Why bioabsorbable coronary stents?

Why bioabsorbable coronary stents?

We know that development of drug eluting stents have revolutionized the results of percutaneous coronary interventions by reducing the incidence of coronary restenosis. But concerns have been raised about the residual effects of a permanent metallic and polymeric implant in the coronary vessels. It is now common knowledge that it can lead to delayed healing, long term endothelial dysfunction and the dreaded very late stent thrombosis which is peculiar to drug eluting stents. Straightening of the tortuosities of the coronary segments by metallic scaffold can also cause damage at stent edges. An ideal stent would be one which gives a good radial force to prevent vessel collapse, have sufficient flexibility to conform to the vessel geometry, providing adequate drug elution to inhibit intimal hyperplasia to prevent restenosis and getting absorbed once the vessel wall is strengthened by the healing process. It is here that the bioabsorbable coronary stents [bioabsorbable vascular scaffolds (BVS)] come in. Gomez-Lara J and associates have reported the comparison of bioresorbable vascular scaffolds (BVS) and metallic platform stents at one year [1]. They concluded that bioresorbable vascular scaffolds or (bioabsorbable coronary stents) tend to restore the coronary configuration and systolic-diastolic movements to those seen before implantation. This is noted from the improved curvatures and angulations of the coronary arteries measured pre and post implant and at follow up.

But the bioresorbable stents have not become popular because of poor long term results in spite of higher cost.

Reference

1. Josep Gomez-Lara, Salvatore Brugaletta, Vasim Farooq, Robert Jan van Geuns, Bernard De Bruyne, Stephan Windecker, Dougal McClean, Leif Thuesen, Dariusz Dudek, Jacques Koolen, Robert Whitbourn, Pieter C Smits, Bernard Chevalier, Marie-Angèle Morel, Cécile Dorange, Susan Veldhof, Richard Rapoza, Hector M Garcia-Garcia, John A Ormiston, Patrick W Serruys. Angiographic Geometric Changes of the Lumen Arterial Wall After Bioresorbable Vascular Scaffolds and Metallic Platform Stents at 1-Year Follow-Up. JACC Cardiovasc Interv. 2011 Jul;4(7):789-99.