FATE OF LESION-RELATED SIDE BRANCHES AFTER CORONARY-ARTERY STENTING

Objectives. The aim of this study was to assess the immediate and long term patency of lesion associated side branches after coronary artery stenting. Background. The possible adverse effects related to implantation of coronary stents are not completely known. An important potential complication of stenting is side branch occlusion due to mechanical obstruction or thrombosis. Methods. Serial coronary angiography was performed in 153 patients (167 lesions) at baseline, after conventional balloon angioplasty, immediately after Palmaz-Schatz stent placement and at 6 months. The patency of side branches, where present, was analyzed at each of these points. Results. Of 167 lesions stented, 57 stent placements spanned 66 side branches with a diameter greater than or equal to 1 mm. Twenty seven (41%) of these side branches had greater than or equal to 50% ostial stenosis before standard balloon angioplasty. Six side branches became occluded after standard balloon angioplasty and remained occluded after stenting. Of the 60 side branches patent after conventional angioplasty, 57 (95%) remained patent immediately after stenting. Ah three side branches that became occluded after stenting had greater than or equal to 50% ostial stenosis at baseline. Ah 60 side branches, including the 3 initially occluded after stenting, were patent at 6-month follow up. Conclusions. These findings demonstrate that 1) acute side branch occlusion due to coronary stenting occurs infrequently; 2) when side branch occlusion occurs, it is associated with intrinsic ostial disease; and 3) the patency of side branch ostia is well maintained at long term follow-up.