptly rather than waiting to see if symptoms resolve on their own. Diagnosis typically involves repeat coronary angiography, sometimes supplemented with intravascular imaging such as IVUS or OCT to characterize the pattern and severity of the regrowth.
How Is In-Stent Restenosis Managed Once Identified?
ISR management depends heavily on the pattern of the renarrowing, the size of the vessel, and whether the restenosis is focal (limited to a short segment) or diffuse (spread across the length of the stent or beyond it). Broadly, an interventional cardiologist weighs several categories of options: balloon angioplasty alone, drug-coated balloon (DCB) angioplasty, placement of an additional stent (re-stenting), or in some cases referral for surgical evaluation. The choice is guided by lesion characteristics, prior stent history, vessel size, and the physician's clinical judgment — there is no single approach used in every case.
What Role Do Drug-Coated Balloons Play in ISR?
DCB for ISR has become a widely discussed option because it allows a physician to treat the renarrowed segment without necessarily adding another layer of permanent metal to the artery. A drug-coated balloon is inflated within the diseased segment to mechanically address the narrowing while also delivering an antiproliferative drug coating intended to help reduce the tissue regrowth that caused the restenosis in the first place. This approach is one of several tools available for ISR and is generally considered alongside re-stenting rather than as an automatic default; the decision still rests with the treating physician based on the specific case.
When Is Re-Stenting Considered Instead?
Re-stenting — placing a new stent within or overlapping the original one — may be considered when balloon-based approaches alone are not expected to adequately address the mechanical or structural cause of the restenosis, such as stent underexpansion identified on intravascular imaging. Because re-stenting adds another metal layer, it introduces its own long-term considerations, which is part of why balloon-based options are often evaluated first in appropriate cases. As with all ISR management decisions, this determination is made by the interventional cardiologist managing the case.
A Balloon Option Used in ISR Cases
Among the tools used for the angioplasty component of ISR management is INVAMED's Extender Drug Eluting PTCA Balloon Catheter (Paclitaxel), a paclitaxel-coated coronary balloon intended to help reduce restenosis during percutaneous transluminal coronary angioplasty (PTCA). It is available in balloon diameters from 2.0–5.0 mm and lengths of 10, 15, 17, 20, 26, and 30 mm, and its coating is designed to deliver paclitaxel during a brief inflation with minimized drug washout during delivery. Devices of this type are used, among other applications, in the management of in-stent restenosis and small-vessel disease, though suitability for any individual patient is determined by the treating physician. General background on coronary interventions is available on INVAMED's coronary artery disease and cardiac interventions category page.
Does in-stent restenosis mean the original stent failed?
Not necessarily — in-stent restenosis is a commonly reported biological response (tissue overgrowth) that can occur after any coronary stent placement, and it is generally considered a recognized possibility rather than a defect in the device itself. A qualified physician can evaluate the specific case to determine the likely contributing factors.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.