By Zulkiple Ibrahim
This is the second feature from a series of three on coronary artery disease
KUALA LUMPUR, Dec 14 (Bernama) -- In the treatment of coronary artery disease (CAD), the idea is to deliver growth inhibition drugs to the dilated stenosis site without implanting a stent.
According to Lam Chee Hong the managing director for B. Braun Medical Supplies Sdn Bhd, this approach resulted in the development of a new treatment option for vascular occlusion, the drug eluting balloon catheter - SeQuent�Please.
He said the drug eluting balloon (DEB) SeQuent�Please is a new therapeutic option for treating narrowing of the coronary arteries which has produced excellent results.
Lam said this is the first and as yet only drug eluting balloon (DEB) with successful proof of efficacy in the treatment of narrowing of the coronary arteries.
SeQuent�Please is used in the same way as a coronary balloon catheter for balloon expansion of narrowed blood vessels (stenosis). Unlike conventional balloon catheters, SeQuent�Please also releases a drug from the balloon surface that is absorbed by the surrounding wall of the blood vessel.
B. Braun's Medical Industries Sdn Bhd manager for regional strategy planning (Asia Pacific), Pallraj Armugum, said the drug is paclitaxel, which has been studied extensively in clinical trials and is also used for drug eluting stents (DES).
To enhance transfer of the drug to the vessel wall, the paclitaxel in SeQuent�Please is embedded in an x-ray contrast medium matrix (iopromide). This technology delivers a sufficient dose of drug from the balloon surface to the vascular wall after a brief contact period of just a few seconds.
Paclitaxel inhibits the growth and spread of smooth muscle cells over a prolonged period and so prevents the expanded artery from closing in again due to cell growth.
The matrix is bioabsorbable and dissolves completely after use. No foreign bodies remain at the intervention site, thereby minimising the risk of thrombosis.
According to Lam, SeQuent�Please is a new treatment option in coronary artery therapy with significant benefits.
Unlike stent implantation, no foreign bodies remain in the artery with the new system, he said.
The drug eluting balloon also reaches narrowed areas that would not be accessible for stent treatment, such as, for instance, very small blood vessels, bifurcations and very long areas of stenosis.
Lam said SeQuent�Please is associated with a significantly lower incidence of restenosis of expanded arterial segments. In addition, the required length of treatment with platelet inhibiting drugs (platelet aggregation inhibitors) is much shorter after the new procedure than after DES implantation.
With the latter, patients generally required treatment for as long as 12 months after the procedure. With SeQuent�Please, a treatment period of no longer than three months is sufficient. This is associated with significantly lower treatment costs.
SeQuent�Please thus has the potential to bring about a paradigm shift in the treatment of vascular restenosis, said Lam.
Lam said when coronary artery disease (CAD) is treated with an uncoated stent, the artery narrows again over time in as many as 30 per cent of cases, and this occurs at the stent implantation site.
In-stent restenosis, as it is called, can be expanded either with a balloon catheter or by the implantation of a second stent into the existing one. However, there is a high likelihood of recurrence of restenosis in both cases.
To establish whether a paclitaxel eluting balloon catheter reduces restenosis, in-stent restenosis in 52 patients was treated either with a novel drug eluting balloon (DEB) or with a conventional uncoated balloon.
Result: re-narrowing occurred within six months in only 5.0 per cent of DEB patients versus 43 per cent of patients treated with the conventional uncoated balloon.
He said another study showed that the drug eluting balloon is significantly superior to drug eluting coronary stents. Again, subjects in this clinical trial had in-stent restenosis.
In this study, however, one half of patients were treated with a paclitaxel eluting stent, while the other half underwent expansion with SeQuent�Please. At six months after the intervention, only 6.7 per cent of the SeQuent� Please patients versus 20.4 per cent of paclitaxel eluting stent recipients required re-intervention.
The positive study findings are already reflected in the guidelines of the German Society of Cardiology (DGK).Good results were also obtained for the use of SeQuent� Please to treat stenosis of small arteries, with restenosis rates of only 5.5 percent in patients treated with SeQuent� Please alone.
Considerably higher percentages have been observed in similar studies of drug eluting coronary stents in this therapeutic indication.
Further applications for SeQuent� Please are currently being investigated by B. Braun Melsungen AG in an extensive study programme.