Despite the questionable role of atherectomy in reducing the incidence of restenosis, this technique may still have an important impact on the treatment of ostial and bifurcation lesions.1–4
In these kinds of lesions, the removal of plaque potentially enhances the immediate procedural success by reducing plaque shift, which is responsible for side branch closure or vessel compromise.5
In patient 1 we regarded plaque excision as the preferred treatment because both balloon angioplasty and stenting presented a very high risk of jeopardising the ostium of the left anterior descending artery, the mid left circumflex, or both. The bifurcation lesion of the crux obviously could have been treated with elective stent implantation. However, bifurcation stenting, even with the use of drug eluting stents, is a complex procedure that is hampered by a considerable incidence of restenosis (Colombo, American Heart Association, 75th Scientific Sessions, 2002). Therefore, excising plaque with conditional stenting may be a strategy for bifurcation lesions to improve immediate and follow up results. The clinical importance of the SH device for the treatment of bifurcations is also reflected by the fact that in a recent registry of this device, 36% of treated lesions were bifurcations.6
Previous directional atherectomy devices required an occlusive balloon dilatation that pushed the cutter into the plaque. The SH catheter is not based on occlusive balloon inflation but on a longitudinal cutting process. This is achieved by advancing the deflected catheter tip with the activated cutter through the lesion allowing the spinning blade to shave material from the plaque. This concept reduces the “Dotter” and balloon angioplasty effects observed with previous atherectomy devices and reduces the possibility of plaque shift. In the case of treatment of the ostial lesion atherectomy effectively avoided any compromise of the other branches (fig 1, right). In the bifurcation lesion the debulking device was used to treat both branches with no plaque shift observed (fig 2, right). Further features of the SH system are the more flexible shaft, the shorter stiff cutting section, and the lower profile—technical characteristics that allow negotiation of complex anatomy. With this regard, in patient 2 the SH catheter was easily advanced through a moderately tortuous right coronary artery to its distal portion by using a conventional medium support percutaneous transluminal coronary angioplasty guidewire. The new concept of selective excision also allows for treatment of smaller vessels. In both of the presented cases an effective excision was achieved in vessels of diameter
3.0 mm. Interestingly in the presented cases plaque debulking was not followed by stent implantation. This, however, was not because atherectomy is seen as an alternative to stent implantation but because of the good angiographic result obtained with only plaque excision and because of the known limitations of stents in ostial and bifurcation lesions situated in small vessels.
In conclusion, the newly designed SH system may offer significant utility in the treatment of complex coronary lesions potentially alleviating the limitations of conventional directional atherectomy devices.