Bioabsorbable everolimus-eluting coronary artery stents (BVS) have been found to be safe and effective in patients with single coronary artery lesions. According to an Article released on March 14, 2008 in The Lancet, there is acceptable in-stent late loss, minimal formation of scar tissue within the stent, and a low stent area of obstruction.

Stents are used to scaffold diseased vessels to improve blood flow. As the vessel continues to remodel after the introduction of the stent, it can be advantageous to have the scaffold disappear, as a bioabsorbable stent would. For example, the presence of foreign materials in the vessel can over time cause blood clots in permanent metallic stents — if the stent is not present, the risk of late stent thrombosis could be reduced. The BVS stent has a backbone and coating of lactic acid, which contributes to a controlled release of everolimus, a drug that prevents scar tissue formation.

To investigate this bioabsorbable stent, Professor Patrick Serruys, Thoraxcenter, Erasmus Medical Center, Rotterdam, Netherlands, and Dr John Ormiston, Auckland City Hosptial, New Zealand, and colleagues performed the ABSORB study, which focused on 30 patients with ischaemia and a single lesion that was suitable for treatment with one of two stents (3×12 mm or 3×18 mm). Academic hospitals in New Zealand, The Netherlands, Poland, and Denmark contributed patients for the study. The endpoints measured included cardiac death, heart attack, and repeated stenting. Additionally, 26 patients were evaluated using angiographs and 24 patients were evaluated by ultrasound.

The success of the procedure was found to be 100%. The success of the device itself, namely implantation of the stent, was 94% (29 out of 31 attempts). One year later, one (3.3%) of the patients had suffered a heart attack. There were no late stent thromboses recorded. The authors conclude that this demonstrates the potential for BVSs: “This study shows the feasibility of implantation of the bioabsorbable everolimus-eluting stents… we noted only one major adverse cardiac event and no instance of stent thrombosis.”

Dr Carlo Di Mario, Royal Brompton Hospital, Imperial College, London, UK, and Dr Giuseppe Ferrante, Catholic University of the Sacred Heart, Rome, Italy, contributed an accompanying comment in which they reinforce the need for studies of this technology. “Events as potentially deadly as stent thrombosis should ideally be eradicated; and radical alternatives to conventional stents, such as biodegradable stents, deserve to be the focus of research investment.”

A bioabsorbable everolimus-eluting coronary stent system for patients with single de-novo coronary artery lesions (ABSORB): a prospective open-label trial
John A Ormiston, Patrick W Serruys, Evelyn Regar, Dariusz Dudek, Leif Thuesen, Mark WI Webster, Yoshinobu Onuma, Hector M Garcia-Garcia, Robert McGreevy, Susan Veldhof
The Lancet – Vol. 371, Issue 9616, 15 March 2008, Pages 899-907
DOI:10.1016/S0140-6736(08)60415-8
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Biodegradable drug-eluting stents: promises and pitfalls
Carlo Di Mario, Giuseppe Ferrante
The Lancet – Vol. 371, Issue 9616, 15 March 2008, Pages 873-874
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Written by Anna Sophia McKenney