Coronary Brachytherapy 2016.

R estenosis is a significant limitation of catheter-based treatment of coronary artery disease. Early in the development of balloon angioplasty, restenosis was quite common, occurring in 30% to 40% of patients (1). Following successful angioplasty, patients who had become symptomfree developed the same symptoms they had experienced prior to the intervention. Repeat angiography demonstrated a recurrence of narrowing at the site of the treated stenosis, sometimes more severe than the original lesion. Initially, treatment options were advancement of medical therapy alone, coronary bypass graft surgery, and repeated angioplasty. Most often at least 1 repeat angioplasty was attempted, although the likelihood of subsequent lesion recurrence was substantially higher than for those having a first angioplasty. Accordingly, restenosis was eventually termed the Achilles’ heel of angioplasty and was a significant shortcoming of this approach to coronary revascularization. Many efforts were explored to avoid restenosis. A host of pharmacological agents were studied in experimental and clinical settings. None were successful. Mechanical devices were also considered. Ablative devices, both mechanical and laser based, were investigated, with the thought that if better angioplasty were performed (i.e., less plaque remained following treatment), there would be more lumen to accommodate the healing that followed angioplasty. Clinical trials, however, failed to demonstrated success of these approaches. In 1987, a stainless steel stent was developed that could be placed into a coronary artery (2). The initial