Vascular brachytherapy revisited for in-stent restenosis in the drug-eluting stent era: Current status and future perspective

Intracoronary brachytherapy has reached its maturity. The technology is improved to be simple, operator-friendly and cost-effective. DES, especially next generation DES surely has a bright future and with the recent trials seems to be on the verge of replacing VBT in ISR. The simplicity and availability of DES have made more clinical widespread applicability and acceptance to DES in every subset of diseases. However, the ISR could not be completely eliminated even with the next generation DES and there are newly developing complications associated with DES such as increasing stent thrombosis due to delayed endothelialization, aneurysm formation, late stent malapposition, DES-associated endothelial dysfunction and clinically significant vasospasm. We can conclude that until the long-term safety and efficacy of DES is surely proved, VBT will continue to be utilized for treatment of ISR and difficult subsets mentioned earlier especially in diffuse long lesions and in patients with repeat DES failure. VBT is definitely a step ahead in the treatment of calcific and vein graft disease. Further simplification of the administration of VBT procedure will help the interventional cardiologists to embark on this therapy more and more. Balloon filled radioactive elements may be a competitive option to DES because it permits ease of administration and optimization of the length of radiation source which is not possible with DES. In de novo lesions DES has surpassed VBT thus reducing its need in the real world interventional practice. Future of coronary intervention will reduce the need for coronary bypass surgery as much as possible. Although the utilization of VBT has dramatically reduced after the introduction of DESs, VBT has been used in nearly 500 catheterization laboratories in United States and has treated 40 000 patients with ISR per annum for several years. Cost effective analysis performed from gamma-1 and INHIBIT studies has shown that though initial cost of treatment is high, it will offset this in the long run due to decrease in the TLR and bypass surgery. Now time will tell us whether VBT will remain a tool to treat DES failures or vice versa. Treatment of coronary atherosclerosis will see a dynamic change in the next 5 years. Progress in antiplatelet agents, pleuripotent agents such as statins, thiozolidenediones, fibrates on the pharmacologic side, advancements in cell therapy for enhanced vascular healing and technologic developments in stent design, drug coated and DESs/balloons are sure to impact on future therapy of coronary atherosclerosis. However, despite all these developments, every therapeutic strategy may have its own limitations. With the complete understanding of various issues and problems, VBT should be considered as a back-up strategy for the shortcomings of other newly developing techniques.