E A Tovar1, A Borsari. 1. Department of Cardiothoracic Surgery, St. Jude Medical Center, Fullerton, California, USA.
Abstract
BACKGROUND: Coronary artery bypass grafting is usually indicated for those patients who undergo open heart surgical procedures who have previously undergone percutaneous transluminal coronary angioplasty regardless of the absence of stenosis. Occasionally, however, if the treated artery has remained patent for many years and there is a shortage of conduit material or the patient is undergoing a complex operation, the branch is left ungrafted. With the gaining popularity of coronary stent placement, patients with these devices are undergoing open heart operations with increasing frequency. METHODS: To determine whether normal surgical manipulation during open heart surgical procedures results in obliteration of the Palmaz-Schatz stents previously deployed in the epicardial arteries, we developed an experimental model using ten isolated adult pig hearts. This allowed us to perform stent deployment and surgical manipulation and to apply direct pressure on the stented areas, with each heart evaluated by angioscopy and angiography and, finally, stent explantation. RESULTS: Retraction of the heart resulted in severe deformity of all left anterior descending artery stents, mild deformity of those in the circumflex artery, and mild or no deformity of those in the right coronary artery. However, direct pressure over the stented epicardial arteries (enough to retract the heart) resulted in complete obliteration of every intracoronary stent. CONCLUSIONS: The findings from this study indicate that once the need for surgical revascularization arises, a previously stented coronary artery should be bypassed even if the angiographic findings are normal, because of the likelihood that manipulation during an open heart operation will result in significant deformity or obliteration of the stent.
BACKGROUND: Coronary artery bypass grafting is usually indicated for those patients who undergo open heart surgical procedures who have previously undergone percutaneous transluminal coronary angioplasty regardless of the absence of stenosis. Occasionally, however, if the treated artery has remained patent for many years and there is a shortage of conduit material or the patient is undergoing a complex operation, the branch is left ungrafted. With the gaining popularity of coronary stent placement, patients with these devices are undergoing open heart operations with increasing frequency. METHODS: To determine whether normal surgical manipulation during open heart surgical procedures results in obliteration of the Palmaz-Schatz stents previously deployed in the epicardial arteries, we developed an experimental model using ten isolated adult pig hearts. This allowed us to perform stent deployment and surgical manipulation and to apply direct pressure on the stented areas, with each heart evaluated by angioscopy and angiography and, finally, stent explantation. RESULTS: Retraction of the heart resulted in severe deformity of all left anterior descending artery stents, mild deformity of those in the circumflex artery, and mild or no deformity of those in the right coronary artery. However, direct pressure over the stented epicardial arteries (enough to retract the heart) resulted in complete obliteration of every intracoronary stent. CONCLUSIONS: The findings from this study indicate that once the need for surgical revascularization arises, a previously stented coronary artery should be bypassed even if the angiographic findings are normal, because of the likelihood that manipulation during an open heart operation will result in significant deformity or obliteration of the stent.