QUANTITATIVE ANGIOGRAPHIC FOLLOW-UP-STUDY OF THE FREE INFERIOR EPIGASTRIC CORONARY-BYPASS GRAFT

Background Attempts to improve late results of bypass coronary surgery have focused on the use of arterial conduits because of the high attr ition rate of venous grafts. Methods and Results In our institution, 1 50 patients received an inferior epigastric artery (EPIG) as a free by pass graft, anastomosed to the right coronary artery in 73% and to a m arginal branch in 20% of cases. These patients were followed prospecti vely by qualitative and quantitative angiography. Angiographic studies were performed in 122 patients (81%) early after surgery (11+/-5 days ), and in 72 cases, a late evaluation (11+/-6 months) was also obtaine d. Quantitative angiography (basal and after isosorbide dinitrate [ISD N]) was performed on the in situ EPIG in a large subset of these patie nts, as well as in 59 patients before bypass surgery. The patency rate was 98% at early control and remained high (93%) at late control. How ever, at late control, 14 EPIGs were occluded or threadlike, but of th ese 14, eight were grafted on a coronary artery with a moderate stenos is (less than or equal to 60%) and with good anterograde perfusion. Me an basal EPIG diameter increased from 2.23+/-0.42 mm before surgery to 2.57+/-0.52 mm at 11 days (P<.01) but decreased to 2.20+/-0.47 mm in late study (P<.01 versus 11 days and P=NS versus before surgery). Vaso dilation of EPIG with ISDN was observed before surgery (+0.34+/-0.20 m m, P<.001) and at late control (+0.20+/-0.17 mm, P<.001) but not in th e early postoperative period for the whole group. Early after surgery, basal diameter was not different from native EPIG dimensions after IS DN (2.57+/-0.52 versus 2.56+/-0.39 mm), suggesting maximal dilation. H owever, vasodilation with ISDN was observed in a subgroup of patients at this time. These responder patients (n=51) had a smaller basal diam eter (2.47+/-0.49 versus 2.67+/-0.54 mm, P<.05) and a smaller runoff ( P<.001) than nonresponder patients. Conclusions EPIG grafts have a goo d early patency rate. The mid-term patency rate remains high and seems to depend, at least partially, on flow through the native coronary ar tery. EPIGs initially increase their lumen size, probably to meet the increased bleed flow due to myocardial requirements. Over time, EPIG d iameters decrease mainly as a result of a higher basal vasomotor tone. Long-term angiographic follow-up (eg, 5 to 10 years) is needed to ass ess late patency rate and the relation with these early findings and w ill define the place of this new coronary bypass conduit.