Can we prevent in-stent restenosis?

Abstract

Nowadays stent placement has replaced balloon angioplasty as the most commonly performed percutaneous coronary interventional procedure, mainly because of its better acute and chronic outcome. As a result, in-stent restenosis (ISR) has become a widespread problem. The incidence of ISR varies from 10% to 50% and depends on the absence or presence of several risk factors, such as small vessel size, longer lesions, and diabetes. Intravascular ultrasound studies have demonstrated that ISR is mainly caused by neointimal proliferation; consequently, this pathologic process has become the target of many preventive and therapeutic approaches. This article provides an overview of such management strategies, highlighting the rather disappointing experiences with mechanical and systemic drug therapies; the relative merits and disadvantages of intracoronary radiation; and the exciting yet realistic promise, embodied by the recent advancements in drug-eluting stent technology, of potentially eradicating ISR in the near future.

Noncardiac surgery in patients with coronary artery stent: what should the anesthesiologist know?

“…Third, the current ACC/AHA perioperative guidelines regarding coronary stents apply only to patients with bare metal stents, not to brachytherapy (e.g., intracoronary radiation with gamma or beta emitters) or drug-eluting stents. 11 Finally, this highly specialized technology evolves rapidly and is constantly challenged by new reports. For example, the four to six weeks' delay recommended by the ACC/AHA was recently questioned following a case of fatal MI due to stent thrombosis in a patient who underwent lung resection six weeks after the prophylactic implantation of a coronary stent.…”

“…Brachytherapy has been used to treat in-stent restenosis and drug-eluting stents have been proven to prevent it. 11 Brachytherapy inhibits the intimal hyperplasia by breaking the cell's DNA and blocking mitosis. Covered with a polymer and a drug spread over the metal, drug-eluting stents provide the slow release of a substance inhibiting cell proliferation.…”

“…Sirolimus (an antifungal with potent cell cycle inhibitory effect) and paclitaxel (a compound with potent anti-tumour activity) are the commonly used substances in drug-eluting stent therapy. 11 A common effect of brachytherapy and drug-eluting stents is delayed re-endothelialization. Little is known on how brachytherapy or drug-eluting stents should be managed perioperatively.…”

“…De plus, les directives péri-opératoires actuelles de l'ACC/AHA sur les endoprothèses coronaires concernent seulement les porteurs de prothèses de métal nu, non la curiethérapie (par ex., rayonnement intracoronaire avec des émetteurs gamma ou bêta) ou les endoprothèses pharmacoactives. 11 Finalement, cette technologie hautement spé-cialisée évolue rapidement et est constamment remise en question par de nouvelles études de cas cliniques. Par exemple, le délai de quatre à six semaines demandé par l'ACC/AHA a été récemment contesté à la suite d'un cas d'IM fatal causé par une thrombose prothé-tique chez un patient opéré pour la résection d'un poumon six semaines après l'implantation prophylactique d'une endoprothèse coronaire.…”

“…La curiethérapie a été utilisée pour traiter la resténose en présence d'endoprothèse et les endoprothèses pharmacoactives ont été reconnues comme pouvant la prévenir. 11 La curiethérapie inhibe l'hyperplasie intimale en fragmentant l'ADN des cellules et en bloquant la mitose. Couvertes d'un polymère et d'un médicament étalé sur le métal, les endoprothèses pharmacoactives assurent la libération lente d'une substance inhibitrice de la prolifération cellulaire.…”